Recording medium conveying device and image forming device

Abstract

To provide a recording medium conveying device which reduces the positional deviation in the conveying direction of a recording medium conveyed by a moving body which moves while holding the recording medium, compared with a case where the recording medium is conveyed without considering the timing at which the moving body which moves while holding the recording medium holds the recording medium.SOLUTION: (B) shows a state in which the timing specified by the timing information is late. In this case, CPU controls an upstream transport mechanism so that the timing at which the paper P conveyed by the upstream transport mechanism reaches a gripper 42 is later than the timing shown in (B). As a result, the timing at which the gripper 42 holds the paper P approaches the original reference timing (see (A)). In this case, the timing at which the paper P reaches the transfer position approaches the original reference timing, and as shown in (D), an image 100X is formed at the original reference position.SELECTED DRAWING: Figure 10

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 an apparatus including a rotating body having a gripper on its surface for gripping a printing medium at a specific rotational position on the surface, a transport unit that transports the printing medium toward the specific rotational position, and a printing unit that prints on the printing medium gripped by the gripper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-49830 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an apparatus that transports a recording medium, the recording medium may be transported by moving a movable body that holds the recording medium. When a movable body that holds a recording medium is used, the position of the recording medium in the transport direction may change depending on whether the recording medium is held early or late. The object of the present invention is to reduce the positional deviation in the transport direction of a recording medium transported by a moving body holding the recording medium, compared to a case where the recording medium is transported without taking into account the timing at which the moving body holding the recording medium holds the recording medium. [Means for solving the problem]

[0005] The invention described in claim 1 is a recording medium transport device comprising a transport means for transporting a recording medium, a moving body for holding and moving the recording medium transported by the transport means, and a processor for controlling the transport means based on timing information which is information about the timing at which the recording medium is held by the moving body. The invention described in claim 2 is a recording medium conveying device described in claim 1, in which the processor controls the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the moving body differs depending on the timing specified by the timing information. The invention described in claim 3 is a recording medium conveying device described in claim 2, in which the processor controls the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is delayed when the timing identified by the timing information is late, compared to when the timing is early. The invention described in claim 4 is a recording medium conveying device described in claim 2, in which the processor controls the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is earlier than when the timing identified by the timing information is earlier or later. The invention described in claim 5 is a recording medium conveying device described in claim 1, wherein the processor controls the conveying means based on the timing information and speed information, which is information about the moving speed of the moving body when it holds the recording medium. The invention described in claim 6 is a recording medium conveying device described in claim 5, in which the processor controls the conveying means so that the moving speed of the recording medium conveyed by the conveying means when it reaches the moving body is different depending on the moving speed identified by the speed information. The invention described in claim 7 is the recording medium conveying device described in claim 5, wherein the recording medium conveyed by the conveying means is handed over to the moving body at a transfer position, and the processor controls the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the transfer position differs depending on the moving speed identified by the speed information. The invention described in claim 8 is the recording medium conveying device described in claim 1, further comprising an image forming means for forming an image on the recording medium that is moved while being held by the moving body, and the processor acquires position information as the timing information, which is information about the position on the recording medium of the image formed on the recording medium by the image forming means in the direction of movement of the recording medium, and controls the conveying means based on the position information. The invention described in claim 9 is a recording medium conveying device described in claim 8, in which the processor controls the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is earlier when the position identified by the position information is shifted toward the leading end of the recording medium in the movement direction of the recording medium from a predetermined reference position, compared to when the position is not shifted. The invention described in claim 10 is a recording medium conveying device described in claim 8, in which the processor controls the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is delayed when the position identified by the position information is shifted toward the rear end side in the movement direction of the recording medium from a predetermined reference position, compared to when there is no shift. The invention described in claim 11 is the recording medium transport device described in claim 1, wherein a plurality of the moving bodies are provided and arranged so that the positions of the moving bodies in the movement direction are different from each other, and the processor controls the transport means for transporting a recording medium to the moving body for each of the plurality of moving bodies based on the timing information obtained for each of the plurality of moving bodies. The invention described in claim 12 is a recording medium transport device comprising a transport means for transporting a recording medium, a moving body for holding and moving the recording medium transported by the transport means, and a processor for controlling the movement of the moving body holding the recording medium based on timing information which is information about the timing at which the moving body holds the recording medium. The invention described in claim 13 is a recording medium conveying device described in claim 12, wherein the processor controls the movement of the moving body holding the recording medium so that the movement speed of the moving body varies depending on the timing identified by the timing information. The invention described in claim 14 is a recording medium conveying device described in claim 13, wherein the processor controls the movement of the moving body holding the recording medium so that the movement speed of the moving body is slower when the timing identified by the timing information is late compared to when the timing is early. The invention described in claim 15 is a recording medium conveying device described in claim 13, wherein the processor controls the movement of the moving body holding the recording medium so that the movement speed of the moving body is faster when the timing identified by the timing information is early compared to when the timing is late. The invention described in claim 16 is a recording medium conveying device described in claim 12, wherein the processor controls changing the position in the movement direction of the moving body, which moves while holding the recording medium, in accordance with the timing specified by the timing information. The invention described in claim 17 is a recording medium conveying device described in claim 16, wherein the processor displaces the moving body performing the movement upstream in the movement direction of the moving body when the timing identified by the timing information is slower than a predetermined standard. The invention described in claim 18 is a recording medium conveying device described in claim 16, wherein the processor displaces the moving body performing the movement downstream in the movement direction of the moving body when the timing identified by the timing information is earlier than a predetermined standard. The invention described in claim 19 is an image forming apparatus comprising a recording medium transporting device that transports a recording medium and an image forming means that forms an image on the recording medium, wherein the recording medium transporting device is configured by the recording medium transporting device described in any one of claims 1 to 18. Effect of the Invention

[0006] According to the invention of claim 1, it is possible to reduce the positional deviation in the transport direction of a recording medium transported by a moving body holding a recording medium, compared to a case in which the recording medium is transported without taking into account the timing at which the moving body holding the recording medium holds the recording medium. According to the invention of claim 2, the timing at which the recording medium reaches the moving body can be varied depending on the timing at which the moving body holds the recording medium. According to the invention of claim 3, if the timing at which the moving body holds the recording medium is delayed, the timing at which the recording medium reaches the moving body can be delayed. According to the invention of claim 4, when the timing at which the moving body holds the recording medium is early, the timing at which the recording medium reaches the moving body can be advanced. According to the invention of claim 5, it is possible to reduce the positional deviation in the transport direction of a recording medium transported by a moving body that moves while holding the recording medium, compared to a case in which the recording medium is transported without taking into account the moving speed of the moving body when holding the recording medium. According to the invention of claim 6, the moving speed of the recording medium when the recording medium transported by the transport means reaches the moving body can be made to differ depending on the moving speed of the moving body. According to the seventh aspect of the present invention, the timing at which the recording medium transported by the transport means reaches the transfer position can be varied depending on the moving speed of the moving body. According to the invention of claim 8, it is possible to control the conveying means when the timing at which the recording medium is held by the movable body differs from the standard, based on the position of the image formed by the image forming means that forms an image on the recording medium that is moved while being held by the movable body. According to the invention of claim 9, the position of the image formed on the recording medium can be brought closer to the reference position compared to a case in which the conveying means is not controlled so as to hasten the timing at which the recording medium conveyed by the conveying means reaches the moving body. According to the invention of claim 10, the position of the image formed on the recording medium can be brought closer to the reference position compared to a case in which the conveying means is not controlled so as to delay the timing at which the recording medium conveyed by the conveying means reaches the moving body. According to the invention of claim 11, the conveyance of the recording medium by the conveyance means can be controlled for each moving body that moves while holding the recording medium conveyed by the conveyance means. According to the invention of claim 12, it is possible to reduce the positional deviation in the transport direction of a recording medium transported by a moving body holding a recording medium, compared to a case where the recording medium is transported without taking into account the timing at which the moving body holding the recording medium holds the recording medium. According to the invention of claim 13, the moving speed of the moving body holding the recording medium can be made to differ depending on the timing at which the moving body holds the recording medium. According to the invention of claim 14, when the timing at which the moving body holds the recording medium is late, the moving speed of the moving body holding the recording medium can be reduced. According to the invention of claim 15, when the timing at which the moving body holds the recording medium is early, the moving speed of the moving body holding the recording medium can be increased. According to the invention of claim 16, the position in the moving direction of the moving body holding the recording medium can be changed according to the timing at which the moving body holds the recording medium. According to the seventeenth aspect of the invention, when the timing at which the moving body holds the recording medium is delayed, the moving body holding the recording medium can be displaced upstream in the moving direction. According to the eighteenth aspect of the invention, when the timing at which the moving body holds the recording medium is early, the moving body holding the recording medium can be displaced downstream in the moving direction. According to the invention of claim 19, it is possible to reduce the positional deviation in the transport direction of a recording medium transported by a moving body holding a recording medium, compared to a case where the recording medium is transported without taking into account the timing at which the moving body holding the recording medium holds the recording medium. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view showing an image forming apparatus. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a diagram illustrating an example of the hardware configuration of a control unit. [Figure 4] FIG. 3 is a diagram showing a state when a transfer cylinder is viewed from a direction indicated by an arrow IV in FIG. 2. [Diagram 5] 13A and 13B are diagrams illustrating the structure around an attachment member provided on a gripper. [Figure 6] FIG. 4 is a diagram illustrating a rotating member. [Figure 7] FIG. 4 is a diagram illustrating a rotating member. [Figure 8] 11A and 11B are diagrams illustrating the movement of a gripper. [Figure 9] FIG. 4 is a diagram illustrating an upstream transport mechanism. [Figure 10] 11A to 11F are diagrams showing the relationship between the timing at which the gripper holds the paper and the image formed. [Figure 11] 6A to 6C are diagrams showing a specific example of control of the upstream transport mechanism. [Figure 12] 4 is a flowchart showing an example of a flow of a process executed in the image forming apparatus. [Figure 13] 13A to 13C are diagrams showing other configuration examples of the chain and the gripper. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a front view showing an image forming apparatus 10 according to the present embodiment. As shown in FIG. 1, an image forming apparatus 10 includes an image forming section 11 that forms an image on a sheet of paper P, which is an example of a recording medium. Furthermore, the image forming apparatus 10 is provided with a paper transport device 200 as an example of a recording medium transport device. Furthermore, the image forming apparatus 10 is provided with a control unit 16 that controls each unit of the image forming apparatus 10.

