Sheet transport device and image forming system

Abstract

This improves work efficiency in tasks such as maintenance of conveying units that transport sheets. [Solution] The system comprises a housing, a support unit 370 detachably mounted to the housing, and a transport unit 380 detachably supported by the support unit 370 for transporting a sheet in the sheet transport direction D1. The support unit 370 has an opening 378 at one end in the width direction W perpendicular to the sheet transport direction D1, which allows the supported transport unit 380 to pass through in the width direction W and be removed from the support unit 370.

Description

Technical Field

[0001] The present invention relates to a sheet conveying device for conveying a sheet and an image forming system to which the same is applied.

Background Art

[0002] As an image forming apparatus using an inkjet or electrophotographic method, those having a registration unit for correcting the skew of a sheet or the position in the width direction of the sheet orthogonal to the sheet conveyance direction with respect to an image before printing or transferring the image have become widespread. For example, as a registration unit (hereinafter also referred to as a registration unit), a configuration has been proposed in which the position of the sheet in the width direction is corrected by moving a roller in the width direction of the sheet (see Patent Document 1). This registration unit has a pair of registration rollers (hereinafter also referred to as a registration roller pair), and the position of the sheet in the width direction is corrected by moving the registration roller pair in the width direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, when performing maintenance such as replacing the registration roller pair, it is necessary to remove the registration roller pair. However, in the registration unit described in Patent Document 1, when removing the registration roller pair, it cannot be pulled out because it abuts against the support frame in the width direction. For this reason, it is necessary to remove the entire registration unit from the apparatus main body and then remove the registration roller pair in the vertical direction or the like from the removed registration unit, and the workability is poor, such as disassembling the support frame of the registration unit.

[0005] The present invention aims to provide a sheet conveying device and an image forming system that can improve work efficiency in maintenance of conveying units that transport sheets. [Means for solving the problem]

[0006] One aspect of the present invention is a sheet conveying device comprising a housing, a support unit detachably mounted to the housing, and a conveying unit detachably supported by the support unit and conveying a sheet in the sheet conveying direction, wherein the support unit has a through hole at one end in the width direction perpendicular to the sheet conveying direction, allowing the supported conveying unit to pass through in the width direction and be removed from the support unit.

[0007] Another aspect of the present invention is an image forming system characterized by comprising an image forming apparatus having an image forming unit for forming an image on a sheet, and the above-mentioned sheet transport apparatus. [Effects of the Invention]

[0008] According to the present invention, it is possible to improve work efficiency in maintenance of conveying units that transport sheets. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing an image forming system according to the first embodiment. [Figure 2] This is a cross-sectional view showing a drying module according to the first embodiment. [Figure 3] This is a perspective view showing a cash register unit according to the first embodiment, where (a) is a view from the upper right front and (b) is a view from the upper left front. [Figure 4] This is a perspective view showing a transport unit according to the first embodiment, where (a) is a view from the upper right front and (b) is a view from the upper left front. [Figure 5] This is a rear view showing a cash register unit according to the first embodiment. [Figure 6]This is a perspective view showing a cash register unit according to the first embodiment. [Figure 7] This is a rear view showing a cash register unit according to the second embodiment. [Modes for carrying out the invention]

[0010] <First Embodiment> The first embodiment will be described below with reference to Figures 1 to 6. This embodiment describes the case in which an image forming system is applied to an inkjet recording system 1. Figure 1 is a schematic diagram showing an example of the general configuration of the inkjet recording system 1. This inkjet recording system 1 is a sheet-fed inkjet recording system that produces a recording material by forming an ink image on a sheet S using two liquids, a reaction liquid and an ink. As shown in Figure 1, the inkjet recording system 1 consists of a feeding module 100, a print module 200, a drying module 300, a fixing module 400, a cooling module 500, an inversion module 600, and an discharge module 700. The cut sheet S supplied from the feeding module 100 is transported along the transport path, processed in each module, and discharged in the discharge module 700.

[0011] In this embodiment, the feed module 100 to the discharge module 700 each have separate housings, and these housings are connected to constitute the inkjet recording system 1. However, this is not limited to this configuration, and the feed module 100, print module 200, drying module 300, fixing module 400, cooling module 500, reversing module 600, and discharge module 700 may be arranged in a single housing. In this embodiment, "sheet" refers to the recording material and includes paper such as sheets and envelopes, plastic films such as overhead projector sheets (OHP), and cloth. In this embodiment, the sheet transport direction D1 is arranged so as to be the left-right direction of the inkjet recording system 1, and the right side is denoted as right direction R, the left side as left direction L, the front side as forward direction F, the back side as rear direction B, the top side as upward direction U, and the bottom side as downward direction D.

