Conveying section cleaning device and image forming apparatus

Abstract

To provide a conveying section cleaning device capable of removing dirt adhering to a recording medium conveying section.SOLUTION: An inkjet recording device 200, which is a conveying section cleaning device, is configured to include: a conveyance drum 40 for sucking and conveying a recording medium 23; a cleaning part 5 for cleaning the conveyance drum 40; and a control part 9 for controlling the cleaning part 5. When the size of the recording medium 23 is changed, the control part 9 causes the cleaning part 5 to clean the conveying drum 40 before starting printing. The control part 9 causes the cleaning part 5 to clean the recording medium carrying part before the start of printing when the size of the recording medium is changed to a larger size than that of the recording medium 23, and does not cause the cleaning part 5 to clean the recording medium carrying part when the size of the recording medium 23 is changed to a smaller size.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a conveyance unit cleaning device and an image forming apparatus including a cleaning unit that cleans a recording medium conveyance unit.

Background Art

[0002] Generally, a printing device adsorbs and fixes printing paper through a porous sheet and conveys it. When the adsorption surface for adsorbing the printing paper is soiled with foreign substances such as paper dust or ink mist, the adsorption performance deteriorates. In that case, there has been a problem that the image quality of the printed surface deteriorates due to the occurrence of paper floating or peeling.

[0003] In addition, since the printing device rubs the paper surface against the inkjet head, it damages the head. In that case, there has been a problem that it affects the downtime and replacement cost because adjustment of printing accuracy, replacement of the head, etc. occur. In addition, when double-sided printing is performed, there has been a problem that image defects occur on the printed surface when foreign substances such as paper dust adhere to the paper surface.

[0004] As a printing device having a function of removing foreign substances and dirt adhering to such printing paper and inkjet heads, for example, the image forming apparatuses described in Patent Documents 1 to 3 are known.

[0005] The image forming apparatus described in Patent Document 1 discharges the recording medium after image formation, cleans the conveyance drum with a cleaning roller, and then injects and blows air in a subsequent area to remove foreign substances in the adsorption pipeline including the adsorption holes.

[0006] The cleaning device described in Patent Document 2 includes a first cleaning unit that passes gas through the adsorption holes of the conveyance belt, and a second cleaning unit that is disposed on the downstream side in the conveyance direction and wipes the conveyance surface with a contact member, and cleans the conveyance surface and the adsorption holes of the conveyance belt.

[0007] The inkjet printing apparatus described in Patent Document 3 includes a conveyance belt for conveying a printing medium, an inkjet head for printing on the printing medium, a cleaning operation unit for cleaning the inkjet head, and a control unit. The control unit acquires the cumulative time of the suction operation, and when the acquired cumulative time reaches a threshold value, controls the cleaning operation unit to perform cleaning, thereby preventing the printing paper from being soiled due to ink gathering on the nozzle surface.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in the image forming apparatuses and the like described in Patent Documents 1 to 3, when the number of printed sheets increases, the amount of dust and the like increases due to the increase in the number of printed sheets. Therefore, it is necessary to increase the number of cleaning times according to the number of printed sheets. For this reason, in the image forming apparatus and the like, the number of cleaning times must be increased according to the number of printed sheets, which is troublesome.

[0010] In addition, in the image forming apparatus and the like, since the cleaning area changes according to the size of the paper, there is a problem that the operation must be stopped each time and the cleaning must be adjusted according to the size of the paper.

[0011] The present invention has been made in view of the above problems, and an object thereof is to provide a conveyance unit cleaning device and an image forming apparatus capable of removing dirt adhering to a recording medium conveyance unit.

Means for Solving the Problems

[0012] The present invention for solving the above problems has the following configuration. (1) A recording medium transport unit that adsorbs and transports a recording medium, a cleaning unit that cleans the recording medium transport unit, and a control unit that controls the cleaning unit. When the size of the recording medium changes, the control unit causes the cleaning unit to clean the recording medium transport unit before printing starts. A transport unit cleaning device.

[0013] (2) When the control unit changes to a size larger than the recording medium, it causes the cleaning unit to clean the recording medium transport unit before printing starts. When the recording medium changes to a smaller size, the cleaning unit does not clean the recording medium transport unit. The transport unit cleaning device according to claim 1.

[0014] (3) When the control unit does not change the size of the recording medium, it does not cause the cleaning unit to clean the recording medium transport unit. The transport unit cleaning device according to claim 1.

[0015] (4) During printing, when the number of printed sheets exceeds a preset number of sheets, the control unit does not cause the cleaning unit 5 to clean the recording medium transport unit. The transport unit cleaning device according to claim 1.

[0016] (5) The recording medium transport unit includes a transport drum that transports the recording medium. The transport unit cleaning device according to claim 1.

[0017] (6) The recording medium transport unit includes a transport roller that transports the recording medium. The transport unit cleaning device according to claim 1.

[0018] (7) The recording medium transport unit includes a transport belt that transports the recording medium. The transport unit cleaning device according to claim 1.

[0019] (8) A paper feeding unit that supplies the recording medium to the recording medium conveyance unit, a paper discharging unit that discharges the printed recording medium, a front-back reversing unit that reverses the recording medium, and a paper discharge / reverse switching unit for switching whether to send the recording medium to the paper discharge unit side or to the front-back reversing unit side. A front-back reversing unit for double-sided printing is provided between the paper discharge / reverse switching unit and the paper feeding unit. The conveyance unit cleaning device according to claim 1.

