Recording medium conveying device and image forming device

Abstract

To reduce the workload for stopping a recess of a transport drum at a maintenance position as compared with the case that an operator brings the recess into stop at the maintenance position by inching the transport drum.SOLUTION: An image forming apparatus 10 includes a transport unit 200 comprising a chain 49 that constitutes a part of a transport route to carry a sheet P, a gripper 42 that is fixed to the chain 49 for circulation and to hold a front end P1 of the sheet P, an image-forming transport drum 39 that is provided with a recess 100 receiving the gripper 42 with which the chain 49 is rotatably engaged and a drying transport drum 302 that is provided with a recess 101, and an operation panel 16 for selecting the image-forming transport drum 39 or the drying transport drum 302, thus having a mode to stop the image-forming transport drum 39 or the drying transport drum 302 such that the recess 100 of the image-forming transport drum 39 or the recess 101 of the drying transport drum 302 selected on the operation panel 16 comes to a maintenance position.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a recording medium transport device and an image forming apparatus. [Background technology]

[0002] Patent Document 1 discloses a fixing device that fixes an image drawn on a recording medium using particles containing at least a resin to the recording medium. This prior art includes a pair of fixing rolls, at least one of which is a heating roll and has a replaceable surface layer, a bonding means having a bonding member, a charging means that charges at least one of the recording medium and the bonding means, and a fixing means that physically fixes the leading edge of the recording medium in the transport direction to the bonding means with a gripping portion. The charging means electrostatically attracts the bonding member and the recording medium, and the fixing means fixes the recording medium to the bonding means. The recording medium is then sandwiched between the pair of fixing rolls and the bonding means and transported, thereby fixing the image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-259223 Summary of the Invention [Problem to be solved by the invention]

[0004] The purpose is to reduce the amount of work required to stop the recess of the conveying drum at the maintenance position, compared to when an operator inches the conveying drum to stop the recess at the maintenance position. [Means for solving the problem]

[0005] The first aspect is a recording medium transport device comprising a rotating member that forms part of a transport path for transporting a recording medium, a holding member that is fixed to the rotating member and rotates, holding the leading end of the recording medium, a plurality of transport drums around which the rotating member is wrapped and which have recesses for accommodating the holding members, and a selection unit that selects one of the plurality of transport drums, and which has a mode in which the transport drum selected by the selection unit stops so that the recesses of the transport drum are positioned at a maintenance position.

[0006] A second aspect is the recording medium transport device according to the first aspect, wherein the maintenance position is within a range in which the circulating member is wound around the transport drum.

[0007] A third aspect is a recording medium transport device according to the second aspect, in which peripheral members are arranged radially outside the range in which the circumferential member is wrapped around the transport drum, and the maintenance position is within the range in which the circumferential member is wrapped around the transport drum and within the range in which the peripheral members are not arranged.

[0008] A fourth aspect is an image forming apparatus comprising a recording medium conveying device according to any one of the first to third aspects, and a droplet image forming unit that forms a droplet image on the recording medium at an image forming position in the circular path of the circulating member of the recording medium conveying device.

[0009] A fifth aspect is the image forming apparatus according to the fourth aspect, wherein one of the plurality of transport drums is an image forming transport drum that transports the recording medium to the image forming position.

[0010] A sixth aspect is an image forming apparatus according to the fifth aspect, which has a drying device that dries the droplet image formed on the recording medium at the image forming position at a drying position, and one of the multiple transport drums is a drying transport drum that transports the recording medium to the drying position.

[0011] A seventh aspect is an image forming apparatus including a recording medium conveying device according to any one of the first to third aspects, and a developer image forming unit that forms a developer image to be transferred to the recording medium at a transfer position in the circular path of the circulating member of the recording medium conveying device.

[0012] An eighth aspect is the image forming apparatus described in the seventh aspect, in which the developer image forming unit includes an image carrier that holds the developer image, and one of the multiple transport drums is a transfer drum that transfers the developer image from the image carrier to the recording medium.

[0013] A ninth aspect is an image forming apparatus according to the eighth aspect, further comprising a fixing device that fixes the developer image to the recording medium onto which the developer image has been transferred at the transfer position, the fixing device having a fixing cylinder that is one of the plurality of transport cylinders, and a heating member that sandwiches the recording medium between the fixing cylinder and the fixing cylinder to fix the developer image. [Effects of the Invention]

[0014] According to the first aspect, the amount of work required to stop the recess of the conveying drum at the maintenance position can be reduced compared to when an operator moves the conveying drum slightly to stop the recess at the maintenance position.

[0015] According to the second aspect, it is easier to access the recessed portion compared to when the maintenance position is outside the range in which the circumferential member is wrapped around the transport drum.

[0016] According to the third aspect, access to the recess is easier than when the maintenance position is outside the range where the circumferential member is wrapped around the conveying drum and within the range where the peripheral members are arranged.

[0017] According to the fourth aspect, the amount of work required to stop the recess of the conveying drum at the maintenance position can be reduced compared to when an operator moves the conveying drum slightly to stop the recess at the maintenance position.

[0018] According to the fifth aspect, the amount of work required to stop the recess of the image forming transport drum at the maintenance position can be reduced compared to when an operator inches the image forming transport drum to stop the recess at the maintenance position.

[0019] According to the sixth aspect, the amount of work required to stop the recess of the drying conveying drum at the maintenance position can be reduced compared to when an operator moves the drying conveying drum slightly to stop the recess at the maintenance position.

[0020] According to the seventh aspect, the amount of work required to stop the recess of the conveying drum at the maintenance position can be reduced compared to when an operator moves the conveying drum slightly to stop the recess at the maintenance position.

[0021] According to the eighth aspect, the amount of work required to stop the recess of the transfer cylinder at the maintenance position can be reduced compared to when an operator inches the transfer cylinder to stop the recess at the maintenance position.