[0012] The feeding module 100 is connected to the print module 200 and transports sheets, thereby supplying sheets to the print module 200 and transferring sheets S between the print module 200 and the feeding module 100. The feeding module 100 has a first supply unit 111, a second supply unit 112, and a third supply unit 113 as sheet supply units that receive and feed the sheets S. Note that the supply units are not limited to three, and may be configured with one, two, or four or more units. The feeding module 100 will be described later.

[0013] The print module 200 is an example of an image forming apparatus and includes a pre-image registration correction unit (not shown), a print belt unit 220, and a recording unit 230, which transport the sheet S. The sheet S transported from the feed module 100 has its tilt and position corrected by the pre-image registration correction unit and is transported to the print belt unit 220. The recording unit 230 is positioned opposite the print belt unit 220 with respect to the transport path. The recording unit 230 is an example of an image forming unit and forms an image on the transported sheet S by performing a recording process (printing) on ​​the sheet S from above using a recording head. Multiple recording heads are arranged along the transport direction. In this embodiment, in addition to the four colors Y (yellow), M (magenta), C (cyan), and Bk (black), there are a total of five line-type recording heads corresponding to the reaction solution. Note that the number of colors is not limited to four, and the number of recording heads is not limited to five. The inkjet method can employ methods using heating elements, piezoelectric elements, electrostatic elements, MEMS elements, etc. Each color of ink is supplied to the recording head from an ink tank (not shown) via an ink tube. The ink contains 0.1% to 20.0% by mass of resin components, water, water-soluble organic solvents, colorants, waxes, additives, etc., based on the total mass of the ink.

[0014] The sheet S printed by the recording unit 230 is transported by the print belt unit 220, ensuring clearance with the recording head. The sheet S printed by the recording unit 230 is then scanned by an inline scanner (not shown) located downstream of the recording unit in the sheet transport direction to detect any misalignment or color density of the image formed on the sheet S. The detection results are used to correct the printed image.

[0015] The drying module 300 includes a decoupling section 320, a drying belt unit 330, and a hot air blowing section 340. It reduces the liquid content of the ink applied to the sheet S by the recording section 230 of the print module 200, thereby improving the adhesion between the sheet S and the ink. The sheet S printed by the recording section 230 of the print module 200 is transported to the decoupling section 320 located upstream of the sheet transport direction in the drying module 300. In the decoupling section 320, the sheet S can be transported from above by air pressure and belt friction, and by weakly holding and transporting the sheet S on the belt, it prevents the sheet S on the print belt unit 220, which forms the ink image, from shifting. The drying belt unit 330 is located below the belt, and the hot air blowing section 340 is located above the belt, facing each other across the belt. The sheet S transported from the decoupling section 320 is transported by suction in the drying belt unit 330, and at the same time, the ink-applied surface is dried by hot air from the hot air blowing section 340. In addition to the method of applying hot air, the drying method may also be configured by combining a method of irradiating the surface of the sheet S with electromagnetic waves (such as ultraviolet or infrared rays) or a conductive heat transfer method using contact with a heating element.

[0016] The ink and the reaction liquid applied to the sheet S by the drying module 300 are heated to promote the evaporation of moisture, so that the ink-absorbing ink portion applied to the sheet S causes the sheet S to locally stretch and wrinkle, and the so-called cockling can be suppressed. As the heater for heating air, for example, heating by a heating wire or an infrared heater is preferable from the viewpoint of energy efficiency. In addition to the method of applying hot air, the drying method may be configured by combining a method of irradiating electromagnetic waves (such as ultraviolet rays and infrared rays) on the sheet surface and a conduction heat transfer method by contact with a heating element.

[0017] The fixing module 400 has a fixing belt unit 410. The fixing belt unit 410 has an upper belt unit and a lower belt unit, and by passing the sheet S conveyed from the drying module 300 between the heated upper belt unit and the lower belt unit, the ink can be fixed to the sheet S.

[0018] The cooling module 500 has a plurality of cooling units 510, and cools the high-temperature sheet S conveyed through the sheet conveyance path from the fixing module 400. The cooling unit 510 takes in outside air into the cooling box with a fan, increases the pressure in the cooling box, and blows the air ejected from the nozzles formed in the conveyance guide against the sheet S, thereby cooling the sheet S. The cooling unit 510 is arranged on both the upper side and the lower side with respect to the conveyance path, and cools the sheet S from both sides.

