Ink jet recording device

Abstract

To provide an ink jet recording device in which nozzle clogging and conveyor belt contamination due to paper powders generated when conveying a paper sheet by electrostatic adsorption system, can be effectively suppressed.SOLUTION: An ink jet recording device comprises: a conveyance part which conveys a paper sheet by electrostatically adsorbing the paper sheet to a conveyor belt; a recording part having a recording head which is located in such a way as to face a conveyance surface of the conveyor belt; a cap mounted to an ink ejection surface of the recording head; a suction pump which sucks air inside the cap; an ink discharge flow channel; a static eliminator; a control part; and a foreign matter suction flow channel. The static eliminator has: a roll-shaped static elimination brush; a brush drive motor which rotates the static elimination brush in a forward direction with respect to a movement direction of the conveyor belt; a duct which covers a side of the static elimination brush opposite to the conveyor belt; and a scraper which scrapes off foreign matters adhered to the static elimination brush. The foreign matter suction flow channel communicates with the duct and the suction pump, and recovers the foreign matters in the duct by using the suction pump and the foreign matter suction flow channel.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an inkjet recording apparatus that performs recording by ejecting ink from ink ejection nozzles provided in a recording head. [Background technology]

[0002] 2. Description of the Related Art Inkjet recording devices, which form images by ejecting ink from nozzles provided in a recording head, are widely used as recording devices such as facsimiles, copiers, and printers because they are capable of forming high-resolution images.

[0003] In such inkjet recording devices, an electrostatic adsorption method is known as a method for transporting paper used as a recording medium. In this method, a resin transport belt is charged by a charging means, and when the paper is pressed against the belt, the internal part of the paper is polarized, generating an electrostatic force that attracts the paper. In this method, it is known that the adsorption force can be increased by discharging the surface of the paper opposite to the surface facing the transport belt (the adsorption surface) using a discharging member such as a conductive discharging brush arranged in a direction perpendicular to the transport direction.

[0004] However, there was a problem in that paper dust generated when the static eliminator rubbed against the paper adhered to the nozzle surface of the recording head and clogged the nozzles, causing nozzle discharge problems (missing pins) and reducing image quality.

[0005] Therefore, various methods have been proposed to prevent nozzle clogging due to paper dust, and for example, Patent Document 1 discloses an inkjet recording device equipped with a static elimination brush that can move on a movement path that includes a direction intersecting the transport direction, and a scraping member that can come into contact with the static elimination brush. The movement path of the static elimination brush includes a curved path, and the scraping member can come into contact with the static elimination brush located on the curved path, and is equipped with a duct that sucks in foreign matter scraped off by the scraping member. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-109813 Summary of the Invention [Problem to be solved by the invention]

[0007] In the configuration of Patent Document 1, the anti-static brush neither moves nor rotates in the transport direction, so the only way to suppress the generation of paper dust during paper transport is to reduce the linear speed of the transport belt. This leads to a problem of reduced image formation efficiency (productivity). Furthermore, a dedicated fan is provided to suck in foreign matter from the duct, which leads to problems of increased size and cost for the device.

[0008] In view of the above problems, an object of the present invention is to provide an inkjet recording apparatus that can effectively prevent nozzle clogging and transport belt contamination caused by paper dust that occurs when transporting paper using an electrostatic adsorption method. [Means for solving the problem]

[0009] To achieve the above object, a first aspect of the present invention is an inkjet recording apparatus including a transport unit, a recording unit, a cap, a suction pump, an ink discharge flow path, a static eliminator, a control unit, and a foreign matter suction flow path. The transport unit transports paper by electrostatically adsorbing it to an endless transport belt. The recording unit has a recording head disposed opposite the transport surface of the transport belt, and ejects ink from the ink ejection ports of the recording head onto the paper transported by the transport belt. The cap is attached to the ink ejection surface of the recording head, forming an airtight space between the cap and the ink ejection surface. The suction pump sucks air from inside the cap. The ink ejection flow path ejects liquid sucked into the cap by the suction pump. The static eliminator is disposed upstream of the recording unit in the paper transport direction and removes electrical charges from the paper. The control unit controls the operation of the transport unit, the recording unit, the suction pump, and the static eliminator. The static eliminator has a static eliminator brush, a brush drive motor, a duct, and a scraper. The static elimination brushes are roll-shaped and arranged facing each other across the entire width of the conveyor belt, perpendicular to the conveying direction, and come into contact with the paper being conveyed by the conveyor belt. A brush drive motor rotates the static elimination brushes in the forward direction relative to the moving direction of the conveyor belt. A duct covers the side of the static elimination brush opposite the conveyor belt and sucks up foreign matter generated by contact between the static elimination brush and the paper or conveyor belt. A scraper protrudes from the inner surface of the duct so as to come into contact with the static elimination brush and scrapes off foreign matter adhering to the static elimination brush. A foreign matter suction passage connects the duct to a suction pump, and the suction pump and the foreign matter suction passage are used to collect foreign matter inside the duct. [Effects of the Invention]

