Recording-medium carrier and image forming apparatus

Abstract

To provide a recording-medium carrier and image forming apparatus made easy to remove the dirt adhered on a transport member.SOLUTION: A recording-medium carrier 42 comprises a transport member 50 to air-suck a medium 23. The transport member 50 has suction holes 51a to suck a medium 23 so that air suction is done during non-transport to remove away dirt 312 adhered on the suction holes 51a. The transport member 50 has a medium-sucking range zoned to suck away dirt 312 with a zoned part thereof taken as a target. The medium suction range 59 has a target zone fallen on an edge area of the medium 23.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a recording medium transport device and an image forming apparatus that are provided with a transport member for transporting a medium by air suction. [Background technology]

[0002] 2. Description of the Related Art In inkjet recording devices, a conveying device that conveys paper by adsorbing the paper onto a conveying surface through suction holes in a conveying belt using air (see, for example, Patent Documents 1 and 2).

[0003] The belt conveying device described in Patent Document 1 removes dirt from the suction holes of the conveying belt by ejecting gas from a cleaning unit toward the outside of the belt into the suction holes of the conveying belt. The belt conveying device described in Patent Document 1 also includes a heating unit that heats the conveying belt, and improves cleaning efficiency by heating the conveying belt with the heating unit.

[0004] In addition, the image forming device described in Patent Document 2 discharges air when no recording medium is placed in the recording medium holding area of ​​the transport drum, which has suction holes, to discharge and clean foreign matter within the opening and air flow path. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-142873 A [Patent Document 2] JP 2009-274272 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the belt conveying device described in Patent Document 1 has a problem in that the number of parts and the number of assembly steps increase because a dedicated cleaning member is required to remove the dirt from inside the suction holes. Also, the belt conveying device described in Patent Document 1 has a problem in that the dirt scatters inside the device when the dirt is removed from inside the suction holes.

[0007] Furthermore, the image forming apparatus described in Patent Document 2 has a problem in that, when removing dirt, air is blown toward the outside of the transport drum to scatter the dirt, making it difficult to collect the foreign matter.

[0008] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a recording medium transport device and an image forming apparatus in which dirt adhering to the transport member can be easily removed. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention has the following configuration. (1) A recording medium transport device having a transport member that adsorbs media with air, the transport member having suction holes that adsorb the media and removes dirt adhering to the suction holes by sucking air when the media is not being transported, the media adsorption range of the transport member being partitioned, and the dirt is sucked up by targeting a portion of the partitioned range.

[0010] (2) The recording medium conveying device according to claim 1, wherein the target area from which the dirt is sucked is an edge area of ​​the medium.

[0011] (3) The recording medium conveying device according to claim 2, wherein a common pipe is used for the suction of the medium and for a suction mechanism for sucking the dirt.

[0012] (4) The recording medium transport device according to claim 1, wherein the transport member for inkjet printing uses ink that softens at high temperatures, and the dirt adhering to the transport member is sucked while the transport member is heated.

[0013] (5) The recording medium transport device according to claim 4, wherein the ink is in a gel state at room temperature, and the transport member is heated to a temperature exceeding the melting temperature of the ink.

[0014] (6) The recording medium transport device according to claim 1, wherein the suction output of the pump that sucks the dirt is greater when sucking the dirt than when transporting the medium.

[0015] (7) The recording medium conveying device according to claim 1, wherein the dirt is sucked when printing is not being performed.

[0016] (8) The recording medium conveying device of claim 6, wherein the control unit that controls the pump measures the suction pressure with a pressure gauge when sucking up the dirt, and drives the pump to continue suction until the suction pressure reaches or exceeds a predetermined value that has been set in advance.

[0017] (9) A recording medium conveying device as described in claim 6, wherein a control unit that controls the pump measures and stores the suction pressure of the pump when not printing in advance, and determines that suction of the dirt is necessary if the suction pressure is below a predetermined value set in advance.

[0018] (10) The recording medium conveying device according to claim 1, wherein the dirt is sucked with the suction holes facing upward.

[0019] (11) The recording medium transport device according to claim 1, further comprising a collector that collects the dirt sucked into the transport member.

[0020] (12) The recording medium transport device according to claim 1, further comprising an ink mist suction section outside the media adsorption range of the transport member.

[0021] (13) The recording medium transport device according to claim 1, wherein the transport member is a drum.