[0009] The image forming apparatus 10 is also provided with a paper storage section 38 that stores paper P before an image is formed thereon, and a paper discharge section 39 onto which paper P after an image is formed is discharged. In this embodiment, the paper P from the paper storage section 38 is supplied to the image forming section 11. Also, in this embodiment, the paper P on which an image has been formed by the image forming section 11 is transported to the paper discharge section 39 and stored in this paper discharge section 39.

[0010] The paper transport device 200 is provided with a paper transport mechanism 210 that holds and transports the paper P from the paper storage unit . The paper transport mechanism 210 is provided with a delivery cylinder 60, a transfer cylinder 36, and a transport cylinder 31. FIG. 2 is a perspective view of the paper transport mechanism 210. As shown in FIG. The delivery cylinder 60 is provided with a sprocket 37. The transfer cylinder 36 is also provided with a sprocket 35. Although not shown in the drawings, the transport cylinder 31 is also provided with a sprocket. Further, the paper transport mechanism 210 is provided with a chain 49 which is a member that performs a circulating movement, and a gripper 42 (not shown in FIG. 2) (details will be described later) which is an example of a holding member. The gripper 42 is supported by the chain 49.

[0011] Furthermore, the paper transport mechanism 210 is provided with a home sensor 291 for identifying the phase of the chain 49, as shown in FIG. The chain 49 is provided with a first light shielding plate 292 as an example of a detection target member to be detected by the home sensor 291. Furthermore, an encoder 293 for detecting one rotation of the transfer cylinder 36 is provided at a position facing the outer periphery of the transfer cylinder 36. Furthermore, a second light shielding plate 294 as an example of a detected member detected by the encoder 293 is provided on the transfer cylinder 36.

[0012] 3 is a diagram showing an example of the hardware configuration of the control unit 16. The control unit 16 is realized by a computer. The control unit 16 includes an arithmetic processing unit 110 that executes digital arithmetic processing according to a program, and a secondary storage unit 91 that stores information. The secondary storage unit 91 is realized by an existing information storage device such as an HDD (Hard Disk Drive), a semiconductor memory, or a magnetic tape.

[0013] The arithmetic processing unit 110 includes a CPU 11a as an example of a processor. The arithmetic processing unit 110 is also provided with a RAM 11b used as a working memory for the CPU 11a, and a ROM 11c in which programs executed by the CPU 11a are stored. The arithmetic processing unit 110 is also provided with a non-volatile memory 11d that is rewritable and can retain data even if the power supply is interrupted.

[0014] The non-volatile memory 11d is composed of, for example, a battery-backed SRAM, a flash memory, etc. In the secondary storage unit 91, various types of information such as programs executed by the arithmetic processing unit 110 are stored. In this embodiment, the CPU 11a provided in the arithmetic processing unit 110 reads programs stored in the ROM 11c or the secondary storage unit 91, whereby various processes performed in the image forming apparatus 10 are executed.

[0015] The program executed by the CPU 11a may be provided to the image forming apparatus 10 in a state where it is stored in a computer-readable recording medium such as a magnetic recording medium (such as a magnetic tape or a magnetic disk), an optical recording medium (such as an optical disk), a magneto-optical recording medium, or a semiconductor memory. The program executed by the CPU 11a may also be provided to the image forming apparatus 10 using a communication means such as the Internet.

[0016] In this specification, the term "processor" refers to a processor in a broad sense, including general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.). In addition, the operations of the processor may not only be performed by one processor, but may be performed by multiple processors in physically separate locations working together. The order of the operations of the processor is not limited to the order described in this embodiment, and may be changed.

[0017] [Explanation of Image Forming Unit] An image forming unit 11 (see FIG. 1) as an example of an image forming means forms an image on a paper P. The image forming unit 11 forms an image on the paper P that is moving while being held by a gripper 42 (described later). The image forming section 11 has a transfer belt 22 that moves in a circular motion, and in the image forming section 11, an image is first formed on the outer peripheral surface of the transfer belt 22. The image formed on the transfer belt 22 is transferred at a transfer position T onto a sheet of paper P held by a gripper 42 (not shown in FIG. 1) provided in the paper transport mechanism 210.

[0018] The image forming unit 11 is provided with a plurality of print heads 12. The plurality of print heads 12 are arranged side by side along the horizontal direction. In this embodiment, a print head 12 is provided for each color. In this embodiment, the print heads 12 are provided as print heads 12Y, 12M, 12C, and 12K for a total of four colors: yellow (Y), magenta (M), cyan (C), and black (K). Each of the print heads 12 uses an inkjet printing method to form an image made of ink on the outer circumferential surface of the transfer belt 22 .

[0019] Furthermore, in this embodiment, a support roll 32 is provided to support the inside of the transfer belt 22. A plurality of support rolls 32 are provided. Furthermore, on the inner side of the transfer belt 22, a transfer roll 33 used for transferring an image from the transfer belt 22 to the paper P is provided. The transfer roll 33 is disposed at a position facing the transfer cylinder 36 with the transfer belt 22 sandwiched therebetween. The transfer belt 22 is not essential, and an image may be formed directly on the paper P by the print head 12.

[0020] In this embodiment, as described above, the print head 12 forms an image using an inkjet printing method, but this is not limited to this, and images may be formed using other printing methods such as electrophotography. In the electrophotographic system, an image is formed on a photoconductor drum, which is an example of an image carrier, through charging, exposure, and development. This image is then transferred to paper P via an intermediate transfer member such as a transfer belt 22, or directly.

[0021] In this embodiment, when a signal instructing the start of image formation is received from the outside, the control unit 16 operates the print head 12 provided in the image forming unit 11 . Furthermore, the control unit 16 controls image data that has been subjected to image processing in a signal processing unit (not shown) to be transmitted to the image forming unit 11. As a result, in the image forming unit 11, an image is formed on the transfer belt 22, and then, at the transfer position T, this image on the transfer belt 22 is transferred onto the paper P that has been transported by the paper transport mechanism 210.

[0022] Referring again to FIG. 2, the paper transport mechanism 210 will now be further described. A transfer cylinder 36 provided in the paper transport mechanism 210 extends in the depth direction of the image forming apparatus 10 . The transfer cylinder 36 has a shaft 36A extending in the depth direction of the image forming apparatus 10, and a roll portion 36B formed in a cylindrical shape and provided at the middle portion in the axial direction of the shaft 36A. Sprockets 35 are attached to both axial ends of the shaft 36A. In this embodiment, the roll portion 36B is disposed between the pair of sprockets 35.

[0023] A chain 49 is wound around the sprocket 35 of the transfer cylinder 36. In other words, in this embodiment, the sprocket 35 of the transfer cylinder 36 and the chain 49 mesh with each other. A recess (not shown) for accommodating a gripper 42 (described later) is provided in the roll portion 36B of the transfer cylinder 36. This recess is provided from one end to the other end in the axial direction of the roll portion 36B.

[0024] A nip region is formed between the transfer cylinder 36 (see FIG. 1) and the transfer belt 22. In the nip region, a roll portion 36B (see FIG. 2) provided on the transfer cylinder 36 and the outer circumferential surface of the transfer belt 22 come into contact with each other. In this embodiment, the transfer cylinder 36 is rotated by a motor (not shown). Accordingly, the roll portion 36B of the transfer cylinder 36 rotates, and a driving force is transmitted from the rotating roll portion 36B to the transfer belt 22. As a result, the transfer belt 22 moves. Further, a driving force is transmitted from the transfer cylinder 36 to the transfer cylinder 60 and the transport cylinder 31 by the chain 49 which moves in a circular motion, and the transfer cylinder 60 and the transport cylinder 31 also rotate. In addition, instead of the transfer cylinder 36 being rotated, the delivery cylinder 60 or the transport cylinder 31 may be rotated.

[0025] In this embodiment, the paper P is transported to the nip region by a gripper 42 (described later). In the nip region, the paper P is sandwiched between the outer periphery of a heated roll unit 36B (see FIG. 2) and the transfer belt 22 (see FIG. 1). The image on the transfer belt 22 is then transferred to the paper P. Furthermore, in this embodiment, as shown in FIG. 1, an upstream transport mechanism 220 and a downstream transport mechanism 230 are provided as other mechanisms that configure the paper transport device 200.

[0026] In the transport direction of the paper P, an upstream transport mechanism 220 is provided upstream of the paper transport mechanism 210. The upstream transport mechanism 220, which is an example of a transport means, transports the paper P from the paper storage unit 38 to the paper transport mechanism 210. In this embodiment, a plurality of paper storage units 38 are provided, and the paper P is transported from one of the plurality of paper storage units 38 to the paper transport mechanism 210. Further, downstream of the paper transport mechanism 210 in the transport direction of the paper P, a downstream transport mechanism 230 that receives the paper P from the paper transport mechanism 210 and transports it is provided. The downstream transport mechanism 230 transports the paper P from the paper transport mechanism 210 to the paper discharge section 39.

[0027] In the paper transport mechanism 210 (see FIG. 1), the paper P is transported using a chain 49 and a gripper 42 (not shown in FIG. 1). On the other hand, each of the upstream transport mechanism 220 and the downstream transport mechanism 230 transports the paper P using a pair of rolls 241 that are driven to rotate. In each of the upstream transport mechanism 220 and the downstream transport mechanism 230, a plurality of roll pairs 241 are arranged in the transport direction of the paper P.

