JP2015063398A - Carrier and image formation device equipped with carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrier and an image formation device equipped with the carrier, enabling imparting a sufficient sucking pressure for making a recording medium tightly fit a carrier to the recording medium independent of a size of the recording medium, preventing a rear end part of the recording medium from peeling from the carrier.SOLUTION: A carrier includes a cylinder part 85 containing an outer peripheral surface being a transportation surface for paper P (recording medium), a plurality of slots 92 (slot part) formed on the outer peripheral surface of the cylinder part 85, a plurality of air passages 96 which extends in an axial direction of the cylinder part 85, being formed in a circumferential direction on the outer peripheral part of the cylinder part 85, for communicating with the slots 92 (slot part), a vacuum chamber 108 connected to the plurality of air passages 96, a plurality of opening/closing valves 110 provided respectively between the vacuum chamber 108 and the plurality of passage openings, and a sucking pump 105 which is connected to the vacuum chamber 100 for sucking air.

Description

  The present invention relates to a conveyance body and an image forming apparatus including the conveyance body, and in particular, a conveyance body that adsorbs and conveys a recording medium by sucking air from a plurality of grooves formed on an outer peripheral surface of a cylindrical portion, and The present invention relates to an image forming apparatus including this conveyance body.

  In an ink jet recording apparatus that transports a sheet-like recording medium with a transport drum, in order not to damage the ink jet head, it is necessary to transport the recording medium in close contact with the transport drum without floating. Therefore, the recording medium is sucked and transported by the transport drum.

  Patent Document 1 discloses a system for transporting a recording medium in which the outer peripheral surface of the cylindrical portion serves as a transport surface for the recording medium, and a plurality of grooves are formed on the outer peripheral surface of the cylindrical portion. An air passage extending in the axial direction of the cylindrical portion is formed in the outer peripheral portion, and one passage opening of the air passage is closed and communicated with the groove portion. Further, it is disclosed that suction force acts on the outer peripheral surface of the cylindrical portion through a groove portion that is sucked by air in the air passage by the suction member and communicates with the air passage.

  Further, Patent Document 2 includes a medium holding unit having a plurality of adsorption grooves that adsorb a sheet-like medium, and an adsorption pressure generating unit that communicates with the plurality of adsorption grooves and generates an adsorption pressure in each adsorption groove. It is disclosed that among the plurality of suction grooves, the suction force of the suction groove that sucks the end portion of the medium is made stronger than the suction force of the suction groove that sucks the center portion of the medium.

JP 2009-242064 A JP 2010-158812 A

  When the recording medium is sucked and transported by the transport drum, the recording medium having a thickness of 0.2 mm or more, particularly 0.3 mm or more is strong, that is, has high rigidity, and is difficult to follow the curvature of the transport drum. The rear end is easy to peel off from the transport drum.

  Therefore, when a recording medium that is strong, that is, has a high rigidity, is transported in close contact by drum transport using suction holes, in order to transport the rear end of the recording medium by suction without peeling, the recording medium has a high height toward the rear end. Adsorption pressure is required.

  In addition, in order to correspond to the sizes of a plurality of types of recording media, a large number of suction holes are provided in accordance with the maximum size, and when a large number of suction holes are sucked by a common pump, a small size recording medium is used. Sometimes, an open suction hole exists, and air leaks from the open suction hole, which leads to improper fixing of the recording medium due to insufficient suction pressure.

  That is, in the configurations of Patent Document 1 and Patent Document 2, when a small-sized recording medium is used, there is a suction hole that is always open, so that the suction pressure applied to the recording medium at the time of suction reaches the necessary suction pressure. However, there is a problem that the rear end of the recording medium is peeled off.

  The present invention has been made in view of such circumstances, and can apply a sufficient adsorption pressure to the recording medium to bring the recording medium into close contact with the conveyance body, regardless of the size of the recording medium. It is an object of the present invention to provide a transport body capable of preventing the rear end portion from being peeled from the transport body, and an image forming apparatus including the transport body.

  In order to achieve the above object, the present invention is a conveyance body that rotates and conveys a recording medium, and has a cylindrical portion having an outer peripheral surface serving as a recording medium conveyance surface and a plurality of outer peripheral surfaces formed on the cylindrical portion. A plurality of air passages that extend in the axial direction of the cylindrical portion, are formed along the circumferential direction of the cylindrical portion along the circumferential direction, communicate with the groove portions, a vacuum chamber connected to the plurality of air passages, and a vacuum chamber And a plurality of open / close valves provided between the plurality of air passages and a suction pump connected to the vacuum chamber and sucking air.

  Since the air passage communicating with the groove portion extending in the axial direction is provided and the open / close valves are provided in the plurality of air passages, the suction area can be switched depending on the length of the recording medium in the transport direction. Then, by opening and closing the open / close valve according to the size of the recording medium, a high adsorption pressure can be applied regardless of the size of the recording medium, so that the trailing edge of the recording medium can be prevented from peeling off.

  In the present embodiment, it is preferable to include a control unit that switches opening and closing of each of the plurality of opening / closing valves based on the length of the recording medium in the conveyance direction.

  In this embodiment, the control means opens and closes each of the open / close valves based on the input length in the conveyance direction of the recording medium, and forms a groove for adsorbing the recording medium on the outer peripheral surface of the cylindrical portion in the vacuum chamber. It is preferable to make it communicate with.

  The operation efficiency can be improved by inputting the size of the recording medium on the operation screen and automatically controlling the opening / closing of the opening / closing valve based on the input data.

  In the present embodiment, it is preferable that the outer peripheral surface of the cylindrical portion further includes a holding portion that restricts the movement of the leading end portion of the recording medium and determines the position of the leading end portion.

  Since the holding portion is provided on the outer peripheral surface of the cylindrical portion, the position of the leading end portion of the recording medium in the conveyance body can be determined. Therefore, the opening / closing of the opening / closing valve can be easily controlled by the length in the conveyance direction of the recording medium. It can be carried out. Therefore, peeling of the rear end portion of the recording medium can be prevented.