[0022] (14) An image forming apparatus comprising: a recording medium transport device according to any one of claims 1 to 13; and an image forming section that forms an image on the medium supplied from the recording medium transport device. Effect of the Invention

[0023] According to the present invention, it is possible to provide a recording medium transport device and an image forming apparatus in which dirt adhering to the transport member can be easily removed. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a diagram showing an example of a recording medium transport device according to an embodiment of the present invention, and is a schematic diagram showing a state in which ink is ejected onto a medium from nozzles provided in an inkjet nozzle of an inkjet recording device. [Diagram 2] 1 is a schematic diagram illustrating an overall configuration of a recording medium transport device according to an embodiment of the present invention; [Diagram 3] FIG. 2 is an explanatory diagram illustrating a conveying member of the recording medium conveying device. [Figure 4] 5 is a schematic cross-sectional view of a conveying member showing a media suction range of a suction hole and an air chamber. FIG. [Diagram 5] 4 is a schematic side view showing an installation state of a collecting unit of the recording medium transport device. FIG. [Figure 6] FIG. 4 is a schematic perspective view showing an installation state of an ink mist suction unit of the recording medium transport device. [Figure 7] 10 is a flowchart showing a suction operation when air is sucked through a suction hole of a conveying member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Next, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same reference numerals are used to designate the same components in the various drawings.

[0026] 1 is a diagram showing an example of a recording medium transport device 42 according to an embodiment of the present invention, and is a schematic diagram showing a state in which ink is ejected onto a medium 23 from nozzles 31Y, 31M, 31C, and 31K provided in an inkjet nozzle of an inkjet recording device 1. FIG. 2 is a schematic diagram showing the overall configuration of the inkjet recording device 1.

[0027] <Media> Before describing the image forming apparatus 100 and the inkjet recording apparatus 1, we will explain the medium 23 used in the image forming apparatus 100 and the inkjet recording apparatus 1. The medium 23 is, for example, paper, fabric, plastic film, glass plate, or other various recording media. In this way, the medium 23 may be any medium that can be used as a recording medium on whose surface an image is formed, and the following description will be given taking the case of using paper as an example.

[0028] Image forming device 2, the image forming apparatus 100 is an inkjet recording device 1 that ejects ink from nozzles 31Y, 31M, 31C, and 31K of a carriage 31 to form (record) an image on a medium 23. The image forming apparatus 100 is composed of an apparatus that forms an image on the medium 23, for example, by a one-pass inkjet method. The image forming apparatus 100 (inkjet recording device 1) includes a paper feed unit 2, a recording medium transport device 42, an image forming unit 3 that forms an image on the medium 23 supplied from the recording medium transport device 42, a paper discharge unit 4, and an ink supply tank (not shown).

[0029] Inkjet recording device 1, the inkjet recording device 1 is a recording device that forms an image on a medium 23 such as paper by ejecting ink from nozzles 31Y, 31M, 31C, and 31K provided on an inkjet head. The inkjet recording device 1 is, for example, a color inkjet recording device that overlaps four colors of ink: black K, yellow Y, cyan C, and magenta M.

[0030] 2, the inkjet recording device 1 has a paper feed section 2, a media supply section 22, an image forming section 3, and a paper discharge section 4. The inkjet recording device 1 forms image data input from an external device on a medium 23.

[0031] As shown in Fig. 1, when the inkjet recording device 1 ejects ink from the nozzles 31Y, 31M, 31C, and 31K, it scatters a mist 311 of fine particles in addition to the main ink droplets that form an image. The mist soils the nozzles 31Y, 31M, 31C, and 31K and the transport section, causing defects in the image and transport. The mist 311 is removed by the mist catcher 32 (see Fig. 2) downstream of the printing section, which sucks in air and collects it with a filter.

[0032] <Ink, ink supply tank> The ink used is in a gel state at room temperature and softens at high temperatures. The ink is heated to a temperature exceeding its melting temperature by a heater (not shown). A predetermined amount of ink is stored in an ink supply tank (not shown). The ink supply tank (not shown) is an ink storage tank for supplying ink to the image forming unit 3.

[0033] <Paper feed section> As shown in FIG. 2, the paper feed unit 2 is a supply means that supplies paper as the media 23. The paper feed unit 2 has a media supply tray 21. The media supply tray 21 is made of a plate-shaped member on which the media 23 (paper) can be placed. The media supply tray 21 is provided so as to be movable in the vertical direction according to the number of sheets of media 23 placed on it. Of the multiple media 23 placed on the media supply tray 21, the topmost media 23 in the vertical direction is held in a position where it will be transported by the media supply unit 22.

[0034] <Media Supply Department> The media supply unit 22 is a media delivery means that transports the topmost media 23 placed on the media supply tray 21 toward the image forming unit 3 and delivers the media 23 to the drum unit 5 of the image forming unit 3 via a delivery roller 22a. The media supply unit 22 is disposed between the paper feed unit 2 and the image forming unit 3. The media supply unit 22 has a delivery roller 22a.

[0035] <Image forming section> 2, the image forming unit 3 is an image forming means that uses ink to form an image on the medium 23. The image forming unit 3 has a carriage 31, a mist catcher 32, a drum unit 5, a fixing unit 33, a temperature sensor 34, an inverting unit 35, a medium ejection unit 36, and a control unit 9.

[0036] <Carriage> 2, the carriage 31 is configured to include, for example, four nozzles 31Y, 31M, 31C, and 31K. The carriage 31 is configured to support the nozzles 31Y, 31M, 31C, and 31K by a support member (not shown) so that the nozzles 31Y, 31M, 31C, and 31K face the outer circumferential surface of the drum unit 5.