[0020] (9) The cleaning unit includes a cleaning roller for cleaning the recording medium conveyance unit. The cleaning roller is divided and arranged at both end portions on both sides in the width direction of the recording medium and at the rear end portion in the conveyance direction of the recording medium. The rear end portion is arranged so that only the cleaning portion contacts the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1.

[0021] (10) The cleaning unit includes an adhesive roller for cleaning the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1.

[0022] (11) The cleaning unit includes an air injection unit that injects air for cleaning the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1.

[0023] (12) The cleaning unit includes a brush for cleaning the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1.

[0024] (13) The cleaning unit includes wet cleaning means for cleaning the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1.

[0025] (14) The cleaning unit is provided upstream and in front of the front-back reversing unit that reverses the recording medium. The conveyance unit cleaning device according to claim 1.

[0026] An image forming apparatus comprising: a conveyance unit cleaning device according to any one of claims 1 to 13; the recording medium conveyance unit; and an image forming unit that forms an image on the recording medium supplied from the recording medium conveyance unit.

Advantages of the Invention

[0027] According to the present invention, it is possible to provide a conveyance unit cleaning device and an image forming apparatus capable of removing dirt adhering to a recording medium conveyance unit.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0029] Next, embodiments of the present invention will be described in detail with appropriate reference to the drawings. In addition, the same reference numerals are given to the members common to each figure. FIG. 1 is a schematic configuration diagram showing the overall configuration of an inkjet recording apparatus 200 according to an embodiment of the present invention.

[0030] ≪Recording Medium≫ Before explaining the inkjet recording apparatus 200 shown in FIG. 1, the recording medium 23 used in these apparatuses will be described. The recording medium 23 is, for example, various recording and storage media such as paper, fabric, plastic film, glass plate, etc. Thus, the recording medium 23 may be any medium that can form an image on its surface, and hereinafter, the case of using paper will be described as an example.

[0031] The sizes of the recording medium 23 consist of, for example, three types such as the recording medium 231 of 393 mm × 545 mm, the recording medium 232 of 469 mm × 636 mm, and the recording medium 233 of 585 mm × 750 mm as shown in FIG. 5.

[0032] ≪Image Forming Apparatus≫ The inkjet recording apparatus 200 shown in FIG. 1 is one that forms (records) an image on the recording medium 23 by ejecting ink from the nozzles 31Y, 31M, 31C, 31K of the carriage 31. The inkjet recording apparatus 200 consists of, for example, an apparatus that forms an image on the recording medium 23 by an inkjet method of the one-pass system. The inkjet recording apparatus 200 includes a paper feeding unit 2, a recording medium supply unit 22, an image forming unit 3, a conveyance unit 4, a cleaning unit 5, a paper discharging unit 6, and an ink supply tank (not shown).

[0033] ≪Inkjet Recording Apparatus≫ As shown in FIG. 1, the inkjet recording apparatus 200 is a recording apparatus that forms an image on a recording medium 23 such as paper by ejecting ink from the nozzles 31Y, 31M, 31C, 31K provided in the inkjet head. The inkjet recording apparatus 200 consists of, for example, a color inkjet recording apparatus that superimposes four colors of ink: black, yellow, cyan, and magenta.

[0034] The inkjet recording apparatus 200 includes a paper feeding unit 2, a recording medium supply unit 22, an image forming unit 3, a conveying unit 4, a cleaning unit 5, a paper discharging unit 6, and an ink supply tank (not shown). The inkjet recording apparatus 200 forms image data input from an external device on a recording medium 23.

[0035] <Ink, Ink Supply Tank> The ink is gel-like at normal temperature and softens at high temperature. The ink is heated by a heater (not shown) to a temperature exceeding the melting temperature. The ink is stored in a predetermined amount in an ink supply tank (not shown). The ink supply tank (not shown) is an ink storage tank for supplying the ink to the image forming unit 3.

[0036] The conveying unit cleaning device or the image forming device which is the inkjet recording apparatus 200 is a device that cleans foreign matters such as paper dust attached to the conveying drum 40 which is a recording medium conveying unit, and ink stains, etc. by the cleaning unit 5.

[0037] <Paper Feeding Unit> As shown in FIG. 1, the paper feeding unit 2 is a supply means for supplying paper as the recording medium 23. The paper feeding unit 2 has a recording medium supply tray 21. The recording medium supply tray 21 is composed of a plate-like member provided so that the recording medium 23 (paper) can be placed thereon. The recording medium supply tray 21 is provided so as to be movable in the vertical direction according to the number of the recording media 23 placed thereon. Among the plurality of recording media 23 placed on the recording medium supply tray 21, the uppermost recording medium 23 in the vertical direction is held at a position where it is conveyed by the recording medium supply unit 22.

[0038] <Recording Medium Supply Unit> The recording medium supply unit 22 is a recording medium delivery means for conveying the uppermost recording medium 23 placed on the recording medium supply tray 21 toward the image forming unit 3 and delivering it to the conveying drum 40 of the image forming unit 3 via the delivery roller 22a. The recording medium supply unit 22 is disposed between the paper feeding unit 2 and the image forming unit 3. The recording medium supply unit 22 has the delivery roller 22a.