  In the present embodiment, it is preferable that a holding portion for holding and transporting a plurality of recording media is provided on the outer peripheral surface of the cylindrical portion, and the opening and closing valves are respectively opened and closed with respect to the transport areas of the plurality of recording media.

  In order to secure the conveyance speed, it is important for the conveyance body to shorten the interval between the continuous recording media. When the conveyance body is adsorbed to the rear end of the recording medium, it starts to adsorb the front end of the next recording medium. Preferably it is. Therefore, it is preferable to have a holding unit that holds and transports a plurality of recording media. In addition, it is preferable that the open / close valve is opened and closed in each of a plurality of transport areas in which a plurality of recording media cover the transport body.

  In this embodiment, it is preferable to have an adsorbing sheet that closes the groove in both widths outside the width direction of the recording medium to be conveyed.

  The suction area is switched depending on the length of the recording medium in the conveyance direction by providing an air passage that is closed at one passage port extending in the axial direction and that is provided with an open / close valve at the other passage port. However, since the grooves on both widths outside the width of the recording medium to be conveyed are open, the suction force to the recording medium is reduced. Therefore, it is preferable to have an adsorption sheet that closes the grooves on both widths outside the width of the recording medium to be conveyed.

  In this embodiment, it is preferable to have a suction sheet provided with a suction region applied to the rear end of the recording medium on which the suction force by the groove is conveyed.

  When there is no groove at the position of the rear end of the recording medium, the recording medium has an adsorption sheet that expands the adsorption area so that the adsorption force by the groove is applied to the rear end of the recording medium to be conveyed. It is possible to further prevent peeling of the rear end portion.

  In this embodiment, the thickness of the recording medium is preferably 0.2 mm or more and 0.8 mm or less. More preferably, the thickness of the recording medium is 0.3 mm or more.

  This embodiment is particularly effective for a stiff recording medium in which the thickness of the recording medium is 0.2 mm or more and 0.8 mm or less.

  In this embodiment, the adsorption pressure applied to the recording medium is preferably −60 kPa or less and −80 kPa or more.

  In the case of tightly conveying a stiff recording medium by drum conveyance by adsorption, in order to adsorb and convey the trailing end of the recording medium without peeling, the adsorption pressure applied to the recording medium requires a high adsorption pressure of −60 kPa to −80 kPa. It is. In this embodiment, the adsorption pressure applied to the recording medium can be suitably −60 kPa or less and −80 kPa or more.

  According to the present invention, regardless of the size of the recording medium, it is possible to apply a sufficient adsorption pressure to the recording medium to bring the recording medium into close contact with the conveying body, and the separation of the trailing end of the recording medium from the conveying body. It is possible to provide a transport body that can prevent the image forming apparatus and an image forming apparatus including the transport body.

Schematic showing the overall configuration of an inkjet recording apparatus to which the present invention is applied Block diagram showing schematic configuration of control system of inkjet recording apparatus The perspective view of embodiment of the carrier concerning the present invention Sectional drawing which shows the long groove and through-hole of the conveyance body which concern on this invention The schematic which looked at the embodiment of the conveyance object concerning the present invention from the top Schematic of the second embodiment of the carrier according to the present invention as seen from above Schematic of the third embodiment of the carrier according to the present invention as seen from above

  Hereinafter, preferred embodiments of an ink jet recording apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

"overall structure"
FIG. 1 is a schematic diagram showing the overall configuration of an ink jet recording apparatus in which a carrier according to the present invention is incorporated.

  An inkjet recording apparatus 10 shown in FIG. 1 is a recording apparatus that records an image on a sheet of paper P using an aqueous ink (an ink containing water as a solvent) by an inkjet method. The ink jet recording apparatus 10 includes a paper feeding unit 20 that feeds the paper P, and a processing liquid application unit 30 that applies a predetermined processing liquid to the recording surface of the paper P. Further, the ink jet recording apparatus 10 ejects ink droplets of cyan (C), magenta (M), yellow (Y), and black (K) colors onto the recording surface of the paper P with an ink jet head, thereby forming a color image. An image recording unit 40 for drawing is provided. Further, the ink jet recording apparatus 10 includes an ink drying unit 50 that dries ink droplets ejected onto the paper P, a fixing unit 60 that fixes an image recorded on the paper P, and a collection unit 70 that collects the paper P. .

  The processing liquid application unit 30, the image recording unit 40, the ink drying unit 50, and the fixing unit 60 are each provided with a processing liquid application drum 31, an image recording drum 41, an ink drying drum 51, as conveying means for the paper P. A fixing drum 61 is provided. The sheet P is fed to the processing liquid application unit 30, the image recording unit 40, the ink drying unit 50, and the fixing unit 60 by the processing liquid application drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61. Each part is conveyed. That is, the treatment liquid application drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61 function as a transport drum.

  The treatment liquid application drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61 are formed corresponding to the sheet width, and are driven by a motor (not shown) to rotate (counterclockwise in FIG. 1). To rotate). A gripper G is provided on each of the peripheral surfaces of the treatment liquid applying drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61, and the leading end of the paper P is gripped by the gripper G. Are transported. In this example, the grippers G are provided at two locations (at intervals of 180 °) on the peripheral surfaces of the treatment liquid applying drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61, and one rotation is performed. Two sheets of paper P can be conveyed.

  In addition, a large number of suction holes are formed on the peripheral surfaces of the treatment liquid application drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61. The surface opposite to the surface) is vacuum-sucked and held on the outer peripheral surface of each of the processing liquid applying drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61.

  Transfer cylinders 80, 90, and 100 are disposed between the processing liquid application unit 30 and the image recording unit 40, between the image recording unit 40 and the ink drying unit 50, and between the ink drying unit 50 and the fixing unit 60, respectively. Yes. The paper P is conveyed between the respective parts by the transfer cylinders 80, 90, 100.

  Each of the transfer cylinders 80, 90, and 100 includes transfer cylinder main bodies 81, 91, and 101 configured by a frame, and a gripper G provided on the transfer cylinder main bodies 81, 91, and 101. The transfer drum main bodies 81, 91, 101 are formed corresponding to the paper width, and are driven to rotate by a motor (not shown) and rotate (clockwise in FIG. 1). Thereby, the gripper G rotates on the same circumference. The paper P is transported with the gripper G gripping the leading end. In this example, the pair of grippers G are arranged at symmetrical positions with the rotation axis in between, and are configured to hold and convey two sheets of paper in one rotation.