[0022] According to the ninth aspect, the amount of work required to stop the recess of the fixing cylinder at the maintenance position can be reduced compared to when an operator moves the fixing cylinder slightly to stop the recess at the maintenance position. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a front view showing an image forming apparatus according to a first embodiment; [Figure 2] FIG. 2 is a front view of the image forming unit of the image forming apparatus according to the first embodiment. [Figure 3] FIG. 2 is a perspective view of the image forming transport drum according to the first embodiment. [Figure 4] FIG. 2 is a perspective view of a drying conveying drum and a drying device according to the first embodiment. [Figure 5] FIG. 10 is an enlarged view showing a state in which a sheet is held by a gripper. [Figure 6] 5A to 5C are cross-sectional views showing the operation of the gripper. [Figure 7]10 is an enlarged view showing the gripper holding the leading edge of the paper. FIG. [Figure 8] FIG. 2 is a cross-sectional view of the image forming transport drum according to the first embodiment. [Figure 9] FIG. 10 is a plan view showing a state in which the transport unit is pulled out. [Figure 10] 1 is a block diagram of a main part of an image forming apparatus; [Figure 11] FIG. 10 is a front view of an image forming unit of an image forming apparatus according to a second embodiment. [Figure 12] FIG. 10 is a perspective view of a transfer cylinder according to a second embodiment. [Figure 13] FIG. 10 is a perspective view of a fixing cylinder and a fixing device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] First Embodiment An image forming apparatus according to a first embodiment of the present invention will be described.

[0025] Note that the arrow UP shown in each figure is vertical and points upward from the device. Also, as shown in FIG. 1, the arrow RH is horizontal and points to the right when facing the device. Also, in the following description, when the up / down direction is specified without any premise, it means the up / down direction of the device shown in FIG. 1. Also, in the following description, when the left / right direction is specified without any premise, it means the left (= L) and right (= R) directions when facing the device shown in FIG. 1. Furthermore, in the following description, when the depth direction (= front and back) is specified without any premise, it means the depth direction when facing the device shown in FIG. 1. Also, as shown in FIG. 9, the front side in the depth direction is indicated by the arrow FR. Note that the opposite direction of the arrow FR is the back side.

[0026] [Overall configuration of image forming device] First, a description will be given of the configuration of the image forming apparatus 10. Fig. 1 is a front view showing an outline of the image forming apparatus 10 according to this embodiment.

[0027] 1, image forming apparatus 10 includes unit 10A located on the right side of the drawing and unit 10B located on the left side of the drawing. Unit 10A located on the right side of the drawing includes a droplet image forming unit 11 that forms an image on paper P, which is an example of a recording medium.

[0028] As shown in FIGS. 1 and 2, the droplet image forming unit 11 includes a droplet ejection mechanism 13 for forming an image by an inkjet method, and a print drum 90.

[0029] The droplet ejection mechanism 13 includes droplet ejection heads 21Y, 21M, 21C, and 21K that form droplet images using ink droplets of each color, for example, black (K), yellow (Y), magenta (M), and cyan (C).

[0030] The droplet ejection heads 21Y, 21M, 21C, and 21K are arranged so that the ejection surfaces 23Y, 23M, 23C, and 23K, respectively, face the print drum 90. The droplet ejection heads 21Y, 21M, 21C, and 21K are replenished with ink of each color from ink tanks (not shown).

[0031] In this embodiment, yellow (Y), magenta (M), cyan (C), and black (K) are the basic colors for outputting a color image. In the following description, when it is not necessary to distinguish between the colors, the Y, M, C, and K characters after the reference numeral are omitted and the droplet ejection head 21 is referred to.

[0032] The droplet ejection heads 21Y, 21M, 21C, and 21K of each color basically have the same structure except for the type of ink used. Furthermore, there are no particular limitations on the method for ejecting ink droplets in the droplet ejection heads 21. For example, a thermal method or a piezoelectric method may be used to eject ink droplets.

[0033] The droplet ejection heads 21Y, 21M, 21C, and 21K each have a length corresponding to the width of the image recording area on the paper P (see FIG. 1), and are full-line heads in which a plurality of ink ejection nozzles (not shown) are arranged on ejection surfaces 23Y, 23M, 23C, and 23K across the entire width of the image recording area. Each droplet ejection head 21 is fixedly installed so as to extend in a direction perpendicular to the transport direction of the paper P (see FIG. 1).

[0034] In this embodiment, an example is given of a configuration in which an image is printed using four colors of ink, CMYK, but this is not limiting, and the ink colors and their combinations may be changed, and for example, light color inks, such as light cyan and light magenta, dark inks, and special color inks may be added as needed. Furthermore, the arrangement order of the heads of each color is not limited to the order shown in the figure.

[0035] Ink droplets of each color ejected from the droplet ejection heads 21Y, 21M, 21C, and 21K of each color land on the print drum 90, forming a droplet image on the print drum 90. The droplet image formed on the print drum 90 is transferred to a sheet of paper P transported by an image forming transport drum 39, which will be described later.

[0036] (Image forming transport drum) 1, 2, and 3, the image forming transport drum 39 has a cylindrical shape with its axis extending in the depth direction of the image forming apparatus 10, and is provided so as to be rotatable in the circumferential direction. A recess 100 (see FIG. 3) is formed on the outer periphery of the image forming transport drum 39, into which a gripper 42 (see FIG. 3), which will be described later, is fitted. A plurality of clips 44 are provided in the axial direction within the recess 100 (see FIG. 3), for gripping the downstream leading edge P1 (see FIG. 5) of the paper P.

[0037] The image forming transport drum 39 is provided with sprockets 37 on both ends in the axial direction, around which a chain 49 (described later) is wound.

[0038] 8, the image forming transport drum 39 is configured to include a drum main body 52 and a sheet-like jacket member 60 that is wrapped around the drum main body 52. The drum main body 52 is formed in a substantially cylindrical shape with the aforementioned recess 100 formed along the axial direction on part of its outer circumferential surface.

[0039] The jacket member 60 has a base layer 62 that is wrapped around the barrel main body 52 without being adhesive, and a surface layer 64 that is wrapped around the outer peripheral surface of the base layer 62 in an adhesive state. A barrel side block 56 is provided at the circumferential end of the bottom wall 55 within the recess 100. The base layer 62 of the jacket member 60 is detachably attached to the barrel main body 52 by having its end 62A fastened to the barrel side block 56 with bolts. In other words, the jacket member 60 is replaceable.

[0040] (Image formation position) The portion where the printing drum 90 and the image forming transport cylinder 39 shown in FIGS. 1 and 2 are in pressure contact with each other is the image forming position 18 .