[0028] 1, in this embodiment, a fixing unit 40 is provided downstream of the transfer position T in the transport direction of the paper P. In the fixing unit 40, heat and pressure are applied to the paper P to which the image has been transferred, and the image transferred to the paper P is fixed to the paper P. The fixing section 40 is provided with a heating roll 43 as a heating section that contacts the paper P being conveyed and heats the paper P. The heating roll 43 is pressed against the transport cylinder 31. In this embodiment, the paper P passes between the heating roll 43 and the transport cylinder 31, whereby the paper P is heated and pressurized, and the image transferred to the paper P is fixed to the paper P.

[0029] Although not shown in the figure, the transport cylinder 31, like the transfer cylinder 36, is provided with a shaft extending in the depth direction of the image forming device 10 and a cylindrical roll portion provided in the middle of the axial direction of this shaft. A recess is provided on the outer surface of the roll portion, extending along the axial direction of the roll portion. The recess is provided from one end of the roll portion to the other end, and in this embodiment, a gripper 42 (described later) is housed in the recess. Furthermore, sprockets (not shown) around which a chain 49 is wound are provided at both axial ends of the shaft provided on the transport drum 31. The transport drum 31 rotates in response to the movement of the chain 49.

[0030] As shown in FIG. 2, in this embodiment, a chain 49 is wound around a sprocket of the transport cylinder 31 (not shown in FIG. 2), a sprocket 35 of the transfer cylinder 36, and a sprocket 37 of the delivery cylinder 60. A sprocket is provided at each of both axial ends of each of the transport cylinder 31, the transfer cylinder 36, and the delivery cylinder 60. Two sets of sprockets are provided for each of the transport cylinder 31, the transfer cylinder 36, and the delivery cylinder 60. In this embodiment, a chain 49 is provided for each of the two sprockets, with one chain 49 meshing with one sprocket and the other chain 49 meshing with the other sprocket.

[0031] FIG. 4 is a diagram showing the transfer cylinder 36 as viewed from the direction indicated by the arrow IV in FIG. FIG. 4 shows a state in which the gripper 42 is accommodated in a recess 36E provided in the transfer cylinder 36. With reference to FIG. 4, the gripper 42 will now be described. The gripper 42, which is an example of a moving body, receives the paper P transported by an upstream transport mechanism 220 (see FIG. 1), which is an example of a transport means, at a location where the delivery drum 60 (see FIG. 1) is installed. Then, the gripper 42 moves while holding the paper P. Fig. 4 shows a state when the gripper 42 holding the paper P (not shown in Fig. 4) reaches the transfer cylinder 36.

[0032] The gripper 42 is attached to a chain 49 (not shown in FIG. 4) via a pair of attachment members 72 disposed on each of both ends of the gripper 42 in the longitudinal direction. The gripper 42 includes a claw member 73 and a claw receiving member 75 with which the tip of the claw member 73 comes into contact, and holds the paper P by pinching the paper P between the claw member 73 and the claw receiving member 75. More specifically, the gripper 42 holds an edge of the paper sheet P. More specifically, the gripper 42 holds an edge of the paper sheet P that is located on the downstream side in the transport direction.

[0033] The claw member 73 is attached to a claw drive shaft 74, and in this embodiment, the claw drive shaft 74 rotates in the direction indicated by the arrow 4A to hold the paper P. This rotation is performed when the gripper 42 reaches the installation position of the transfer cylinder 60 (see FIG. 1). In this embodiment, the gripper drive shaft 74 rotates in the direction opposite to the direction indicated by the arrow 4A, thereby no longer holding the paper P. This rotation in the opposite direction occurs when the gripper 42 reaches the installation position of the transport drum 31 (see FIG. 1). In this embodiment, a plurality of grippers 42 are provided. In this embodiment, the plurality of grippers 42 are arranged such that the positions of the plurality of grippers 42 are different from one another in the movement direction of the chain 49.

[0034] Figures 5(A) and (B) are diagrams for explaining the structure around the mounting member 72 provided on the gripper 42. Figure 5(A) is a diagram of the mounting member 72 as viewed from the direction indicated by the arrow VA in Figure 4. Figure 5(B) is a diagram of the mounting member 72 as viewed from the direction indicated by the arrow VB in Figure 5(A). As shown in FIG. 5(A), the mounting member 72 includes a support portion 721 that rotatably supports the end of the claw drive shaft 74 (see FIG. 4), and a fixing portion 722 to which the end of the claw receiving member 75 is fixed. An annular bearing member 724 made of synthetic resin or the like is provided in the support hole 723 of the support portion 721. In this embodiment, the support portion 721 rotatably supports the pawl drive shaft 74 (see FIG. 4) via the bearing member 724.

[0035] In this embodiment, the length of the pawl drive shaft 74 (see FIG. 4) is greater than the length along the axial direction of the transfer cylinder 36. The pawl drive shaft 74 is formed of a cylindrical member. In this embodiment, the claw member 73 is supported by the claw drive shaft 74. In this embodiment, the claw members 73 are provided in plurality and are arranged on the claw drive shaft 74 in a line in the axial direction.

[0036] In this embodiment, as shown in FIG. 4, a rotation member 76 used to rotate the pawl drive shaft 74 is attached to an end of the pawl drive shaft 74. In this embodiment, when the rotating member 76 rotates, the claw drive shaft 74 that is linked to the rotating member 76 rotates, and as a result, the claw member 73 holds the paper P and releases the hold.

[0037] 6 and 7 are diagrams illustrating the rotating member 76. FIG. FIG. 6 shows the rotating member 76 as viewed from the direction indicated by the arrow VI in FIG. As shown in FIG. 6, the rotation member 76 has an opening 761 into which the end of the pawl drive shaft 74 fits, and in this embodiment, the end of the pawl drive shaft 74 fits within this opening 761. An opening 761 of the rotation member 76 is divided at its upper end into two by a slit-shaped notch 762 along the radial direction of the rotation member 76.

[0038] A flange portion 764 is connected to the cutout portion 762, and in this embodiment, a screw 763 is passed through this flange portion 764. In this embodiment, the diameter of the opening 761 is reduced by this screw 763, thereby fixing the rotation member 76 to the claw drive shaft 74. In this embodiment, the claw drive shaft 74 and the rotating member 76 are configured to work in conjunction with each other, so that when the rotating member 76 rotates, the claw drive shaft 74 rotates.

[0039] A coil spring 77 as an example of a biasing means is provided on the outer periphery of the claw drive shaft 74. In this embodiment, the coil spring 77 rotates the rotation member 76 relative to the support portion 721 (see FIG. 4). One end (not shown in FIG. 6) of the coil spring 77 is configured to be hooked onto a pin 726 provided on the outer surface of the support portion 721 of the mounting member 72 (see FIG. 5(A)). As shown in FIG. 6, the other end of the coil spring 77 is hooked onto a pin 765 provided on the rotation member . As a result, in this embodiment, a biasing force acts on the rotation member 76 and the pawl drive shaft 74 that moves in conjunction with the rotation member 76 in the direction indicated by the arrow 4A in FIG.

[0040] Furthermore, in this embodiment, as shown in FIG. 7, a cam follower 766 is provided for rotating the rotating member 76 in the counterclockwise direction. The cam follower 766 is configured by a roll-shaped member rotatably attached to an arm portion 767 that is provided so as to protrude downward. In this embodiment, as shown in FIG. 7, a cam member 768 is provided along the movement path of the rotation member 76, and in this embodiment, the rotation member 76 is rotated by this cam member 768.

[0041] As shown in FIG. 5(A), two pins 861 and 862 are fixed to the fixing portion 722 of the mounting member 72. In this embodiment, the two pins 861 and 862 are fixed to the chain 49, thereby fixing the mounting member 72 to the chain 49.

[0042] 8 is a diagram for explaining the movement of the gripper 42. Fig. 8 shows the state of the gripper 42 when viewed from the direction indicated by the arrow VIII in Fig. 4. In this embodiment, when the gripper 42 reaches the transfer cylinder 60 (see FIG. 1), the rotating member 76 is rotated counterclockwise in FIG. 7 by the cam member 768 (see FIG. 7). As a result, as shown in FIG. 8, the claw drive shaft 74 rotates in the direction indicated by the arrow 8X, and in accordance with this, the claw member 73 separates from the claw receiving member 75, and the gripper 42 enters an open state. In this embodiment, when the gripper 42 is in the released state, the paper P conveyed by the upstream conveyance mechanism 220 is supplied to the gripper 42.

[0043] Then, in this embodiment, after the paper P enters between the claw receiving member 75 and the claw member 73, the rotating member 76 is rotated in the clockwise direction in FIG. 7 by the cam member 768 (see FIG. 7). As a result, the claw drive shaft 74 rotates in the direction opposite to the direction indicated by the arrow 8X in FIG. 8, and the claw member 73 approaches the claw receiving member 75. This brings the gripper 42 into a closed state. In other words, the gripper 42 is in a closed state. Thereafter, the gripper 42 moves to the transport cylinder 31 via the transfer cylinder 36 (see FIG. 1) while maintaining the closed state.

[0044] When the gripper 42 reaches the transport drum 31, the cam member 768 (see FIG. 7) rotates the rotating member 76 in the counterclockwise direction in FIG. 7. This causes the gripper 42 to be in an open state. Then, the paper P between the claw receiving member 75 (see FIG. 8) and the claw member 73 provided on the gripper 42 in the open state reaches the downstream transport mechanism 230 (see FIG. 1). Then, the paper P is transported to the paper discharge section 39 by the downstream transport mechanism 230.

[0045] Although the configuration of one end side in the axial direction of the pawl drive shaft 74 has been described with reference to FIG. 4, the configuration of the other end side in the axial direction of the pawl drive shaft 74 is similar to the configuration of this one end side. In addition, in the above description, the chain 49 is used as an example of the circulating member, but the circulating member is not limited to the chain 49. The circulating member may be, for example, a belt member such as a timing belt having an uneven inner circumference.

[0046] FIG. 9 is a diagram illustrating the upstream transport mechanism 220. As shown in FIG. As described above, the upstream transport mechanism 220 is provided with a plurality of roll pairs 241. In this embodiment, a transport roll 221 formed by the roll pair 241 and a registration roll 222 are provided. In each of the conveying roll 221 and the registration roll 222, one roll-shaped member constituting the roll pair 241 rotates by receiving a driving force from a motor, and the other roll-shaped member rotates by receiving a driving force from the one roll-shaped member.

