SHEET CONVEYING DEVICE AND IMAGE FORMING SYSTEM

Abstract

To prevent damage associated with a door closing operation even when a guide plate is at an open position.SOLUTION: An upstream-side closing unit 50 having an upstream-side holding release part 51 and an upstream-side guide part 52 is provided at a position on an inner surface of a front door 120 opposite to an upstream conveying unit 40. When the front door 120 is closed, the upstream-side holding release part 51 comes into contact with the tip of a jamming release lever 41, and thereby an upper guide part 40A is separated from a guide holding body 130. The upstream-side guide part 52 is provided with a retraction member 52a, and in association with closing of the front door 120, the tip of the jamming release lever 41 is brought into contact with the retraction member 52a. The retraction member 52a is pushed by the jamming release lever 41 and rotates toward the front door 120. In this way, the upstream-side closing unit 50 releases the holding of a second guide plate held by the guide holding body 130, and moves the second guide plate to a closed position while retracting so as to prevent the upper guide part 40A from being pushed by the front door 120 and damaged.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sheet transport device that transports a sheet, and an image forming system including the same. [Background technology]

[0002] Conventionally, image forming apparatuses such as copying machines, printers, and facsimiles that form images on sheets (recording materials) are provided with a sheet transport device for transporting the sheets. In the image forming apparatus, a so-called jam may occur in which a sheet is stuck in a sheet transport path. In such a case, the sheet transport device is provided with a pair of guide plates that are arranged opposite to each other so as to sandwich the sheet and can be opened and closed so that the user can remove the sheet stuck in the sheet transport device (Patent Document 1). Then, one of the guide plates is provided with a jam release lever that can be held and operated by the user so that the user can manually open the sheet transport path. The user can operate the jam release lever with a door that is attached to the device body so as to be able to be opened and closed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-204142 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, when a jam occurs, the user can open the door and operate the jam release lever to move one of the guide plates to an open position where the sheet transport path is open, and remove the sheet stuck in the sheet transport device. At this time, the moved guide plate is held in the open position so that it does not return to the closed position where the sheet transport path is not open while the user is removing the sheet. Therefore, after removing the sheet, the user needs to return the guide plate to the closed position before closing the door. In the device described in the above-mentioned Patent Document 1, if the guide plate is not returned to the closed position, it is difficult to close the door. However, if the user forgets to return the guide plate to the closed position and forcibly closes the door with the guide plate in the open position, there is a risk that the guide plate and the like will be damaged by being strongly pressed by the door.

[0005] The present invention has been made in consideration of the above problems, and aims to provide a sheet conveying device and image forming system that can prevent damage to the guide plates that are caused by the door closing action, even if the door is closed while a pair of guide plates that guide the sheets are in the open position. [Means for solving the problem]

[0006] A sheet transporting device according to one embodiment of the present invention comprises a transport means for transporting a sheet, a first guide for guiding a sheet transported by the transport means, a second guide arranged opposite the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position which forms the sheet transport path and a second position which opens the sheet transport path, a holding means for holding the second guide in the second position, and a cover which constitutes part of the exterior of the device and is movable between a closed position which covers the second guide and an open position in which the second guide can be operated. a support frame supporting the first guide, the second guide, and the cover; a contact portion provided on the cover and contacting the second guide, the cover is capable of being opened and closed about a rotation axis that extends in a vertical direction relative to the support frame, and the second guide is capable of being rotated between the first position and the second position about a rotation axis that extends in a horizontal direction,The abutment portion is arranged so as to abut against the second guide, thereby releasing the holding of the second guide by the holding means, when the cover moves from the open position to the closed position while the second guide, which is located at the second position, is held by the holding means.

[0007] An image forming system according to one embodiment of the present invention includes an image forming unit that forms a toner image on a sheet, a fixing device that fixes the toner image by heating the sheet on which the toner image has been formed, and a sheet cooling device that cools the sheet heated by the fixing device, the sheet cooling device including a sheet cooling means having a first belt, a second belt that contacts an outer peripheral surface of the first belt to form a nip portion for nipping and transporting the sheet, and a heat sink that contacts an inner peripheral surface of the first belt, a conveying means that conveys the sheet, a first guide that guides the sheet conveyed by the conveying means, and a sheet cooling means that is provided at least one of upstream and downstream of the sheet cooling means in the sheet conveying direction at the nip portion, the sheet cooling means being arranged opposite to the first guide, The sheet cooling device comprises a second guide that is rotatable to a first position that, together with the first guide, forms a sheet transport path through which a sheet passes and a second position that opens the sheet transport path, a holding means that holds the second guide at the second position, a cover that constitutes part of the appearance of the sheet cooling device and is movable to a closed position that covers the second guide and an open position in which the second guide can be operated, and an abutment portion provided on the cover that abuts against the second guide, wherein the abutment portion is positioned so as to release the holding of the second guide by the holding means by abutting against the second guide when the cover moves from the open position to the closed position while the second guide is positioned at the second position and is held by the holding means. A sheet transport device according to an embodiment of the present invention includes a transport means for transporting a sheet, a first guide for guiding a sheet transported by the transport means, a second guide provided to face the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position which forms the sheet transport path and a second position which opens the sheet transport path, a holding means for holding the second guide at the second position, a cover which constitutes a part of the exterior of the device and which is movable between a closed position which covers the second guide and an open position in which the second guide can be operated, and a holding means provided on the cover. the cover is provided with a first abutment portion that abuts against the second guide, and a second abutment portion that is provided on the cover and abuts against the second guide at a position different from the first abutment portion, wherein the first abutment portion is arranged to abut against the second guide, thereby releasing the holding of the second guide by the holding means, when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means, and the second abutment portion is arranged to abut against the second guide to position the second guide at the first position when the cover is in the closed position. Effect of the Invention

[0008] According to the present invention, when the second guide plate is in the open second position in which the sheet transport path is open to the first guide plate, even if the door is closed, a simple configuration can be used to prevent damage to the guide plates caused by the closing action of the door. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a configuration of an image forming system according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 4 is a partial perspective view showing the external cooling device with the front door open. [Figure 4] FIG. [Diagram 5] FIG. 2 is a schematic diagram showing a sheet cooling unit. [Figure 6] 1A is a perspective view showing an upstream transport unit as viewed obliquely from above, and FIG. 1B is a perspective view showing an upstream transport unit as viewed obliquely from below. [Figure 7] FIG. [Figure 8] FIG. 4 is an enlarged perspective view of an upstream holding release portion. [Figure 9] FIG. 4 is an enlarged top view of the upstream holding release portion. [Figure 10] 5A to 5D are schematic diagrams to explain the upstream guide section, (a) before the front door is closed, (b) when the front door is partially closed, (c) when the front door is closed further partially, and (d) after the front door is closed. [Figure 11] FIG. 4 is an enlarged perspective view of a downstream holding release portion. [Figure 12] FIG. 4 is an enlarged top view showing the downstream holding release portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Image forming system> The schematic configuration of the image forming system of this embodiment will be described with reference to Figures 1 and 2. The image forming system 1X shown in Figure 1 includes an image forming apparatus 100, an external cooling device 110, and a sheet processing apparatus 310.

[0011] <Image forming device> The image forming apparatus 100 is a tandem-type full-color printer of an electrophotographic system. The image forming apparatus 100 has image forming units PY, PM, PC, and PK that form images of yellow, magenta, cyan, and black, respectively. The image forming apparatus 100 forms and fixes a toner image on a sheet S in response to an image signal from an external device, such as a document reading device (not shown) connected to the apparatus main body 100A or a personal computer connected to the apparatus main body 100A so as to be communicable therewith. The sheet S may be various types of sheet materials, such as plain paper, thick paper, rough paper, textured paper, coated paper, plastic film, cloth, and the like. In this embodiment, the image forming units PY to PK, the primary transfer roller 5, the intermediate transfer belt 8, the secondary transfer inner roller 9, the secondary transfer outer roller 10, and the tension rollers 121 and 122 constitute an image forming unit 200 that forms a toner image on the sheet S.