[0041] (drying equipment) The drying device 300 shown in Fig. 1 is disposed downstream of the image forming position 18 in the transport direction of the paper P. As shown in Figs. 1 and 4, the drying device 300 is composed of a drying transport drum 302 and a heater unit 304 facing the drying transport drum 302. The drying transport drum 302 and the heater unit 304 are disposed so as to face each other across a paper transport path A, which will be described later. In other words, the paper P to be dried is transported so as to pass between the drying transport drum 302 and the heater unit 304.

[0042] 4, the drying transport drum 302 has a cylindrical shape with its axis extending in the depth direction of the image forming apparatus 10, and is provided so as to be rotatable in the circumferential direction. A recess 101 is formed on the outer periphery of the drying transport drum 302, into which a gripper 42 (see FIG. 3), which will be described later, is fitted. The drying transport drum 302 also has sprockets 37, on both axial ends thereof, around which a chain 49, which will be described later, is wound.

[0043] Like the image forming transport drum 39 (see FIG. 8), the drying transport drum 302 is also configured to include a drum main body (not shown) and a sheet-like jacket member wrapped around the drum main body. The drum main body is formed with the aforementioned recess 101, and a drum side block is provided within the recess 101. The end of the base layer of the jacket member is fastened to the drum side block with a bolt, thereby detachably attaching the jacket member to the drum main body.

[0044] (Paper transport path) 1, a paper transport path A, which is an example of a transport path, has a function of transporting paper P supplied from a paper tray 38. Paper P supplied from the paper tray 38 is transported along the paper transport path A. Then, the paper P passes through the image forming position 18 and the drying device 300, and is discharged to a paper discharge tray 390.

[0045] More specifically, the paper transport path A is configured to pass through the unit 10A and the unit 10B in that order. As a result, the paper P transported along the paper transport path A is supplied from the paper tray 38 arranged in the unit 10, and then passes through the unit 10B before being discharged.

[0046] (Basic image formation operation) Next, an outline of the basic operation of forming an image on paper P in image forming apparatus 10 will be described.

[0047] Various operations in the image forming apparatus 10 are performed by a control unit 160 built into the apparatus (see also FIG. 10). When the control unit 160 receives an image formation command from the outside, it activates the droplet ejection mechanism 13 and other components of the droplet image forming unit 11. The control unit 160 also sends image data that has been subjected to image processing in an image signal processing unit (not shown) to the droplet image forming unit 11. Then, at the image forming position 18, the droplet image formed on the print drum 90 by the droplet ejection heads 21 of each color is transferred from the print drum 90 to the paper P being transported by the image formation transport drum 39 from the print drum 90 at the image forming position 18.

[0048] The paper P onto which the droplet image has been transferred is transported toward the drying device 300, where the droplet image on the paper P is dried.

[0049] (gripper) As shown in FIGS. 5 and 6, the image forming apparatus 10 includes a gripper 42 as an example of a holding member that holds a leading end P1 (see FIG. 5) of the paper P being conveyed and assists in conveying the paper P.

[0050] The gripper 42 includes a clip 44, a rectangular case 46 that covers the clip 44, and a shaft 48 that extends in the depth direction. A plurality of clips 44 are provided across the depth direction of the device (see FIG. 5). The clips 44 are fixed to the shaft 48 and are configured to be rotatable in accordance with the rotation of the shaft 48 in the circumferential direction.

[0051] The case 46 has its length in the depth direction and is held by a shaft 48. The case 46 is configured to rotate independently of the rotation of the clip 44. The case 46 is configured to cover the clip 44 on two sides, the upstream and downstream sides in the paper transport direction, and the back surface of the paper P. The "back surface" refers to the non-image-forming surface of the paper P. In this structure, the tip 45 of the clip 44 and the fixed claw 47 at the rear end of the case 46 are configured to be able to clamp the tip P1 of the paper P in the transport direction. The reference numeral 47A in FIG. 6 denotes the tip of the fixed claw 47.

[0052] (chain) 5, both ends of the shaft 48 in the depth direction are held by a conveying chain 49, which is an example of a circulating member. As the chain 49 rotates, the shaft 48 fixed to the chain 49 also rotates. As a result, the gripper 42 is held by the chains 49 provided on the front and back sides of the image forming apparatus 10 and rotates along a predetermined circulating path D (see FIG. 1).

[0053] 2, the chain 49 is wound around sprockets 37 provided at both axial ends of the image forming transport drum 39 (see FIG. 3), the drying transport drum 302 (see FIG. 4), and a transport body 371 (described later), and is configured to revolve along a circulation path D by these. The outer periphery of the sprocket 37 is set radially outward from the bottoms of the recesses 100 and 101.

[0054] The chain 49 wound around the image forming conveying drum 39 (see Figure 3), the drying conveying drum 302 (see Figure 4), and the sprocket 37 (see Figure 5, etc.) is configured to be driven in a circular motion by a drive mechanism 79 (see Figure 10).

[0055] (Circuit Route D) 1, circular path D is provided so as to partially overlap with paper transport path A when viewed from the front of image forming apparatus 10. In detail, circular path D is configured to overlap with paper transport path A from the time it passes through the contact point with paper transport path A on the outer periphery of transport body 371, which has sprockets 37 provided on the underside of image forming transport drum 39 at both axial ends, until it passes receiving position D2, which will be described later.

[0056] At the start point of overlap between paper transport path A and circular path D, tip 45 of clip 44 and fixed claw 47 of case 46 come close to each other, and gripper 42 grips tip P1 of paper P (see FIG. 7). The position at which gripper 42 starts to hold paper P on circular path D is transfer position D1 where paper P is transferred from paper transport path A to gripper 42.

[0057] Furthermore, at the end point of the overlap between the circular path D and the paper transport path A, the tip 45 of the clip 44 and the fixed claw 47 of the case 46 separate, releasing the tip P1 of the paper P. The release position of the gripper 42 for the paper P on the circular path D is the receiving position D2 where the paper P is received from the gripper 42 and transferred to the paper transport path A. The delivery position D1 is located below the receiving position D2.

[0058] 1, in this embodiment, when the paper P is transferred from the paper transport path A to the circular path D, the paper P is transferred from the left side to the right side with respect to the image forming position. In other words, the paper feed direction at the transfer position D1 is from the left side to the right side.

[0059] On the other hand, when the sheet P is received on the circulation path D, the sheet P is received from the right side to the left side in the figure. In other words, the sheet is discharged from the receiving position D2 in the direction from the right side to the left side.