[0037] <Nozzle> As shown in Fig. 2, the inkjet head having the nozzle 31Y forms an image using yellow Y ink. The inkjet head having the nozzle 31M forms an image using magenta M ink. The inkjet head having the nozzle 31C forms an image using cyan C ink. The inkjet head having the nozzle 31K forms an image using black K ink. As an example of the inkjet recording apparatus 1, a case where ultraviolet curable ink is used will be described.

[0038] Further, the multiple nozzles 31Y, 31M, 31C, and 31K are disposed above the drum unit 5 at appropriate intervals in the circumferential direction. In the inkjet recording apparatus 1 of the present embodiment, the image forming unit 3 is provided with four nozzles 31Y, 31M, 31C, and 31K to form an image using four color inks, but the number of nozzles may be changed as appropriate. In the following, a carriage 31 equipped with four nozzles 31Y, 31M, 31C, and 31K will be described as an example.

[0039] <Mist Catcher> 2, the mist catcher 32 is a mist collecting means that collects the mist 311 (see FIG. 1) generated by the ink ejected from the nozzles 31Y, 31M, 31C, and 31K of the carriage 31. The mist catcher 32 is disposed downstream of the nozzle 31K in the transport direction b of the medium 23 by the transport member 50.

[0040] <Fixing section> The fixing unit 33 is a fixing means for curing the ink on the medium 23 by irradiating ultraviolet rays on the medium 23 transported by the rotation of the transport member 50. The transport member 50 adsorbs the medium 23 with air. The fixing unit 33 is disposed downstream of the mist catcher 32 in the transport direction b of the medium 23. The ink on the medium 23 refers to the ink that forms an image on the medium 23. The fixing unit 33 has a function of fixing an image formed on the medium 23 using ink to the medium 23. Fixing of an image by the fixing unit 33 is not limited to irradiation with ultraviolet rays, and may be irradiation with energy rays that can cure the ink depending on the properties of the ink, or heating the medium 23 to dry the ink, etc.

[0041] When the ink reacts with ultraviolet light and hardens, heat is generated in the ink. The heat generated when the ink hardens increases the temperature of the drum unit 5. The temperature of the drum unit 5 also increases due to heat from the fixing unit 33 and heat generated when the multiple nozzles 31Y, 31M, 31C, and 31K eject ink.

[0042] <Temperature sensor> 2, the temperature sensor 34 is a temperature detection unit that measures the temperature of the surface of the transport member 50. The temperature sensor 34 is disposed upstream of the multiple nozzles 31Y, 31M, 31C, and 31K in the transport direction b. The temperature sensor 34 is disposed facing the transport member 50 that constitutes the drum unit 5. The temperature sensor 34 is connected to the control unit 9, and temperature information measured by the temperature sensor 34 is output to the control unit 9.

[0043] <Heater> The heater (not shown) is a heating means for heating the transport surface of the transport drum 51 and the media 23 so that the temperature of the media 23 transported by the transport member 50 falls within a predetermined temperature range. The heater (not shown) is installed between the position of the media supply unit 22 and the position of the drum unit 5. The heater (not shown) is made up of, for example, an infrared heater. The heater (not shown) passes electricity through the infrared heater based on a control signal supplied from the control unit 9 (see FIG. 4) to cause the infrared heater to generate heat.

[0044] <Media ejection section> The media discharge unit 36 ​​is a media discharge means that receives the media 23 from the drum unit 5 by multiple transport rollers 36a, 36b and transports it toward the paper discharge unit 4. The media discharge unit 36 ​​is located downstream in the transport direction b from the fixing unit 33. The media discharge unit 36 ​​has multiple transport rollers 36a, 36b.

[0045] <Inversion section> The reversing unit 35 is a reversing means that turns the medium 23 over so as to form images on both sides of the medium 23. The medium discharge unit 36 ​​is provided with the reversing unit 35.

[0046] <Paper ejection section> The paper discharge unit 4 is a discharge unit that discharges media 23 such as paper on which an image has been formed. The paper discharge unit 4 stores the media 23 sent out from the image forming unit 3 by the media discharge unit 36. The paper discharge unit 4 has a flat media discharge tray 41. The media 23 on which an image has been formed is placed on the media discharge tray 41 .

[0047] <Drum unit (recording medium transport device)> 2, the drum unit 5 is composed of a recording medium transport device 42 that receives the medium 23 from the media supply section 22 and transports the medium 23 toward the media discharge section 36. The drum unit 5 (recording medium transport device 42) is configured to include a transport member 50, a rotation drive section (not shown), a collector 55 (see FIG. 5), an ink mist suction section 56 (see FIG. 6), a valve 82, a pump 7, a pressure gauge 8, and a control section 9. At opposing positions on the outer circumferential surface of the drum unit 5, a plurality of nozzles 31Y, 31M, 31C, 31K, a mist catcher 32, a fixing section 33, a temperature sensor 34, and a heater (not shown) are arranged.