[0019] Further, the cooling module 500 has a conveyance path switching unit 520, and can switch the conveyance path of the sheet S according to whether the sheet S is conveyed to the inversion module 600 or to the duplex conveyance path used during duplex printing. During duplex printing, the sheet S is conveyed to the conveyance path below the cooling module 500. In this case, from the cooling module 500, it is further conveyed along the duplex conveyance paths of the fixing module 400, the drying module 300, the printing module 200, and the feeding module 100. A first inversion unit 420 for inverting the front and back of the sheet S is provided in the duplex conveyance path of the fixing module 400. Then, again, it is conveyed from the feeding module 100 to the pre-image registration correction unit, the print belt unit 220, and the recording unit 230 of the printing module 200, and is printed by the recording unit 230.

[0020] The inversion module 600 has a second inversion unit 640, can invert the front and back of the conveyed sheet S, and can change the front and back orientation of the discharged sheet S. The discharge module 700 has a top tray 720 and a stacking unit 750, and stacks the sheets S conveyed from the inversion module 600 in an aligned manner.

[0021] [Drying Module] Next, the configuration of the drying module 300 will be described using FIG. 2. The drying module 300 is an example of a sheet conveyance device that conveys the sheet S, and has a housing 31, a decoupling unit 320, a drying belt unit 330, a duplex conveyance unit 35, and a control unit 30. The decoupling unit 320 and the drying belt unit 330 are housed and supported in the upper part of the housing 31, and the duplex conveyance unit 35 is housed and supported in the lower part of the housing 31.

[0022] The double-sided transport unit 35 has a horizontal sheet transport path 35a, and the sheet transport direction D1 is from the left (L) side to the right (R) side. The double-sided transport unit 35 has, in order from the upstream side in the sheet transport direction D1, a pre-registration unit 36, a double-sided registration unit (hereinafter referred to as the registration unit 37), and a transport unit 39. The pre-registration unit 36 ​​is an example of an upstream unit, and in the sheet transport direction D1, it is positioned adjacent to the upstream of the registration unit 37 and transports sheets to the registration unit 37. The transport unit 39 is an example of a downstream unit, and in the sheet transport direction D1, it is positioned adjacent to the downstream of the registration unit 37 and transports sheets S from the registration unit 37.

[0023] The registration unit 37 corrects the skew of the sheet S that occurs when the sheet S is transported in the sheet transport direction D1 via the transport path switching unit 520 after image is formed on the surface of the sheet S. This ensures that the registration unit 37 does not exceed the capacity of the pre-image registration correction unit when image is formed on the back surface of the print module 200. The pre-registration unit 36 ​​has a drive roller and a driven roller, and a cam mechanism (not shown) allows the driven roller to be separated from the drive roller, thereby releasing the roller nip. This makes it possible to avoid interference with the operation when the sheet S shifts during the registration correction operation described later.

[0024] These pre-registration units 36 and transport units 39 are arranged so as to overlap with the register unit 37 when viewed from, for example, the horizontal direction to the right (R) or left (L). Here, the decoupling unit 320 corresponds to the upper unit located above the register unit 37. Therefore, the register unit 37 is arranged with other units provided on the left, right, and upper sides at the bottom of the housing 31. For this reason, it is difficult to remove the register unit 37 from the register unit 37 in the left-right or up-down direction during maintenance, and it is designed to be pulled out towards the front. In other words, these pre-registration units 36, register unit 37, transport units 39, and other transport units of the double-sided transport path can be attached to and detached from the housing 31 of the drying module 300 from the front (F) side.

[0025] Next, the cash register unit 37 will be described in detail using Figures 3(a) to 5. Figures 3(a) and 3(b) are perspective views of the cash register unit 37, and Figures 4(a) and 4(b) are perspective views of the transport unit 380. Figure 5 is a rear view of the cash register unit 37. The cash register unit 37 includes a support unit 370 that is detachably mounted on the housing 31, and a transport unit 380 that is detachably supported by the support unit 370 and transports the sheet S in the sheet transport direction D1.