[0039] <<Conveyor>> The conveyor 4 shown in FIG. 1 receives and adsorbs the recording medium 23 from the recording medium supply unit 22 to the conveyance drum 40, and conveys the recording medium 23 to the paper discharge unit 6 or the front - back inversion unit 46 via the facing position of the image forming unit 3 and the paper discharge inversion switching unit 44. The conveyor 4 includes a rotation drive unit (not shown), a conveyance drum 40 which is a recording medium conveyance unit, a paper discharge inversion switching unit 44, a paper discharge inversion conveyance roller 45, a front - back inversion unit 46, a paper discharge destination switching unit 47, and a control unit 9. At the facing location on the outer peripheral surface of the conveyor 4, a delivery roller 22a, nozzles 31Y, 31M, 31C, 31K, a fixing unit 32, an image reading unit 33, a paper discharge inversion switching unit 44, a front - back inversion unit 46, and a cleaning unit 5 are arranged.

[0040] <<Conveyance Drum>> The conveyance drum 40 shown in FIG. 1 is a recording medium conveyance unit, and is a drum unit that adsorbs the recording medium 23 received from the recording medium supply unit 22 and conveys it toward the facing position of the image forming unit 3 and the paper discharge inversion switching unit 44. The conveyance drum 40 is a recording medium conveyance member for air - adsorbing and conveying the recording medium 23. The conveyance drum 40 includes a conveyance cylinder 41 which is a hollow cylindrical drum, a lid - shaped support portion 42 that closes the opening of the conveyance cylinder 41, and a rotation shaft 43, and is formed in a hollow cylindrical shape.

[0041] The conveyance drum 40 conveys the recording medium 23 by rotating while winding the recording medium 23 supplied from the paper feed unit 2 around the outer peripheral surface of the conveyance drum 40. Therefore, the conveyance surface for conveying the recording medium 23 is formed by the outer peripheral surface of the conveyance drum 40. The conveyance drum 40 adsorbs the recording medium 23 to the outer peripheral surface of the conveyance drum 40 by suction of air, for example, and rotates in this state to convey the recording medium 23 in the direction of arrow 7b.

[0042] <<Conveyance Cylinder>> The conveyance cylinder 41 is a cylindrical member that forms the outer peripheral surface of the conveyance drum 40. The conveyance cylinder 41 is made of a plate member such as a net-like stainless steel having innumerable suction holes (for example, through holes with a diameter of φ1 mm) (not shown) for adsorbing the recording medium 23. A sheet having porosity formed in a resin-made PFA (PerFluoroalkoxy Alkane) sheet is placed on the plate member so that the suction holes on the adsorption surface do not affect printing. In order to be able to adsorb the recording media 23 of a plurality of sizes well, the conveyance cylinder 41 closes the suction holes in the regions outside the size (near both end portions in the width direction of the recording medium 23) to improve the adsorption force. The conveyance cylinder 41 for inkjet uses ink that softens at a high temperature, and while heating the conveyance drum 40 with a heater (not shown), sucks dirt from the suction holes (not shown). Then, the dirt adhering to the suction holes (not shown) of the conveyance cylinder 41 is removed by the cleaning unit 5.

[0043] Since the conveyance cylinder 41 can convey the recording medium 23 in close contact therewith while preventing the recording medium 23 from being lifted by air adsorption to the suction holes (not shown), the recording medium 23 can be conveyed without slipping. For this reason, when the recording medium 23 has so-called paper float, the conveyance cylinder 41 can prevent the recording medium 23 from contacting the nozzles 31Y, 31M, 31C, 31K and causing image defects and nozzle damage.

[0044] The rotating shaft 43 is provided on the central axis of the conveyance drum 40 and projects axially from the support portion 42. The rotating shaft 43 is rotatably supported by a pair of bearing members (not shown). A rotation driving portion (not shown) is provided at one axial end portion of the rotating shaft 43 via, for example, a reduction gear mechanism (not shown). The rotating shaft 43 and the conveyance drum 40 rotate when the rotation driving portion (not shown) is driven.

[0045] <Image forming unit> As shown in FIG. 1, the image forming unit 3 is an image forming means for forming an image on the recording medium 23 supplied from the recording medium supply unit 22 using ink. The image forming unit 3 includes a carriage 31, a conveyance unit 4, a fixing unit 32, an image reading unit 33, and a control unit 9.

[0046] <Carriage> As shown in FIG. 1, the carriage 31 is configured to include, for example, four nozzles 31Y, 31M, 31C, and 31K. The carriage 31 is supported by a support member (not shown) so that the nozzles 31Y, 31M, 31C, and 31K face the outer peripheral surface of the conveyance unit 4. The carriage 31 is driven by a printing control unit 34 to eject ink from the nozzles 31Y, 31M, 31C, and 31K onto the recording medium 23.

[0047] <Nozzle> As shown in FIG. 1, the inkjet head having the nozzle 31Y ejects yellow ink onto the recording medium 23 to form an image. Further, the inkjet head having the nozzle 31M ejects magenta ink onto the recording medium 23 to form an image. The inkjet head having the nozzle 31C ejects cyan ink onto the recording medium 23 to form an image. Also, the inkjet head having the nozzle 31K ejects black ink onto the recording medium 23 to form an image. In the inkjet recording apparatus 200, as an example, the case where ultraviolet curable ink is used will be described.

[0048] Further, the plurality of nozzles 31Y, 31M, 31C, and 31K are arranged above the conveyance drum 40 at appropriate intervals in the circumferential direction. In the inkjet recording apparatus 200 of the present embodiment, four nozzles 31Y, 31M, 31C, and 31K for forming an image using four colors of ink are provided in the image forming unit 3, but the number of nozzles may be appropriately changed. Hereinafter, the carriage 31 provided with the four nozzles 31Y, 31M, 31C, and 31K will be described as an example.