[0048] <Transportation components> FIG. 3 is an explanatory diagram showing the transport member 50 of the recording medium transport device 42. As shown in FIG. The transport member 50 shown in Fig. 3 is a media transport member for transporting the media 23 (see Fig. 2) by air suction. The transport member 50 is formed into a hollow cylindrical shape and includes a transport drum 51 consisting of a hollow cylindrical drum, a rotating shaft 54, a lid-shaped support part 52 that closes an opening on one side of the transport drum 51, a lid-shaped support part 53 that closes an opening on the other side of the transport drum 51, and a non-rotating body 58.

[0049] <Transport cylinder> As shown in FIG. 3, the transport cylinder 51 has numerous suction holes 51a (for example, 1 mm diameter through holes) for adsorbing the medium 23 (see FIG. 2). The transport cylinder 51 for inkjet printing uses ink that softens at high temperatures, and while the transport member 50 is heated by a heater (not shown), it sucks dirt 312 (see FIG. 5) through the suction holes 51a. The dirt 312 attached to the suction holes 51a of the transport cylinder 51 is removed by air suction when the medium 23 is not being transported. In addition, the transport cylinder 51 can transport the medium 23 in close contact while preventing the medium 23 from floating up by air adsorbing the medium 23 to the suction holes 51a, so that the medium 23 can be transported without slipping. Therefore, when the medium 23 shown in FIG. 2 is so-called paper floating, the transport cylinder 51 can prevent the medium 23 from contacting the nozzles 31Y, 31M, 31C, and 31K, causing image defects and nozzle damage.

[0050] <Suction hole> 3, the suction hole 51a of the transport drum 51 is connected to the pump 7 by a pipe 81. Air is sucked from the suction hole 51a when a side hole (not shown) is connected while the transport drum 51 is rotating.

[0051] <Rotation axis> 3, the rotating shaft 54 ​​is provided on the central axis of the transport member 50 and protrudes from the support parts 52 and 53 in the axial direction. The rotating shaft 54 ​​is rotatably supported by a pair of bearing members (not shown). One end of the rotating shaft 54 ​​in the axial direction is provided with a rotation drive part (not shown), for example, via a reduction gear mechanism (not shown). The rotating shaft 54 ​​and the transport member 50 are rotated by being driven by the rotation drive part (not shown).

[0052] <Non-rotating body> 3, non-rotating body 58 is a non-rotating member disposed on the side of conveying member 50, which is a rotating body. Non-rotating body 58 is provided with arc-shaped tubular portion 81b of piping 81. Pipe 81 is composed of main pipe 81a made of metal piping having a base end connected to pump 7, arc-shaped tubular portion 81b made of metal piping connected to a tip end of main pipe 81a, and resin hose 81c having a base end connected to arc-shaped tubular portion 81b and a tip end disposed inside conveying drum 51.

[0053] <Air chamber> FIG. 4 is a schematic cross-sectional view of the transport member 50 showing the media suction range 59 of the suction hole 51 a in the transport member 50 and the air chamber 6 . 4, a hollow air chamber 6 is formed inside the transport member 50. The inside of the transport member 50 is partitioned by partitions 57 into a plurality of air chambers 6, and a plurality of media suction ranges 59 are partitioned.

[0054] The air chamber 6 is divided into five chambers, a first air chamber 61, a second air chamber 62, a third air chamber 63, a fourth air chamber 64, and a fifth air chamber 65, by partitions 57, for example. The first air chamber 61 is divided by the partitions 57 at a position near the center of the hollow conveying member 50. The second air chamber 62 is divided by the partitions 57 at a position near the support portion 53 of the hollow conveying member 50. The third air chamber 63 is divided by the partitions 57 at a position near the lower side of the outer periphery of the hollow conveying member 50. The fourth air chamber 64 is divided by the partitions 57 at a position near the upper side of the outer periphery of the hollow conveying member 50. The fifth air chamber 65 is divided by the partitions 57 at a position near the support portion 52 of the hollow conveying member 50.

[0055] <Media adsorption range> The air chamber 6 is divided into five sections, a first air chamber 61, a second air chamber 62, a third air chamber 63, a fourth air chamber 64, and a fifth air chamber 65, by the partitions 57, so that the media suction range 59 is divided into five sections corresponding to the respective air chambers 6. The media suction range 59 is divided into a first media suction range 591 formed at the upper part of the first air chamber 61 in the circumferential direction, a second media suction range 592 formed at the upper part of the second air chamber 62 in the circumferential direction, a third media suction range 593 formed at the upper part of the third air chamber 63 in the circumferential direction, a fourth media suction range 594 formed at the upper part of the fourth air chamber 64 in the circumferential direction, and a fifth media suction range 595 formed at the upper part of the fifth air chamber 65 in the circumferential direction. Dirt 312 (see FIG. 5) is sucked into a part of the divided media suction range 59. The target section of the media suction range 59 is the edge region of the media 23 (for example, the outer peripheral end and the axial end of the media suction range 59).