[0047] Furthermore, in this embodiment, in the transport direction of the paper P, a movement restriction portion 223 that restricts the movement of the transported paper P is provided between the transport roll 221 and the registration roll 222. Furthermore, downstream of the movement restricting portion 223 in the transport direction of the paper P and upstream of the registration roll 222 in the transport direction of the paper P, a paper sensor 229 that detects the leading edge of the paper P is provided.

[0048] In this embodiment, when the paper P is conveyed to the movement restricting section 223, the leading edge of the paper P abuts against the movement restricting section 223, and the movement of the leading edge is temporarily restricted. Thereafter, in this embodiment, at a preset timing, the movement restriction unit 223 retreats from the movement path of the paper P. This causes the paper P to be sent out at a specific, predetermined timing, and the position of the paper P in the transport direction is prevented from varying from one paper P to another. Thereafter, the paper P is directed to the registration roll 222 .

[0049] In this embodiment, images can be formed on both sides of the paper P. When forming images on both sides of the paper P, the paper P that has passed through the fixing unit 40 (see FIG. 1) is once sent to the first branched transport path 100B. Thereafter, the paper P passes through the main transport path 100R and the second branch transport path 100C, and is sent to the upstream transport mechanism 220. Then, the paper P is supplied again to the image forming unit 11. As a result, an image is formed on the back side of the paper P.

[0050] [Control of the upstream transport mechanism 220] Next, the control of the upstream transport mechanism 220 will be described. In this embodiment, the upstream transport mechanism 220 (see FIG. 9) is controlled by a CPU 11a (as an example of a processor) provided in the control unit 16 (see FIG. 3). When controlling the upstream transport mechanism 220, the CPU 11a acquires timing information about the timing at which the gripper 42, which is an example of a moving body, holds the paper P (a specific example of the timing at which the paper P is held will be described later). Then, the CPU 11a controls the upstream transport mechanism 220 based on the acquired timing information.

[0051] The CPU 11a controls the upstream transport mechanism 220 so that the timing at which the paper P transported by the upstream transport mechanism 220 reaches the gripper 42 varies depending on the timing specified by the timing information. When the timing specified by the timing information is late, the CPU 11a controls the upstream conveying mechanism 220 so that the timing at which the paper P transported by the upstream conveying mechanism 220 reaches the gripper 42 is delayed compared to when the timing specified by the timing information is earlier than this timing.

[0052] When the timing specified by the timing information is late, the closing timing of the gripper 42 is late, and the gripper 42 holds the paper P after a larger amount of the paper P has been conveyed. In this case, the CPU 11a controls the upstream transport mechanism 220 so that the timing at which the paper sheet P reaches the gripper 42 becomes later.

[0053] In addition, when the timing specified by the timing information is early, the CPU 11a controls the upstream conveying mechanism 220 so that the timing at which the paper P transported by the upstream conveying mechanism 220 reaches the gripper 42 is earlier than when the timing specified by the timing information is later than this timing. When the timing specified by the timing information is early, the closing timing of the gripper 42 is early, and the gripper 42 holds the paper P while the transport amount of the paper P is small. In this case, the CPU 11a controls the upstream transport mechanism 220 so that the timing at which the paper sheet P reaches the gripper 42 becomes earlier.

[0054] 10(A) to 10(F) are diagrams showing the relationship between the timing at which the gripper 42 holds the paper P and the image 100X that is formed. Note that the gripper 42 is shown in schematic form in FIG. In this embodiment, due to differences in the closing timing of the gripper 42, the timing at which the gripper 42 holds the paper P may deviate from the reference timing, which is the originally scheduled reference timing. FIG. 10A shows a state where the timing at which the gripper 42 holds the paper P is the reference timing.

[0055] If the timing at which the gripper 42 holds the paper P deviates from the reference timing, the timing at which the gripper 42 holds the paper P may be earlier or later than the originally scheduled reference timing. Specifically, for example, the closing timing of the gripper 42 deviates from the originally scheduled reference closing timing due to expansion of each part due to heat, installation errors of each member, etc. This causes the closing timing of the gripper 42 to be earlier or later than the originally scheduled reference timing.

[0056] If the closing timing of the gripper 42 becomes earlier or later than the originally scheduled reference timing, the situations shown in FIGS. 10(B) and (C) occur. In other words, if the timing at which the gripper 42 holds the paper P becomes earlier or later than the originally scheduled reference timing, the situations shown in FIGS. 10B and 10C occur.

[0057] FIG. 10B shows a situation in which the position of the leading edge of the paper P in the transport direction is located downstream in the transport direction of the paper P from the originally scheduled reference position. FIG. 10C shows a situation in which the position of the leading edge of the paper P in the transport direction is located upstream of the originally scheduled reference position in the transport direction of the paper P. In this way, when the position of the leading edge of the paper P in the transport direction deviates from the originally planned reference position, the formation position of the image 100X on the paper P deviates as shown in FIG. 10(E) and FIG. 10(F).

[0058] FIG. 10E shows the state of the paper P when the timing at which the gripper 42 holds the paper P is later than the originally scheduled reference timing. If the timing at which the gripper 42 holds the paper P is later than the originally scheduled reference timing, as shown in Figure 10 (B), the position of the leading edge of the paper P will be downstream in the transport direction of the paper P from the originally scheduled reference position. In this case, the timing at which the paper P reaches the transfer position T (see Figure 1) is earlier than the reference timing, which is the original timing, and the image 100X is formed in a position shifted toward the rear end side of the paper P in the transport direction, as shown in Figure 10 (E).

[0059] FIG. 10F shows the state of the sheet P when the timing at which the gripper 42 holds the sheet P is earlier than the originally scheduled reference timing. If the timing at which the gripper 42 holds the paper P is earlier than the originally scheduled reference timing, the position of the leading edge of the paper P will be located upstream in the transport direction of the paper P than the originally scheduled reference position, as shown in Figure 10 (C). In this case, the timing at which the paper P reaches the transfer position T is delayed from the reference timing, which is the original timing, and the image 100X is formed in a state shifted toward the leading edge of the paper P in the transport direction, as shown in Figure 10 (F).

[0060] Fig. 10B shows a state where the timing specified by the timing information is late. In this case, the CPU 11a controls the upstream transport mechanism 220 so that the timing at which the paper P transported by the upstream transport mechanism 220 reaches the gripper 42 is later than the timing shown in Fig. 10B. As a result, the timing at which the gripper 42 holds the paper P approaches the original reference timing (see FIG. 10(A)). In this case, the timing at which the paper P reaches the transfer position T approaches the original reference timing, and as shown in FIG. 10(D), the image 100X is formed at the original reference position.

[0061] 10C shows a state where the timing specified by the timing information is earlier than the timing shown in FIG. 10C. In this case, the CPU 11a controls the upstream transport mechanism 220 so that the timing at which the paper P transported by the upstream transport mechanism 220 reaches the gripper 42 is earlier than the timing shown in FIG. As a result, also in this case, the timing at which the gripper 42 holds the paper P approaches the original reference timing (see FIG. 10(A)). In this case as well, the timing at which the paper P reaches the transfer position T approaches the original reference timing, and the image 100X is also formed at the original reference position, as shown in FIG. 10(D).

[0062] In this embodiment, after the gripper 42 holds the paper P, the positional relationship between the paper P and the image 100X formed on the paper P does not change. In this embodiment, a chain 49 provided in the paper transport mechanism 210 (see FIG. 1) and a transfer belt 22 provided in the image forming unit 11 are configured to work in conjunction with each other. In this case, no misalignment occurs between the paper P held by the gripper 42 supported by the chain 49 and the image 100X formed on the transfer belt 22 provided in the image forming unit 11. Therefore, after the gripper 42 holds the paper P, the positional relationship between the paper P and the image 100X formed on the paper P does not change.

[0063] [Timing Information] The timing information will now be described. In this embodiment, the CPU 11a acquires, as timing information, position information which is information about the position on the paper P of the image 100X formed on the paper P by the image forming unit 11, and is information about the position in the movement direction of the paper P when the paper P passes through the image forming unit 11. The CPU 11a then controls the upstream transport mechanism 220 based on this position information, which is an example of timing information.

[0064] In this embodiment, when acquiring the timing information, the CPU 11a first issues an instruction to output a test paper for identifying the closing timing of the gripper . When this instruction is output, the upstream transport mechanism 220 (see FIG. 1) starts transporting the paper P, and the paper P is transported to the paper discharge section 39 via the transfer position T. As a result, a test paper on which the test image is formed is generated, and the test paper is stacked in the paper discharge section 39. In this embodiment, the test papers P are generated in a number corresponding to the number of grippers 42. In other words, in this embodiment, a test paper P is generated for each gripper 42.

[0065] In this embodiment, the user then places the test papers in a scanner device (not shown), which then reads each of the test papers. This generates a scanned image, which is an image obtained by scanning the test paper. Then, this scanned image is sent to the image forming apparatus 10. Next, the CPU 11a provided in the image forming apparatus 10 analyzes the read image and obtains timing information.

[0066] When acquiring the timing information, the CPU 11a analyzes the read image and acquires position information, which is information about the position of the test image included in the read image. Then, the CPU 11a sets the acquired position information as the above-mentioned timing information. The position information obtained is the distance from one end of the paper P that is the basis for the test paper, located at one end in the direction of movement of the paper P as it passes through the image forming unit 11, to the test image formed on the paper P. In other words, the position information obtained is the distance from one end of the test paper to the test image. In other words, the position information obtained is information about the size of the margin located between one edge of the test paper and the test image.

[0067] If the position specified by the position information is on the rear end side of the paper P in the moving direction relative to a predetermined reference position, it indicates that the closing timing of the gripper 42 is late. Moreover, if the position specified by the position information is closer to the leading end side in the moving direction of the paper P than the predetermined reference position, it indicates that the closing timing of the gripper 42 is earlier.