[0026] The support unit 370 includes a transport guide pair 371, a first rail 372a, a second rail 372b, a front plate 373, a rear plate 374, and the like. The transport guide pair 371, the first rail 372a, and the second rail 372b are provided with the width direction W perpendicular to the sheet transport direction D1 as their longitudinal direction. The front plate 373 and the rear plate 374 are provided at both ends of the transport guide pair 371, the first rail 372a, and the second rail 372b in the width direction W, and support the transport guide pair 371, the first rail 372a, and the second rail 372b. The rear plate 374 is an example of a side end member provided at the rear end, which is one end of the width direction W. In this embodiment, the transport guide pair 371, the first rail 372a, and the second rail 372b are described as being supported at both ends in the width direction W by plate-shaped members, the front plate 373 and the rear plate 374, but the embodiment is not limited to this. The front plate 373 and the rear plate 374 (side end members) may be, for example, block-shaped members or frame-shaped members.

[0027] The first rail 372a is an example of a rail and guide section, and is positioned upstream of the center of the conveying unit 380 in the sheet conveying direction D1, attached to the support unit 370, and supports the conveying unit 380 so as to be movable in the width direction W. The second rail 372b is positioned downstream of the center of the conveying unit 380 in the sheet conveying direction D1, attached to the support unit 370, and supports the conveying unit 380 so as to be movable in the width direction W.

[0028] The transport unit 380 includes a register guide pair 381, a front register roller pair 382, ​​a rear register roller pair 383, a first rail roller 384a, a second rail roller 384b, a third rail roller 384c, a fourth rail roller 384d, a register roller support 385, and the like. The front register roller pair 382 is an example of a first transport roller pair that grips and transports a sheet. The rear register roller pair 383 is an example of a second transport roller pair, which is positioned differently from the front register roller pair 382 in the width direction W, and also grips and transports a sheet S. In this embodiment, the front register roller pair 382 and the rear register roller pair 383 are arranged coaxially.

[0029] The first rail roller 384a is an example of a first roller, a roller, and a guided part, positioned above the center of the first rail 372a and attached to the transport unit 380. The first rail roller 384a is rotatable in contact with the first rail 372a and is supported by the first rail 372a so as to be movable in the width direction W. The second rail roller 384b is an example of a second roller, positioned above the center of the second rail 372b and attached to the transport unit 380. The second rail roller 384b is rotatable in contact with the second rail 372b and is supported by the second rail 372b so as to be movable in the width direction W. The third rail roller 384c is an example of a third roller, attached to the transport unit 380, rotatably in contact with the first rail 372a below the center of the first rail 372a, and clamps the first rail 372a between itself and the first rail roller 384a. The fourth rail roller 384d is an example of a fourth roller, and is attached to the transport unit 380. It rotatably contacts the second rail 372b below its center and clamps the second rail 372b between itself and the second rail roller 384b.

[0030] As a result, the transport unit 380 can shift along the first rail 372a and the second rail 372b, which extend in the width direction W. The first rail roller 384a and the second rail roller 384b support the weight of the transport unit 380 by resting on the first rail 372a and the second rail 372b, and at the same time, the first rail roller 384a and the second rail roller 384b rotate to perform the shifting operation. In addition, the third rail roller 384c and the fourth rail roller 384d are biased toward the first rail 372a and the second rail 372b by a biasing mechanism. Therefore, the third rail roller 384c and the fourth rail roller 384d clamp the first rail 372a and the second rail 372b between themselves and the first rail roller 384a and the second rail roller 384b. As a result, the transport unit 380 is positioned and shifted in the vertical direction relative to the first rail 372a and the second rail 372b, thereby improving the accuracy of width position correction.

[0031] The register unit 37 has a drive unit 388 that moves the transport unit 380 in the width direction W relative to the support unit 370. The drive unit 388 has a drive section 389 and a rack gear 386. The drive section 389 has a drive motor 375 attached to the support unit 370 and a pinion gear 376 attached to the drive shaft of the drive motor 375. The rack gear 386 is attached to the transport unit 380 and the pinion gear 376 meshes with the transport unit 380 when the transport unit 380 is supported by the support unit 370.

[0032] The register unit 37 includes a CIS 377 that detects the widthwise position of the sheet S being transported by the transport unit 380, and a control unit 30 (see Figure 2) that controls the drive unit 388. The CIS 377 is an example of a widthwise detection unit and is located on the transport guide pair 371. Based on the detection result of the CIS 377, the control unit 30 controls the drive unit 388 to change the widthwise position of the sheet S being transported by the transport unit 380, thereby executing a shift operation.

[0033] The transport unit 380 includes a first roller drive unit 391 that drives the front register roller pair 382 and a second roller drive unit 392 that drives the rear register roller pair 383. The first roller drive unit 391 and the second roller drive unit 392 use drive motors connected to the drive rollers of the front register roller pair 382 and the rear register roller pair 383, respectively. In this embodiment, the case in which each roller pair is directly connected to the drive motor is described, but it is not limited to this and may be connected via a gear train or the like.