[0012] As shown in Fig. 1, the image forming units PY, PM, PC, and PK are arranged in line in the moving direction of an intermediate transfer belt 8 inside the apparatus main body 100A (inside the apparatus main body). The intermediate transfer belt 8 is stretched around multiple rollers and configured to run in the direction of arrow R2 in the figure. The intermediate transfer belt 8 carries and transports a toner image transferred from a photosensitive drum 1 (see Fig. 2). A secondary transfer outer roller 10 is arranged at a position facing a secondary transfer inner roller 9 that stretches the intermediate transfer belt 8 and sandwiches the intermediate transfer belt 8 therebetween, constituting a secondary transfer unit T2 that transfers the toner image on the intermediate transfer belt 8 to a sheet S.

[0013] A cassette 12 containing a sheet S is disposed at the bottom of the image forming apparatus 100. The sheet S is conveyed from the cassette 12 toward a registration roller 14 by a conveying roller 13. Thereafter, the registration roller 14 starts to rotate in synchronization with a toner image formed on the intermediate transfer belt 8 as described later, so that the sheet S is conveyed to the secondary transfer section T2. ​​Although only one cassette 12 is shown here, a plurality of cassettes 12 may be disposed so as to be able to accommodate sheets S of different sizes and thicknesses. In this case, the sheet S is conveyed selectively from one of the plurality of cassettes 12. The sheet S is not limited to the sheet S accommodated in the cassette 12, but may be conveyed from a manual feed section (not shown) or an external paper feed device (not shown) connected to the apparatus main body 100A.

[0014] The four image forming units PY, PM, PC, and PK included in the image forming apparatus 100 have substantially the same configuration, except for the different developing colors. Therefore, the image forming unit PK that forms a black image will be described here as a representative, and descriptions of the other image forming units will be omitted.

[0015] As shown in Fig. 2, the image forming unit PK is provided with a cylindrical photosensitive drum 1 as a photosensitive member. The photosensitive drum 1 rotates in the direction of arrow R1 at a predetermined process speed. Around the photosensitive drum 1, a charging device 2, an exposure device 3, a developing device 4, a primary transfer roller 5, and a cleaning device 6 are arranged.

[0016] A process of forming a full-color image by the image forming apparatus 100 will be described. First, when an image forming operation is started, the surface of the rotating photosensitive drum 1 is uniformly charged by the charging device 2. The charging device 2 is, for example, a corona charger that irradiates charged particles associated with corona discharge to charge the photosensitive drum 1 to a uniform negative dark potential. Next, the photosensitive drum 1 is scanned and exposed by a laser beam L corresponding to an image signal emitted from an exposure device 3. As a result, an electrostatic latent image corresponding to the image signal is formed on the surface of the photosensitive drum 1. The electrostatic latent image formed on the photosensitive drum 1 is visualized by the toner (developer) contained in the developing device 4, becoming a visible image.

[0017] The toner image formed on the photosensitive drum 1 is primarily transferred to the intermediate transfer belt 8 at a primary transfer portion T1 constituted between the photosensitive drum 1 and a primary transfer roller 5 arranged with the intermediate transfer belt 8 sandwiched therebetween. At this time, a primary transfer voltage is applied to the primary transfer roller 5. The toner remaining on the surface of the photosensitive drum 1 after the primary transfer is removed by a cleaning device 6.

[0018] Returning to FIG. 1, these operations are performed in sequence in each of the yellow, magenta, cyan, and black image forming units PY to PK, and the four color toner images are superimposed on the intermediate transfer belt 8. Thereafter, in accordance with the timing of the formation of the toner images, the sheet S stored in the cassette 12 is conveyed to the secondary transfer unit T2. Then, a secondary transfer voltage is applied to the outer secondary transfer roller 10, so that the full-color toner images formed on the intermediate transfer belt 8 are secondarily transferred to the sheet S all at once.

[0019] The sheet S onto which the toner image has been secondarily transferred is transported to a fixing device 11. The fixing device 11 has a fixing roller 11a arranged to be freely rotatable, and a pressure roller 11b which rotates while being in pressure contact with the fixing roller 11a. The fixing roller 11a is rotated by a drive motor (not shown) while being in pressure contact with the pressure roller 11b. A halogen heater 11c is arranged within the fixing roller 11a, and the halogen heater 11c heats the fixing roller 11a.

[0020] The fixing device 11 pinches and conveys the sheet S on which the toner image has been formed in a fixing nip T3 formed by the fixing roller 11a and the pressure roller 11b, and heats and pressurizes the conveyed sheet S to fix the toner image to the sheet S. That is, the toner of the toner image formed on the sheet S is melted and mixed by the heating and pressure, and is fixed to the sheet S as a full-color image. In this manner, a series of image formation processes is completed. Then, the sheet S on which the toner image has been fixed is conveyed by the conveying device 170.

[0021] In the present embodiment, the image forming apparatus 100 is capable of double-sided printing. In the case of single-sided printing, the sheet S on which the toner image is fixed is discharged by the discharge roller 15 to the outside of the apparatus main body 100A (outside the apparatus main body). In the case of double-sided printing, the sheet S on which the toner image is fixed is conveyed to the double-sided inversion conveyance path 600. In the double-sided inversion conveyance path 600, the sheet S is inverted to switch the front and back sides of the sheet S. The inverted sheet S is conveyed toward the registration roller 14, and conveyed to the secondary transfer section T2 by the registration roller 14 with the unprinted back side facing the intermediate transfer belt 8 side. In the secondary transfer section T2, the full-color toner image formed on the intermediate transfer belt 8 is secondarily transferred to the sheet S (back side) all at once. Thereafter, the toner image is fixed to the sheet S by the fixing device 11, and the sheet S is discharged to the outside of the apparatus main body 100A.

[0022] An external cooling device 110 and a sheet processing device 310 are connected to the image forming apparatus 100 so as to be able to deliver the sheet S in this order from the upstream side in the conveying direction of the sheet S. The external cooling device 110 and the sheet processing device 310 are configured so as to be able to be connected to the image forming apparatus 100 as peripheral devices (optional units) that can be added later to expand the functions of the image forming apparatus 100. The image forming apparatus 100, the external cooling device 110, and the sheet processing device 310 are connected to each other so as to be able to transmit and receive data via communication cables (not shown) capable of serial communication and parallel communication. By being connected to be able to communicate with each other via the communication cables, the image forming apparatus 100 controls the external cooling device 110 and the sheet processing device 310.

[0023] The external cooling device 110 of this embodiment includes a sheet cooling unit 20 as a sheet cooling means for cooling the sheet S, and an upstream transport unit 40 and a downstream transport unit 60 for transferring the sheet S between the sheet cooling unit 20 and the sheet cooling unit 20. The upstream transport unit 40 transports the sheet S discharged from the image forming device 100 and transfers it to the sheet cooling unit 20, and the downstream transport unit 60 receives the sheet S from the sheet cooling unit 20 and transports it toward the sheet processing device 310. In the external cooling device 110, the upstream transport unit 40, the downstream transport unit 60, and the sheet cooling unit 20 form a series of sheet transport paths 210. A detailed description of the external cooling device 110 as a sheet transport device (or sheet cooling device) will be given later.