  Under the transfer cylinders 80, 90, 100, arc-shaped guide plates 83, 93, 103 are arranged along the transport path of the paper P. The paper P conveyed by the transfer cylinders 80, 90, 100 is conveyed while the back surface (the surface opposite to the recording surface) is guided by the guide plates 83, 93, 103.

  Further, dryers 84, 94, and 104 that blow hot air toward the paper P conveyed by the transfer cylinder 80 are disposed inside the transfer cylinders 80, 90, and 100. The hot air blown from the dryers 84, 94, 104 is blown against the recording surface of the paper P conveyed by the transfer cylinders 80, 90, 100.

  The paper P fed from the paper feeding unit 20 is transferred to the processing liquid application drum 31 which is a transport drum of the processing liquid application unit 30, and is transferred from the processing liquid application drum 31 through the transfer drum 80 to the image recording unit 40. The image is transferred to the image recording drum 41 which is a transport drum. Then, the ink is transferred from the image recording drum 41 via the transfer drum 90 to the ink drying drum 51 which is the transfer drum of the ink drying unit 50, and is transferred from the ink drying drum 51 via the transfer drum 100 as the transfer drum of the fixing unit 60. Passed to the fixing drum 61. Then, the toner is delivered from the fixing drum 61 to the collecting unit 70. In this series of conveyance processes, the paper P is subjected to necessary processing, and an image is formed on the recording surface.

  The treatment liquid application drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61 convey the paper P with its recording surface facing outward, and transfer cylinders 80, 90, and 100 are The paper P is conveyed with its recording surface facing inward.

  Hereinafter, the configuration of each part of the inkjet recording apparatus 10 of the present embodiment will be described in detail.

<Paper Feeder>
The paper feeding unit 20 includes a paper feeding device 21, a paper feeding tray 22, and a transfer cylinder 23, and continuously feeds the sheets P one by one to the processing liquid application unit 30.

  The paper feeding device 21 feeds the paper P stacked in a magazine (not shown) one by one to the paper feeding tray 22 one by one from the top.

  The paper feed tray 22 sends out the paper P fed from the paper feeder 21 toward the transfer cylinder 23.

  The transfer cylinder 23 receives the paper P delivered from the paper feed tray 22, transports it along a predetermined transport path, and transfers it to the processing liquid application drum 31 of the processing liquid application unit 30.

  As the paper P, a general-purpose recording paper (recording medium) that is not an inkjet dedicated paper is used.

<Processing liquid application part>
The processing liquid application unit 30 applies a predetermined processing liquid to the recording surface of the paper P. The treatment liquid application unit 30 includes a treatment liquid application drum 31 as a conveyance drum that conveys the paper P, and a treatment liquid application device that applies a predetermined treatment liquid to the recording surface of the paper P conveyed by the treatment liquid application drum 31. 32.

  The treatment liquid application drum 31 receives the paper P from the transfer drum 23 of the paper supply unit 20 (holds and receives the leading edge of the paper P with the gripper G), and rotates to convey the paper P.

  The treatment liquid application device 32 applies a treatment liquid having a function of aggregating the color material in the ink onto the recording surface of the paper P conveyed by the treatment liquid application drum 31. The treatment liquid application device 32 is constituted by, for example, a coating device that applies a treatment liquid to a roller, and presses and contacts the application roller with the treatment liquid applied to the peripheral surface against the surface of the paper P, thereby recording the recording surface of the paper P. The treatment liquid is applied to Even when a general-purpose recording sheet is used by applying such a processing liquid to the recording surface of the paper P in advance and ejecting ink onto the recording surface of the paper P to which the processing liquid has been applied, Feathering and bleeding can be suppressed, and high-quality recording can be performed. In addition to the coating device, the treatment liquid application device 32 may be configured to be applied using a droplet discharge head similar to an inkjet head described later, or configured to be applied by spraying.

  According to the treatment liquid application unit 30 configured as described above, the paper P is conveyed along a predetermined conveyance path by the treatment liquid application drum 31, and the treatment liquid is applied from the treatment liquid application device 32 to the recording surface during the conveyance process. Is done. The paper P with the treatment liquid applied to the recording surface is then transferred from the treatment liquid application drum 31 to the transfer cylinder 80 at a predetermined position.

  Here, as described above, a dryer 84 is installed inside the transfer drum 80, and hot air is blown out toward the guide plate 83. The sheet P is blown with hot air on the recording surface in the process of being conveyed from the processing liquid applying unit 30 to the image recording unit 40 by the transfer cylinder 80, and the processing liquid applied to the recording surface is dried (processing liquid). The solvent component therein is removed by evaporation).

<Image recording unit>
The image recording unit 40 ejects ink droplets of C, M, Y, and K colors on the recording surface of the paper P, and draws a color image on the recording surface of the paper P. The image recording unit 40 presses an image recording drum 41 as a transport drum for transporting the paper P and a recording surface of the paper P transported by the image recording drum 41, and the back surface of the paper P is pressed by the image recording drum 41. A sheet pressing roller 42 that is in close contact with the peripheral surface, and inkjet heads 44C, 44M, 44Y, and 44K that discharge ink droplets of C, M, Y, and K colors onto the sheet P are provided.

  The image recording drum 41 receives the paper P from the transfer cylinder 80 and rotates to convey the paper P. At this time, as described above, the paper P is conveyed while being held by suction on the outer peripheral surface of the image recording drum 41. Therefore, the sheet P is on the conveying surface which is an arcuate surface (the area from receiving the sheet P from the transfer cylinder 80 to delivering the sheet P to the transfer cylinder 90) defined by the outer peripheral surface of the image recording drum 41. It is transported on the transport route set to. Note that the conveyance path passes through the center of the image recording drum 41 and is set corresponding to the width of the paper P.