[0034] The register unit 37 has a diagonal detection unit 387 that detects the diagonal movement of the sheet S being transported by the transport unit 380. The diagonal detection unit 387 applies two optical sensors arranged side by side in the width direction W on the register guide pair 381, and can detect the passage of the leading edge of the transported sheet S and detect the diagonal movement of the sheet S based on the time difference. Based on the detection result of the diagonal detection unit 387, the control unit 30 performs a diagonal correction operation by controlling the first roller drive unit 391 and the second roller drive unit 392 to correct the diagonal movement of the sheet S being transported by the transport unit 380.

[0035] [Skew correction] When correcting for skew, the process is carried out in two stages. The first stage is tip angle correction. A skew detection unit 387 provided on the register guide pair 381 detects the edge on the leading edge side in the transport direction of the sheet S. The control unit 30 obtains the angle component with respect to the width direction W based on the difference in timing of passing the skew detection unit 387 at this time, and obtains the tip angle correction amount. The tip angle of the sheet S is corrected by rotating the sheet S by creating a transport speed difference between the front register roller pair 382 and the rear register roller pair 383, which are arranged coaxially in the width direction W. Since the front register roller pair 382 and the rear register roller pair 383 are rotated by separate drive trains, the first roller drive unit 391 and the second roller drive unit 392, a speed difference can be created.

[0036] After completing the first stage of tip angle correction, the second stage of width direction position correction is performed. In width direction position correction, the control unit 30 reads the edge position of the sheet S in the width direction from the CIS 377 and obtains the difference distance from the target edge position of the inkjet recording system 1. To correct this difference distance, the control unit 30 performs width direction position correction by operating the aforementioned drive motor 375 to move the transport unit 380 in the width direction W. During correction, the sheet S is held between the front register roller pair 382 and the rear register roller pair 383, and the sheet S moves as the transport unit 380 moves in the width direction W.

[0037] This two-stage correction is performed in the section from when the sheet S is gripped by the front register roller pair 382 and the rear register roller pair 383 until it is gripped by the next downstream conveyor roller, and is performed while the conveyor rollers of the pre-register unit 36 ​​are separated. This prevents malfunctions when the sheet S rotates or moves in the width direction W, and avoids damage to the sheet S. In this embodiment, diagonal correction is performed using the difference in rotational speed of the roller pair, but this is not limited to this, and for example, a method in which the roller pair is stopped and the leading edge of the sheet is brought into contact with it to correct the diagonal can be applied. Also, the register unit 37 is not limited to performing both diagonal correction and lateral position correction, and may perform only lateral position correction.

[0038] [Challenges in maintenance, etc.] In the register unit 37 described above, suppose a malfunction occurs in one of the roller drives, requiring maintenance work to replace the roller drive motor. In this case, the roller drive motor cannot be removed without removing the transport unit 380 from the support unit 370. To do this, the first rail 372a and the second rail 372b, which hold the transport unit 380 to the support unit 370, must be removed. Since the first rail 372a and the second rail 372b are held by the front side plate 373 and the rear side plate 374 of the support unit 370, one of the side plates must be removed. Consequently, the workability for separating the transport unit 380 becomes poor, the number of man-hours increases, and as a result, it becomes a factor that worsens the running costs of the device.

[0039] Therefore, in this embodiment, as shown in Figure 5, an opening 378 is provided in the rear plate 374. The opening 378 is wider than the contour of the transport unit 380 when viewed from the width direction W, and the transport unit 380 can be separated from the register unit 37 through the opening 378. That is, the opening 378 is an example of a pass-through hole, and is formed at one end (rear end) of the support unit 370 in the width direction W to allow the supported transport unit 380 to pass through in the width direction W and be removed from the support unit 370. In this embodiment, when the transport unit 380 is supported by the support unit 370 and viewed from the width direction W, the transport unit 380 overlaps the opening 378.

[0040] In this embodiment, the transport unit 380 is positioned so that it overlaps the opening 378 when viewed from the width direction W while supported by the support unit 370, but this is not the only configuration. For example, if the transport unit 380 has a variable portion on its outer surface that can be easily deformed, suppose this variable portion overlaps the rear plate 374 other than the opening 378 when viewed from the width direction W while the transport unit 380 is supported by the support unit 370. In this case, the transport unit 380 can be easily pulled out by deforming the variable portion when the transport unit 380 is pulled out from the opening 378.