[0024] The sheet S cooled by the external cooling device 110 is conveyed to the sheet processing device 310. The sheet S conveyed to the sheet processing device 310 is subjected to a punching process in which holes are made in the sheet S, or a stapling process in which a plurality of sheets S are bound and stapled by the sheet processing device 310. When the sheet processing device 310 performs a punching process, the sheet S is temporarily stopped in a punching process unit 314 and punched. Thereafter, a conveying path is switched by a discharge destination switching unit 311, and the punched sheet S is discharged to an upper discharge tray 312. On the other hand, when the sheet processing device 310 performs a staple process, the discharge destination switching unit 311 switches a conveying path and conveys the sheet S to a staple processing tray 315. Then, when a predetermined number of sheets S are placed on the staple processing tray 315, staples are made by a stapler 316. Then, the stapled bundle of sheets S is discharged to a lower discharge tray 313.

[0025] <External cooling device> Next, the external cooling device 110 will be described with reference to Fig. 3 to Fig. 12(d). Fig. 3 is a schematic diagram showing the external cooling device 110 with the front door 120 open, and Fig. 4 is a top cross-sectional view showing the external cooling device 110 with the front door 120 open.

[0026] As shown in FIG. 3 and FIG. 4, the device body 110A of the external cooling device 110 is provided with a front door 120 that can be rotated between an open state and a closed state. When the front door 120 is closed, the front door 120 constitutes a part of the external cooling device 110. When the front door 120 is opened, the user can access the sheet cooling unit 20, the upstream transport unit 40, the downstream transport unit 60, and the like in the device body 110A from outside the device body 110A. In this embodiment, the front door 120 can be opened and closed around a rotation shaft extending vertically to the device body 110A, which is the support frame of the device body 110A (for example, the frame 112). In addition, the front door 120 is provided on the downstream side in the sheet transport direction, closer to the downstream transport unit 60 than the upstream transport unit 40, with the front door 120 open. When a jam occurs, the user can manually operate the upstream transport unit 40 or the downstream transport unit 60 with the front door 120 open to remove the sheet S that is stuck therein. As will be described in more detail later, an upstream closing unit 50 and a downstream closing unit 70 are provided on the inner surface of the front door 120 in positions facing the upstream conveying unit 40 and the downstream conveying unit 60, respectively, when the front door 120 is closed.

[0027] <Seat cooling unit> An example of the sheet cooling unit 20 is shown in Fig. 5. The sheet cooling unit 20 shown in Fig. 5 is a cooling device of a belt cooling type. As shown in Fig. 5, the sheet cooling unit 20 is roughly divided into a first cooling unit 21U and a second cooling unit 25U. The first cooling unit 21U has an endless first belt 21, and the second cooling unit 25U has an endless second belt 25 that sandwiches and transports the first belt 21 and the sheet S. The first belt 21 and the second belt 25 are endless belts formed into a film shape using a resin such as high-strength polyimide.

[0028] The first belt 21 is wound around a plurality of first belt tension rollers 22a to 22d, and at least one of the first belt tension rollers 22a to 22d is rotated by a drive motor (not shown). As a result, the first belt 21 rotates in the direction of the arrow B in the figure. On the other hand, the second belt 25 is wound around a plurality of second belt tension rollers 26a to 26d, and is in contact with the outer circumferential surface of the first belt 21. Therefore, the second belt 25 can rotate following the first belt 21. Note that, in this embodiment, the first belt 21 is driven to make the second belt 25 follow the first belt 21, but the second belt 25 may be driven to make the first belt 21 follow the second belt 25. Alternatively, both the first belt 21 and the second belt 25 may be driven.

[0029] The sheet S discharged from the image forming apparatus 100 is sandwiched between the first belt 21 and the second belt 25, and is transported in the transport direction (the direction of the arrow C in the figure) according to the rotation of these belts. At that time, the sheet S passes through a cooling nip T4 formed by the contact between the first belt 21 and the second belt 25. In the case of the present embodiment, the first cooling unit 21U has a heat sink 30, and the first belt 21 is cooled by the heat sink 30. The heat sink 30 is disposed so as to contact the inner peripheral surface of the first belt 21 at a position forming the cooling nip T4 in order to efficiently cool the sheet S. The sheet S is cooled via the first belt 21 when passing through the cooling nip T4. As the sheet S is cooled, the toner on the sheet S is cooled and more firmly fixed on the sheet S.

[0030] The heat sink 30 serving as cooling means is a heat dissipation plate made of metal such as aluminum. The heat sink 30 has a heat receiving section 30a for contacting the first belt 21 to absorb heat from the first belt 21, a heat dissipation section 30b for dissipating heat, and a fin base 30c for conducting heat from the heat receiving section 30a to the heat dissipation section 30b. The heat dissipation section 30b is formed of a large number of heat dissipation fins in order to increase the contact area with the air and promote efficient heat dissipation. Also, in order to forcibly cool the heat sink 30 itself, a cooling fan 140 is provided which blows air towards the heat sink 30 (more specifically, the heat dissipation section 30b). The cooling fan 140 is driven by a motor (not shown) and has an air volume of, for example, "2 m 3 The cooling of the heat sink 30 is not limited to the cooling fan 140.

[0031] Although the heat sink 30 is in contact with the first belt 21 to cool the first belt 21, the present invention is not limited to this, and the heat sink 30 may be provided in the second cooling unit 25U to cool the second belt 25. Alternatively, one heat sink 30 may be provided in each of the first cooling unit 21U and the second cooling unit 25U to cool both the first belt 21 and the second belt 25. In addition to the heat sink 30, a belt cooling fan that blows air toward the belts, or a water cooling unit that brings a pipe through which cooled liquid is circulated into contact with the belts, or the like may be provided to cool the first belt 21 and the second belt 25.

[0032] Returning to FIG. 3, the sheet cooling unit 20 described above is provided with the first cooling unit 21U rotatably relative to the second cooling unit 25U. In this embodiment, a rotation shaft (not shown) extending along the sheet conveying direction is provided at the "rear side" opposite the front door 120 in the front-rear direction, which is a direction perpendicular to the vertical direction and the sheet conveying direction. The first cooling unit 21U is configured so that the "front side" where the front door 120 is located in the front-rear direction is opened and closed in the up-down direction. A user can lift the first cooling unit 21U upward by operating the handle 202 of the first cooling unit 21U to release the engagement with the second cooling unit 25U by the latch part 201 having a hook-shaped tip. This is to enable the user to remove the sheet S that is stuck in the sheet cooling unit 20 when a jam occurs. The first cooling unit 21U employs a so-called free stop configuration in which a damper is provided on the hinge part of the rotation shaft (not shown) so that the first cooling unit 21U can remain at any position in the open state.

[0033] <Transport unit> 3, the external cooling device 110 has an upstream transport unit 40 disposed on the upstream side and a downstream transport unit 60 disposed on the downstream side (here, the side closer to the rotation axis of the front door 120) so as to sandwich the sheet cooling unit 20 in the sheet transport direction. The upstream transport unit 40 and the downstream transport unit 60 are also configured to be rotatable so that a user can remove the sheet S remaining in the upstream transport unit 40 or the downstream transport unit 60 in the event of a jam. The upstream transport unit 40 and the downstream transport unit 60 will be described with reference to FIGS. 6(a) and 6(b).

[0034] Although the upstream transport unit 40 and the downstream transport unit 60 are partially different, they are substantially the same in configuration, so the downstream transport unit 60 will be described here as an example. For the upstream transport unit 40, the reference numerals of corresponding parts are written in parentheses in the drawings. Also, Fig. 6(a) and Fig. 6(b) show a case where the upper guide portion 60A is in an open position relative to the lower guide portion 60B in which no sheet transport path is formed in the sheet cooling unit 20.

[0035] 6(a) and 6(b), the downstream transport unit 60 includes a lower guide portion 60B and an upper guide portion 60A. In this embodiment, when the upper guide portion 60A is in a closed position where it is closed relative to the lower guide portion 60B, the lower guide portion 60B and the upper guide portion 60A form a part of the sheet transport path 210 in the external cooling device 110 (see FIG. 1), and the sheet S can be transported.