  The sheet pressing roller 42 is installed in the vicinity of the sheet receiving position of the image recording drum 41 (the position where the sheet P is received from the transfer drum 80). It is pressed against the circumferential surface. The sheet P transferred from the transfer cylinder 80 to the image recording drum 41 is nipped by passing through the sheet pressing roller 42, and the back surface is in close contact with the outer peripheral surface of the image recording drum 41.

  The four inkjet heads 44C, 44M, 44Y, and 44K are arranged at regular intervals along the transport path of the paper P. The inkjet heads 44C, 44M, 44Y, and 44K are constituted by line heads corresponding to the paper width, and ink droplets of corresponding colors are directed toward the image recording drum 41 from the nozzle rows formed on the nozzle surfaces. Discharge.

  According to the image recording unit 40 configured as described above, the paper P is transported along a predetermined transport path by the image recording drum 41. The paper P transferred from the transfer cylinder 80 to the image recording drum 41 is first nipped by the paper pressing roller 42 and brought into close contact with the outer peripheral surface of the image recording drum 41. Next, ink droplets of the respective colors C, M, Y, and K are ejected from the inkjet heads 44C, 44M, 44Y, and 44K onto the recording surface, and a color image is drawn on the recording surface.

  Here, in the ink jet recording apparatus 10 of this example, water-based ink in which a thermoplastic resin is dispersed in ink is used for each color. Even when such water-based ink is used, since the predetermined processing liquid is applied to the paper P as described above, high-quality recording is performed without causing feathering or bleeding. be able to.

  The paper P on which the image is drawn is transferred to the transfer cylinder 90, conveyed along a predetermined transfer path by the transfer cylinder 90, and transferred to the ink drying drum 51 of the ink drying unit 50. As described above, the transfer drum 90 is provided with the dryer 94 therein, and hot air is blown out toward the guide plate 93. The ink drying process is performed in the ink drying unit 50 at the subsequent stage, but the paper P is also subjected to the drying process when being conveyed by the transfer cylinder 90.

  Although not shown, the image recording unit 40 includes a maintenance unit that performs maintenance of the inkjet heads 44C, 44M, 44Y, and 44K. The inkjet heads 44C, 44M, 44Y, and 44K are necessary. Accordingly, it is configured to move to the maintenance unit and receive the required maintenance.

<Ink drying section>
The ink drying unit 50 dries the liquid component remaining on the paper P after image recording. The ink drying unit 50 includes an ink drying drum 51 that is a transport drum that transports the paper P, and an ink drying device 52 that performs a drying process on the paper P transported by the ink drying drum 51.

  The ink drying drum 51 receives the paper P from the transfer cylinder 90 and rotates to convey the paper P.

  The ink drying device 52 is constituted by, for example, a dryer (in this example, constituted by three dryers arranged along the conveyance path of the paper P), and hot air is directed toward the paper P conveyed by the ink drying drum 51. To dry the ink (evaporate the liquid component present on the paper).

  According to the ink drying unit 50 configured as described above, the paper P is conveyed by the ink drying drum 51. Then, hot air is blown from the ink drying device 52 onto the recording surface during the conveyance process, and the ink applied to the recording surface is dried.

  The paper P that has passed through the ink drying device 52 is then transferred from the ink drying drum 51 to the transfer cylinder 100 at a predetermined position. Then, the paper is transported along a predetermined transport path by the transfer drum 100 and transferred to the fixing drum 61 of the fixing unit 60.

  In addition, as described above, the dryer 104 is installed in the transfer drum 100, and hot air is blown out toward the guide plate 103. Therefore, the paper P is also subjected to a drying process when it is conveyed by the transfer drum 100.

<Fixing part>
The fixing unit 60 heats and presses the paper P to fix the image recorded on the recording surface. The fixing unit 60 includes a fixing drum 61 that is a transport drum that transports the paper P, heat rollers 62 and 63 that apply heat and pressure to the paper P transported by the fixing drum 61, and the temperature of the paper P after recording. And an in-line sensor 64 for detecting a humidity and the like and capturing a recorded image.

  The fixing drum 61 receives the paper P from the transfer cylinder 100 and rotates to convey the paper P.

  The heat rollers 62 and 63 heat and press the ink applied to the recording surface of the paper P, thereby welding the thermoplastic resin dispersed in the ink and forming a film of the ink. At the same time, deformation such as cockling and curling generated on the paper P is corrected. Each of the heat rollers 62 and 63 is formed with substantially the same width as the fixing drum 61 and is heated to a predetermined temperature by a built-in heater. Further, the heat rollers 62 and 63 are pressed and brought into contact with the peripheral surface of the fixing drum 61 with a predetermined pressing force by a pressing unit (not shown). The sheet P passes through the heat rollers 62 and 63 and is heated and pressed by the heat rollers 62 and 63.

  The in-line sensor 64 includes a thermometer, a hygrometer, a CCD line sensor, and the like, detects the temperature, humidity, and the like of the paper P conveyed by the fixing drum 61 and captures an image recorded on the paper P. Based on the detection result of the in-line sensor 64, abnormalities in the apparatus, defective ejection of the head, and the like are checked.

  According to the fixing unit 60 configured as described above, the paper P is transported by the fixing drum 61, and in the transport process, the heat rollers 62 and 63 are pressed against the recording surface to be heated and pressurized. As a result, the thermoplastic resin dispersed in the ink is welded to form a film of the ink. At the same time, the deformation generated in the paper P is corrected.

  Thereafter, the sheet P subjected to the fixing process is transferred from the fixing drum 61 to the collecting unit 70 at a predetermined position.

<Recovery Department>
The collection unit 70 collects and collects the sheets P on which a series of recording processes have been performed on the stacker 71. The collection unit 70 receives the paper P collected from the fixing drum 61 and the stacker 71 that collects the paper P from the fixing drum 61. 72.

  The paper P fixed by the fixing unit 60 is transferred from the fixing drum 61 to the paper discharge conveyor 72, conveyed to the stacker 71 by the paper discharge conveyor 72, and collected in the stacker 71.

<Control system>
FIG. 2 is a block diagram showing a schematic configuration of a control system of the inkjet recording apparatus 10 of the present embodiment.