[0041] In this embodiment, when the transport unit 380 is pulled out from the support unit 370, the entire transport unit 380 is designed to pass through the opening 378 without touching the rear plate 374. That is, when the transport unit 380 is supported by the support unit 370 and viewed from the width direction W, the first rail roller 384a, the second rail roller 384b, the third rail roller 384c, and the fourth rail roller 384d overlap the opening 378. Also, when the transport unit 380 is supported by the support unit 370 and viewed from the width direction W, at least the portion of the first rail 372a that contacts the first rail roller 384a and the third rail roller 384c overlaps the opening 378. Also, when the transport unit 380 is supported by the support unit 370 and viewed from the width direction W, at least the portion of the second rail 372b that contacts the second rail roller 384b and the fourth rail roller 384d overlaps the opening 378. Furthermore, when the transport unit 380 is supported by the support unit 370 and viewed from the width direction W, the rack gear 386, CIS 377, and oblique detection unit 387 overlap the opening 378. Also, when the transport unit 380 is supported by the support unit 370 and viewed from the width direction W, the front register roller pair 382, ​​the rear register roller pair 383, the first roller drive unit 391, and the second roller drive unit 392 overlap the opening 378.

[0042] As shown in Figure 5, the register unit 37 has a stopper 379 at its rear end. The stopper 379 is an example of a restricting part and is movable between a restricting position that restricts the movement of the transport unit 380 in the width direction W and a retracted position that does not restrict movement. When the stopper 379 is in the restricting position, it restricts the movement of the transport unit 380 so that it does not fall off the support unit 370. In this embodiment, when the stopper 379 is in the restricting position, it is screwed to the lower part of the rear plate 374 so as to block a part of the opening 378. Also, when the stopper 379 is in the retracted position, it is removed from the rear plate 374 to open the opening 378. That is, when the stopper 379 is in the restricting position, it is attached to the support unit 370 and at least a part of it overlaps with the opening 378 when the support unit 370 is viewed from the width direction W. Also, when the stopper 379 is in the retracted position, it does not overlap with the opening 378 when the support unit 370 is viewed from the width direction W.

[0043] Figure 6 is a perspective view of the transport unit 380 being removed from the support unit 370. To remove the transport unit 380 from the support unit 370, the stopper 379, which is attached to prevent the transport unit 380 from falling out, is removed, and then the transport unit 380 can be separated by pulling it out in the width direction W.

[0044] In this embodiment, the stopper 379 is described as a member that is attached to and detached from the rear plate 374 by screws, but it is not limited to this. For example, it may be a member that is rotatably attached to the rear plate 374 in a restricting position and a retracted position. Alternatively, in this embodiment, the stopper 379 is described as being attached to the support unit 370 side, but it is not limited to this and may be attached to the transport unit 380 side. In this case, the transport unit 380 can be prevented from falling off by the stopper attached to the transport unit 380 coming into contact with the rear plate 374 or other components of the support unit 370.

[0045] As described above, according to this embodiment, when attaching or detaching the transport unit 380, an opening 378 is provided in the rear plate 374 that forms the support unit 370, allowing the transport unit 380 to pass through. Therefore, the transport unit 380 can be attached and detached without disassembling the support unit 370, such as by removing the rear plate 374, thus improving work efficiency in maintenance of the transport unit 380 that transports the sheet S.

[0046] <Second Embodiment> Next, a second embodiment will be described with reference to Figure 7. This embodiment differs from the first embodiment in that the opening 378A is formed by the rear plate 374A and the auxiliary member 374B. However, the other components are the same as in the first embodiment, so the same reference numerals are used and detailed explanations are omitted.

[0047] Figure 7 is a rear view of the register unit 37A in the second embodiment. In this embodiment, the rear plate cannot be made large in size due to the positional relationship of the surrounding components. For this reason, it is not possible to provide an opening 378 in a rear plate made of a single component. It is conceivable to divide the rear plate and provide it separately, but in that case, it would be impossible to maintain high rigidity of the support unit 370A.

[0048] Therefore, in this embodiment, rigidity is ensured by attaching an auxiliary member 374B to the rear plate 374A. The rear plate 374A here has a roughly U-shape with an open top, and the open portion is reinforced by connecting it with the auxiliary member 374B and fastening it with screws. When used attached to the drying module 300, the rear plate 374A and the auxiliary member 374B are fastened together. When removing the transport unit 380 for maintenance, an opening 378A can be provided to separate the transport unit 380 by removing the auxiliary member 374B.