[0036] The lower guide portion 60B is provided with a first guide plate 65 and a drive roller 64 (first roller), and the upper guide portion 60A is provided with a second guide plate 62 and a driven roller 63 (second roller). When the upper guide portion 60A is in the closed position, the lower guide portion 60B and the upper guide portion 60A face each other so as to sandwich the sheet S. The first guide plate 65 is disposed along the sheet transport path so as to guide one side of the sheet S, and the second guide plate 62 is disposed along the sheet transport path so as to guide the other side of the sheet S opposite to the one side.

[0037] An opening is formed in the first guide plate 65, and a drive roller 64 that is driven to rotate by a motor (not shown) is provided so as to be exposed from the opening and rotatable. A similar opening is formed in the second guide plate 62, and a driven roller 63 is provided so as to be exposed from the opening and rotatable by the drive roller 64 so as to come into contact with the drive roller 64. The driven roller 63 presses the drive roller 64 by the biasing force of a compression spring (not shown), and thus the drive roller 64 and the driven roller 63 as rotating conveying means can sandwich and convey the sheet S.

[0038] The upper guide portion 60A is provided rotatably with respect to the lower guide portion 60B so as to move between a closed position (first position) where a sheet transport path is formed to transport the sheet S, and an upper open position (second position) where the sheet transport path is opened to not transport the sheet S. The second guide plate 62 of the upper guide portion 60A is rotatable between the closed position and the open position with a horizontally extending rotation axis as a rotation center. The upper guide portion 60A is provided with a jam release lever 61 as an operating means that is held and operated by a user so that the user can manually rotate the upper guide portion 60A between the closed position and the open position. The jam release lever 61 is provided from an end of the second guide plate 62 in the width direction (direction intersecting the sheet transport direction) toward the "front side" where the front door 120 is located (see FIG. 4) so ​​that the user can operate it with the front door 120 (see FIG. 3) open. When moving the upper guide portion 60A from the closed position to the open position, the user grasps and raises the jam release lever 61 upward, and when moving the upper guide portion 60A from the open position to the closed position, the user grasps and lowers the jam release lever 61 downward. Note that the jam release lever 61 protrudes toward the front door 120 side more than the sheet cooling unit 20 so that the user can easily grasp and operate it (see FIG. 4).

[0039] In addition, the second guide plate 62 is formed with a pin 68 that protrudes toward the first guide plate 65. When the upper guide portion 60A is moved to the closed position, the pin 68 is inserted into a pin fitting hole 67 formed in the first guide plate 65. As a result, the movement of the pin 68 in the sheet conveying direction is restricted by the pin fitting hole 67, and the relative positions of the upper guide portion 60A and the lower guide portion 60B in the sheet conveying direction are determined. The pin 68 and the pin fitting hole 67 are formed near the rotation axes of the driven roller 63 and the driving roller 64, respectively, in the sheet conveying direction. In this way, in the downstream conveying unit 60 that is configured to be openable and closable, it is possible to suppress the amount of deviation in the alignment of the driven roller 63 and the driving roller 64 that rotate in contact with each other. If the deviation in the alignment between the driven roller 63 and the drive roller 64 can be suppressed, the rotation axis of the driven roller 63 and the rotation axis of the drive roller 64 can be maintained parallel to each other, thereby suppressing skew of the sheet S during transport.

[0040] Further, in order to hold the upper guide portion 60A in the closed position, as shown in FIG. 6(b), a magnet 69 (guide holding magnet) long in the sheet conveying direction is attached to the surface of the second guide plate 62 on which the pin 68 is formed. Also, as shown in FIG. 6(a), the first guide plate 65 is formed with a magnet attachment portion 66 at a position facing the magnet 69 when the upper guide portion 60A is in the closed position. When the upper guide portion 60A is moved to the closed position, the magnet 69 is attached to the magnet attachment portion 66 by a magnetic force, so that the upper guide portion 60A is held in the closed position. The pin 68, the magnet 69, the pin fitting hole 67, and the magnet attachment portion 66 are provided on the outside (end side) of the width direction area W that allows the passage of the maximum size of the sheet S to be conveyed so as not to interfere with the conveyance of the sheet S by the driven roller 63 and the driving roller 64.

[0041] In addition, in the sheet conveying direction, the magnet 69 is preferably provided at a position where at least a part of it overlaps with the rotation axis N of the driven roller 43, and accordingly, the magnet attachment portion 66 is preferably provided at a position where at least a part of it overlaps with the rotation axis M of the drive roller 44. In this way, when the upper guide portion 60A is in the closed position, the magnetic force of the magnet 69 causes the driven roller 43 and the drive roller 44 to abut against each other with uniform and appropriate pressure in the rotation axis direction (width direction), so that variation in the sheet conveying force can be suppressed.

[0042] In this embodiment, unlike the first cooling unit 21U, the upper guide portion 60A does not have a free stop configuration, and therefore the upper guide portion 60A cannot remain at any position in the open state. However, if the upper guide portion 60A is not maintained in the open position and falls to the closed position by its own weight, it is difficult for the user to remove the sheet S.

[0043] In this embodiment, as shown in Fig. 3, two guide holders 130 are provided on the frame 112 of the apparatus main body 110A so as to hold the upper guide portions 40A (60A) of the upstream transport unit 40 and the downstream transport unit 60 in the open position. The guide holders 130 will be described using Fig. 7 with reference to Fig. 3.

[0044] <Guide holder> 7, the guide holder 130 has a magnet 131 as a holder, and a magnet attachment portion 132. The magnet 131 is attached to the magnet attachment portion 132 with its tip facing the upper guide portion 60A side (here, downward). The guide holder 130 is fixed to the frame 112 of the device main body 110A via the magnet attachment portion 132. A magnet attachment portion 61a made of sheet metal is provided on the tip side in the width direction of the second guide plate 62. The magnet attachment portion 61a may be formed integrally with the jam release lever 61 described above.

[0045] The magnet 131 is disposed on a path along which the magnet attachment portion 61a moves as the second guide plate 62 rotates, and when the rotating second guide plate 62 reaches the open position, the magnet 131 is attached to the magnet attachment portion 61a by magnetic force. This holds the upper guide portion 60A in the open position and prevents it from moving from the open position to the closed position due to its own weight. In this case, in order to enable the upper guide portion 60A to move from the open position to the closed position, it is necessary to release the magnet 131 from holding the second guide plate 62. The user can release the magnet 131 from holding the second guide plate 62 by gripping the jam release lever 61 and lowering it downward.

[0046] In this embodiment, the upper guide portion 60A is held in the open position by the magnet 131, but the present invention is not limited to this. For example, instead of the magnet 131, a hook-shaped engagement protrusion may be provided on the frame 112 of the device main body 110A, and instead of the magnet attachment portion 61a, an engagement hole may be formed in the upper guide portion 60A. In this case, the upper guide portion 60A is held in the open position by engaging the engagement protrusion with the engagement hole. In addition, the upper guide portion 60A is held in the closed position by the magnet 69, but the present invention is not limited to this. However, as described above, in order to suppress the variation in the sheet conveying force, it is preferable to hold the upper guide portion 60A in the closed position by the magnet 69.

[0047] The protruding amount (length) of the pin 68 from the second guide plate 62 is set so that the tip of the pin 68 is inserted into the pin fitting hole 67 before the magnet 69 reaches the magnet attachment portion 66 when the upper guide portion 60A moves from the open position to the closed position. That is, as shown in FIG. 6(b), the tip of the pin 68 protrudes toward the lower guide portion 60B more than the magnet 69 (the protruding amount is larger). That is, the pin 68 is inserted into the pin fitting hole 67 before the upper guide portion 60A reaches the closed position. In this way, when the upper guide portion 60A moving from the open position to the closed position reaches a position where the pin 68 fits into the pin fitting hole 67, the upper guide portion 60A and the lower guide portion 60B are positioned in the planar direction by the pin 68 and the pin fitting hole 67. Therefore, the upper guide part 60A moves to the closed position while being guided by the pin 68 and the pin fitting hole 67, so that the magnet 69 provided on the upper guide part 60A can be reliably attached to the magnet attachment part 66 provided on the lower guide part 60B. This allows the driven roller 63 and the driving roller 64 to be appropriately abutted against each other.