[0060] A tension roll 31 is provided on the circular path D downstream of the receiving position D2 in the conveying direction to push the chain 49 from the outside to the inside of the circular path D. This tension roll 31 applies tension to the chain 49, thereby stabilizing the position of the gripper 42 on the circular path. The pushing direction of the tension roll 31 is from the outside to the inside of the circular path D. Therefore, the entire circular path D can be made smaller than in a configuration in which tension is applied from the inside to the outside of the circular path D.

[0061] The portion of the circular path D that passes through tension roll 31 and passes through the junction with paper transport path A is configured to slope downward. This configuration allows for more space to be provided between the circular path D and paper transport path A, compared to a configuration in which the circular path D descends vertically after passing through fixing device 400.

[0062] (Position adjustment part) 1 and 2, the position adjustment unit 50 is disposed on a junction path provided between the direction change path B and the delivery position D1 on the paper transport path A. The position adjustment unit 50 is configured to include a registration roll 551, a transport roll and a passage sensor (not shown), etc. Each roll is disposed above and below the paper transport path A. The operation of the transport roll and the registration roll 551 is then appropriately controlled by the control unit 160 (see also FIG. 10) that receives a signal from the passage sensor (not shown).

[0063] Specifically, when the leading edge P1 (see Figure 5) of the paper P reaches the registration roll 551, the transport of the paper P stops temporarily, and the registration roll 551 is rotated at a set timing, thereby sending the paper P to the delivery position D1.

[0064] (Paper handover) 7(A) to 7(C), the paper sheet P that has passed through the position adjustment unit 50 (see FIG. 2) is clamped on the circumference of the lower conveying body 371 in FIG. 2 by the fixed claw portion 47 of the case 46 of the gripper 42 and the tip portion 45 of the clip 44. The gripper 42 is supplied while moving along the circular path D in accordance with the conveyance timing of the tip portion P1 of the paper sheet P.

[0065] At this time, as shown in FIG. 7(A), the case 46 and the clip 44 are in an open state.

[0066] 7(B), gripper 42 is configured so that case 46 and clip 44 gradually approach each other while moving along circular path D in synchronization with the transport timing of paper sheet P. Then, tip 45 of clip 44 lifts tip P1 of paper sheet P from paper transport path A.

[0067] 7(C), the leading end P1 of the paper P is further lifted by the clip 44, and is transferred from the paper transport path A to the circular path D while being clamped between the fixed claw portion 47 of the case 46 and the leading end 45 of the clip 44. Thereafter, the paper P is transported along the circular path D by the gripper 42.

[0068] The position where the paper P is transferred from the paper transport path A to the circular path D is referred to as a transfer position D1.

[0069] (Paper reversal) 1, after being delivered to the circular path D, the paper P is turned over along the outer periphery of the image forming transport drum 39. Then, the paper P is transported to the image forming position 18 provided on the outer periphery of the image forming transport drum 39.

[0070] When the paper P passes through the image forming position 18, the surface facing the backup roll 33 is the image forming surface, that is, the front surface. In other words, at the position adjustment unit 50 and the delivery position D1, the paper P is transported with the back surface, which is the non-image forming surface, facing upward.

[0071] (Receiving the form) The paper sheet P is received from the circular path D onto the paper transport path A. The branch point between the circular path D and the paper transport path A is the receiving position D2. At the receiving position D2, the gripper 42 holding the leading edge P1 (see FIG. 3) of the paper sheet P is released, and the paper sheet P is received from the circular path D onto the paper transport path A.

[0072] [Main components] Next, the main configuration of this embodiment will be described.

[0073] (Transport unit) 2, the transport unit 200 includes a chain 49, an image forming transport cylinder 39, a drying transport cylinder 302, and a drying device 300. Reference numeral 279 denotes a drive force transmission mechanism as an example of a peripheral member around the image forming transport cylinder 39.

[0074] 9, the transport unit 200 is slidable in the depth direction. Maintenance work on the image forming transport drum 39, the drying transport drum 302, etc. can be performed with the transport unit 200 pulled out to the front side of the apparatus.

[0075] In addition, reference numeral 202 in FIG. 9 denotes a transport unit of a second embodiment, which will be described later.

[0076] (Maintenance position) Next, the maintenance positions of the recesses 100, 101 (see FIG. 3 or 4) when performing maintenance on the image forming transport drum 39 (see FIG. 3) and the drying transport drum 302 (see FIG. 4) will be described.

[0077] In this embodiment, maintenance of the image forming conveying drum 39 (see Figure 3) and the drying conveying drum 302 (see Figure 4) includes, but is not limited to, replacing the jacket member 60 (see Figure 8).

[0078] The maintenance position is a position where a worker performing maintenance can access the recesses 100 and 101. Furthermore, the maintenance position is preferably a position where a worker performing maintenance can easily access the recesses 100 and 101.

[0079] As mentioned above, when performing maintenance on the image forming transport drum 39 (see Figure 3) and the drying transport drum 302 (see Figure 4), the maintenance is performed with the transport unit 200 pulled out forward as shown in Figure 9.

[0080] Maintenance position for image forming transport drum 3, the maintenance position of the recess 100 in the image forming transport drum 39 is within a range H1. Specifically, the maintenance position range H1 is within a range in which the chain 49 is wound around the image forming transport drum 39 and within a range in which the drive force transmission mechanism 279 is not provided. In this embodiment, the range in which the chain 49 is wound around the image forming transport drum 39 and the range in which the drive force transmission mechanism 279 is not provided partially overlap.

[0081] From another perspective, the range H1 is within the angle range in which the chain 49 is wound around the image forming transport drum 39 and in which the drive force transmission mechanism 279 is not provided.

[0082] In this embodiment, the maintenance position of the recess 100 of the image forming transport drum 39 is the 2 o'clock position when viewed from the front, which is the position shown in FIG.

[0083] Maintenance position for the drying conveyor drum 4, the maintenance position of the recess 101 in the drying conveying drum 302 is within the range H2. Specifically, the maintenance position range H2 is within the range in which the chain 49 is wound around the drying conveying drum 302 and within the range in which the heater unit 304 is not provided. In this embodiment, the range in which the chain 49 is wound around the drying conveying drum 302 and the range in which the heater unit 304 is not provided partially overlap.