[0056] <Piping> As shown in Fig. 3 and Fig. 4, the piping 81 is composed of a metal piping or a resin hose for connecting the air chamber 6 in the conveying member 50 and the pump 7 that sucks air. As shown in Fig. 4, the piping 81 is composed of a first piping 811, a second piping 812, a third piping 813, a fourth piping 814, a fifth piping 815, a pump connecting piping 816, and a pressure gauge connecting piping 817. The piping 81 used for suction of the media 23 and the piping 81 of the suction mechanism 70 that sucks the dirt 312 (see Fig. 5) are the same. In other words, the piping 81 is used for suction of the media and is also used as a piping for the suction mechanism that sucks the dirt 312.

[0057] The first pipe 811 is connected to the first air chamber 61 at one end and to the first valve 821 at the other end. The second pipe 812 is connected to the second air chamber 62 at one end and to the second valve 822 at the other end. The third pipe 813 is connected to the third air chamber 63 at one end and to the third valve 823 at the other end. The fourth pipe 814 is connected to the fourth air chamber 64 at one end and to the fourth valve 824 at the other end. The fifth pipe 815 is connected to the fifth air chamber 65 at one end and to the fifth valve 825 at the other end. The pump connection pipe 816 is connected to the first valve 821, the second valve 822, the third valve 823, the fourth valve 824, and the fifth valve 825 at one end and to the pump 7 at the other end. The pressure gauge connection pipe 817 is connected to the pump connection pipe 816.

[0058] <Valve> 4 is provided in the pipe 81 and is composed of a solenoid valve for opening and closing the pipe 81 disposed between each air chamber 6 and the pump 7. The valve 82 includes a first valve 821 provided in the first pipe 811, a second valve 822 provided in the second pipe 812, a third valve 823 provided in the third pipe 813, a fourth valve 824 provided in the fourth pipe 814, and a fifth valve 825 provided in the fifth pipe 815. Each valve 82 is electrically connected to the control unit 9 and opens and closes in response to a drive signal from the control unit 9.

[0059] ≪Suction mechanism≫ 4, the suction mechanism 70 is a suction device for sucking the dirt 312 and removing it from the suction hole 51a. The suction mechanism 70 includes the conveying member 50 having the air chamber 6, a pipe 81 connected to the partitioned air chamber 6 at one end and connected to the pump 7 via a valve 82 at the other end, the valve 82, the pump 7, a pressure gauge 8, and a control unit 9.

[0060] <Pump> The pump 7 is a drive source for sucking dirt 312 (see FIG. 5) and the like adhering to the transport drum 51 into the transport drum 51 through the suction hole 51a when printing is not being performed. The pump 7 is connected to the valve 82 through a pump connection pipe 816. The pump 7 is electrically connected to the control unit 9 and configured to be driven in response to a drive signal from the control unit 9. The pump 7 receives a drive signal from the control unit 9 to drive the pump 7 when sucking the dirt 312, measures the suction pressure of the pump 7 with the pressure gauge 8, and continues to drive until the suction pressure reaches or exceeds a predetermined threshold value. The suction output of the pump 7 when sucking the dirt 312 is set by the control unit 9 to be greater when sucking the dirt 312 than when transporting the medium 23.

[0061] <Pressure gauge> The pressure gauge 8 is a measuring instrument for measuring the suction pressure sucked by the pump 7. The pressure gauge 8 is connected to a pump connection pipe 816, which is a common pipe on the pump 7 side, via a pressure gauge connection pipe 817. The pressure gauge 8 is electrically connected to the control unit 9.

[0062] <Control Unit> The control unit 9 shown in FIG. 4 is composed of a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), an input / output circuit, and the like. The control unit 9 measures the suction pressure beforehand during non-printing with the pressure gauge 8, and if the suction pressure is equal to or lower than a predetermined value, it determines that suction of the dirt 312 (see FIG. 5) is necessary and drives the pump 7. When suctioning the dirt 312, the control unit 9 measures the suction pressure with the pressure gauge 8 and drives the pump 7 to continue suction until the suction pressure reaches or exceeds a predetermined value. The control unit 9 also controls a heater (not shown) provided in the drum unit 5 based on temperature information output from the temperature sensor 34. The control unit 9 may be a control device that controls the entire inkjet recording device 1, or may be a control device that controls only the image forming unit 3 and the drum unit 5.

[0063] <Collection section> FIG. 5 is a schematic side view showing an installation state of the collecting unit 55 of the recording medium transport device 42. As shown in FIG. As shown in Fig. 5, the collecting unit 55 is a collecting means for collecting the dirt 312 sucked into the inside. The collecting unit 55 is made of, for example, an adhesive material to which the dirt 312 adheres. The conveying body 51 (drum) sucks the dirt 312 when the suction holes 51a are facing vertically upward. The collecting unit 55 may be a mist collecting filter.