[0068] When the position identified by the position information is closer to the rear end in the direction of movement of the paper P than a predetermined reference position, the CPU 11a controls the upstream conveying mechanism 220 so that the timing at which the paper P being conveyed by the upstream conveying mechanism 220 reaches the gripper 42 is delayed compared to when it is at the reference position. In addition, when the position identified by the position information is closer to the leading end of the paper P in the direction of movement of the paper P than a predetermined reference position, the CPU 11a controls the upstream conveying mechanism 220 so that the paper P being conveyed by the upstream conveying mechanism 220 reaches the gripper 42 at an earlier timing than when it is at the reference position.

[0069] In the above description, the CPU 11a provided in the image forming apparatus 10 analyzes the read image and acquires the above-mentioned position information. However, the process of acquiring the position information is not limited to this. For example, a device other than the image forming device 10 may analyze the read image and obtain the position information. Then, location information may be transmitted from a device other than the image forming device 10 to the image forming device 10, and the image forming device 10 may acquire this location information.

[0070] Also, the position information may not necessarily be acquired by a device such as the image forming device 10, but a user may manually measure the position of the test image on the test paper. In this case, the measurement result obtained by the user is transmitted to the image forming device 10 via a PC (Personal Computer) (not shown) or the like, and the image forming device 10 acquires the measurement result as position information. Also, for example, a scanner device may be installed inside the image forming apparatus 10, and the test paper may be automatically read by this scanner device. In this case, the CPU 11a of the image forming apparatus 10 obtains position information based on the read image of the test paper that is automatically read.

[0071] The acquired location information is registered in a secondary storage unit 91 (see FIG. 3), which is an example of an information storage unit. In this embodiment, as described above, a test paper is generated for each gripper 42, and position information is obtained for each gripper 42. In other words, timing information is obtained for each gripper 42. In the secondary storage unit 91, identification information, which is information for identifying each gripper 42, and position information are registered in a mutually associated state for each gripper 42. In other words, in the secondary storage unit 91, for each gripper 42, identification information for identifying each gripper 42 and information for specifying the closing timing of the gripper 42 are registered in a mutually associated state.

[0072] Although not explained above, each test paper is provided with information for identifying each gripper 42, and the CPU 11a or the user performing the above measurements obtains the identification information based on the information provided on the test paper P. Then, the CPU 11a causes the acquired identification information and timing information to be registered in the secondary storage unit 91 in a state in which the identification information and timing information are associated with each other. When controlling the upstream transport mechanism 220, the CPU 11a controls the upstream transport mechanism 220 based on information for identifying the closing timing, which is registered in the secondary storage unit 91 for each gripper .

[0073] [Specific Example of Control of the Upstream Transport Mechanism 220] 11A to 11C are diagrams showing a specific example of control of the upstream transport mechanism 220. FIG. 11A shows a specific example of control of the upstream transport mechanism 220 when the closing timing is the reference timing. In this embodiment, when the closing timing is the reference timing, the CPU 11a starts decelerating the rotation speed of the registration roll 222 (see FIG. 9) when the reference timing indicated by the reference symbol 11A is reached. As a result, the paper P in the decelerated state is transported to the gripper 42.

[0074] In this embodiment, when the upstream transport mechanism 220 transports the paper P, the paper P temporarily hits the movement control section 223 (see FIG. 9), and the transport speed of the leading edge of the paper P temporarily becomes zero, as shown by the symbol 11B in FIG. 11(A). Then, in this embodiment, thereafter, the movement restricting portion 223 is retracted, and the transport of the paper P is started. Furthermore, in this embodiment, as described above, a paper sensor 229 (see FIG. 9) for detecting the leading edge of the paper P is provided downstream of the movement restricting portion 223. The CPU 11a determines that the reference timing has arrived when a predetermined time has elapsed since the leading edge of the paper P was detected by the paper sensor 229. In this case, the CPU 11a decelerates the registration roll 222.

[0075] FIG. 11B shows a specific example of control of the upstream transport mechanism 220 when the closing timing of the gripper 42 is delayed compared to the original reference timing. In other words, FIG. 11B shows a specific example of control of the upstream transport mechanism 220 in the case where the position specified by the position information is on the rear end side of the paper P with respect to the reference position. In this embodiment, when the closing timing is later than the reference timing, as shown in FIG. 11(B), the CPU 11a advances the deceleration start timing 11Y to be earlier than the reference timing indicated by reference symbol 11A (see FIG. 11(A)).

[0076] More specifically, the CPU 11a obtains a new deceleration start timing, which is the timing at which the registration roll 222 starts to decelerate, by multiplying the reference deceleration start timing by a coefficient or by adding a correction value, which will be described later, to this reference deceleration start timing. The reference deceleration start timing is determined based on the elapsed time from the detection of paper P by the paper sensor 229. In this embodiment, when a specific elapsed time has elapsed from the detection of paper P by the paper sensor 229, it is determined that the reference deceleration start timing has been reached. The CPU 11a obtains a new deceleration start timing by multiplying this specific elapsed time by a coefficient or by adding a correction value, which will be described later, to this specific elapsed time.

[0077] When the CPU 11a controls the upstream transport mechanism 220 based on the newly obtained deceleration start timing, the deceleration start timing 11Y becomes earlier than the reference timing, as shown in FIG. 11(B). In this case, the timing at which the paper P reaches the gripper 42 is delayed. As a result, when the gripper 42 holds the paper P, the leading edge of the paper P is positioned at the originally intended reference position.

[0078] FIG. 11C shows a specific example of control of the upstream transport mechanism 220 when the closing timing is earlier than the original reference timing. In other words, FIG. 11C shows a specific example of control of the upstream transport mechanism 220 in the case where the position specified by the above position information is on the leading edge side of the paper P. In this embodiment, when the closing timing is earlier than the original reference timing, the CPU 11a makes the deceleration start timing 11Y later than the reference timing, as shown in FIG. 11(C).

[0079] More specifically, in this case, the CPU 11a also obtains a new deceleration start timing by multiplying the reference deceleration start timing of the registration roll 222 by a coefficient or by adding a correction value, which will be described later, to the reference deceleration start timing of the registration roll 222. More specifically, the CPU 11a obtains a new deceleration start timing by multiplying the specific elapsed time by a coefficient, or by adding a correction value (to be described later) to the specific elapsed time, in the same manner as described above.

[0080] When the CPU 11a controls the upstream transport mechanism 220 based on the newly obtained deceleration start timing, the deceleration start timing 11Y becomes later than the reference timing, as shown in FIG. 11C. In this case, the timing at which the paper P reaches the gripper 42 becomes earlier. As a result, when the gripper 42 holds the paper P, the leading edge of the paper P is positioned at the originally intended reference position.

[0081] In this embodiment, by changing the deceleration start timing of the registration roll 222 in this manner, the position of the sheet P when the gripper 42 holds the sheet P is changed. In other words, in this embodiment, a new deceleration start timing is set, and the deceleration start timing of the registration roll 222 is set to the new deceleration start timing, thereby changing the position of the paper P when the gripper 42 holds the paper P. As a result, the position of the paper P approaches the originally planned reference position, and the position of the image 100X formed on the paper P approaches the originally planned reference position.

[0082] As described above, in this embodiment, a plurality of grippers 42 are provided. The plurality of grippers 42 are disposed so that their positions in the movement direction of the chain 49 are different from each other. In this embodiment, the deceleration start timing is changed for each gripper 42. In this embodiment, as described above, the process of acquiring position information is performed for each gripper 42, and the acquired position information is registered in the secondary storage unit 91 in association with the corresponding gripper 42. In other words, in this embodiment, information on the closing timing is obtained for each gripper 42, and the obtained information on the closing timing is registered in the secondary storage unit 91 in a state in which it is associated with the corresponding gripper 42.

[0083] In this embodiment, when the paper P is sequentially held and transported by the grippers 42, information on the closing timing corresponding to the grippers 42 holding the paper P is obtained from the secondary storage unit 91. Then, the CPU 11a controls the upstream transport mechanism 220 that transports the paper P based on the information about the closing timing.

[0084] The CPU 11a controls the upstream transport mechanism 220 that transports the paper P to the gripper 42 for each gripper 42 based on information about the closing timing obtained for each of the multiple grippers 42. As a result, the deceleration start timing of the registration roll 222 is changed for each gripper 42, and the position of the paper P that reaches the gripper 42 approaches the reference position. In this embodiment, no matter which gripper 42 is used, the position of the image 100X formed on the paper P approaches the original reference position.

[0085] [Specific Processing of Gripper 42] The process of identifying the gripper 42 will now be described. In this embodiment, when the deceleration start timing of the registration roll 222 is changed, a process of identifying the gripper 42 located at the transport destination of the paper P transported by the registration roll 222 is performed. In this embodiment, based on the above-mentioned timing information registered in the secondary storage unit 91 in association with the identified gripper 42, the deceleration start timing for the paper P moving toward this gripper 42 is set. In other words, in this embodiment, the deceleration start timing for the paper P approaching the gripper 42 is set based on the position information of the test image on the test paper that is associated with the gripper 42 and registered in the secondary storage unit 91.

[0086] In this embodiment, the number of times that the encoder 293 (see FIG. 1) has been turned on is identified, and the gripper 42 that is about to hold the paper P is identified based on this number. More specifically, in this embodiment, the time when the home sensor 291 (see FIG. 1) turns on is set as a reference time, and the number of times that the encoder 293 has turned on since the reference time is specified. Then, based on the specified number of times, the gripper 42 that is about to hold the paper P is specified. Then, based on the timing information registered in association with the identified gripper 42, the deceleration start timing for the paper P heading toward the gripper 42 is set.

[0087] In this embodiment, as shown in FIG. 1, a home sensor 291 for identifying the phase of the chain 49 is provided on the movement path of the chain 49. Further, the chain 49 is provided with a first light blocking plate 292 through which the home sensor 291 performs detection. Furthermore, in this embodiment, an encoder 293 for detecting that the transfer cylinder 36 has made one rotation is provided at a position facing the outer periphery of the transfer cylinder 36. Furthermore, the transfer cylinder 36 is provided with a second light shielding plate 294 for detection by the encoder 293.