[0049] Furthermore, although Figure 7 shows a stopper 379 as in the first embodiment, the stopper 379 may be omitted by providing an auxiliary member 374B. Even in this case, the auxiliary member 374B functions as a stopper, so the transport unit 380 can be prevented from falling off. That is, the auxiliary member 374B is an example of a restricting part and is movable between a restricting position (see Figure 7) that restricts the transport unit 380 from moving in the width direction W and a retracted position that does not restrict it.

[0050] As described above, according to this embodiment, when attaching or detaching the transport unit 380, an opening 378A is provided in the rear plate 374A that forms the support unit 370A, allowing the transport unit 380 to pass through. Therefore, the transport unit 380 can be attached and detached without disassembling the support unit 370A, such as by removing the rear plate 374A, thus improving work efficiency in maintenance of the transport unit 380 that transports the sheet S.

[0051] In the embodiments described above, the first rail 372a and the second rail 372b were described as being provided on the support unit 370, but the invention is not limited to this, and they may also be provided on the transport unit 380. In this case, the support unit 370 is provided with rollers.

[0052] Furthermore, in the embodiments described above, the first rail 372a and the second rail 372b are straight, and the transport unit 380 is described as being attached and detached linearly along the first rail 372a and the second rail 372b, but the present invention is not limited to this. The present invention can also be applied when the first rail 372a and the second rail 372b are not straight, or when there are no rails. In that case as well, when attaching and detaching the transport unit 380, the transport unit 380 can be attached and detached without disassembling the support units 370 and 370A by passing it through the openings 378 and 378A of the rear side plates 374 and 374A.

[0053] Furthermore, while the above-described embodiments mention the application of the drying module 300 as the sheet transport device, the invention is not limited to this. For example, it can be widely applied to image forming apparatuses, skew correction devices for feed decks, and other sheet transport devices. Also, while the invention was described in the case where the image forming system is applied to an inkjet recording system 1 using an inkjet recording method, the invention is not limited to this and may also be applied to an electrophotographic image forming apparatus. [Explanation of symbols]

[0054] 1…Inkjet recording system (image forming system), 30…Control unit, 36…Pre-resist unit (upstream unit), 38…Transport unit (downstream unit), 200…Print module (image forming apparatus), 230…Recording unit (image forming unit), 300…Drying module (sheet transport apparatus), 301…Housing, 320…Decoupling unit (upper unit), 370…Support unit, 372a…First rail (guide unit, rail), 372b…Second rail, 374,374A…Rear side plate (side end member), 375…Drive motor, 376…Pinion gear, 377…CIS (width direction detection unit), 378,378 A...Opening (pass-through hole), 374B...Auxiliary member (regulating part), 379...Stopper (regulating part), 380...Conveying unit, 382...Front register roller pair (first conveying roller pair), 383...Rear register roller pair (second conveying roller pair), 384a...First rail roller (guided part, roller, first roller), 384b...Second rail roller (second roller), 384c...Third rail roller (third roller), 384d...Fourth rail roller (fourth roller), 386...Rack gear, 387...Skewing detection unit, 388...Drive unit, 389...Drive unit, 391...First roller drive unit, 392...Second roller drive unit, D1...Sheet conveying direction, S...Sheet

Claims

1. The casing and A support unit is detachably attached to the aforementioned housing, The system comprises a conveying unit that is removably supported by the support unit and conveys the sheet in the sheet conveying direction, The support unit has a through hole at one end in the width direction perpendicular to the sheet conveying direction, which allows the supported conveying unit to pass through in the width direction and be removed from the support unit. A sheet conveying device characterized by the following features.

2. When the transport unit is supported by the support unit and viewed from the width direction, the transport unit overlaps the passage hole. The sheet conveying device according to feature 1.

3. The support unit has a side end member provided at one end in the width direction, The aforementioned through-hole portion is located in the side end member. The sheet conveying device according to feature 1.

4. A guide portion attached to the support unit and supporting the transport unit so as to be movable in the width direction, The transport unit is equipped with a guided portion which is supported by the guide portion so as to be movable in the width direction, When the transport unit is supported by the support unit and viewed from the width direction, the guided portion overlaps the passage hole portion. The sheet conveying device according to feature 1.

5. The guide portion is a rail whose width direction is the longitudinal direction, The guided portion is a roller that is in contact with the rail and can rotate, When the transport unit is supported by the support unit and viewed from the width direction, at least the portion of the rail that contacts the roller overlaps the passage hole. The sheet conveying device according to feature 4.