  As shown in the figure, the inkjet recording apparatus 10 includes a system controller 200, a communication unit 201, an image memory 202, a conveyance control unit 203, a paper feed control unit 204, a processing liquid application control unit 205, an image recording control unit 206, an ink A drying control unit 207, a fixing control unit 208, a collection control unit 209, an operation unit 210, a display unit 211, and the like are provided.

  The system controller 200 functions as a control unit that performs overall control of each unit of the inkjet recording apparatus 10 and also functions as a calculation unit that performs various calculation processes. The system controller 200 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and operates according to a predetermined control program. The ROM stores a control program executed by the system controller 200 and various data necessary for control.

  The communication unit 201 includes a required communication interface and transmits / receives data to / from a host computer connected to the communication interface.

  The image memory 202 functions as a temporary storage unit for various data including image data, and data is read and written through the system controller 200. Image data captured from the host computer via the communication unit 201 is stored in the image memory 202.

  The conveyance control unit 203 includes a treatment liquid application drum 31, an image recording drum 41, and an ink drying unit which are conveyance drums for conveying the paper P in the processing liquid application unit 30, the image recording unit 40, the ink drying unit 50, and the fixing unit 60. The driving of the drum 51, the fixing drum 61, and the transfer drums 80, 90, 100 is controlled.

  That is, the conveyance control unit 203 controls driving of the motor that drives each of the processing liquid application drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61. The opening and closing of the gripper G provided in each of the drum 41, the ink drying drum 51, and the fixing drum 61 is controlled.

  Similarly, the conveyance control unit 203 controls the driving of the motors that drive the transfer cylinders 80, 90, and 100, and controls the opening and closing of the gripper G provided in the transfer cylinders 80, 90, and 100.

  Further, the processing liquid application drum 31, the image recording drum 41, the ink drying drum 51, and the fixing drum 61 are provided with a mechanism for sucking and holding the paper P on the peripheral surface. Controls the drive of the suction holding mechanism. For example, in the present embodiment, since the sheet P is vacuum-sucked, the driving of the vacuum pump as the negative pressure generating unit is controlled.

  Further, since each of the transfer cylinders 80, 90, 100 is provided with the dryers 84, 94, 104, the transport control unit 203 controls the driving (heating amount and blowing amount).

  The processing liquid application drum 31, the image recording drum 41, the ink drying drum 51, the fixing drum 61, and the transfer cylinders 80, 90, and 100 are driven in accordance with commands from the system controller 200.

  The paper feed control unit 204 controls the drive of each unit (the paper feed device 21, the transfer drum 23, etc.) constituting the paper feed unit 20 in accordance with a command from the system controller 200.

  The processing liquid application control unit 205 controls driving of each unit (processing liquid application device 32 and the like) constituting the processing liquid application unit 30 in accordance with a command from the system controller 200.

  The image recording control unit 206 controls driving of each unit (paper pressing roller 42, ink jet heads 44C, 44M, 44Y, 44K, etc.) constituting the image recording unit 40 in accordance with a command from the system controller 200.

  The ink drying control unit 207 controls driving of each unit (such as the ink drying device 52) constituting the ink drying unit 50 in accordance with a command from the system controller 200.

  The fixing control unit 208 controls driving of each unit (the heat rollers 62 and 63, the inline sensor 64, etc.) constituting the fixing unit 60 in accordance with a command from the system controller 200.

  The collection control unit 209 controls the drive of each unit (the paper discharge conveyor 72 and the like) constituting the collection unit 70 in response to a command from the system controller 200.

  The operation unit 210 includes necessary operation means (for example, operation buttons, a keyboard, a touch panel, and the like), and outputs operation information input from the operation means to the system controller 200. The system controller 200 executes various processes in accordance with the operation information input from the operation unit 210.

  The display unit 211 includes a required display device (for example, an LCD panel or the like), and displays required information on the display device in response to a command from the system controller 200.

  Further, as described above, the image data to be recorded on the paper P is taken into the inkjet recording apparatus 10 from the host computer via the communication unit 201 and stored in the image memory 202. The system controller 200 performs necessary signal processing on the image data stored in the image memory 202 to generate dot data, and controls the driving of each inkjet head of the image recording unit 40 according to the generated dot data. An image represented by the image data is recorded on a sheet.

  The dot data is generally generated by performing color conversion processing and halftone processing on image data. The color conversion process is a process of converting image data expressed in sRGB or the like (for example, RGB 8-bit image data) into ink amount data of each color of ink used in the inkjet recording apparatus 10 (in this example, C, It is converted into ink amount data for each color of M, Y, and K.) The halftone process is a process of converting the ink amount data of each color generated by the color conversion process into dot data of each color by a process such as error diffusion.

  The system controller 200 performs color conversion processing and halftone processing on the image data to generate dot data for each color. Then, according to the generated dot data of each color, the drive of the corresponding ink jet head is controlled to record the image represented by the image data on the paper.

<Recording operation>
Next, a recording operation by the inkjet recording apparatus 10 will be described.

  When a paper feed command is output from the system controller 200 to the paper feeding device 21, the paper P is fed from the paper feeding device 21 to the paper feeding tray 22. The paper P fed to the paper feed tray 22 is transferred to the processing liquid application drum 31 of the processing liquid application unit 30 via the transfer cylinder 23.

  The paper P delivered to the treatment liquid application drum 31 is conveyed by the treatment liquid application drum 31 along a predetermined conveyance path, passes through the treatment liquid application device 32 in the conveyance process, and the treatment liquid is applied to the recording surface. The

  The sheet P to which the processing liquid is applied is transferred from the processing liquid applying drum 31 to the transfer cylinder 80, transported along a predetermined transport path by the transfer cylinder 80, and transferred to the image recording drum 41 of the image recording unit 40. . Then, hot air is blown onto the recording surface from a dryer 84 installed inside the transfer drum 80 in the course of conveyance by the transfer drum 80, and the treatment liquid applied to the recording surface is dried.

  The paper P transferred from the transfer cylinder 80 to the image recording drum 41 first passes through the paper pressing roller 42, is nipped by the paper pressing roller 42, and is brought into close contact with the outer peripheral surface of the image recording drum 41. CMYK ink droplets are ejected from each of the inkjet heads 44C, 44M, 44Y, 44K. Thereby, a color image is drawn on the recording surface. Thereafter, the paper P on which the image is drawn is transferred from the image recording drum 41 to the transfer cylinder 90.