[0088] In this embodiment, the time when the first light shielding plate 292 reaches the home sensor 291 and the home sensor 291 turns on is set as a reference time, and the number of times the encoder 293 has turned on since this reference time is specified. In this embodiment, the number of times the encoder 293 has turned on is specified, which is the number of times the encoder 293 has turned on since the reference time. In this embodiment, the specified number of times is reset every time the home sensor 291 is turned on, and the count of the number of times is started from one every time the home sensor 291 is turned on.

[0089] In this embodiment, the number of times that the encoder 293 detects the second light shielding plate 294 is counted and specified after the home sensor 291 is turned on. Then, based on the identified number of times, it is identified which gripper 42 is currently holding the paper P.

[0090] A specific example will be given below to explain the case. Here, it is assumed that six grippers 42, namely a first gripper to a sixth gripper, are provided. In addition, here, a configuration is assumed in which the first gripper reaches the transfer cylinder 60 when the encoder 293 detects the second light blocking plate 294 for the first time.

[0091] In this configuration, if the number of times that the encoder 293 has been turned on since the reference time is, for example, 2, the CPU 11a determines that the gripper 42 attempting to hold the paper P at that time is the second gripper 42, that is, the second gripper. In this case, the CPU 11a acquires the above-mentioned position information registered in the secondary storage unit 91 in association with this second gripper. Then, based on this acquired position information, the upstream transport mechanism 220 that transports the paper P toward the second gripper 42 is controlled.

[0092] In this embodiment, the home sensor 291 is turned on every time the chain 49 makes one revolution. In other words, in this embodiment, the home sensor 291 detects the first light shielding plate 292 every time the chain 49 makes one revolution. Furthermore, in this embodiment, the number of times that the encoder 293 turns on from one time that the home sensor 291 turns on until the next time that the home sensor 291 turns on matches the number of grippers 42 that are installed.

[0093] Furthermore, in this embodiment, the length of the chain 49 is an integer multiple of the outer periphery of the transfer cylinder 36 . In this case, from when the home sensor 291 is turned on until the next time the home sensor 291 is turned on, the encoder 293 is turned on the same number of times as the number of installed grippers 42. In this embodiment, the gripper 42 is identified by identifying the number of times the encoder 293 is turned on.

[0094] [Control by the moving speed of the gripper 42] In addition, the upstream transport mechanism 220 may be controlled not only based on the timing information, but also based on information about the movement speed of the gripper 42 when the gripper 42 holds the paper P (hereinafter referred to as "speed information"). In this case, the CPU 11a controls the upstream transport mechanism 220 based on the timing information and the speed information.

[0095] When the speed information is also taken into consideration, the CPU 11a controls the upstream transport mechanism 220 so that the deceleration start timing varies depending on the moving speed specified by the speed information. More specifically, the CPU 11a controls the upstream transport mechanism 220 so that the deceleration start timing is delayed when the moving speed specified by the speed information is high, compared to when the moving speed is low.

[0096] For example, if the moving speed specified by the speed information is greater than a predetermined reference speed, when the paper P reaches the gripper 42, the gripper 42 may be located downstream of the originally scheduled reference position. In this case, the paper P may be delayed relative to the gripper 42. In this case, if the deceleration start timing is delayed as described above, the paper P is less likely to be delayed relative to the gripper 42.

[0097] Furthermore, when the moving speed specified by the speed information is low, the CPU 11a controls the upstream transport mechanism 220 so that the deceleration start timing is earlier than when the moving speed specified by the speed information is high. For example, if the moving speed identified by the speed information is smaller than a predetermined reference speed, when the paper P reaches the gripper 42, the gripper 42 will be located upstream of the originally planned reference position. In this case, the relative position of the paper P with respect to the gripper 42 will be located downstream of the originally intended reference position. In this case, if the deceleration start timing is made earlier as described above, the relative position of the paper P with respect to the gripper 42 approaches the originally intended reference position.

[0098] In other words, in this embodiment, the CPU 11a controls the upstream conveying mechanism 220 so that the timing at which the paper P conveyed by the upstream conveying mechanism 220 reaches the transfer position varies depending on the movement speed identified by the speed information. In this embodiment, the paper sheet P transported by the upstream transport mechanism 220 is delivered to the gripper 42 at a delivery position indicated by reference symbol 9X in FIG. In this embodiment, as described above, if the deceleration start timing is delayed or advanced, the timing at which the paper P transported by the upstream transport mechanism 220 reaches the transfer position will differ. This makes it difficult for the paper P to be delayed relative to the gripper 42, or for the relative position of the paper P with respect to the gripper 42 to be located downstream of the originally intended reference position.

[0099] In addition, the CPU 11a may control the upstream conveying mechanism 220 so that the movement speed of the paper P transported by the upstream conveying mechanism 220 when it reaches the gripper 42 differs depending on the movement speed specified by the speed information. More specifically, the CPU 11a may control the upstream conveying mechanism 220 so that the movement speed of the paper P transported by the upstream conveying mechanism 220 when it reaches the gripper 42 is faster when the movement speed identified by the speed information is high than when it is low.

[0100] More specifically, when the moving speed identified by the speed information is greater than a predetermined reference speed, the CPU 11a may control the upstream conveying mechanism 220 so that the conveying speed of the paper P by the registration roll 222 after the registration roll 222 decelerates is faster than when the moving speed is less than this reference speed. In this case, the conveying speed of the paper P, indicated by reference symbol 11R in FIGS. 11(A) to (C), increases, and in this case as well, the situation in which the paper P is delayed relative to the gripper 42 is less likely to occur, as in the case described above.

[0101] In addition, the CPU 11a may control the upstream conveying mechanism 220 so that the movement speed of the paper P transported by the upstream conveying mechanism 220 when it reaches the gripper 42 is slower than when the movement speed specified by the speed information is slower. More specifically, the CPU 11a may control the upstream conveying mechanism 220 so that, for example, when the moving speed identified by the speed information is smaller than a predetermined reference speed, the conveying speed of the paper P by the registration roll 222 after deceleration of the registration roll 222 is slower than when the moving speed identified by the speed information is greater than this reference speed. In this case, the conveying speed of the paper P, indicated by reference symbol 11R in FIGS. 11(A) to (C), decreases, and in this case, the relative position of the paper P with respect to the gripper 42 approaches the originally intended reference position.

[0102] The moving speed of the gripper 42 is determined based on, for example, the elapsed time from when the home sensor 291 (see FIG. 1) is turned on until the next time the home sensor 291 is turned on, and the circumferential length of the chain 49. In this case, the moving speed of the gripper 42 can be determined by dividing the circumferential length of the chain 49 by the elapsed time. Alternatively, for example, a dedicated speed sensor may be provided for detecting the movement speed of the chain 49 and the gripper 42, and the movement speed of the gripper 42 may be determined based on the output from this dedicated speed sensor.

[0103] [Explanation of processing flow] Fig. 12 is a flowchart showing an example of the flow of processing executed by the image forming apparatus 10. In the processing shown in Fig. 12, processing executed under a situation where the above-mentioned timing information has already been acquired will be described. In this embodiment, first, the CPU 11a outputs a control signal to start the movement of the chain 49 (step S101). Next, the CPU 11a outputs an instruction to start a job (step S102). Furthermore, the CPU 11a acquires speed information, which is information about the movement speed of the chain 49 (step S103). Next, the CPU 11a identifies the gripper 42 moving toward the delivery cylinder 60 (step S104). In this embodiment, the CPU 11a identifies the gripper 42 based on the number of times the encoder 293 is turned on, as described above.

[0104] Next, the CPU 11a reads and acquires the timing information corresponding to the gripper 42 identified in step S104 from the secondary storage unit 91 (step S105). Then, the CPU 11a sets the timing for starting deceleration of the paper P based on the speed information acquired in step S103 and the timing information acquired in step S105 (step S106).

[0105] More specifically, the CPU 11a generates, for example, a correction value for changing the deceleration start timing of the paper P based on the speed information and timing information. Then, the CPU 11a obtains a new deceleration start timing by adding this correction value to the reference deceleration start timing. In other words, the CPU 11a obtains a new deceleration start timing by adding this correction value to the above-mentioned specific elapsed time that serves as a reference. Here, the correction value may be not only a positive value but also a negative value.

[0106] A specific example will be given for explanation. Here, it is also assumed that six grippers 42, namely, a first gripper to a sixth gripper, are provided as the grippers 42. In addition, it is also assumed here that there is a discrepancy in the closing timing of the second gripper. Specifically, for the second gripper, it is assumed that the test image on the test paper is shifted 1 mm toward the rear end of the paper P. In addition, the conveying speed of the paper P before deceleration is assumed to be 500 mm / s. In other words, the conveying speed of the paper P by the upstream conveying mechanism 220, which is the conveying speed of the paper P before the registration roll 222 starts to decelerate, is assumed to be 500 mm / s. Further, it is assumed here that the movement speed of the gripper 42 is a reference movement speed.

[0107] Under these conditions, the closing timing of the second gripper is late, and in this case, a process is performed to advance the timing at which the sheet P starts to decelerate and delay the timing at which the sheet P reaches the second gripper. As a result, when the paper P is located at the reference position, the paper P is held by the second gripper, and the positional deviation of the image 100X formed on the paper P transported by the second gripper is reduced.

[0108] In this processing example, the correction value for the deceleration start timing is set to, for example, −2 (ms). In this processing example, this -2 (ms) is added to the reference deceleration start timing to obtain a new deceleration start timing. In this example, the following (Equation 1) is used to generate the above correction value for the deceleration start timing. (Formula 1) Correction value (ms) = deviation amount of test image on test paper (mm) / conveyance speed of paper P before deceleration of registration roll 222 (mm / s)

[0109] In this example, the deviation of the test image formed on the test paper held by the second gripper is −1 mm. In this example, the conveying speed of the paper P before the registration roll 222 starts to decelerate is 500 mm / s. Explaining with reference to FIGS. 11(A) to (C), the conveying speed of the paper P, indicated by reference numeral 11S, is 500 mm / s.