[0048] Incidentally, when a jam occurs, the user first opens the front door 120, and then performs the task of removing the sheet S that is stuck in the upstream transport unit 40 or the downstream transport unit 60. For example, when the sheet S is stuck in the downstream transport unit 60, the user lifts the jam release lever 61 upward to move the upper guide portion 60A from the closed position to the open position. After removing the sheet S, the user pushes the jam release lever 61 downward to move the upper guide portion 60A from the open position to the closed position. Then, the user closes the front door 120. However, if the user closes the front door 120 without returning the upper guide portion 60A to the closed position, the downstream transport unit 60 may be pushed by the front door 120 and damaged. Also, the upstream transport unit 40 may be damaged in a similar state.

[0049] Therefore, in this embodiment, even if the user closes the front door 120 without returning the upper guide portion 40A or the upper guide portion 60A to the closed position, the upstream transport unit 40 or the downstream transport unit 60 is not damaged. The configuration of this embodiment to achieve this will be described below.

[0050] 3, an upstream closing unit 50 and a downstream closing unit 70 are provided on the inner surface of the front door 120. In this embodiment, as the front door 120 closes, the downstream closing unit 70 first comes into contact with the jam release lever 61 of the downstream conveying unit 60, and as the front door 120 closes thereafter, the upstream closing unit 50 comes into contact with the jam release lever 41 of the upstream conveying unit 40.

[0051] <Upstream closing unit> The upstream closing unit 50 will be described with reference to Fig. 3 and Fig. 8 to Fig. 10(d). As shown in Fig. 3, the upstream closing unit 50 has an upstream holding release part 51 as a release means and an upstream guiding part 52 as a guiding means.

[0052] <Upstream side holding release part> First, the upstream holding release portion 51 will be described. The upstream holding release portion 51 is provided so as to protrude from the inner surface of the front door 120 and form an inclined surface 51a inclined in the direction of gravity, and the inclined surface 51a is formed so that the upper side penetrates deeper into the device main body 110A than the lower side in the vertical direction. As the front door 120 closes, the upstream holding release portion 51 abuts against the jam release lever 41 of the upstream conveying unit 40, and releases the holding of the second guide plate 42 by the upstream guide holder 130 (more specifically, the magnet 131, see FIG. 7) in the open position.

[0053] That is, as shown in Fig. 8 and Fig. 9, when the front door 120 is closed, the upstream holding release part 51 of the front door 120 hits the tip of the jam release lever 41 as an operating means. Note that in Fig. 9, the downstream closing unit 70 is omitted. When the front door 120 is further closed after the upstream holding release part 51 hits the tip of the jam release lever 41, the jam release lever 41 is pushed by the front door 120 and moved downward in the direction of gravity along the inclined surface 51a of the upstream holding release part 51. As a result, the upper guide part 40A moves downward and the magnet attachment part 41a moves away from the guide holder 130, so that the holding of the upper guide part 40A (i.e., the second guide plate 42) by the magnet 131 (see Fig. 7) is released.

[0054] After the holding is released, the upper guide portion 40A moves downward as if being pushed by the front door 120, with the jam release lever 41 abutting against the upstream holding release portion 51. In other words, the upstream holding release portion 51 is formed so that the force in the width direction applied to the upper guide portion 40A in association with the closing operation of the front door 120 by the user is divided into the width direction and the downward direction by the inclined surface 51a. This suppresses damage to the upper guide portion 40A in association with the closing operation of the front door 120 while the upper guide portion 40A is in contact with the upstream holding release portion 51. In addition, since the force in the width direction is applied to the upper guide portion 40A even if the force is divided, the upper guide portion 40A does not fall to the closed position in one go due to its own weight.

[0055] In this embodiment, while the jam release lever 41 is in contact with the upstream holding release portion 51, one end of the upper guide portion 40A in the sheet conveying direction abuts against the guide holder 130, and the movement of the moving sheet in the conveying direction is restricted by the guide holder 130. To achieve this, the magnet mounting portion 132 is formed with a restricting surface that extends in the direction of gravity, in this case, in the opening and closing direction of the upper guide portion 40A. That is, the guide holder 130 abuts against the second guide plate 42 on the side of the rotation shaft 125 of the front door 120 (the rotation shaft side, see FIG. 4) in the sheet conveying direction, and also functions as a restricting means that restricts the movement of the second guide plate 42 toward the side of the rotation shaft 125 of the front door 120.

[0056] <Upstream guide section> Next, the upstream guide section 52 will be described. As described above, when the upper guide section 40A after the holding is released is moved downward along the inclined surface 51a of the upstream hold releasing section 51, the jam release lever 41 is moved vertically downward and reaches the upstream guide section 52 provided continuously below the upstream hold releasing section 51. The upstream guide section 52 guides the second guide plate 42 to the closed position (first position) via the jam release lever 41 while suppressing the movement of the jam release lever 41 of the second guide plate 42 released from the holding by the upstream hold releasing section 51 in the sheet conveying direction.

[0057] 3, the upstream guide section 52 is formed in a hollow rectangular box shape, and a retracting member 52a is provided therein as a retracting means. An opening is formed in the upstream guide section 52 on the same side as the inclined surface 51a of the upstream hold release section 51, and the retracting member 52a is provided inside the upstream guide section 52 and exposed from the opening. As described later, the retracting member 52a is provided so as to be movable in the direction opposite to the closing direction of the front door 120 by hitting the jam release lever 41 as the front door 120 closes.

[0058] As shown in FIG. 10(a), the retracting member 52a is provided rotatably on the upstream guide section 52. In this embodiment, the retracting member 52a has a rotation shaft 53 provided on the upper side, and rotates around the upper side as a rotation center and an elastic member 52b side (pressing means side) provided vertically below the rotation center as a free end. The retracting member 52a and the elastic member 52b are provided integrally. The retracting member 52a is biased by a torsion spring 54 as a biasing means toward the opening side of the upstream guide section 52, in other words, toward the same direction as the direction in which the front door 120 is closed.

[0059] As described above, when the upstream holding release portion 51 of the front door 120 hits the tip of the jam release lever 41 as the user closes the front door 120, a widthwise force F1 is applied to the upper guide portion 40A. The widthwise force F1 applied to the upper guide portion 40A is divided into widthwise and downward forces by the inclined surface 51a of the upstream holding release portion 51 (resultant force f1). Then, the retention of the upper guide portion 40A by the magnet 131 is released by the resultant force f1, and the upper guide portion 40A falls downward while causing the jam release lever 41 to slide against the inclined surface 51a.

[0060] As the front door 120 continues to close, the tip of the jam release lever 41 reaches the upstream guide portion 52, and the tip of the jam release lever 41 enters the upstream guide portion 52 from the opening and abuts against the retracting member 52a, as shown in FIG. 10(b). If the front door 120 is further closed in this state, the retracting member 52a is pushed by the jam release lever 41 and rotates around the rotation shaft 53 in the direction R3 opposite to the biasing direction of the torsion spring 54. That is, the retracting member 52a abuts against the jam release lever 41 as the upper guide portion 40A moves from the open position to the closed position, and thus swings in the R3 direction. Then, the retracting member 52a retracts the elastic member 52b from the movement trajectory of the jam release lever 41.