[0049] <Fixing unit> The fixing unit 32 shown in Fig. 1 is a fixing means for curing and fixing the ink on the recording medium 23 by irradiating ultraviolet rays on the recording medium 23 conveyed by the rotation of the conveyance drum 40. The conveyance drum 40 air-adsorbs the recording medium 23. The ink on the recording medium 23 refers to the ink forming an image on the recording medium 23. The fixing unit 32 has a function of fixing the image formed on the recording medium 23 using the ink to the recording medium 23. The fixing of the image by the fixing unit 32 is not limited to a UV (Ultra Violet) lamp that irradiates ultraviolet rays, but may be one that irradiates energy rays capable of curing the ink according to the properties of the ink, one that heats the recording medium 23 to dry the ink, and the like.

[0050] <Image reading unit> The image reading unit 33 is a device that reads the image formed on the recording medium 23. The image reading unit 33 is disposed on the opposing surface of the conveyance cylinder 41 on the downstream side of the fixing unit 32 on the outer peripheral surface of the conveyance cylinder 41. The image reading unit 33 outputs the result of the read image to the image receiving unit 35. The image reading unit 33 includes, for example, a linear image sensor in which a plurality of imaging elements such as a CCD (charge-coupled device) image sensor are arranged, a generation unit that generates image data from the imaging elements, and a light source that irradiates light on the recording medium 23.

[0051] <Image receiving unit and image determination unit> The image receiving unit 35 is a device that receives the image from the image reading unit 33. The image determination unit 36 determines whether the image of the recording medium 23 is a normally printed recording medium 23 that satisfies a predetermined image condition or a defective recording medium 23 that is a soiled paper with foreign matters such as paper powder or dirt attached thereto. The determination result of the image determination unit 36 is sent to the paper discharge destination switching unit 47 via the control unit 9.

[0052] <Paper discharge inversion switching unit> The paper discharge inversion switching unit 44 shown in FIG. 1 is a conveyance destination switching means for switching and sending out whether to send the recording medium 23 sent by the conveyance unit 4 to the paper discharge unit 6 or to the front-back inversion unit 46. The paper discharge inversion switching unit 44 has a switching conveyance roller 44a for conveying the recording medium 23. The paper discharge inversion switching unit 44 is arranged on the outer peripheral portion of the conveyance cylinder 41 on the downstream side in the direction of the arrow 7a which is the conveyance direction of the conveyance drum 40.

[0053] <Paper discharge inversion conveyance roller> The paper discharge inversion conveyance roller 45 is a roller for conveying the recording medium 23 in the direction of the paper discharge unit 6 or for inverting the recording medium 23 and conveying it in the direction of the front-back inversion unit 46. The paper discharge inversion conveyance roller 45 is arranged at a position where the recording medium 23 sent from the conveyance drum 40 in the direction of the paper discharge unit 6 can be sandwiched between the paper discharge inversion switching unit 44 and the paper discharge inversion conveyance roller 45.

[0054] <Front-back inversion unit> The front-back inversion unit 46 shown in FIG. 1 is an inversion means for inverting the front and back of the recording medium 23 in order to form images on both sides of the recording medium 23. The front-back inversion unit 46 for double-sided printing is provided between the paper discharge inversion switching unit 44 and the paper feed unit 2. For this reason, the front-back inversion unit 46 is arranged so as to invert the recording medium 23 sent from the paper discharge inversion switching unit 44 and send it out to the delivery roller 22a side on the outer peripheral surface of the conveyance drum 40.

[0055] <Paper discharge destination switching unit> The paper discharge destination switching unit 47 is a switching means for switching the paper discharge destination of the recording medium 23. The paper discharge destination switching unit 47 is a device that switches the paper discharge destination to either the good product paper discharge unit 61 where the normally printed recording media 23 are accumulated or the defective product paper discharge unit 62 where the waste paper that has become unusable as a product in the printing process is accumulated. The switching of the paper discharge destination between the good product paper discharge unit 61 and the defective product paper discharge unit 62 by the paper discharge destination switching unit 47 is performed according to the instruction of the control unit 9.

[0056] <Cleaning unit> The cleaning unit 5 shown in FIG. 1 is a cleaning means for cleaning foreign matters such as paper dust attached to the surface of the conveyance drum 40 which is a recording medium conveyance unit, and dirt soiled by ink mist. The cleaning unit 5 is configured to include, for example, a cleaning roller 50 that cleans the conveyance drum 40. The cleaning unit 5 is provided on the upstream side in front of the front-back reversing unit 46 that reverses the recording medium 23 on the outer peripheral portion of the conveyance cylinder 41.

[0057] The cleaning roller 50 is composed of a roller having a cleaning surface on its outer peripheral portion for cleaning foreign matters such as paper dust attached to the conveyance drum 40 and dirt such as ink mist. The cleaning surface is formed in a sheet shape by a material having a high surface adhesion force to which foreign matters such as paper dust and dirt such as ink mist adhere, or is formed in a layer on the outer peripheral surface of the cleaning roller 50. Examples of the material having a high surface adhesion force include polyimide resin, nylon resin, polyester resin, polyurethane resin, polycarbonate resin, polyimide resin, nylon resin, etc. Alternatively, a woven fabric, non-woven fabric, sponge, or the like, which is a member having high ink absorbency, may be attached to the cleaning surface.