  The paper P delivered to the transfer cylinder 90 is conveyed along a predetermined conveyance path by the transfer cylinder 90 and is transferred to the ink drying drum 51 of the ink drying unit 50. Then, hot air is blown onto the recording surface from a dryer 94 installed inside the transfer cylinder 90 during the conveyance process, and the ink applied to the recording surface is dried.

  The paper P delivered to the ink drying drum 51 is transported through a predetermined transport path by the ink drying drum 51, and hot air is blown from the ink drying device 52 onto the recording surface in the course of transporting, and the liquid remaining on the recording surface. The ingredients are dried.

  The dried paper P is transferred from the ink drying drum 51 to the transfer drum 100, transferred along a predetermined transfer path, and transferred to the fixing drum 61 of the fixing unit 60. Then, hot air is blown to the recording surface from the dryer 104 installed inside the transfer drum 100 in the course of conveyance by the transfer drum 100, and the ink applied to the recording surface is further dried.

  The paper P delivered to the fixing drum 61 is transported along a predetermined transport path by the fixing drum 61, and is heated and pressed by the heat rollers 62 and 63 in the transport process, and the image recorded on the recording surface is fixed. The Thereafter, the paper P is transferred from the fixing drum 61 to the paper discharge conveyor 72 of the collecting unit 70, conveyed to the stacker 71 by the paper discharge conveyor 72, and discharged into the stacker 71.

  As described above, in the ink jet recording apparatus 10 of the present embodiment, the paper P is transported by drum, and in the transport process, the processing liquid is applied to the paper P, the processing liquid is dried, the ink droplets are ejected, and the drying is performed. Each process of fixing is performed, and a predetermined image is recorded on the paper P.

<Conveyor>
Next, the conveyance body (conveyance drum) according to the embodiment of the present invention will be described.

  As shown in FIG. 1, in the inkjet recording apparatus 10, the processing liquid application unit 30, the image recording unit 40, the ink drying unit 50, and the fixing unit 60 each have a processing liquid application drum 31, an image as a conveyance body for paper P. The recording drum 41, the ink drying drum 51, and the fixing drum 61 are used. The conveyance body according to the embodiment of the present invention will be described as being applied to the image recording drum 41 of the image recording unit 40. Since the image recording drum 41 of the image recording unit 40 does not damage the inkjet head, it is necessary to transport the paper P in close contact with the outer peripheral surface thereof, so that the transport body according to the embodiment of the present invention is used. Is particularly effective.

  The image recording drum 41 is provided with a rotation shaft (not shown), and a cylindrical drum (cylindrical portion) 85 is fixed to the rotation shaft. As shown in FIG. 3, both ends of the drum 85 are closed by side plates 86 and 88, and a rotation shaft (not shown) passes through the center of the side plates 86 and 88.

  On the outer peripheral surface of the drum 85, cut portions 98 having a substantially trapezoidal shape in a side view are formed along the rotation axis direction (hereinafter simply referred to as the axial direction) of the drum 85 at intervals of 180 °. The leading edge of the conveyed paper is held by a gripper (holding part) G provided in the notch part 98, so that the paper is restricted in movement and positioned on the drum 85. Note that the outer peripheral surface of the drum 85 in FIG. 3 has two regions divided by the cut portion 98. The drum 85 is configured to hold and transport two sheets of paper in one rotation by holding one sheet of paper P in each of the two areas.

  A plurality of elliptical long grooves 92 extending along the circumferential direction of the drum 85 are formed on the outer peripheral surface of the drum 85 along the axial direction of the drum 85. As shown, a round hole 92A is formed. Further, the long grooves 92 are arranged to be staggered in the circumferential direction of the drum 85. That is, the groove portion is formed on the outer peripheral surface of the cylindrical portion by the long groove 92 and the round hole 92A.

  Furthermore, a plurality of substantially cylindrical through holes (air passages) 96 are formed in the drum 85 along the circumferential direction on the outer periphery of the drum 85. A round hole 92A is provided from the through hole 96 along the radial direction of the drum 85, and the through hole 96 communicates with the long groove 92 through the round hole 92A.

  One passage port of the plurality of through-holes 96 extending in the axial direction is blocked by a side plate 88, but the other passage port passes through the side plate 86 and is connected to the vacuum chamber 108 via a pipe 106. .

  Further, the vacuum chamber 108 is connected to the suction pump 105 via the tube 102 (see FIGS. 5 to 7).

  In the present embodiment, each of the pipes 102 connected to the plurality of through holes 96 extending in the axial direction is provided with an opening / closing valve 110.

  FIG. 5 is a schematic view of the state in which the sheet P is sucked and conveyed by the image recording drum 41 configured as described above, as viewed from the outer peripheral surface side of the drum 85. 5 shows the drum 85 in a state where the rear end portion 140 of the sheet P being sucked and conveyed can be seen.

  As shown in FIG. 5, when the size of the paper P is small, there are many long grooves 92 (grooves) on the outside of the paper P conveyed on the image recording drum 41. In such a case, air leaks from the long groove 92 on the outside of the paper P, a sufficient suction pressure is not applied to the paper P, and the rear end portion 140 of the paper peels off. In particular, in the image recording drum 41 configured to hold and convey two sheets as described above, the sheet may be conveyed continuously, but the final sheet of a plurality of sheets may be used. As described above, since no paper is present in one of the two regions divided by the notch 98 on the outer peripheral surface of the drum 85, the pressure for adsorbing the paper is increased. The problem of not being sufficient is likely to occur. In addition, when the paper thickness is 0.2 mm or more, particularly 0.3 mm or more, the trailing edge 140 is likely to be peeled off.

  Therefore, in the present embodiment, the opening / closing control of the opening / closing valve 110 is performed so as not to suck the long groove 92 (groove portion) in the area behind the rear end portion 140 of the paper P where the paper P does not exist.