[0110] In this case, based on the above (Equation 1), the correction value is −2 (ms). In this case, as described above, −2 (ms) is added to the reference deceleration start timing to obtain a new deceleration start timing. In this embodiment, as described above, the deceleration start timing of the registration roll 222 is determined by the specific elapsed time. To obtain a new deceleration start timing, −2 (ms) is added to this specific elapsed time to obtain the new deceleration start timing.

[0111] In this embodiment, as described above, a situation may occur in which the moving speed of the gripper 42 differs from the predetermined reference speed. In this case, a correction value is generated based on the moving speed of the gripper 42 as well. Then, this correction value is added to the reference deceleration start timing to obtain a new deceleration start timing.

[0112] When the closing timing is different from the reference timing and the moving speed of the gripper 42 is different from the reference speed, two correction values ​​are generated: a correction value corresponding to the closing timing and a correction value corresponding to the moving speed of the gripper 42. In this case, each of these two correction values ​​is added to the reference deceleration start timing to obtain a new deceleration start timing. As described above, there are cases where the reference deceleration start timing is multiplied by a coefficient to obtain a new deceleration start timing. In this case, the reference deceleration start timing is multiplied by each of a coefficient corresponding to the closing timing and a coefficient corresponding to the moving speed of the gripper 42 to obtain a new deceleration start timing.

[0113] [Process for changing timing for starting transport of paper P] In the above, the case has been described where the position of the image 100X on the paper P is set to the originally planned reference position by changing the deceleration start timing of the paper P transported by the upstream transport mechanism 220. However, the present invention is not limited to this, and the position of the image 100X on the paper P may be set to the originally planned reference position by changing the timing at which the transport of the paper P starts. In this embodiment, as described above, the transport of paper P is started by retracting the movement regulating section 223 (see FIG. 9). However, by changing the timing of retracting the movement regulating section 223, the position of the image 100X on the paper P may be set to the originally planned reference position.

[0114] Specifically, for example, when the closing timing is delayed and the position of the image 100X on the paper P is located on the rear end side of the paper P, the retraction timing of the movement restriction part 223 is delayed from the reference timing. As a result, the paper P reaches the gripper 42 at a later timing. Also, for example, when the closing timing is early and the position of the image 100X on the paper P is located on the leading edge side of the paper P, the retraction timing of the movement restricting part 223 is made earlier than the reference timing. This allows the paper P to reach the gripper 42 at an earlier timing.

[0115] [Control of Gripper 42 Movement] In the above, an example has been described in which the upstream transport mechanism 220 is controlled. However, the present invention is not limited to this, and the displacement of the image 100X formed on the paper P may be reduced by controlling the movement of the gripper 42 holding the paper P. In this case, the CPU 11a controls the movement of the gripper 42 holding the paper sheet P, based on the above-mentioned timing information, which is information about the timing at which the gripper 42 holds the paper sheet P.

[0116] More specifically, in this case, the CPU 11a performs control to change the position in the movement direction of the gripper 42 that moves while holding the paper sheet P, in accordance with the timing specified by the timing information. More specifically, when the timing identified by the timing information is later than a predetermined reference timing, the CPU 11a displaces the gripper 42, which moves while holding the paper P, upstream in the movement direction of the gripper 42. Furthermore, when the timing specified by the timing information is earlier than a predetermined reference timing, the CPU 11a displaces the gripper 42, which moves while holding the paper P, downstream in the movement direction of the gripper 42.

[0117] FIG. 13 is a diagram showing another example of the configuration of the chain 49 and the gripper 42. In FIG. When changing the position of the grippers 42 in the movement direction, a movement mechanism 429 is provided for each gripper 42, as shown in FIG. 13, for moving the gripper 42 upstream and downstream in the movement direction of the gripper 42. The moving mechanism 429 is supported by a chain 49. Furthermore, a plurality of the moving mechanisms 429 are provided, the number of which corresponds to the number of the grippers 42.

[0118] The moving mechanism 429 is provided with a driving source such as a motor or a solenoid, and a moving unit that uses the driving force from the driving source to move the gripper 42. The moving unit uses existing technology such as a cam or a gear. The moving unit is not particularly limited. When the gripper 42 is moved to the upstream side or downstream side in the movement direction of the gripper 42, the movement mechanism 429 operates based on a control signal from the CPU 11a. As a result, the gripper 42 moves to the upstream side or downstream side in the movement direction of the gripper 42, as shown by the arrow 13A. It should be noted that the control signal from the CPU 11a to the moving mechanism 429 may be transmitted wirelessly instead of via a wire.

[0119] Additionally, the movement of the gripper 42 may be controlled so that the movement speed of the gripper 42 holding the paper P varies depending on the timing specified by the timing information. Specifically, in this case, the CPU 11a controls the movement of the gripper 42 so that the movement speed of the gripper 42 holding the paper P is slower when the timing specified by the timing information is late than when it is early. Specifically, in this case, the CPU 11a temporarily reduces the rotational speed of the transfer cylinder 36 when the gripper 42 holding the paper P moves toward the transfer position T, thereby controlling the movement of the gripper 42 so that the movement speed of the gripper 42 holding the paper P is reduced.

[0120] Furthermore, the CPU 11a controls the movement of the gripper 42 so that the movement speed of the gripper 42 holding the paper P is faster when the timing specified by the timing information is early than when it is late. Specifically, in this case, the CPU 11a temporarily increases the rotational speed of the transfer cylinder 36 when the gripper 42 holding the paper P moves toward the transfer position T, thereby controlling the movement of the gripper 42 so that the movement speed of the gripper 42 holding the paper P increases.

[0121] In this manner, when the moving speed of the gripper 42 holding the paper P is varied to bring the timing at which the paper P reaches the transfer position T closer to the reference timing, the paper transport mechanism 210 (see FIG. 1) and the transfer belt 22 are not linked. In other words, when the movement speed of the gripper 42 holding the paper P is varied to bring the timing at which the paper P reaches the transfer position T closer to the reference timing, the paper transport mechanism 210 and the transfer belt 22 are driven separately.

[0122] In a configuration in which the paper transport mechanism 210 and the transfer belt 22 are linked, even if the movement speed of the gripper 42 is increased or decreased by varying the movement speed of the gripper 42, the movement speed of the transfer belt 22 also increases or decreases accordingly. In this case, the positional relationship between the paper P and the image 100X on the transfer belt 22 does not change, and the positional deviation of the image 100X transferred onto the paper P is not reduced. In contrast, if the paper transport mechanism 210 and the transfer belt 22 are not linked, the position of the paper P relative to the image 100X reaching the transfer position T can be changed, and the position of the image 100X on the paper P can be brought closer to the originally intended reference position.

[0123] In addition, in the above process in which the position in the movement direction of gripper 42, which moves while holding paper P, is changed using movement mechanism 429 (see Figure 13), the movement speed of gripper 42 also changes temporarily. Furthermore, in the above process in which the position in the movement direction of gripper 42, which moves while holding paper P, is changed using movement mechanism 429, the average speed of gripper 42 from the time when gripper 42 holds paper P to the time when gripper 42 reaches transfer position T changes.

[0124] Therefore, in the above process of changing the position in the movement direction of the gripper 42 while holding the paper P using the movement mechanism 429, it can be said that the movement of the gripper 42 is controlled so that the movement speed of the gripper 42 holding the paper P is different. When performing a process of changing the position of the gripper 42 in the movement direction using the movement mechanism 429, the paper transport mechanism 210 and the transfer belt 22 may remain configured to be linked together, and even if they are configured to be linked together, the position of the paper P relative to the image 100X on the transfer belt 22 can be changed.

[0125] 〔others〕 Although the embodiment in which the gripper 42 is supported by the chain 49 has been described above, as described above, the gripper 42 may be supported by a belt or the like. Also, the gripper 42 may be attached to the outer periphery of a cylindrical member, and the gripper 42 may be supported by this cylindrical member. The cylindrical member can be regarded as a trunk-shaped member, and the gripper 42 may be attached to the outer periphery of the trunk-shaped member, and the gripper 42 may be supported by this trunk-shaped member. In this case, the gripper 42 moves by rotating this cylindrical member.

[0126] Even when the gripper 42 is supported by a belt or a cylindrical member, the position of the image 100X on the paper P may be shifted due to differences in the closing timing of the gripper 42, similar to the above. Even when the gripper 42 is supported by a belt or a cylindrical member, as described above, by controlling the upstream conveying mechanism 220 and controlling the movement of the gripper 42, it is possible to reduce the positional deviation of the image 100X on the paper P.