[0064] <Ink mist suction part> FIG. 6 is a schematic perspective view showing an installation state of the ink mist suction unit 56 of the recording medium transport device 42. As shown in FIG. The ink mist suction unit 56 shown in Fig. 6 is a portion that sucks up stains 312 (see Fig. 5) such as ink adhering to the suction hole 51a by the suction force of the pump 7 (see Fig. 4). The tip end of a pipe 81, the base end of which is connected to the pump 7 (see Fig. 4), is connected to the ink mist suction unit 56. The ink mist suction unit 56 is disposed outside the media adsorption range 59 of the transport member 50.

[0065] ≪Effect≫ FIG. 7 is a diagram showing the recording medium transport device 42 and the image forming apparatus 100 according to the embodiment of the present invention, and is a flow chart showing the operation of cleaning the suction holes 51a of the transport drum 51.

[0066] Next, the operation of the recording medium transport device 42 and the image forming apparatus 100 will be described with reference to FIG. 7 mainly and to FIGS. First, cleaning of the suction holes 51a of the transport drum 51 shown in FIG. 3 is started.

[0067] The ink in the carriage 31 is in a gel state at room temperature, and dissolves into liquid at 50°C or higher. Therefore, the ink adhering to the transport drum 51 is heated to 50°C or higher to become liquid, making it easier to remove. When cleaning the suction holes 51a of the transport drum 51, the transport drum 51 is heated by a heater (not shown) to 60°C, which exceeds the melting temperature of the ink, during non-printing and non-transport time (step S1).

[0068] 4, suction holes 51a consisting of countless through holes are formed in the transport drum 51. Each air chamber 6 in the transport drum 51 is connected to a pump 7 via a pipe 81 and a valve 82. Then, when the side hole (not shown) is connected to the pump 7 while the transport drum 51 is rotating, the control unit 9 drives the pump 7 to suck air from each air chamber 6 (step S2).

[0069] Next, the control unit 9 opens the third valve 823 communicating with the second air chamber 62 as the one portion of the air chamber 6 where the edge of the medium 23 is placed, and causes the pump 7 to suck at 100% output (70% of the maximum output during printing). In this way, the air chamber 6 is sucked at 100% output of the pump 7 (step S3).

[0070] The threshold value of the suction pressure P in the pump connection pipe 816 when the suction hole 51a is clogged with dirt 312 or the like is set to -10 kPa or less. P≦-10KPa It is monitored whether the negative pressure has reached the threshold (step S4).

[0071] If the suction pressure P is greater than -10 KPa, the control unit 9 determines that the dirt 312 adhering to the suction hole 51a has been sucked and removed, and that the suction hole 51a is not clogged (Yes in step S4), and ends suction of each air chamber 6 (step S6).

[0072] If the suction pressure P is less than -10 KPa, the control unit 9 determines that the dirt 312 adhering to the suction holes 51a has not been removed and that the suction holes 51a are clogged (No in step S4).Then, the control unit 9 continues suction of each air chamber 6 to remove the dirt 312 clogging the suction holes 51a (step S5).

[0073] As in step S4, the control unit 9 determines whether the suction pressure P measured by the pressure gauge 8 is P≦-10KPa The monitoring continues to determine whether the negative pressure has reached the predetermined value (step S6).

[0074] Then, the control unit 9 drives the pump 7 until the pressure in the pump connecting pipe P6 exceeds the threshold value of -10 kPa, thereby allowing the pump 7 to continue suction. If the pressure in the pump connecting pipe P6 measured by the pressure gauge 8 is not reached for up to one minute (Yes in step S6), the control unit 9 sends a drive signal to the display unit (not shown) to display an error (step S7). If an error is displayed, the control unit 9 ends suction of each air chamber 6 and stops suction by the pump 7 (steps S8 and S9).

[0075] Furthermore, when the suction pressure P is less than -10 KPa, the control unit 9 determines that the dirt 312 adhering to the suction hole 51a has not been removed and the suction hole 51a is clogged (No in step S6). In this case, the control unit 9 ends the suction of each air chamber 6 and stops the suction by the pump 7 (steps S8 and S9).

[0076] Then, the transport drum 51 is cooled to an appropriate temperature (step S10). The cooling of the transport drum 51 is completed when the transport drum 51 is cooled to the original temperature.

[0077] In this manner, cleaning of the dirt 312 in the suction holes 51a is completed. The above-mentioned operation is performed at a conveying drum angle where suction hole 51a faces upward, as shown in Fig. 5. At this time, dirt that has been stuck in suction hole 51a falls by gravity and is collected in collection section 55 in air chamber 6. By providing collection section 55 in air chamber 6, the risk that dirt 312 sucked into conveying drum 51 will scatter inside conveying drum 51 can be reduced.