[0058] FIG. 5 is a schematic plan view showing a state when the cleaning roller 50 is installed at both end portions 51 and 52 on both sides in the width direction of the recording medium 23. As shown in FIG. 5, the cleaning roller 50 is disposed at both end portions 51 and 52 on both sides in the width direction of the recording medium 23 where foreign matters such as paper dust and dirt such as ink are likely to adhere. The cleaning roller 50 can efficiently clean the regions of both end portions in the width direction of the recording medium 23 where foreign matters are likely to adhere by the cleaning portions 51a and 52a at both end portions 51 and 52.

[0059] FIG. 6 is a schematic plan view showing a state when the cleaning roller 50 is installed at both end portions 51 and 52 on both sides in the width direction of the recording medium 23 and at the rear end portion 53 on the conveyance direction side of the recording medium 23. Also, as shown in FIG. 6, the cleaning roller 50 is divided and arranged at both end portions 51 and 52 on both sides in the width direction of the recording medium 23 and at the rear end portion 53 on the conveyance direction side of the recording medium 23. The rear end portion 53 is arranged so that only the cleaning portion 53a contacts the conveyor 4. Since the conveyance cylinder 41 of the conveyance drum 40 shown in FIG. 1 has three sides, it is possible to clean all three sides with the cleaning portions 51a and 52a at the end portions 51 and 52 and the cleaning portion 53a at the rear end portion 53.

[0060] <Paper discharge unit> The paper discharge unit 6 shown in FIG. 1 is a place where the recording medium 23 such as paper after the formation of the image is discharged by the conveyor 4 and temporarily stored. The paper discharge unit 6 stores the recording medium 23 sent out from the image forming unit 3 through the paper discharge reverse switching unit 44 and the paper discharge destination switching unit 47. The paper discharge unit 6 includes a good product paper discharge unit 61 and a defective product paper discharge unit 62.

[0061] The good product paper discharge unit 61 has a flat recording medium discharge tray 61a on which the good product recording medium 23 after the formation of the image is placed. The defective product paper discharge unit 62 has a flat recording medium discharge tray 62a on which the defective product recording medium 23 is placed.

[0062] <Control unit> The control unit 9 shown in FIG. 1 is configured to include a CPU (Central Processing Unit), a ROM (Read-Only Memory), a RAM (Random Access Memory), an input / output circuit, etc. The control unit 9 controls the carriage 31, the fixing unit 32, the image reading unit 33, the conveyance drum 40, the paper discharge reverse switching unit 44, the paper discharge reverse conveyance roller 45, the front-back reversal unit 46, the paper discharge destination switching unit 47, etc.

[0063] Based on the determination result of the image determination unit 36, the control unit 9 controls the paper discharge destination switching unit 47 to convey the normally printed recording medium 23 to the good product paper discharge unit 61. The control unit 9 further controls to convey the defective recording medium 23 to the defective product paper discharge unit 62. Further, when the size of the recording medium 23 is changed, the control unit 9 causes the cleaning unit 5 to clean the conveyance unit 4 before the start of printing.

[0064] Further, when the size of the recording medium 23 is changed to a larger size, the control unit 9 causes the cleaning unit 5 to clean the conveyance drum 40 before the start of printing. And when the size of the recording medium 23 is changed to a smaller size, the control unit 9 does not cause the cleaning unit 5 to clean the conveyance drum 40. Further, when the size of the recording medium 23 is not changed, the control unit 9 does not cause the cleaning unit 5 to clean the conveyance drum 40. Further, during printing, when the preset number of printed sheets is exceeded, the control unit 9 does not cause the cleaning unit 5 to perform cleaning.

[0065] ≪Operation of Inkjet Recording Apparatus≫ FIG. 2 is a schematic configuration diagram showing the overall configuration of the inkjet recording apparatus 200 according to an embodiment of the present invention, and shows a state when the recording medium 23 is conveyed toward the front-back inversion unit 46. FIG. 3 is a schematic configuration diagram showing the overall configuration of the inkjet recording apparatus 200 according to an embodiment of the present invention, and shows a state when the recording medium 23 is being front-back inverted. FIG. 4 is a schematic configuration diagram showing the overall configuration of the inkjet recording apparatus 200 according to an embodiment of the present invention, and shows a state when the inverted recording medium 23 is sent out toward the delivery roller 22a side.

[0066] Next, the operation of the inkjet recording apparatus 200 will be described with reference to FIGS. 1 to 6. First, cleaning of the suction holes (not shown) of the conveyance cylinder 41 shown in FIG. 1 is started.

[0067] The ink in the carriage 31 is gel-like at normal temperature and becomes liquid when the temperature reaches 50° C. or higher. For this reason, the ink adhering to the conveyance cylinder 41 is made into an easily removable state by heating it to 50° C. or higher to make it liquid. When cleaning the suction holes (not shown) of the conveyance cylinder 41, it is preferable to heat the conveyance cylinder 41 with a heater (not shown) to a temperature exceeding the melting temperature of this ink (for example, 60° C.) during non-printing and non-conveying.

[0068] When printing one side of the recording medium 23 with the inkjet recording apparatus 200, as shown in FIG. 1, the recording medium 23 in the paper feeding unit 2 is fed to positions 7A, 7B, and 7C in sequence, and printed on the surface of the recording medium 23 by the carriage 31. The printed recording medium 23 is fixed by the fixing unit 32 while being fed to position 7E by the conveyance drum 40. Then, after the printing status of the recording medium 23 is read by the image reading unit 33, it is fed to position 7F in the paper discharging unit 6 via the paper discharge reversing switching unit 44 and the paper discharge destination switching unit 47. When the recording medium 23 is determined to be a good product by the image reading unit 33, it is sent from the paper discharge destination switching unit 47 to the good product paper discharging unit 61. When the recording medium 23 is determined to be a defective product by the image reading unit 33, it is sent from the paper discharge destination switching unit 47 to the defective product paper discharging unit 62. When the conveyance drum 40 is conveying the recording medium 23, the cleaning unit 5 cleans and removes foreign matters such as paper dust adhering to the periphery of the conveyance drum 40. In this way, the inkjet recording apparatus 200 prints one side of the recording medium 23.