[0127] (Additional Note) (((1))) A conveying means for conveying a recording medium; a moving body that holds and moves the recording medium conveyed by the conveying means; a processor that controls the conveying means based on timing information that is information regarding the timing at which the moving body holds the recording medium; A recording medium transport device comprising: (((2))) The processor, controlling the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the moving body varies depending on the timing specified by the timing information; The recording medium transport device according to (((1))). (((3))) The processor, When the timing specified by the timing information is late, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is delayed compared to when the timing information is early. The recording medium transport device according to (((2))). (((4))) The processor, When the timing specified by the timing information is early, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is earlier than when the timing specified by the timing information is late. The recording medium transport device according to (((2))). (((5))) The processor, controlling the conveying means based on the timing information and speed information, which is information about a moving speed of the moving body when the moving body holds the recording medium; The recording medium transport device according to (((1))). (((6))) The processor, controlling the conveying means so that the moving speed of the recording medium conveyed by the conveying means when the recording medium reaches the moving body varies depending on the moving speed specified by the speed information; The recording medium transport device according to (((5))). (((7))) The recording medium conveyed by the conveying means is delivered to the moving body at a delivery position, The processor, controlling the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the delivery position varies depending on the moving speed specified by the speed information; The recording medium transport device according to (((5))). (((8))) The image forming apparatus further includes an image forming unit for forming an image on the recording medium that is moved while being held by the moving body, The processor, acquiring, as the timing information, position information which is information about a position on the recording medium of the image formed on the recording medium by the image forming means and a position in a moving direction of the recording medium, and controlling the conveying means based on the position information; A recording medium transport device according to any one of ((1)) to ((7)). (((9))) The processor, When the position specified by the position information is shifted toward the leading end side in the moving direction of the recording medium from a predetermined reference position, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is made earlier than when there is no shift. The recording medium transport device according to (((8))). (((10))) The processor, When the position specified by the position information is shifted toward the rear end side in the moving direction of the recording medium from a predetermined reference position, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is delayed compared to when there is no shift. The recording medium transport device according to (((8))). (((11))) The moving body is provided in plurality and is arranged so that the positions of the moving bodies in the moving direction are different from each other; The processor, controlling the conveying means for conveying the recording medium to each of the plurality of movable bodies based on the timing information acquired for each of the plurality of movable bodies; A recording medium transport device according to any one of ((1)) to ((10)). (((12))) A conveying means for conveying a recording medium; a moving body that holds and moves the recording medium conveyed by the conveying means; a processor that controls movement of the moving object holding the recording medium based on timing information that is information about a timing at which the moving object holds the recording medium; A recording medium transport device comprising: (((13))) The processor, controlling the movement of the moving body holding the recording medium so that the moving speed of the moving body varies according to the timing specified by the timing information; The recording medium transport device according to (((12))). (((14))) The processor, When the timing specified by the timing information is late, the movement of the moving body holding the recording medium is controlled so that the moving speed of the moving body is slower than when the timing specified by the timing information is early. The recording medium transport device according to (((13))). (((15))) The processor, controlling the movement of the moving body holding the recording medium so that the moving speed of the moving body is faster when the timing specified by the timing information is early than when the timing is late; The recording medium transport device according to (((13))). (((16))) The processor, performing control to change a position in a moving direction of the moving body, which moves while holding the recording medium, in accordance with the timing specified by the timing information; The recording medium transport device according to (((12))). (((17))) The processor, When the timing specified by the timing information is later than a predetermined reference, the moving object is displaced upstream in the moving direction of the moving object. The recording medium transport device according to (((16))). (((18))) The processor, When the timing specified by the timing information is earlier than a predetermined reference, the moving object is displaced downstream in the moving direction of the moving object. The recording medium transport device according to (((16))). (((19))) An image forming apparatus comprising a recording medium transport device that transports a recording medium and an image forming means that forms an image on the recording medium, the recording medium transport device being configured using any one of the recording medium transport devices described in (((1))) to (((18))).

[0128] According to the recording medium transport device of (((1))), it is possible to reduce the positional deviation in the transport direction of the recording medium transported by the moving body holding the recording medium, compared to a case where the recording medium is transported without taking into account the timing at which the moving body holding the recording medium holds the recording medium. According to the recording medium transport device of (((2))), the timing at which the recording medium reaches the moving body can be varied depending on the timing at which the moving body holds the recording medium. According to the recording medium transport device of (((3))), if the timing at which the moving body holds the recording medium is delayed, the timing at which the recording medium reaches the moving body can be delayed. According to the recording medium transport device of (((4))), if the timing at which the moving body holds the recording medium is early, the timing at which the recording medium reaches the moving body can be advanced. According to the recording medium transport device of (((5))), it is possible to reduce the positional deviation in the transport direction of the recording medium transported by the moving body holding the recording medium, compared to a case where the recording medium is transported without taking into account the moving speed of the moving body when holding the recording medium. According to the recording medium transport device of (((6))), the moving speed of the recording medium transported by the transport means when it reaches the moving body can be made to differ depending on the moving speed of the moving body. According to the recording medium transport device of (((7))), the timing at which the recording medium transported by the transport means reaches the transfer position can be varied depending on the moving speed of the moving body. According to the recording medium transporting device of (((8))), it is possible to control the transporting means when the timing at which the recording medium is held by the moving body differs from a standard, based on the position of an image formed by an image forming means that forms an image on the recording medium that is moved while being held by the moving body. According to the recording medium transporting device of (((9))), the position of the image formed on the recording medium can be brought closer to the reference position compared to a case in which the transporting means is not controlled so as to hasten the timing at which the recording medium transported by the transporting means reaches the moving body. According to the recording medium transporting device of (((10))), the position of the image formed on the recording medium can be brought closer to the reference position compared to a case in which the transporting means is not controlled so as to delay the timing at which the recording medium transported by the transporting means reaches the moving body. According to the recording medium transport device of (((11))), the transport of the recording medium by the transport means can be controlled for each moving body that holds and moves the recording medium transported by the transport means. According to the recording medium transport device of (((12))), it is possible to reduce the positional deviation in the transport direction of the recording medium transported by the moving body holding the recording medium, compared to a case in which the recording medium is transported without taking into account the timing at which the moving body holding the recording medium holds the recording medium. According to the recording medium transport device of (((13))), the moving speed of the moving body holding the recording medium can be made to differ depending on the timing at which the recording medium is held by the moving body. According to the recording medium transport device of (((14))), when the timing at which the moving body holds the recording medium is delayed, the moving speed of the moving body holding the recording medium can be reduced. According to the recording medium transport device of (((15))), when the timing at which the moving body holds the recording medium is early, the moving speed of the moving body holding the recording medium can be increased. According to the recording medium transport device of (((16))), the position in the movement direction of the moving body holding the recording medium can be changed depending on the timing at which the moving body holds the recording medium. According to the recording medium transport device of (((17))), when the timing at which the moving body holds the recording medium is delayed, the moving body holding the recording medium can be displaced upstream in the movement direction. According to the recording medium transport device of (((18))), when the timing at which the moving body holds the recording medium is early, the moving body holding the recording medium can be displaced downstream in the movement direction. According to the image forming device of (((19))), it is possible to reduce the positional deviation in the transport direction of the recording medium transported by the moving body holding the recording medium, compared to a case where the recording medium is transported without taking into account the timing at which the moving body holding the recording medium holds the recording medium. [Explanation of symbols]

[0129] 10: image forming apparatus, 11: image forming section, 11a: CPU, 16: control section, 42: gripper, 49: chain, 200: paper transport device, 220: upstream transport mechanism, P: paper

Claims

1. A conveying means for conveying a recording medium; a moving body that holds and moves the recording medium conveyed by the conveying means; a processor that controls the conveying means based on timing information that is information regarding the timing at which the moving body holds the recording medium; A recording medium transport device comprising:

2. The processor, controlling the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the moving body varies depending on the timing specified by the timing information; The recording medium transport device according to claim 1 .

3. The processor, When the timing specified by the timing information is late, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is delayed compared to when the timing information is early. The recording medium transport device according to claim 2 .

4. The processor, When the timing specified by the timing information is early, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is earlier than when the timing specified by the timing information is late. The recording medium transport device according to claim 2 .

5. The processor, controlling the conveying means based on the timing information and speed information, which is information about a moving speed of the moving body when the moving body holds the recording medium; The recording medium transport device according to claim 1 .

6. The processor, controlling the conveying means so that the moving speed of the recording medium conveyed by the conveying means when the recording medium reaches the moving body varies depending on the moving speed specified by the speed information; The recording medium transport device according to claim 5 .

7. The recording medium conveyed by the conveying means is delivered to the moving body at a delivery position, The processor, controlling the conveying means so that the timing at which the recording medium conveyed by the conveying means reaches the transfer position varies depending on the moving speed specified by the speed information; The recording medium transport device according to claim 5 .

8. The image forming apparatus further includes an image forming unit for forming an image on the recording medium that is moved while being held by the moving body, The processor, acquiring, as the timing information, position information which is information about a position on the recording medium of an image formed on the recording medium by the image forming means and a position in a moving direction of the recording medium, and controlling the conveying means based on the position information; The recording medium transport device according to claim 1 .

9. The processor, When the position specified by the position information is shifted toward the leading end side in the moving direction of the recording medium from a predetermined reference position, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is made earlier than when there is no shift. The recording medium transport device according to claim 8.

10. The processor, When the position specified by the position information is shifted toward the rear end side in the moving direction of the recording medium from a predetermined reference position, the conveying means is controlled so that the timing at which the recording medium conveyed by the conveying means reaches the moving body is delayed compared to when there is no shift. The recording medium transport device according to claim 8.

11. The moving body is provided in plurality and is arranged so that the positions of the moving bodies in the moving direction are different from each other; The processor, controlling the conveying means for conveying the recording medium to each of the plurality of movable bodies based on the timing information acquired for each of the plurality of movable bodies; The recording medium transport device according to claim 1 .

12. A conveying means for conveying a recording medium; a moving body that holds and moves the recording medium conveyed by the conveying means; a processor that controls movement of the moving object holding the recording medium based on timing information that is information about a timing at which the moving object holds the recording medium; A recording medium transport device comprising:

13. The processor, controlling the movement of the moving body holding the recording medium so that the moving speed of the moving body varies according to the timing specified by the timing information; The recording medium transport device according to claim 12.

14. The processor, When the timing specified by the timing information is late, the movement of the moving body holding the recording medium is controlled so that the moving speed of the moving body is slower than when the timing specified by the timing information is early. The recording medium transport device according to claim 13.

15. The processor, controlling the movement of the moving body holding the recording medium so that the moving speed of the moving body is faster when the timing specified by the timing information is early than when the timing is late; The recording medium transport device according to claim 13.

16. The processor, performing control to change a position in a moving direction of the moving body, which moves while holding the recording medium, in accordance with the timing specified by the timing information; The recording medium transport device according to claim 12.

17. The processor, When the timing specified by the timing information is later than a predetermined reference, the moving object is displaced upstream in the moving direction of the moving object. The recording medium transport device according to claim 16.

18. The processor, When the timing specified by the timing information is earlier than a predetermined reference, the moving object is displaced downstream in the moving direction of the moving object. The recording medium transport device according to claim 16.

19. 19. An image forming apparatus comprising a recording medium transport device for transporting a recording medium and an image forming means for forming an image on the recording medium, the recording medium transport device being configured by the recording medium transport device according to any one of claims 1 to 18.

Images