[0078] As shown in FIG. 4, the present invention is a recording medium transport device 42 equipped with a transport member 50 that air-adsorbs the media 23 (see FIG. 2), the transport member 50 having suction holes 51a that adsorb the media 23 and removes dirt 312 (see FIG. 5) adhering to the suction holes 51a by suctioning with air when the media is not being transported, the media adsorption range 59 of the transport member 50 being partitioned, and dirt 312 is sucked from a portion of the partitioned range. According to this configuration, the recording medium transport device 42 of the present invention removes dirt 312 adhering to the suction holes 51a by suctioning air when the medium 23 is not being transported and the transport drum 51 is stopped, making it easier to suction the dirt 312 with air. The media suction range 59 of the transport member 50 is partitioned and dirt 312 is sucked from a portion of the partitioned area, making it easier to remove the dirt 312 adhering to the transport member 50. This makes it possible for the recording medium transport device 42 to eliminate a condition in which ink mist adheres to and blocks the suction holes 51a, reducing the suction power of the medium 23 and making the medium 23 more likely to float.

[0079] As shown in FIG. 4, the target area for sucking the dirt 312 is the edge area of ​​the medium 23 (see FIG. 2). With this configuration, the target section of the media suction range 59 can suck air into the edge area into which ink mist easily flows and into which the suction holes 51a easily become clogged, thereby preventing the media 23 from warping or floating up. If the media 23 floats up, it is possible to prevent the media 23 from coming into contact with the nozzles 31Y, 31M, 31C, and 31K, which could result in poor image quality, or damage to the nozzles 31Y, 31M, 31C, and 31K, thereby preventing malfunction of the nozzles 31Y, 31M, 31C, and 31K.

[0080] As shown in FIG. 4, the piping used for suction of the media 23 and the piping of the suction mechanism 70 for sucking the dirt 312 share a common piping 81. According to this configuration, the piping for suctioning the media 23 and the piping for suctioning the dirt 312 are common, so it is possible to reduce the number of parts and the number of assembly steps, thereby reducing costs. Also, the pump 7 and piping 81 for suction when suctioning the media 23 and the pump 7 and piping 81 for suction when suctioning the suction hole 51a for cleaning are common, so it is possible to reduce the space and costs required for installation.

[0081] As shown in FIG. 2, the inkjet transport member 50 uses ink that softens at high temperatures, and dirt 312 (see FIG. 5) adhering to the transport member 50 is sucked while the transport member 50 is heated. With this configuration, the recording medium transport device 42 heats the transport member 50 while sucking the ink stains 312 that are attached to the transport member 50 and soften at high temperatures, thereby making it possible to efficiently and easily remove the stains 312. This makes it possible to prevent the medium 23 from being unable to be properly attracted to the transport drum 51 due to the suction holes 51a of the transport drum 51 being clogged with ink mist.

[0082] Furthermore, the ink is in a gel state at room temperature, and the transport member 50 is heated to a temperature exceeding the melting temperature of the ink. According to this configuration, the ink is heated by a heater (not shown) to a temperature (for example, 50 to 60° C.) that exceeds the melting temperature, so that the ink stains 312 can be dissolved and easily removed.

[0083] As shown in FIG. 4, the suction output of the pump 7 that sucks the dirt 312 (see FIG. 5) is greater when sucking the dirt 312 than when transporting the medium 23 (see FIG. 2). According to this configuration, the pump 7 has a larger suction output when sucking the dirt 312 than when transporting the media 23, so that the dirt 312 can be sucked more reliably when sucking the dirt 312.

[0084] Also, dirt 312 (see FIG. 5) is sucked in when printing is not being performed. According to this configuration, the control unit 9 drives the pump 7 to suck the dirt 312 when printing is not being performed, and therefore sucks the dirt 312 when ink is not being ejected from the nozzles 31Y, 31M, 31C, and 31K, thereby preventing unnecessary ink mist from being sucked in. Therefore, the dirt 312 can be sucked in efficiently.

[0085] Also, as shown in FIG. 4, the control unit 9 that controls the pump 7 measures the suction pressure with a pressure gauge 8 when suctioning dirt 312 (see FIG. 5), and drives the pump 7 to continue suction until the suction pressure reaches or exceeds a predetermined value that has been set in advance. According to this configuration, when sucking up dirt 312, the control unit 9 drives the pump 7 to continue suction until the suction pressure reaches or exceeds a predetermined value set in advance, so that the dirt 312 can be sucked up until the suction hole 51a is clean.

[0086] Furthermore, the control unit 9 that controls the pump 7 measures and stores the suction pressure of the pump 7 beforehand when not printing, and determines that suction of the dirt 312 is necessary if the suction pressure is equal to or lower than a preset value. According to this configuration, the control unit 9 determines that suction of the dirt 312 is necessary if the suction pressure is equal to or lower than a predetermined value, and therefore, when dirt 312 adheres to the suction hole 51a, the control unit 9 can automatically drive the pump 7 to remove the dirt 312. In addition, the control unit 9 can prevent ink from clogging the suction hole 51a.