6. The support unit has a side end member provided at one end in the width direction, The through-hole portion is located on the side end member, One end of the rail is supported by the side end member. The sheet conveying device according to feature 5.

7. The rail is a first rail positioned upstream of the center of the conveying unit in the sheet conveying direction, The roller is a first roller that is in contact with the first rail and can rotate, A second rail is attached to the support unit downstream of the center of the conveying unit in the sheet conveying direction, and supports the conveying unit so as to be movable in the width direction, The transport unit is equipped with a second roller that is attached to the second rail and is rotatable in contact with the second rail, When the transport unit is supported by the support unit and viewed from the width direction, the second roller and at least the portion of the second rail that contacts the second roller overlap the passage hole. The sheet conveying device according to feature 5.

8. The first rail and the second rail are arranged with the horizontal direction as the longitudinal direction. The first roller is positioned above the center of the first rail, The second roller is positioned above the center of the second rail. A third roller is attached to the transport unit, rotatably contacts the first rail below the center of the first rail, and clamps the first rail between itself and the first roller, The transport unit is equipped with a fourth roller which is attached to the second rail and rotatably contacts the second rail below the center of the second rail, and which clamps the second rail between itself and the second roller, When the transport unit is supported by the support unit and viewed from the width direction, the third roller and the fourth roller overlap the passage hole. The sheet conveying device according to feature 7.

9. The system includes a drive unit that moves the transport unit in the width direction relative to the support unit, The sheet conveying device according to feature 4.

10. The aforementioned drive unit is A drive unit having a drive motor attached to the support unit and a pinion gear attached to the drive shaft of the drive motor, The transport unit is attached to a rack gear in which the pinion gear meshes with the transport unit when the transport unit is supported by the support unit, When the transport unit is supported by the support unit and viewed from the width direction, the rack gear overlaps the passage hole. The sheet conveying device according to feature 9.

11. A width direction detection unit for detecting the width direction position of the sheet being transported by the transport unit, The drive unit comprises a control unit for controlling the drive unit, When the transport unit is supported by the support unit and viewed from the width direction, the width direction detection unit overlaps the passage hole portion. The control unit controls the drive unit to change the widthwise position of the sheet being transported by the transport unit based on the detection result of the widthwise detection unit. The sheet conveying device according to feature 9.

12. The aforementioned transport unit is A first pair of conveying rollers that grips and transports the sheet, A second pair of conveying rollers is positioned in a different location from the first pair of conveying rollers in the width direction and is used to grip and convey the sheet. A first roller drive unit that drives the first pair of transport rollers, It includes a second roller drive unit that drives the second pair of transport rollers, When the transport unit is viewed from the width direction while supported by the support unit, the first transport roller pair, the second transport roller pair, the first roller drive unit, and the second roller drive unit overlap the passage hole. The sheet conveying device according to feature 1.

13. A diagonal movement detection unit detects the slanting of the sheet being transported by the transport unit, The system comprises a control unit that controls the first roller drive unit and the second roller drive unit, When the transport unit is supported by the support unit and viewed from the width direction, the oblique detection unit overlaps the passage hole portion. The control unit controls the first roller drive unit and the second roller drive unit to correct the skew of the sheet being transported by the transport unit based on the detection result of the skew detection unit. The sheet conveying device according to feature 12.

14. The transport unit is equipped with a restricting part that can move to a restricting position that restricts movement in the width direction and to a retracted position that does not restrict movement. The sheet conveying device according to feature 1.

15. The aforementioned regulatory body, When positioned in the aforementioned restricted position, it is attached to the support unit, and when the support unit is viewed from the width direction, at least a portion of it overlaps with the passage hole. When positioned in the aforementioned retracted position, the support unit is positioned such that it does not overlap the passage hole when viewed from the width direction. The sheet conveying device according to feature 14.

16. In the sheet transport direction, an upstream unit is positioned adjacent to the upstream of the support unit and transports the sheet to the transport unit, The unit comprises a downstream unit positioned adjacent to the support unit in the sheet transport direction, and from which the sheet is transported by the transport unit. The sheet conveying device according to feature 1.

17. The upstream unit and the downstream unit are arranged so as to overlap with the support unit when viewed from the horizontal direction. The support unit is supported at the bottom of the housing, The unit comprises an upper unit positioned above the support unit, The sheet conveying device according to feature 16.

18. An image forming apparatus having an image forming unit that forms an image on a sheet, A sheet transport device comprising: An image forming system characterized by the following features.

Images