[0061] As shown in FIG. 10(c), the upper guide portion 40A is moved to the closed position while the jam release lever 41 slides against the retracting member 52a. At this time, since a force F1 in the width direction is applied to the upper guide portion 40A via the retracting member 52a, the upper guide portion 40A does not fall to the closed position in one go due to its own weight. In addition, since the retracting member 52a operates to retract from the jam release lever 41 toward the outside of the front door 120, damage to the upper guide portion 40A caused by the closing operation of the front door 120 is suppressed. In other words, since the retracting member 52a swings to retract from the rotation trajectory of the jam release lever 41, damage to the upper guide portion 40A caused by the closing operation of the front door 120 is suppressed. Note that, since the jam release lever 41 is maintained in a state of being inserted into the upstream guide portion 52 from the opening until the upper guide portion 40A is moved to the closed position, the upstream guide portion 52 restricts the movement of the upper guide portion 40A in the sheet conveying direction during the movement.

[0062] When the upper guide portion 40A is moved to the closed position, the driven roller 43 of the upper guide portion 40A and the driving roller 44 of the lower guide portion 40B come into contact with each other, and the magnet 49 (guide holding magnet) of the upper guide portion 40A sticks to the magnet attachment portion 46 of the lower guide portion 40B. However, since the driven roller 43 is biased by a compression spring (not shown), when the driven roller 43 (second roller) and the driving roller 44 (first roller) come into contact with each other, a reaction force O acts due to the biasing force of the compression spring. Therefore, when the upper guide portion 40A reaches the closed position, the magnet 49 may not immediately stick to the magnet attachment portion 46, but may stick after the upper guide portion 40A bounces for a while. Therefore, it is preferable to generate a force f3 by the action of the weight of the retracting member 52a and the torsion spring 54, so that the magnet 49 sticks to the magnet attachment portion 46 without bouncing the upper guide portion 40A. To achieve this, in this embodiment, an elastic member 52b such as a rubber plate is provided at the lower end of the retracting member 52a. This elastic member 52b is elastically deformed by hitting against the jam release lever 41, and presses the second guide plate 42 toward the first guide plate 45 via the jam release lever 41. In other words, the elastic member 52b is an example of a pressing means for pressing the jam release lever 41. The elastic member 52b presses the jam release lever 41 of the second guide plate 42 while the second guide plate 42 is moving from the open position to the closed position, thereby pressing the second guide plate 42 against the first guide plate 45 and causing the magnet 49 to adhere to the magnet attachment portion 46. In addition, the elastic member 52b continues to press the jam release lever 41 of the second guide plate 42 at the closed position, so that the second guide plate 42 is positioned at the closed position. In addition, since the elastic member 52b swings together with the retracting member 52a so as to retract from the rotation trajectory of the jam release lever 41, damage to the upper guide portion 40A caused by the closing operation of the front door 120 is suppressed.

[0063] However, the elastic member 52b does not need to always be in contact with the jam release lever 41 when the front door 120 is in the closed state. Even if the elastic member 52b is not in contact with the jam release lever 41 when the front door 120 is in the closed state, the magnet 49 can be attached to the magnet attachment portion 46 without repelling the upper guide portion 40A even if the biasing force of the torsion spring 54 is increased. Also, the elastic member 52b may not be in contact with the jam release lever 41 when the front door 120 is in the closed state, as long as the elastic member 52b can apply a force to contact the jam release lever 41 and attach the magnet 49 to the magnet attachment portion 46 during the process of the front door 120 moving from the open state to the closed state. Note that, in the case of a configuration in which the magnet 49 is not provided as described above, it is sufficient that the elastic member 52b is always in contact with the jam release lever 41 and presses the second guide plate 42 against the first guide plate 45 when the front door 120 is in the closed state.

[0064] 10(d), the force applied by the weight of the retracting member 52a and the biasing force of the torsion spring 54 generate a force f3 in the elastic member 52b of the retracting member 52a, causing the magnet 49 to stick to the magnet attachment portion 46, and the upper guide portion 40A is held in the closed position. In this way, the upstream guide portion 52 moves the upper guide portion 40A in accordance with the closing operation of the front door 120 so that the second guide plate 42, which has been released from the hold by the magnet 131, does not fall all at once to the closed position under its own weight, while retracting so as not to be damaged by being pushed by the front door 120.

[0065] <Downstream closing unit> Next, the downstream closing unit 70 will be described with reference to Figures 3, 11 and 12. As shown in Figure 3, the downstream closing unit 70 has a downstream holding release section 71 as a release means and a downstream guide section 72 as a guide means. The downstream guide section 72 is formed in a hollow rectangular box shape, and a retraction member 72a as a retraction means is provided therein. The downstream guide section 72 is the same as the upstream guide section 52 of the upstream closing unit 50 described above, and therefore a description thereof will be omitted.

[0066] <Downstream holding release section> The downstream side holding release section 71 releases the holding of the second guide plate 62 by the downstream side guide holder 130 (more specifically, the magnet 131, see FIG. 7). The downstream side holding release section 71 may have the same inclined surface as the inclined surface 51a of the upstream side holding release section 51 described above, but as shown in FIG. 3, in this embodiment, an inclined member 71a is provided that forms an inclined surface inclined in the width direction as well as in the gravity direction. This is because, since the downstream conveying unit 60 is disposed on the side closer to the rotation axis of the front door 120, if the inclined surface is the same as the inclined surface 51a of the upstream side holding release section 51, it is difficult to release the holding of the second guide plate 62 by the guide holder 130 in response to the closing operation of the front door 120. In other words, when the downstream side is disposed on the side closer to the rotation axis of the front door 120, if the inclined surface is the same as the far side, a larger force must be applied to separate the magnet 131 from the magnet attachment section 61a (see FIG. 7) than the far side. Therefore, there is a high risk of damaging the downstream conveying unit 60.

[0067] Therefore, in this embodiment, as shown in Figures 11 and 12, an inclined member 71a is provided in the downstream hold releasing portion 71. Figures 11 and 12 show a state in which the inclined member 71a of the downstream hold releasing portion 71 starts to contact the jam release lever 61 of the upper guide portion 60A that is held by the guide holder 130 and in the open position.

[0068] The inclined member 71a is provided so as to face the side of the rotation shaft 125 of the front door 120. The position of the inclined member 71a and the direction of the inclined surface are determined based on the rotation direction (arrow V11) of the front door 120 and the position of the guide holder 130 relative to the upper guide portion 60A. As the position of the downstream hold releasing portion 71 approaches the rotation axis of the front door 120, the ease of applying the force required to separate the magnet 131 from the magnet attachment portion 61a changes. Therefore, the ease of applying the force required to separate the magnet 131 from the magnet attachment portion 61a is adjusted by the direction in which the inclined surface of the inclined member 71a is faced.

[0069] In the present embodiment, the inclined surface (butting portion) of the inclined member 71a is formed at an angle such that the lower side approaches the inner surface of the front door 120 more than the upper side in the vertical direction. The inclined surface (butting portion) of the inclined member 71a is formed at an angle such that the side closer to the rotation axis of the front door 120 approaches the inner surface of the front door 120 more than the far side. The inclined member 71a is preferably provided so that the angle θ between "a straight line Z that is perpendicular to the rotation axis X of the upper guide portion 60A located in the open position and passes through the abutment point Q at which the jam release lever 61 of the inclined surface (butting portion) of the inclined member 71a abuts" and "a straight line Y that passes through the abutment point Q and the abutment point T at which the second guide plate 62 of the guide holder 130 abuts" is 3° or more and 10° or less. The inclined member 71a is preferably provided so that the angle formed between the downstream hold releasing portion 71 and the rotation axis of the front door 120 is about 3.5°, although this depends on the distance between them.