[0084] From another perspective, the range H2 is within the angle within which the chain 49 is wound around the drying conveying drum 302 and within the angle within which the heater portion 304 is not provided.

[0085] In this embodiment, the maintenance position of the recess 101 of the drying conveying drum 302 is the 10 o'clock position when viewed from the front, which is the position in FIG.

[0086] (position detection mechanism) 3 is a mechanism for detecting the rotational position of the image forming transport drum 39. In this embodiment, the position detection mechanism 270 has a patch 272 and an optical sensor 274. The patch 272 is attached to the axial end of the image forming transport drum 39. The optical sensor 274 reads the position of the patch 272, thereby detecting the rotational position of the image forming transport drum 39.

[0087] 4 is a mechanism for detecting the rotational position of the drying transport drum 302. In this embodiment, the position detection mechanism 271 has a patch 273 and an optical sensor 275. The patch 273 is attached to the axial end of the drying transport drum 302. The optical sensor 275 reads the position of the patch 273, thereby detecting the rotational position of the drying transport drum 302.

[0088] In this embodiment, the position detection mechanisms 270 and 271 are used to stop the recesses 100 and 101 of the image forming transport drum 39 and the drying transport drum 302 so that they are positioned at the maintenance positions.

[0089] (Operation panel) 1 and 2, the image forming apparatus 10 has an operation panel 16. When performing maintenance, the operator operates the operation panel 16 to display a maintenance target selection screen and selects the component to be maintained. Specifically, in this embodiment, the maintenance target is selected to be the image forming transport drum 39 or the drying transport drum 302.

[0090] (Control unit) 10 (see also FIG. 1) has the function of controlling the entire image forming apparatus 10. The hardware configuration of the control unit 160 is made up of a computer including a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) that stores programs for implementing each processing routine, a RAM (Random Access Memory) that temporarily stores data, an HDD (Hard Disk Drive) as storage means, a network interface, etc.

[0091] The control unit 160 is electrically connected to the position detection mechanisms 270 and 271, the operation panel 16, and a drive mechanism 79 having a drive function and a stop function. The control unit 160 controls the rotation and stop of the drive mechanism 79. When the operator selects the image forming transport drum 39 as the maintenance target on the operation panel 16, the control unit 160 controls the drive mechanism 79 so that the recessed portion 100 of the image forming transport drum 39 is located at the maintenance position shown in FIG. 3 within range H1. Similarly, when the operator selects the drying transport drum 302 as the maintenance target on the operation panel 16, the control unit 160 controls the drive mechanism 79 so that the recessed portion 101 of the drying transport drum 302 is located at the maintenance position shown in FIG. 4 within range H2.

[0092] From another perspective, when the operator selects the image forming transport drum 39 as the maintenance target on the operation panel 16, the control unit 160 controls the drive mechanism 79 to stop the recessed portion 100 of the image forming transport drum 39 at the maintenance position shown in Fig. 3. Similarly, when the operator selects the drying transport drum 302 as the maintenance target on the operation panel 16, the control unit 160 controls the drive mechanism 79 to stop the recessed portion 101 of the drying transport drum 302 at the maintenance position shown in Fig. 4.

[0093] <effect> Next, the operation of this embodiment will be described.

[0094] When the operator selects the image forming conveying drum 39 as the maintenance target on the operation panel 16, the control unit 160 controls the drive mechanism 79 so that the recess 100 of the image forming conveying drum 39 is positioned at the maintenance position shown in Figure 3 within range H1, and when the operator selects the drying conveying drum 302 as the maintenance target, the control unit 160 controls the drive mechanism 79 so that the recess 101 of the drying conveying drum 302 is positioned at the maintenance position shown in Figure 4 within range H2.

[0095] Therefore, the amount of work required to stop the recesses 100, 101 at the maintenance position can be reduced compared to when an operator slightly moves the image forming conveying drum 39 or drying conveying drum 302 to be maintained and stops the recesses 100, 101 at the maintenance position.

[0096] Here, the "stopping of the recess at the maintenance position by inching" will be described.

[0097] The worker operates switches, buttons, levers, etc. to slightly drive the drive mechanism 79, slightly rotating the image forming transport drum 39 and the drying transport drum 302, and then stopping them. This operation is then repeated, and the worker visually positions the recesses 100 and 101 at the maintenance positions.

[0098] Furthermore, the maintenance positions of the recess 100 of the image forming conveying drum 39 and the recess 101 of the drying conveying drum 302 are within the range in which the chain 49 is wound, so that the recesses 100 and 101 are easier to access than when the maintenance positions of the recesses 100 and 101 are outside the range in which the chain 49 is wound.

[0099] If the recesses 100, 101 are located outside the area around which the chain 49 is wound, it is not easy to access the recesses 100, 101, as maintenance would have to be performed from between the upper and lower chains 49. Therefore, by positioning the maintenance positions for the recesses 100, 101 within the area around which the chain 49 is wound, it becomes easier to access the recesses 100, 101.

[0100] Furthermore, since the maintenance positions of the recesses 100 and 101 are within the range where the chain 49 is wound around and outside the range where the driving force transmission mechanism 279 or the heater 304 is located, it is easier to access the recesses 100 and 101 compared to when the maintenance positions are outside the range where the chain 49 is wound around and within the range where the driving force transmission mechanism 279 or the heater 304 is located.

[0101] Second Embodiment Next, an image forming apparatus according to a second embodiment will be described. The same components as those in the first embodiment are designated by the same reference numerals, and redundant explanations will be omitted. The only difference from the first embodiment is the unit 10A, so only the unit 10A will be illustrated and described.

[0102] 11 includes an image forming unit 12 for forming an image by electrophotography, an intermediate transfer belt 22 for holding the formed image, and an intermediate transfer unit 14 for mounting and supporting the intermediate transfer belt 22. The image forming device 17 also includes a transfer cylinder 36, which is provided on the lower left side of the intermediate transfer unit 14 and transfers the image from the intermediate transfer unit 14 to a sheet P for image recording.

[0103] The contact point between the intermediate transfer belt 22 and the transfer cylinder 36 is the secondary transfer position 20, which is an example of an image forming position, and at this secondary transfer position 20, the developer image formed by the image forming unit 12 is transferred onto the surface of the paper P via the intermediate transfer belt 22 attached to the intermediate transfer unit 14.