[0069] Furthermore, when printing both sides of the recording medium 23 with the inkjet recording apparatus 200, as shown in FIG. 2, the recording medium 23 in the paper feeding unit 2 is fed to positions 7A, 7B, 7C, and 7D, and the surface of the recording medium 23 is printed by the carriage 31. The printed recording medium 23 is fixed by the fixing unit 32 while being fed to position 7E by the conveyance drum 40, and the printing status is read by the image reading unit 33. Thereafter, the recording medium 23 is fed to the position 7F on the side of the paper discharge reversing conveyance roller 45 and the front-back reversing unit 46 by the paper discharge reversing switching unit 44. Also at this time, when the conveyance drum 40 is conveying the recording medium 23, the cleaning unit 5 cleans and removes foreign matters such as paper dust adhering to the periphery of the conveyance drum 40.

[0070] Next, as shown in position 7F in FIG. 3, the recording medium 23 sent to the front-back reversing unit 46 is turned over so that the front and back are reversed when the front-back reversing unit 46 rotates. Also at this time, when the conveyance drum 40 is conveying the recording medium 23, the cleaning unit 5 cleans foreign matters such as paper dust adhering to the conveyance drum 40.

[0071] Subsequently, the position 7F of the recording medium 23 that has been turned inside out is sent out to the outer peripheral surface of the conveyance drum 40 in a state where the front and back sides are reversed, as shown in FIG. 4, by the rotation of the front-back inversion unit 46. The position 7F of the recording medium 23 sent out to the outer peripheral surface of the conveyance drum 40 is sent to the position 7C via the delivery roller 22a, and the back surface of the recording medium 23 is printed by the carriage 31. Also at this time, when the conveyance drum 40 is conveying the recording medium 23, the cleaning unit 5 cleans foreign matters such as adhered paper dust. In this way, the recording medium 23 is printed on both sides.

[0072] As shown in FIG. 1, the conveyance unit cleaning device which is the inkjet recording device 200 according to the present invention includes a paper feeding unit 2 that supplies the recording medium 23, a conveyance drum 40 that adsorbs and conveys the recording medium 23, a cleaning unit 5 that cleans the conveyance drum 40, and a control unit 9 that controls the cleaning unit 5. When the size of the recording medium 23 is changed, the control unit 9 causes the cleaning unit 5 to clean the conveyance drum 40 before the start of printing.

[0073] According to such a configuration, when the size of the recording medium 23 is changed, the control unit 9 causes the cleaning unit 5 to automatically clean the recording medium conveyance unit (for example, the conveyance drum 40) before the start of printing to remove foreign matters and dirt, so that the labor of manual cleaning can be saved. Further, the conveyance unit cleaning device can maintain the adsorption performance without skill by cleaning the conveyance drum 40. Therefore, the conveyance unit cleaning device which is the inkjet recording device 200 of the present invention can automatically clean the conveyance surface of the conveyance drum 40 to maintain the adsorption force of the recording medium 23 and prevent a decrease in the conveyance force so that an error due to paper lifting does not occur.

[0074] Also, as shown in FIG. 1, when the recording medium 23 is changed to a larger size, the control unit 9 causes the cleaning unit 5 to clean the conveyance drum 40 before the start of printing, and when the recording medium 23 is changed to a smaller size, the control unit 9 does not cause the cleaning unit 5 to clean the recording medium conveyance unit.

[0075] According to such a configuration, when the size of the recording medium 23 is changed to a larger size, the control unit 9 causes the cleaning unit 5 to clean the conveyance drum 40 before printing starts. Therefore, when printing a large-sized recording medium 23 after printing a small-sized recording medium 23, it is possible to prevent paper powder remaining under the recording medium 23 from clogging the suction holes of the conveyance drum 40, deteriorating the suction force, and causing paper floating.

[0076] Further, when the size of the recording medium 23 is changed to a smaller size, the control unit 9 does not cause the cleaning unit 5 to clean the conveyance drum 40. Therefore, in the present invention, it is possible to maintain the adhesiveness of the adhesive type cleaning unit 5 and prevent the adhesiveness from decreasing, or reduce the frequency of water exchange of the wet cleaning unit 5 by the number of times corresponding to not cleaning. As a result, since the cleaning unit 5 cleans only when necessary, it can be cleaned efficiently and the life of the cleaning unit 5 can be extended.

[0077] Also, as shown in FIG. 1, when the control unit 9 does not change the size of the recording medium 23, it does not cause the cleaning unit 5 to clean.

[0078] According to such a configuration, since foreign matters such as paper powder are unlikely to occur on the outer peripheral surface of the conveyance drum 40 when the size of the recording medium 23 is not changed, the suction force does not deteriorate. Therefore, when the size of the recording medium 23 is not changed, it is possible to save waste by not cleaning the conveyance drum 40.

[0079] Also, as shown in FIG. 1, during printing, when the control unit 9 exceeds a preset number of printed sheets, it does not cause the cleaning unit 5 to clean the recording medium conveyance unit.