[0087] As shown in FIG. 5, the dirt 312 is sucked with the suction holes 51a facing upward. According to this configuration, when the recording medium conveying device A sucks up the dirt 312, it does so with the suction holes 51a facing vertically upward, so that the dirt 312 can be sucked up efficiently without scattering sideways.

[0088] As shown in FIG. 5, the conveying member 50 further includes a collecting portion 55 for collecting dirt 312 (see FIG. 5) sucked into the conveying member 50. As shown in FIG. According to this configuration, the conveying member 50 has a collection section 55 therein, so that the dirt 312 sucked into the inside of the conveying member 50 can be collected by the collection section 55. This makes it possible to prevent the dirt 312 from flowing to the valve 82 or the pump 7 side and clogging them (see FIG. 4). In addition, since the conveying member 50 sucks the dirt 312 inside, it is possible to prevent the dirt 312 from being re-scattered inside the conveying drum 51, as compared to a method in which the dirt 312 is sprayed out to the outside, and further, the dirt 312 can be collected by the collection section 55 to reliably prevent scattering.

[0089] As shown in FIG. 6, the conveying member 50 is provided with an ink mist suction section 56 outside the media suction range 59 thereof. According to this configuration, the transport member 50 is provided with the ink mist suction portion 56 outside the media adsorption range 59, so that the ink mist can be efficiently collected without scattering.

[0090] As shown in FIG. 2, the conveying member 50 is a drum. According to this configuration, since the conveying member 50 is a drum, it is possible to suck the ink mist into the inside so that the ink mist does not scatter to the outer periphery.

[0091] As shown in FIG. 2, the image forming apparatus 100 includes a recording medium conveying device 42 and an image forming section 3 that forms an image on the medium 23 supplied from the recording medium conveying device 42. According to this configuration, image forming apparatus 100 is equipped with recording medium transport device 42 and image forming section 3, and is therefore able to efficiently form an image on medium 23 while transporting medium 23.

[0092] [Variations] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the gist of the present invention.

[0093] In the embodiment, the recording medium transport device 42 has been described with the transport member 50 made of a drum as an example, but the transport member 50 is not limited to this. The transport member 50 may be, for example, a belt type in which the media 23 is placed on a transport belt, a load is generated in the suction holes, and the media 23 is adsorbed and transported. [Explanation of symbols]

[0094] 1 Inkjet recording device 3. Image forming section 5 Drum unit 7. Pump 8. Pressure gauge 9. Control Unit 23 Media 31Y, 31M, 31C, 31K Nozzles 42 Recording medium transport device 50 Transport member 51 Transport cylinder 51a Suction hole 55 Collection section 56 Ink mist suction unit 59 Media suction range 70 Suction mechanism 81 Piping 100 Image forming device 312 Dirt

Claims

1. A recording medium conveying device having a conveying member that adsorbs a medium by air, the transport member has suction holes for adsorbing the medium, and removes dirt adhering to the suction holes by sucking air when the medium is not being transported; The media suction range of the conveying member is partitioned, and the dirt is sucked in from a portion of the partitioned range. Recording medium transport device.

2. The target area for sucking dirt is the edge area of ​​the media; The recording medium transport device according to claim 1 .

3. The piping used for suction of the media and the piping of the suction mechanism for suctioning the dirt are common piping. The recording medium transport device according to claim 2 .

4. The inkjet transport member uses ink that softens at high temperatures, and the dirt adhering to the transport member is sucked while the transport member is heated. The recording medium transport device according to claim 1 .

5. the ink is in a gel state at room temperature, and the conveying member is heated to a temperature exceeding a melting temperature of the ink; The recording medium transport device according to claim 4 .

6. the suction output of the pump for suctioning the dirt is greater when suctioning the dirt than when transporting the media; The recording medium transport device according to claim 1 .

7. The dirt is sucked when printing is not being performed. The recording medium transport device according to claim 1 .

8. The control unit that controls the pump measures the suction pressure with a pressure gauge during suction of the dirt, and drives the pump to continue suction until the suction pressure reaches or exceeds a predetermined value. The recording medium transport device according to claim 6.

9. a control unit that controls the pump measures and stores a suction pressure of the pump when printing is not being performed, and determines that suction of the dirt is necessary if the suction pressure is equal to or lower than a predetermined value that is set in advance. The recording medium transport device according to claim 6.

10. The dirt is sucked in with the suction hole facing upward. The recording medium transport device according to claim 1 .

11. A collector is provided to collect the dirt sucked into the conveying member. The recording medium transport device according to claim 1 .

12. an ink mist suction section provided outside the media suction range of the conveying member; The recording medium transport device according to claim 1 .

13. The conveying member is a drum. The recording medium transport device according to claim 1 .

14. A recording medium transport device according to any one of claims 1 to 13, an image forming unit that forms an image on the medium supplied from the recording medium conveying device; Equipped with Image forming device.

Images