[0104] The developer image forming section 99 is provided with a plurality of image forming units 12 for forming toner layers of each color. In this embodiment, a total of four image forming units 12 are provided, one for each color: a yellow image forming unit 12Y, a magenta image forming unit 12M, a cyan image forming unit 12C, and a black image forming unit 12K.

[0105] Yellow (Y), magenta (M), cyan (C), and black (K) are the basic colors for outputting a color image. In the following description, when there is no need to distinguish between the colors of each image forming unit 12, they will simply be referred to as "image forming unit 12," and the symbols Y, M, C, and K representing the image forming units corresponding to each color may be omitted as appropriate.

[0106] The image forming units 12 for each color are basically configured the same, except for the type of toner used. Each image forming unit 12 includes a rotating, cylindrical photoconductor 24 and a charger 26 that charges the photoconductor 24. The image forming unit 12 also includes an exposure device 28 that irradiates the charged photoconductor 24 with exposure light to form an electrostatic latent image, and a development device 30 that develops the electrostatic latent image into an image formed by a toner layer using a developer containing toner. The image forming unit 12 also includes a cleaner 29 that removes any toner remaining on the surface of the photoconductor 24 after the toner is transferred from the photoconductor 24 to the intermediate transfer belt 22.

[0107] The photoreceptors 24 for each color are configured to be able to come into contact with the outer peripheral surface of the intermediate transfer belt 22. In addition, the image forming units 12 corresponding to yellow, magenta, cyan, and black are arranged side by side from the upstream side to the downstream side in the rotation direction of the intermediate transfer belt 22.

[0108] In this embodiment, an example is given of a configuration in which an image is recorded using four colors of toner, CMYK, but this is not limiting, and the colors of the toner and their combinations may be changed, and for example, light color toners, light toners such as light cyan and light magenta, dark toners, special color toners, etc. may be added as needed. In addition, the arrangement order of the image forming units 12 for each color is not limited to the order shown in the figure.

[0109] (Intermediate transfer unit) The intermediate transfer unit 14 includes a primary transfer roll 34 arranged opposite the image forming unit 12 of each color, and a backup roll 33 arranged opposite a transfer cylinder 36 .

[0110] (Intermediate transfer belt) The intermediate transfer belt 22 is formed in an endless shape. The intermediate transfer belt 22 is wound around a plurality of rolls 32 to determine its position. In this embodiment, the intermediate transfer belt 22 is oriented in the width direction of the device when viewed from the front, and has a generally obtuse triangular shape with an obtuse-angled convex portion facing downward. One of the rolls 32 (not shown) has the function of rotating the intermediate transfer belt 22 in the direction of arrow X using the power of a motor (not shown). By rotating in the direction of arrow X, the intermediate transfer belt 22 transports the primarily transferred image to the secondary transfer position 20.

[0111] The intermediate transfer belt 22 is configured to be able to rotate in the direction of arrow X while being in contact with or spaced from the photosensitive members 24 of the respective colors.

[0112] (Primary Transcript) Each primary transfer section 19 is configured by a contact portion between a photoconductor 24, an intermediate transfer belt 22, and a primary transfer roll 34. The primary transfer roll 34 is disposed opposite the photoconductor 24, with the intermediate transfer belt 22 sandwiched therebetween. The primary transfer roll 34 and the intermediate transfer belt 22 are configured to contact each other with a predetermined load.

[0113] A voltage is applied to the primary transfer roll 34 by a power supply unit (not shown). This voltage is a primary transfer voltage for primarily transferring the developer image formed on the photoreceptor 24 onto the intermediate transfer belt 22 between the photoreceptor 24 and the primary transfer roll 34.

[0114] (Transfer body) A transfer cylinder 36 is provided at a position opposite the backup roll 33 across the intermediate transfer belt 22. The transfer cylinder 36 has a cylindrical shape with its axis extending in the depth direction of the image forming apparatus 10, and is provided so as to be rotatable in the circumferential direction.

[0115] A voltage is applied to the transfer cylinder 36 by a power supply unit (not shown). This voltage is used as a secondary transfer voltage when the developer image transferred and superimposed on the intermediate transfer belt 22 is secondarily transferred onto the paper P transported to the secondary transfer position 20.

[0116] 12, the transfer cylinder 36 has a cylindrical shape with its axis extending in the depth direction of the image forming apparatus 10 and is provided so as to be rotatable in the circumferential direction. A recess 100 is formed on the outer periphery of the transfer cylinder 36 to accommodate the gripper 42. A plurality of clips 44 are provided in the recess 100 in the axial direction to grip the downstream leading edge P1 (see FIG. 5) of the paper P.

[0117] The transfer cylinder 36 is provided with sprockets 37 on both axial ends thereof, around which a chain 49 is wound.

[0118] Like the image forming transport cylinder 39 (see FIG. 8), the transfer cylinder 36 is also composed of a cylinder main body (not shown) and a sheet-like jacket member wrapped around the cylinder main body. A recess 100 is formed in the cylinder main body, and a cylinder side block is provided within the recess 100. The ends of the base layer of the jacket member are bolted to the cylinder side block, thereby detachably attaching the jacket member to the cylinder main body.

[0119] (Secondary transcription) 11, the secondary transfer position 20 is formed by the contact portion between the intermediate transfer belt 22 and the roll-shaped transfer cylinder 36. The intermediate transfer belt 22 is configured to contact the transfer cylinder 36 with a predetermined load by the backup roll 33 disposed opposite the transfer cylinder 36.

[0120] (fixing device) As shown in FIG. 11, the fixing device 400 is disposed downstream of the secondary transfer position 20 in the transport direction of the paper P.

[0121] 11 and 13, fixing device 400 is configured to include a pair of opposing rolls. One of the pair of rolls is fixing cylinder 402 around which chain 49 is wound, and the other roll is heating roll 404. Fixing cylinder 402 and heating roll 404 are installed so as to face each other with paper transport path A in between. Therefore, paper P to be fixed is transported so as to pass between fixing cylinder 402 and heating roll 404. Then, as paper P passes between fixing cylinder 402 and heating roll 404, the developer image transferred to paper P is fixed to paper P.

[0122] 13, fixing cylinder 402 has a cylindrical shape with its axis extending in the depth direction of image forming apparatus 10, and is provided so as to be rotatable in the circumferential direction. The aforementioned recess 100, into which gripper 42 is fitted, is formed on the outer periphery of fixing cylinder 402. A plurality of grippers 42 are provided in recess 100 in the axial direction, for gripping the downstream leading edge P1 (see FIG. 5) of paper P.