[0070] Here, the downstream side holding release portion 71 has been mainly described, but the same relationship is also established for the inclined surface 51a of the upstream side holding release portion 51. However, since the positional relationship between the upper guide portion 40A and the upstream side guide holder 130 is reversed with respect to the positional relationship between the upper guide portion 60A and the downstream side guide holder 130, the shape of the inclined surface 51a of the upstream side holding release portion 51 and the inclined surface of the downstream side inclined member 71a are different. Since the upstream side holding release portion 51 is provided at a position farther away from the rotation axis of the front door 120 than the downstream side holding release portion 71, the inclined surface 51a can be inclined in the width direction with respect to the jam release lever 41 as the front door 120 is closed. Therefore, even if the inclined surface 51a has a configuration having an inclined surface different from that of the inclined member 71a, the upstream side holding release portion 51 can release the holding of the upper guide portion 60A.

[0071] When closing the front door 120, the inclined member 71a applies pressure to the upper guide part 60A in the rotation direction (arrow V11) of the front door 120 via the jam release lever 61 at a point (abutment point Q) where the inclined member 71a contacts the jam release lever 61. This pressure direction (arrow V11) is set to a direction having an angle of 3° to 10° with respect to a direction (straight line Z) perpendicular to a rotation axis X of the rotation shaft 53 (see FIG. 10(a)) of the upper guide part 60A that rotates between an open position and a closed position. The inclined member 71a is provided so that this occurs.

[0072] In such a case, when the force of closing the front door 120 causes the inclined member 71a to press the upper guide portion 60A in the rotation direction (arrow V11) of the front door 120 via the jam release lever 61, the upper guide portion 60A can move in the direction of the arrow V12. Then, the edge of the upper guide portion 60A comes into contact with the regulating surface of the guide holder 130 fixed to the frame 112 (see FIG. 3) of the device main body 110A from the direction of the arrow V12. Then, as shown in FIG. 10(a) above, the downstream side holding release portion 71 of the front door 120 hits the tip of the jam release lever 61, and the force F1 in the width direction applied to the upper guide portion 60A is divided into the width direction and the downward direction by the inclined surface of the inclined member 71a (resultant force f1). Then, due to the resultant force f1, the upper guide part 60A is released from the guide holder 130, and the upper guide part 60A falls downward while causing the jam release lever 61 to rub against the inclined surface of the inclined member 71a. In other words, although the upper guide part 60A has a long length up to the rotation shaft 53 (see FIG. 10(a)), the pressure is applied at a short distance from the jam release lever 61, which is the pressure point, to the regulating surface of the guide holder 130. Therefore, the upper guide part 60A only needs to have the rigidity required for the transport function and for normal operation by the user.

[0073] As described above, in this embodiment, the upstream closing unit 50 and the downstream closing unit 70 are provided on the inner surface of the front door 120. The downstream closing unit 70 (similar to the upstream closing unit 50) has a downstream holding release portion 71 (51), which abuts against the jam release lever 61 (41) when the front door 120 is closed, and releases the holding of the upper guide portion 60A (40A) by the guide holder 130. In addition, the downstream closing unit 70 (50) has a downstream guide portion 72 (52), and the retracting member 72a (52a) is provided on the downstream guide portion 72 (52) so as to be freely rotatable. As the front door 120 is closed, the jam release lever 61 (41) abuts against the retracting member 72a (52a). If the front door 120 is further closed in this state, the retracting member 72a (52a) is pushed by the jam release lever 61 (41) and retracts in the opposite direction to the closing direction of the front door 120 while sliding against the jam release lever 61 (41). This prevents damage to the downstream transport unit 60 (upstream transport unit 40) even if the user closes the front door 120 while forgetting to close the upper guide portion 60A (40A).

[0074] [Other embodiments] In the above embodiment, as shown in Fig. 10(a) to Fig. 10(d), the retracting member 52a is biased by the torsion spring 54 on the upstream transport unit 40 side, but this is not limited to the above. For example, it is possible to apply a force (f3) equivalent to that applied when the torsion spring 54 is provided to the jam release lever 41 by increasing the weight of the retracting member 52a, particularly by making the lower tip side heavier, without providing the torsion spring 54. The same may be true for the downstream transport unit 60 side.

[0075] In the above-mentioned embodiment, as shown in Fig. 8 and Fig. 12, the upstream guide holder 130 is provided on the upstream side in the sheet conveying direction with respect to the upstream upper guide portion 40A, and the guide holder 130 is provided on the downstream side in the sheet conveying direction with respect to the downstream upper guide portion 60A, but this is not limited thereto. The positional relationship between the guide holder 130 and the upper guide portion 40A (60A) may be reversed from that in the above-mentioned embodiment as long as the angle θ between "a straight line Z that is perpendicular to the rotation axis X of the upper guide portion 60A located in the open position and passes through the abutment point Q at which the jam release lever 61 of the inclined surface (abutment portion) of the inclined member 71a abuts" and "a straight line Y that passes through the abutment point Q and the abutment point T at which the second guide plate 62 of the guide holder 130 abuts" is 3° or more and 10° or less.

[0076] As in the above-described embodiment, the present invention is not limited to application to the external cooling device 110, but may be applied to, for example, a conveying device 170 (see FIG. 1) that conveys a sheet S in the apparatus body 100A of the image forming apparatus 100. The above-described embodiment can also be applied to a sheet conveying device that is capable of transferring the sheet S between the sheet cooling unit 20 provided in the apparatus body 100A of the image forming apparatus 100 and the sheet cooling unit 20. That is, the sheet conveying device of this embodiment may be disposed in any arrangement, whether it is disposed in the apparatus body 100A of the image forming apparatus 100 or in the apparatus body 110A of the external cooling device 110. [Explanation of symbols]

[0077] 1X...image forming system, 11...fixing device, 20...sheet cooling means (sheet cooling unit), 21...first belt, 25...second belt, 30...cooling means (heat sink), 41(61)...operation means (jam release lever), 42(62)...second guide plate, 43(63)...conveying means (second roller, driven roller), 44(64)...conveying means (first roller, drive roller), 45(65)...first guide plate, 49(69)...guide holding magnet (magnet), 51(71)...release means (upstream holding release section, downstream holding release section), 52 (72)...guide means (upstream guide portion, downstream guide portion), 52a (72a)...retraction means (retraction member), 52b...pressure means (elastic member), 54...urging means (torsion spring), 71a...butting portion, 100...image forming apparatus, 110...sheet conveying apparatus (sheet cooling apparatus, external cooling apparatus), 110A...apparatus main body (support frame), 120...door (front door), 130...regulation means (guide holder), 131...holding means (magnet), 200...image forming unit, 210...sheet conveying path, S...recording material, T3...nip portion (fixing nip portion)

Claims

1. A conveying means for conveying a sheet; a first guide that guides the sheet conveyed by the conveying means; a second guide provided opposite to the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position at which the sheet transport path is formed and a second position at which the sheet transport path is opened; a holding means for holding the second guide at the second position; a cover constituting a part of the external appearance of the device, the cover being movable between a closed position covering the second guide and an open position in which the second guide can be operated; a support frame supporting the first guide, the second guide, and the cover; a contact portion provided on the cover and contacting the second guide, the cover is capable of being opened and closed about a rotation axis that extends in a vertical direction relative to the support frame; the second guide is rotatable between the first position and the second position about a rotation axis extending in a horizontal direction; the abutment portion is disposed so as to release the holding of the second guide by the holding means when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means. A sheet conveying device comprising:

2. When the holding means releases the second guide, the second guide moves from the second position to the first position by its own weight.

2. The sheet transport device according to claim 1.

3. an operating means provided on the second guide and operated when rotating the second guide; a pressing means provided on the cover and configured to press the operating means so that the second guide is positioned at the first position; a retracting means provided on the cover, the retracting means being brought into contact with the operating means of the second guide moving from the second position to the first position and swinging to retract the pressing means from a moving trajectory of the operating means when the second guide moves from the first position to the second position, 3. The sheet conveying device according to claim 1, wherein the sheet conveying device is a sheet conveying device.