[0080] According to such a configuration, when the cleaning unit 5 exceeds a predetermined number of printed sheets, it can efficiently clean the conveyance surface of the conveyance drum 40 by cleaning the conveyance drum 40 which is the recording medium conveyance unit. Therefore, the cleaning unit 5 can maintain the suction force of the recording medium 23 of the conveyance drum 40 and prevent the conveyance force from decreasing.

[0081] Further, as shown in FIG. 1, the recording medium conveyance unit includes a conveyance drum 40 that conveys the recording medium 23.

[0082] According to such a configuration, the recording medium conveyance unit is specifically the conveyance drum 40, and it is possible to suck the ink mist inside so as not to scatter on the outer peripheral portion. Further, since the recording medium conveyance unit is composed of the conveyance drum 40, the conveyance path can be shortened and the entire apparatus can be downsized.

[0083] Also, as shown in FIG. 1, a paper discharge unit 6 that discharges the printed recording medium 23, a front-back inversion unit 46 that inverts the recording medium 23, and a paper discharge inversion switching unit 44 for switching whether to send the recording medium 23 to the paper discharge unit 6 side or to the front-back inversion unit 46 side are provided. A front-back inversion unit 46 for double-sided printing is provided between the paper discharge inversion switching unit 44 and the paper feeding unit 2.

[0084] According to such a configuration, since the front-back inversion unit 46 is provided between the paper discharge inversion switching unit 44 and the paper feeding unit 2, both single-sided printing and double-sided printing can be performed.

[0085] Also, as shown in FIG. 6, the cleaning unit 5 includes a cleaning roller 50 that cleans the conveyor 4. The cleaning roller 50 is divided and arranged at both end portions 51, 52 on both sides in the width direction of the recording medium 23 and at the rear end portion 53 on the conveyance direction side of the recording medium 23. The rear end portion 53 is arranged so that only the cleaning portion 53a contacts the conveyor 4.

[0086] According to such a configuration, the cleaning roller 50 is arranged at both end portions 51, 52 on both sides in the width direction of the recording medium 23 and at the rear end portion 53 on the conveyance direction side of the recording medium 23. Therefore, the cleaning roller 50 can be arranged at the end portions 51, 52 and the rear end portion 53 to limit the cleaning range, thereby reducing the size of the cleaning unit 5. Further, the cleaning roller 50 can appropriately clean a cleaning area that changes according to the size of the recording medium 23. In particular, since the cleaning units 51a and 52a are arranged at both end portions in the width direction of the recording medium 23 where paper dust and ink mist are likely to collect, efficient cleaning can be performed. As a result, the cleaning roller 50 can perform cleaning according to the number of printed sheets and the size of the recording medium 23, so that downtime can be reduced.

[0087] Also, as shown in FIG. 1, the cleaning unit 5 is provided in front of the upstream side of the front-and-back reversing unit 46 that reverses the recording medium 23.

[0088] According to such a configuration, in the outer peripheral portion of the conveyance drum 40, the cleaning unit 5 cannot be cleaned during double-sided printing when it is between the front-and-back reversing unit 46 and the delivery roller 22a of the paper feeding unit 2. For this reason, by arranging the cleaning unit 5 in front of the upstream side of the front-and-back reversing unit 46, the conveyance device 4 can be efficiently cleaned during single-sided printing and double-sided printing.

[0089] Also, as shown in FIG. 1, the inkjet recording device 200 is a conveyance unit cleaning device, and includes a conveyance device 4 and an image forming unit 3 that forms an image on the recording medium 23 supplied from the conveyance device 4.

[0090] According to such a configuration, the conveyance unit cleaning device that is the inkjet recording device 200 includes the conveyance device 4 and the image forming unit 3, so that an image can be efficiently formed on the recording medium 23 while the recording medium 23 is being conveyed. Further, the inkjet recording device 200 can efficiently clean foreign matters such as paper dust generated when forming an image and dirt.

[0091] [First Modified Example] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be appropriately changed without departing from the gist of the present invention.

[0092] For example, the conveyor 4 composed of the conveyance drum 40 shown in FIG. 1 may include a conveyance roller (not shown) that conveys the recording medium 23. According to such a configuration, since the conveyor 4 is composed of one equipped with a conveyance roller, it is possible to provide an adhesive member, a member with a large frictional resistance, a surface with a rough surface roughness, etc. on the conveyance surface to facilitate the conveyance of the recording medium 23.

[0093] [Second Modification Example] Also, the conveyor 4 shown in FIG. 1 may be a conveying device configured to include a conveying belt (not shown) that conveys the recording medium 23. According to such a configuration, since the conveyor 4 is equipped with a conveying belt, it is easy to bring the surface of the conveying belt into contact with the conveyor 4, so that cleaning can be performed efficiently.

[0094] [Third Modification Example] Also, the cleaning unit 5 shown in FIG. 1 may include an adhesive roller (not shown) that cleans the conveyor 4. In this case, the adhesive roller has an adhesive surface on the outer peripheral surface of the roller for adhering foreign matters such as paper dust attached to the conveyance drum 40. The adhesive surface has a replaceable adhesive sheet attached to the outer peripheral surface of the adhesive roller. According to such a configuration, since the cleaning unit 5 is equipped with an adhesive roller, foreign matters such as paper dust attached to the conveyor 4 can be adhered to the adhesive surface of the adhesive roller and cleaned. When the adhesive force of the adhesive sheet attached to the outer peripheral surface of the adhesive roller decreases, the adhesive force can be maintained by appropriately replacing it.