[0123] The transfer cylinder 36 and the fixing cylinder 402 are provided with sprockets 37 on both ends in the axial direction, around which a chain 49 is wound.

[0124] Like the image forming transport drum 39 (see FIG. 8), the fixing drum 402 is also configured to have a drum main body (not shown) and a sheet-like jacket member wrapped around the drum main body. The aforementioned recess 101 is formed in the drum main body, and a drum side block is provided within the recess 101. The end of the base layer of the jacket member is fastened to the drum side block with a bolt, so that the jacket member is detachably attached to the drum main body.

[0125] (Basic image formation operation) Next, an outline of a basic image forming operation on the paper P in the developer image forming unit 99 shown in FIG. 11 will be described.

[0126] When the control unit 160 receives an image formation command from the outside, it operates each image forming unit 12. The photoconductors 24 of each color are charged by the chargers 26 while rotating. The control unit 160 also sends image data that has been image processed in an image signal processing unit (not shown) to each exposure device 28. Each exposure device 28 irradiates each photoconductor 24 with exposure light in accordance with the image data, thereby exposing each charged photoconductor 24. As a result, an electrostatic latent image is formed on the outer peripheral surface of each photoconductor 24. The electrostatic latent image formed on each photoconductor 24 is developed by each developing device 30, and a toner image, an example of a developer image for each color, is formed on the photoconductor 24 corresponding to each color.

[0127] The toner images of each color formed on the photoreceptors 24 of each color are primarily transferred to the intermediate transfer belt 22 by the primary transfer rolls 34 of each color at the respective primary transfer portions. At this time, as the intermediate transfer belt 22 rotates, the toner images of each color are sequentially primarily transferred to the intermediate transfer belt 22 while being superimposed on each other. The superimposed toner images are transported to the secondary transfer position 20 by the rotation of the intermediate transfer belt 22. The superimposed toner images are then transferred from the intermediate transfer belt 22 to the paper P at the secondary transfer position 20.

[0128] The paper P onto which the toner image has been secondarily transferred is transported toward the fixing device 400. In the fixing device 400, the paper P is heated and pressed by a heating roll 404 and a fixing cylinder 402. As a result, the toner images formed by the image forming units 12 are fixed onto the paper P.

[0129] [Main components] Next, the main configuration of this embodiment will be described.

[0130] (Transport unit) As shown in FIG. 11, the transport unit 202 includes a chain 49, a transfer cylinder 36, a fixing cylinder 402, a fixing device 400, and the like.

[0131] 9, the transport unit 202 can be slid in the depth direction. Maintenance work on the transfer cylinder 36, the fixing cylinder 402, etc. (see FIG. 11) can be performed with the transport unit 202 pulled out to the front side.

[0132] (Maintenance position) Next, the maintenance positions of the recesses 100, 101 (see FIG. 12 or 13) when performing maintenance on the transfer cylinder 36 (see FIG. 12) and the fixing cylinder 402 (see FIG. 13) will be described.

[0133] In this embodiment, maintenance of the transfer cylinder 36 (see FIG. 12) and the fixing cylinder 402 (see FIG. 13) means replacing the jacket member 60 (see FIG. 8), etc. As described above, when maintenance is performed on the transfer cylinder 36 (see FIG. 12) and the fixing cylinder 402 (see FIG. 13), the transport unit 200 is pulled out to the front as shown in FIG.

[0134] Transfer cylinder maintenance position 12, the maintenance position of the recess 100 in the transfer cylinder 36 is within range H3. Specifically, the maintenance position range H3 is within the range in which the chain 49 is wound around the transfer cylinder 36 and the range in which the drive force transmission mechanism 279 is not provided. In this embodiment, the range in which the chain 49 is wound around the transfer cylinder 36 and the range in which the drive force transmission mechanism 279 is not provided partially overlap.

[0135] From another perspective, the range H3 is within the angle range in which the chain 49 is wound around the transfer cylinder 36 and in which the driving force transmission mechanism 279 is not provided.

[0136] In this embodiment, the maintenance position of the recess 100 of the transfer cylinder 36 is the 2 o'clock position when viewed from the front, which is the position shown in FIG.

[0137] Fixing cylinder maintenance position 13, the maintenance position of recess 101 in fixing cylinder 402 is within range H4. Specifically, maintenance position range H4 is within the range where chain 49 is wound around fixing cylinder 402 and where heating roll 404 is not provided. In this embodiment, the range where chain 49 is wound around fixing cylinder 402 and the range where heating roll 404 is not provided partially overlap.

[0138] From another perspective, range H4 is within the angle range where chain 49 is wound around fixing cylinder 402 and where heating roll 404 is not provided.

[0139] In this embodiment, the maintenance position of the recess 101 of the fixing cylinder 402 is the 10 o'clock position when viewed from the front, which is the position shown in FIG.

[0140] (position detection mechanism) 12 and 13 are the same mechanisms as those in the first embodiment, and are mechanisms for detecting the rotational positions of the transfer cylinder 36 (see FIG. 12) and the fixing cylinder 402 (see FIG. 13). The positions of the patches 272 and 273 are read by the optical sensors 274 and 275, thereby detecting the rotational positions of the transfer cylinder 36 (see FIG. 12) and the fixing cylinder 402 (see FIG. 13).

[0141] In this embodiment, the position detection mechanisms 270 and 271 are used to stop the recesses 100 and 101 of the transfer cylinder 36 and the fixing cylinder 402 so that they are positioned within the ranges H3 and H4, which are the maintenance positions.

[0142] (Control unit) As in the first embodiment, when an operator selects transfer cylinder 36 on operation panel 16 as the maintenance target, control unit 160 shown in Fig. 10 controls drive mechanism 79 so that recess 100 of transfer cylinder 36 (see Fig. 12) is located at the maintenance position shown in Fig. 12 within range H3. Similarly, when an operator selects fixing cylinder 402 (see Fig. 13)2 on operation panel 16 as the maintenance target, control unit 160 controls drive mechanism 79 so that recess 101 of fixing cylinder 402 (see Fig. 13) is located at the maintenance position shown in Fig. 13 within range H4.