4. a guide means provided on the cover, which guides the second guide to the first position via the operation means while suppressing movement of the second guide in the sheet conveying direction of the conveying means when the second guide moves from the second position to the first position; 4. The sheet transport device according to claim 3.

5. the guiding means has an opening into which the operating means of the second guide enters when the second guide moves from the second position to the first position, and guides the operating means along the opening, the operating means moving vertically downward as the cover moves from the open state to the closed state; The retracting means is provided inside the guiding means and is exposed through the opening.

5. The sheet transport device according to claim 4.

6. The retracting means has a rotation center above the pressing means in the vertical direction, and is provided integrally with the pressing means so as to be rotatable with the pressing means side as a free end.

6. The sheet transport device according to claim 3, wherein the sheet transport device is a sheet conveying device.

7. The retracting means includes a biasing means for biasing the cover in a closing direction.

4. The sheet transport device according to claim 3.

8. the pressing means includes an elastic member that is elastically deformed by hitting against the operating means and presses the second guide toward the first guide via the operating means.

4. The sheet transport device according to claim 3.

9. a guide holding magnet provided on at least one of the first guide and the second guide, the elastic member presses the operating means so that the second guide is held at the first position by the magnetic force of the guide holding magnet; 9. The sheet transport device according to claim 8.

10. The conveying means includes a first roller provided in the first guide, and a second roller provided in the second guide, which is in contact with and presses the first roller at the first position.

10. The sheet transport device according to claim 1, wherein the sheet transport device is a sheet conveying device.

11. the holding means is a magnet, and holds the second guide at the second position by a magnetic force of the magnet; 11. The sheet transport device according to claim 1, wherein the sheet transport device is a sheet conveying device.

12. The abutment portion is formed obliquely so that a lower side thereof is closer to the inner surface of the cover than an upper side thereof in the vertical direction. The sheet transport device according to any one of claims 1 to 11.

13. The abutment portion is formed obliquely so that a side closer to the rotation axis of the cover approaches the inner surface of the cover more than a side farther from the rotation axis. The sheet transport device according to claim 12 .

14. a restricting means for restricting movement of the second guide toward the pivot shaft of the cover by contacting the second guide on the pivot shaft side of the cover in the sheet conveying direction of the conveying means; The sheet transport device according to claim 13 .

15. an operating means provided on the second guide and operated when the second guide is rotated; The second guide is provided so that an angle formed by a straight line perpendicular to the rotation axis of the second guide and passing through a contact point of the contact portion where the operating means contacts, and a straight line passing through the contact point and a contact point of the regulating means where the second guide contacts, is equal to or greater than 3° and equal to or less than 10°.

15. The sheet transport device according to claim 14.

16. an image forming unit that forms a toner image on a sheet; a fixing device that fixes the toner image on the sheet by applying heat; a sheet cooling device that cools the sheet heated by the fixing device, The sheet cooling device includes: a sheet cooling means including a first belt, a second belt that contacts an outer peripheral surface of the first belt to form a nip portion for nipping and conveying a sheet, and a heat sink that contacts an inner peripheral surface of the first belt; a conveying means provided at least one of upstream and downstream of the sheet cooling means in the sheet conveying direction in the nip portion, the conveying means conveying the sheet; a first guide that guides the sheet conveyed by the conveying means; a second guide provided opposite to the first guide and rotatable between a first position forming a sheet transport path through which a sheet passes together with the first guide and a second position opening the sheet transport path; a holding means for holding the second guide at the second position; a cover that constitutes a part of the exterior of the sheet cooling device and that is movable between a closed position that covers the second guide and an open position that allows the second guide to be operated; a contact portion provided on the cover and contacting the second guide, the abutment portion is disposed so as to release the holding of the second guide by the holding means when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means.

1. An image forming system comprising:

17. A conveying means for conveying a sheet; a first guide that guides the sheet conveyed by the conveying means; a second guide provided opposite to the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position at which the sheet transport path is formed and a second position at which the sheet transport path is opened; a holding means for holding the second guide at the second position; a cover constituting a part of the external appearance of the device, the cover being movable between a closed position covering the second guide and an open position in which the second guide can be operated; a first contact portion provided on the cover and contacting the second guide; a second contact portion provided on the cover and contacting the second guide at a position different from the first contact portion; the first abutment portion is disposed so as to release the holding of the second guide by the holding means when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means, and the second abutment portion is disposed so as to abut against the second guide to position the second guide at the first position when the cover is in the closed position; A sheet conveying device comprising:

18. When the holding means releases the second guide, the second guide moves from the second position to the first position by its own weight.

20. The sheet transport device according to claim 17,

19. an operating means provided on the second guide and operated when rotating the second guide; a pressing means provided on the cover and configured to press the operating means so that the second guide is positioned at the first position; a retracting means provided on the cover, the retracting means being brought into contact with the operating means of the second guide moving from the second position to the first position and swinging to retract the pressing means from a moving trajectory of the operating means when the second guide moves from the first position to the second position, 19. The sheet transport device according to claim 17 or 18.

20. a guide means provided on the cover, which guides the second guide to the first position via the operation means while suppressing movement of the second guide in the sheet conveying direction of the conveying means when the second guide moves from the second position to the first position; 20. The sheet transport apparatus according to claim 19.

21. the guiding means has an opening into which the operating means of the second guide enters when the second guide moves from the second position to the first position, and guides the operating means along the opening, the operating means moving vertically downward as the cover moves from the open state to the closed state; The retracting means is provided inside the guiding means and is exposed through the opening.

21. The sheet transport apparatus according to claim 20.

22. The retracting means has a rotation center above the pressing means in the vertical direction, and is provided integrally with the pressing means so as to be rotatable with the pressing means side as a free end.

22. The sheet transport device according to claim 19, wherein the sheet transport device is a sheet conveying device.

23. The retracting means includes a biasing means for biasing the cover in a closing direction.

20. The sheet transport apparatus according to claim 19.

24. the pressing means includes an elastic member that is elastically deformed by hitting against the operating means and presses the second guide toward the first guide via the operating means.

20. The sheet transport apparatus according to claim 19.

25. a guide holding magnet provided on at least one of the first guide and the second guide, the elastic member presses the operating means so that the second guide is held at the first position by the magnetic force of the guide holding magnet; 25. The sheet transport apparatus according to claim 24.

26. The conveying means includes a first roller provided in the first guide, and a second roller provided in the second guide, which is in contact with and presses the first roller at the first position.

26. The sheet transport device according to claim 17,

27. the holding means is a magnet, and holds the second guide at the second position by a magnetic force of the magnet; 27. The sheet transport device according to claim 17,

28. The first contact portion and the second contact portion are each formed obliquely so that a lower side of the first contact portion and the second contact portion are closer to the inner surface of the cover than an upper side of the first contact portion in the vertical direction.

28. The sheet transport device according to claim 17,

29. The first contact portion is formed obliquely so that a side closer to the rotation axis of the cover is closer to the inner surface of the cover than a side farther from the rotation axis.

29. The sheet transport apparatus according to claim 28.

30. a restricting means for restricting movement of the second guide toward the pivot shaft of the cover by contacting the second guide on the pivot shaft side of the cover in the sheet conveying direction of the conveying means; 30. The sheet transport apparatus according to claim 29.

31. an operating means provided on the second guide and operated when the second guide is rotated; The second guide is provided such that an angle between a straight line perpendicular to a rotation axis of the second guide and passing through a contact point of the first contact portion where the operating means contacts, and a straight line passing through the contact point and a contact point of the regulating means where the second guide contacts, is 3° or more and 10° or less.

31. The sheet transport apparatus according to claim 30.

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