  In particular, in the image recording drum 41 configured to hold and convey two sheets as described above, the final sheet is the rear end when images are continuously formed on a plurality of sheets. In the state where the drum 85 is adsorbed to the outer peripheral surface of the drum 85, all the open / close valves of the air passages communicating with the grooves formed in the region of the outer peripheral surface not adsorbing the sheet are closed.

In the image recording drum 41 of FIG. 5, the open / close valve 110 _n-2 connected to the air passages 96 _n-2 and 96 _n-3 communicating with the long groove 92 (groove) in the area behind the rear end 140 of the paper P. 110 _n-3 are closed. The on-off valve 110 connected to the air passage 96 communicating with the long groove 92 (groove portion) in the region where the paper P other than the on _- off valves 110 _n-2 and 110 _n-3 is present opens to suck the paper P. To.

  Control for switching opening and closing of the open / close valve according to the paper size (length in the transport direction) is preferably performed by the system controller 200 shown in FIG. The determination of the paper size may depend on the paper size information input by the operator to the operation unit 210, or the paper size may be determined by a sensor (not shown) provided in the ink jet recording apparatus 10. . Further, if the gripper (holding part) G (see FIGS. 1 and 3) is provided in the drum 85, the position of the leading end of the paper is determined, so that the control for switching the opening / closing of the opening / closing valve becomes easier. .

  By controlling the image recording drum 41 according to the present embodiment as described above, a high suction pressure can be applied to the paper P even when the paper size is small. Peeling from 85 can be prevented. In the present embodiment, the configuration in which two sheets can be held and conveyed has been described. However, the number of sheets is not limited to two, and three or more sheets may be conveyed while being held by the drum 85. .

  FIG. 6 is a modification of FIG. 5, and similarly to FIG. 5, a schematic view of the state in which the sheet P is sucked and conveyed by the image recording drum 41 configured as described above, as viewed from the outer peripheral surface side of the drum 85. It is.

As shown in FIG. 5, on-off valves 110 _n-2 , 110 _n connected to the air passages 96 _n-2 , 96 _n-3 communicating with the long grooves 92 (grooves) in the area behind the rear end 140 of the paper P. _{When -3} is closed, the open / close valve 110 connected to the air passage 96 communicating with the long groove 92 in the region where the paper P exists other than the open / close valves 110 _n-2 and 110 _n-3 is open. In such a case, air leaks from the long grooves 92 (groove portions) on both side ends of the paper P, and the adsorption pressure on the paper P tends to be insufficient.

  Therefore, in the embodiment of FIG. 6, the suction sheets 120 having regions that block the long grooves 92 (groove portions) that are both widths outside the width of the conveyed paper P are provided on both side ends of the conveyed paper P. I did it. The suction holes and suction grooves of the suction sheet 120 can adopt any shape. By wrapping the suction sheet 120 around the outer peripheral surface of the drum 85, a suction hole and a suction groove (not shown) that are closely fixed by the suction force of the suction pump 105 are provided.

  In FIG. 5, the suction region can be switched depending on the length of the paper in the transport direction, but the long grooves 92 on both sides of the drum 85 that are outside the width of the paper P to be transported are open. As a result, air leaks from the groove 92 and the suction force to the paper P is reduced. On the other hand, as shown in FIG. 6, by providing the suction sheet 120 that closes the long grooves 92 at both widths of the drum 85 outside the width of the sheet to be conveyed, the air is discharged from the long grooves 92 that are blocked by the suction sheet 120. Can be prevented, and as a result, the paper P can be adsorbed at a sufficient adsorbing pressure. Therefore, it is possible to prevent the rear end portion 140 of the paper P from being peeled from the drum 85.

  5 and 6, the long groove 92 that sucks the rear end portion 140 of the paper P is completely closed by the paper P. However, depending on the length of the paper P in the conveyance direction, it is assumed that the long groove 92 that sucks the rear end portion 140 of the paper P is not completely blocked by the paper P.

  When the long groove 92 that sucks the rear end portion 140 of the paper P is not completely closed by the paper P, the long groove 92 (groove portion) is provided so that the paper P can be adsorbed by the long groove 92 that is not completely closed by the paper P. It is conceivable to open the opening / closing valve 110 connected to the air passage 96 communicating with the air passage 96). However, in the long groove 92 that is not completely blocked by the paper P, air leaks from the groove portion 92 and the suction force to the paper P decreases.

Therefore, as shown in FIG. 7, it is conceivable to provide a suction sheet 130 having a suction region 132 _n that matches the shape of the rear end portion 140 of the paper P.

The suction sheet 130 of FIG. 7 includes a suction region 132 _n that extends to the rear end portion 140 of the paper P in the range of the paper width in order to suck the rear end portion 140 of the paper P by the suction force of the air passage 96 _n. Yes. Further, the suction region 132 _n−1 having a concave portion corresponding to the width of the paper P is formed up to the rear end 140 of the paper P so that the suction force by the air passage 96 _n-1 is not applied to the rear end 140 of the paper P. I have. The suction holes and suction grooves of the suction regions 132 _n and 132 _n-1 can adopt any shape, but by winding the suction sheet 130 around the outer peripheral surface of the drum 85, the suction force of the suction pump 105 can be increased. It has suction holes and suction grooves that are tightly fixed (not shown). Further, the suction area 132 _n of the suction sheet 130 has a suction groove (not shown) that can suck the sheet up to a range extended in the range of the sheet width to the rear end portion 140 of the sheet P.

The suction sheet 130 is provided on the outer peripheral surface of the drum 85 so that the opening / closing valve 110 _n is opened and the opening / closing valve 110 _n-1 is closed.

  Thereby, since a high suction pressure can be applied to the paper P, it is possible to prevent the rear end portion 140 of the paper P from being peeled off from the drum 85. In the present embodiment, the suction sheet 130 needs to be prepared in advance according to the size of the paper to be used.

  Further, as shown in FIG. 7, it is preferable to set a suction area 132 for each air passage 96 to expand the effective suction area or to block both side ends of the conveyed paper P.

  As described above, the air passage extending in the axial direction communicating with the groove portion is provided, and the open / close valve is provided in the air passage. Therefore, the suction area can be switched depending on the length of the recording medium in the conveyance direction. Then, by opening and closing the open / close valve according to the size of the recording medium, a sufficient adsorption pressure can be applied regardless of the size of the recording medium, so that the trailing edge of the recording medium can be prevented from peeling off.