[0143] From another perspective, when the operator selects transfer cylinder 36 as the maintenance target on operation panel 16, control unit 160 controls drive mechanism 79 to stop recess 100 of transfer cylinder 36 at the maintenance position shown in Fig. 12. Similarly, when the operator selects fixing cylinder 402 as the maintenance target on operation panel 16, control unit 160 controls drive mechanism 79 to stop recess 100 of fixing cylinder 402 at the maintenance position shown in Fig. 13.

[0144] <effect> Next, the operation of this embodiment will be described.

[0145] When the operator selects the transfer cylinder 36 as the maintenance target on the operation panel 16, the control unit 160 controls the drive mechanism 79 so that the recess 100 of the transfer cylinder 36 is positioned at the maintenance position shown in Figure 12 within range H3, and when the operator selects the fixing cylinder 402 as the maintenance target, the control unit 160 controls the drive mechanism 79 so that the recess 101 of the fixing cylinder 402 is positioned at the maintenance position shown in Figure 13 within range H4.

[0146] Therefore, the amount of work required to stop the recesses 100, 101 at the maintenance position can be reduced compared to when an operator slightly moves the transfer cylinder 36 or fixing cylinder 402 to be maintained and stops the recesses 100, 101 at the maintenance position.

[0147] Furthermore, since the maintenance positions of the recess 100 of the transfer cylinder 36 and the recess 101 of the fixing cylinder 402 are within the range in which the chain 49 is wound, the recesses 100 and 101 are easily accessible compared to when the maintenance positions of the recesses 100 and 101 are outside the range in which the chain 49 is wound.

[0148] Furthermore, since the maintenance positions of the recesses 100 and 101 are within the range where the chain 49 is wound around and outside the range where the driving force transmission mechanism 279 or the heating roll 404 is disposed, access to the recesses 100 and 101 is easier than when the maintenance positions are outside the range where the chain 49 is wound around and within the range where the driving force transmission mechanism 279 or the heating roll 404 is disposed.

[0149] <Other> The present invention is not limited to the above embodiment.

[0150] Furthermore, for example, in the above embodiment, the gripper 42 as an example of a holding member is exemplified as a configuration that physically holds the leading edge P1 of the paper P, but it is not limited to such a structure and may, for example, hold the leading edge of the paper P by the force of sucking air.

[0151] Furthermore, for example, in the above embodiment, the circulating member is a chain, but is not limited to this, and may be, for example, a belt.

[0152] Furthermore, for example, in the above embodiment, the inkjet method or the dry electrophotographic method has been described as an example of the method of forming an image on the paper P, but the method is not limited to this. For example, a wet electrophotographic method using a liquid developer or an offset printing method may also be adopted.

[0153] In addition, for example, in the above embodiment, the maintenance targets were the image forming transport cylinder 39, the drying transport cylinder 302, the transfer cylinder 36, and the fixing cylinder 402, but are not limited to these. The present invention can be applied to any transport cylinder that is provided with a recess and transports a recording medium.

[0154] Furthermore, for example, the maintenance positions of the recesses 100 and 101 are not limited to those in the above embodiment. The maintenance positions may be within a range where the chain 49 is not wound around the conveying drum, or within a range where peripheral components are provided.

[0155] The configuration of the image forming apparatus is not limited to that of the above embodiment, and various other configurations are possible. Furthermore, the present invention can be embodied in various forms without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0156] 10 Image forming device 11 Droplet image forming section 16 Operation panel (example of selection section) 18 Image forming position 20 Secondary transfer position (an example of an image forming position and a transfer position) 22 Intermediate transfer belt (an example of an image carrier) 36 Transfer cylinder (an example of a transfer cylinder) 39 Image forming transport cylinder (an example of a transport cylinder) 42 Gripper (an example of a holding member) 49 Chain (an example of a rotating component) 99 Developer image forming unit 100 recess 101 recess 200 Transport unit (an example of a recording medium transport device) 202 Transport unit (an example of a recording medium transport device) 279 Drive force transmission mechanism (an example of peripheral components) 300 Drying equipment 302 Drying conveying drum (an example of a conveying drum) 400 Fixing device 402 Fixing cylinder (an example of a conveying cylinder) 404 Heating roll (an example of a heating element) P Paper (an example of a recording medium)

Claims

1. a rotating member that forms part of a transport path for transporting a recording medium; a holding member that is fixed to the rotating member and rotates, and holds the leading end of the recording medium; a plurality of conveying drums around which the circumferential member is wound and each having a recess for accommodating the holding member; a selection unit for selecting one of the plurality of conveying drums; Equipped with a mode in which the conveying cylinder is stopped so that the recessed portion of the conveying cylinder selected by the selection unit is positioned at a maintenance position, The maintenance position is Within the range in which the circulating member is wound around the conveying drum, Recording medium transport device.

2. A peripheral member is arranged radially outside the range in which the circumferential member is wound around the conveying drum, the maintenance position is within a range where the circumferential member is wound around the conveying drum and where the peripheral member is not disposed; The recording medium transport device according to claim 1 .

3. A recording medium conveying device according to claim 1 or claim 2; a droplet image forming unit that forms a droplet image on the recording medium at an image forming position on the rotation path of the rotating member of the recording medium transport device; An image forming apparatus comprising:

4. One of the plurality of transport drums is an image forming transport drum that transports the recording medium to the image forming position. The image forming apparatus according to claim 3 .

5. A drying device that dries the droplet image formed on the recording medium at the image forming position at a drying position, one of the plurality of conveying drums is a drying conveying drum that conveys the recording medium to the drying position; The image forming apparatus according to claim 4 .

6. A recording medium conveying device according to claim 1 or claim 2; a developer image forming unit that forms a developer image to be transferred onto the recording medium at a transfer position in the rotation path of the rotating member of the recording medium transport device; An image forming apparatus comprising:

7. The developer image forming unit includes an image carrier that holds the developer image, one of the plurality of transport cylinders is a transfer cylinder that transfers the developer image from the image carrier to the recording medium; The image forming apparatus according to claim 6 .

8. A fixing device is provided which fixes the developer image to the recording medium onto which the developer image has been transferred at the transfer position, the fixing device, a fixing cylinder which is one of the plurality of conveying cylinders; a heating member that fixes the developer image by sandwiching the recording medium between the fixing cylinder and the heating member; It has The image forming apparatus according to claim 7 .

Images