[0095] [Fourth Modification Example] Also, the cleaning unit 5 shown in FIG. 1 may include an air injection unit (not shown) that injects air for cleaning the conveyor 4. According to such a configuration, since the conveyor 4 is equipped with an air injection unit, by blowing the air injected from the air injection unit onto the conveyor 4, foreign matters such as paper dust can be efficiently removed and cleaned.

[0096] [Fifth Modification Example] Further, the cleaning unit 5 shown in FIG. 1 may be provided with a brush (not shown) for cleaning the conveyor 4. According to such a configuration, since the conveyor 4 is provided with a brush, by making sliding contact with the conveyor 4 that rotates the brush, it is possible to efficiently remove foreign matters such as paper dust and dirt and perform cleaning.

[0097] [Sixth Modification Example] Further, the cleaning unit 5 shown in FIG. 1 may be provided with wet cleaning means (not shown) for cleaning the conveyor 4. According to such a configuration, since the conveyor 4 is provided with wet cleaning means, by replenishing the cleaning liquid, it is possible to use the conveyor 4 for a long time with paper dust, ink, toner, etc. adhering thereto.

[0098] [Other Modification Examples] Further, the conveyor 4 may be provided with a heater (not shown) for heating the conveyance drum 40 and a suction device (not shown) for sucking ink stains and the like adhering to the conveyance drum 40, at the peripheral portion of the conveyance drum 40. According to such a configuration, since the conveyor 4 has a heater, it is possible to heat the conveyance drum 40 and soften the ink stains adhering to the conveyance drum 40. Further, since the conveyor 4 has a suction device, it is possible to easily suck and remove the ink stains softened by the heater. For this reason, the present invention can prevent the recording medium 23 from being unable to be normally adsorbed to the conveyance cylinder 41 due to clogging of the suction holes (not shown) of the conveyance cylinder 41 with ink mist.

Explanation of Reference Numerals

[0099] 2 Paper Feeding Unit 3 Image Forming Unit 4 Conveyor 5 Cleaning Unit 6 Paper Discharging Unit 9 Control Unit 23 Recording Medium 40 Conveyance Drum (Recording Medium Conveying Unit) 44 Paper Discharge Reversal Switching Unit 46 Front and back inversion part 50 Cleaning roller 51, 52 Ends 53 Rear end 53a Cleaning part 200 Inkjet recording apparatus (transport unit cleaning apparatus)

Claims

1. A recording medium conveyance unit that adsorbs and conveys a recording medium, A cleaning unit that cleans the recording medium conveyance unit, A control unit that controls the cleaning unit, Comprising, When the size of the recording medium changes, the control unit causes the cleaning unit to clean the recording medium conveyance unit before the start of printing, A conveyance unit cleaning device.

2. When the size changes to a size larger than the recording medium, the control unit causes the cleaning unit to clean the recording medium conveyance unit before the start of printing, When the recording medium changes to a smaller size, the cleaning unit does not clean the recording medium conveyance unit, The conveyance unit cleaning device according to claim 1.

3. When the size of the recording medium does not change, the control unit does not cause the cleaning unit to clean the recording medium conveyance unit, The conveyance unit cleaning device according to claim 1.

4. During printing, when the preset number of printed sheets is exceeded, the control unit does not cause the cleaning unit to clean the recording medium conveyance unit, The conveyance unit cleaning device according to claim 1.

5. The recording medium conveyance unit includes a conveyance drum that conveys the recording medium, The conveyance unit cleaning device according to claim 1.

6. The recording medium conveyance unit includes a conveyance roller that conveys the recording medium, The conveyance unit cleaning device according to claim 1.

7. The recording medium conveyance unit includes a conveyance belt that conveys the recording medium, The conveyance unit cleaning device according to claim 1.

8. A paper feeding unit that supplies the recording medium to the recording medium conveyance unit, A paper discharging unit that discharges the printed recording medium, A front-back reversing unit that reverses the recording medium, A paper discharge / reverse switching unit for switching whether to send the recording medium to the paper discharge unit side or to the front-back reversing unit side, and is provided with, Between the paper discharge / reverse switching unit and the paper feeding unit, the front-back reversing unit for double-sided printing is provided, The conveyance unit cleaning device according to claim 1.

9. The cleaning unit includes a cleaning roller that cleans the recording medium conveyance unit, The cleaning roller is divided and arranged at both end portions on both sides in the width direction of the recording medium and at the rear end portion in the conveyance direction of the recording medium, The rear end portion is arranged so that only the cleaning portion contacts the recording medium conveyance unit, The conveyance unit cleaning device according to claim 1.

10. The cleaning unit includes an adhesive roller that cleans the recording medium conveyance unit, The conveyance unit cleaning device according to claim 1.

11. The cleaning unit includes an air injection unit that injects air for cleaning the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1. Claim 12 The cleaning unit includes a brush for cleaning the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1. Claim 13 The cleaning unit includes wet cleaning means for cleaning the recording medium conveyance unit. The conveyance unit cleaning device according to claim 1. Claim 14 The cleaning unit is provided upstream of the front and back inversion unit that inverts the recording medium. The conveyance unit cleaning device according to claim 1. Claim 15 The conveyance unit cleaning device according to any one of claims 1 to 13, the recording medium conveyance unit, an image forming unit that forms an image on the recording medium supplied from the recording medium conveyance unit, and is provided with. An image forming apparatus.

Images