  By the way, when a strong recording medium (thickness of 0.2 mm or more and 0.8 mm or less) is transported in close contact by drum transport by suction, in order to transport the rear end of the recording medium by suction without peeling, the recording medium is -60 kPa to It is necessary to apply an adsorption pressure of −80 kPa. In this embodiment, the adsorption pressure applied to the recording medium can be set to −60 kPa or less and −80 kPa or more.

  In the present embodiment, as shown in FIG. 4, the through hole 96 and the long groove 92 are communicated with each other via the round hole 92A, but the through hole 96 and the long groove 92 may be directly communicated with each other. Further, the shape of the long groove 92 is not particularly limited as long as the long groove 92 can communicate with the through hole 96, but the influence on the paper P (the surface corresponding to the long groove 92 is recessed) is considered. Smaller is better.

  In the present embodiment, as shown in FIG. 4, one passage port of the through hole 96 is closed by the side plate 88. For example, one side passage port is connected to the side plate 88 in the same manner as the other passage port. You may penetrate and connect to the vacuum chamber 108 through the pipe | tube 106 and an on-off valve, respectively.

  In the above embodiment, the image recording drum 41 has been described. However, according to the present invention, the sheet can be reliably sucked on the drum, and may be applied to other drums.

  Furthermore, in the above-described embodiment, an image forming apparatus that discharges ink and forms an image on a sheet has been described. However, the present invention can be applied to various apparatuses in general.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording apparatus, 20 ... Paper feed part, 21 ... Paper feed apparatus, 22 ... Paper feed tray, 23 ... Transfer cylinder, 30 ... Treatment liquid provision part, 31 ... Treatment liquid provision drum, 32 ... Treatment liquid provision apparatus, DESCRIPTION OF SYMBOLS 40 ... Image recording part, 41 ... Image recording drum (conveyance body), 42 ... Paper pressing roller, 44C, 44M, 44Y, 44K ... Inkjet head, 50 ... Ink drying part, 51 ... Ink drying drum, 52 ... Ink drying apparatus , 60 ... fixing section, 61 ... fixing drum, 62, 63 ... heat roller, 64 ... in-line sensor, 70 ... collection section, 71 ... stacker, 72 ... discharge conveyor, 80 ... transfer cylinder, 81 ... transfer cylinder main body, 83 ... Guide plate, 85 ... Drum (cylindrical part), 86, 88 ... Side plate, 90 ... Transfer cylinder, 91 ... Transfer cylinder body, 93 ... Guide plate, 94 ... Dryer, 96 ... Through hole (air passage), 9 DESCRIPTION OF SYMBOLS ... Cutting part, 100 ... Transfer cylinder, 101 ... Transfer cylinder main body, 103 ... Guide plate, 104 ... Dryer, 105 ... Suction pump, 108 ... Vacuum chamber, 110 ... Opening / closing valve, 120, 130 ... Adsorption sheet, 132 ... Adsorption Area 140, rear end of paper, 200, system controller, 201, communication unit, 202, image memory, 203, transport control unit, 204, paper feed control unit, 205, processing liquid application control unit, 206, image recording Control unit, 207 ... Ink drying control unit, 208 ... Fixing control unit, 209 ... Collection control unit, 210 ... Operation unit, 211 ... Display unit, 212 ... Warning unit, P ... Paper (recording medium), G ... Gripper

Claims (12)

A carrier for rotating and carrying a recording medium,
A cylindrical portion having an outer peripheral surface serving as a conveying surface of the recording medium;
A plurality of grooves formed on the outer peripheral surface of the cylindrical portion;
A plurality of air passages extending in the axial direction of the cylindrical portion, formed along the circumferential direction on the outer peripheral portion of the cylindrical portion, and communicating with the groove portion;
A vacuum chamber connected to the plurality of air passages;
A plurality of on-off valves respectively provided between the vacuum chamber and the plurality of air passages;
A suction pump connected to the vacuum chamber and sucking air;
Conveying body having   The transport body according to claim 1, further comprising a control unit that switches opening and closing of each of the plurality of on-off valves based on a length of the recording medium in a transport direction.   The control means opens and closes each of the opening and closing valves based on the input length in the conveyance direction of the recording medium, and the groove portion for adsorbing the recording medium to the outer peripheral surface of the cylindrical portion is The carrier according to claim 2, which is in communication with a vacuum chamber.   The conveyance body according to any one of claims 1 to 3, further comprising a holding portion that restricts movement of the leading end portion of the recording medium and determines a position of the leading end portion on an outer peripheral surface of the cylindrical portion. A holding part that holds and conveys a plurality of recording media is provided on the outer peripheral surface of the cylindrical part,
The transport body according to any one of claims 1 to 4, wherein the open / close valve is opened and closed with respect to a transport area of the plurality of recording media.   The conveyance body according to any one of claims 1 to 5, further comprising an adsorption sheet that covers the groove portions on both outer widths of the recording medium conveyed.   The conveyance body according to any one of claims 1 to 6, further comprising: an adsorption sheet having an adsorption region where an adsorption force by the groove portion is applied to a rear end portion of the recording medium to be conveyed.   The conveyance body according to claim 1, wherein the recording medium has a thickness of 0.2 mm or more and 0.8 mm or less.   The transport body according to claim 8, wherein the recording medium has a thickness of 0.3 mm or more.   The conveyance body according to claim 1, wherein an adsorption pressure applied to the recording medium is −60 kPa or less and −80 kPa or more. The carrier according to any one of claims 1 to 10,
An image forming unit that is provided facing the transport body and forms an image on the surface of a recording medium held by the transport body;
An image forming apparatus. The transport body has a holding portion that holds and transports a plurality of recording media on the outer peripheral surface of the cylindrical portion,
When an image is continuously formed on a plurality of the recording media, an air passage that communicates with a groove portion on a surface that does not adsorb the recording medium in a state where the final recording medium is adsorbed to the conveyance body to the rear end. The image forming apparatus according to claim 11, wherein all the on-off valves are closed.

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