[0010] According to the first aspect of the present invention, by rotating the anti-static brush in the forward direction relative to the movement direction of the conveyor belt during printing, the anti-static brush is prevented from rubbing against the paper surface. As a result, the paper can be neutralized without generating unnecessary paper dust. This reduces the generation of paper dust from the paper being conveyed to the recording unit, effectively preventing clogging of ink ejection orifices and contamination of the conveyor belt due to paper dust. Furthermore, the paper dust removed from the conveyor belt is sucked up using a suction pump used to perform a suction purge process for the recording head. This eliminates the need for a separate pump for paper dust suction, contributing to a reduction in the number of parts and cost. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a side cross-sectional view showing the schematic structure of a printer 100 as an inkjet recording apparatus according to an embodiment of the present invention. [Figure 2] FIG. 1 is a plan view of a recording unit 9 included in a printer 100 according to an embodiment of the present invention; [Figure 3] 1 is a side cross-sectional view of the first belt conveyance unit 5 and the recording unit 9 and its surroundings in the printer 100 of this embodiment. [Figure 4] FIG. 1 is a schematic diagram illustrating a suction path of a suction pump 55 connected to a static eliminator 40 of a printer 100 according to this embodiment and a cap 50 attached to a recording head 17. [Figure 5] FIG. 1 is a block diagram showing an example of a control path of a printer 100 according to an embodiment of the present invention. [Figure 6] 1 is a flowchart showing the static elimination operation and paper dust removal operation executed when printing with the printer 100 of this embodiment.

[0012] 1. Configuration of Inkjet Recording Apparatus Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing the general configuration of a printer 100 as an inkjet recording device according to an embodiment of the present invention. The printer 100 is equipped with a paper feed cassette 2, which is a paper storage unit. The paper feed cassette 2 is located at the bottom inside the printer main body 1. Inside the paper feed cassette 2, paper P, which is an example of a recording medium, is stored.

[0013] A paper feed device 3 is disposed downstream in the paper transport direction of the paper feed cassette 2, i.e., above the right side of the paper feed cassette 2 in Fig. 1. The paper feed device 3 separates and feeds the paper P one sheet at a time toward the upper right of the paper feed cassette 2 in Fig. 1.

[0014] A first paper transport path 4a is also provided inside the printer 100. The first paper transport path 4a is located in the upper right corner, in the paper feed direction, of the paper feed cassette 2. Paper P sent out from the paper feed cassette 2 is transported vertically upward along the side of the printer body 1 by the first paper transport path 4a.

[0015] A pair of registration rollers 13 is provided at the downstream end of the first paper transport path 4a in the paper transport direction. Furthermore, a first belt transport unit (transport unit) 5 and a recording unit 9 are arranged immediately downstream of the pair of registration rollers 13. The paper P sent out from the paper feed cassette 2 passes through the first paper transport path 4a and reaches the pair of registration rollers 13. The pair of registration rollers 13 corrects skewed feeding of the paper P and sends the paper P towards the first belt transport unit 5, timing it with the ink ejection operation performed by the recording unit 9.

[0016] The paper P sent to the first transport unit 5 by the pair of registration rollers 13 is transported by the first transport belt 8 to a position facing the recording unit 9 (particularly recording heads 17a to 17c, which will be described later). Ink is ejected from the recording unit 9 onto the paper P, thereby recording an image on the paper P. The ejection of ink in the recording unit 9 is controlled by a control device 110 inside the printer 100.

[0017] The first belt conveying section 5 includes an endless first conveying belt 8 (see FIG. 2) wound around a first driving roller 6 and a first driven roller 7. The paper P sent out from the pair of registration rollers 13 passes below the recording section 9 while being electrostatically attracted to the conveying surface 8a of the first conveying belt 8.

[0018] In the paper transport direction, a second belt transport section 12 is disposed downstream of the first transport unit 5 (on the left side in FIG. 1). The paper P on which an image has been recorded by the recording section 9 is sent to the second belt transport section 12. The ink ejected onto the surface of the paper P is dried while passing through the second belt transport section 12.

[0019] In the paper transport direction, a decurler unit 14 is provided downstream of the second transport unit 12 and near the left side of the printer body 1. The paper P from which the ink has been dried by the second transport unit 12 is sent to the decurler unit 14, where any curl that has occurred in the paper P is straightened.

[0020] In the paper transport direction, a second paper transport path 4b is provided downstream (upper in Figure 1) of the decurler unit 14. If double-sided recording is not being performed, the paper P that has passed through the decurler unit 14 passes through the second paper transport path 4b and is discharged to a paper discharge tray 15a provided outside the left side of the printer 100. Below the paper discharge tray 15a, a sub-discharge tray 15b is provided for discharging unwanted paper P (broken paper) that has suffered printing defects or the like.

[0021] A reverse transport path 16 for double-sided recording is provided at the top of the printer main body 1, above the recording unit 9 and second transport unit 12. When double-sided recording is performed, after recording on one side (first side) of the paper P is completed and the paper P passes through the second transport unit 12 and the decurler unit 14, it is sent to the reverse transport path 16 via the second paper transport path 4b.

[0022] After being sent to the reverse transport path 16, the transport direction of the paper P is then switched so that recording can be performed on the other side (second side) of the paper P. The paper P then passes over the top of the printer main body 1 and is transported to the right side, passes through the pair of registration rollers 13, and is sent again to the first transport unit 5 with its second side facing up. In the first transport unit 5, the paper P is transported to a position facing the recording unit 9, and an image is recorded on the second side by ink ejection from the recording unit 9. After double-sided recording, the paper P passes through the second transport unit 12, the decurler unit 14, and the second paper transport path 4b in that order, and is then discharged to the paper discharge tray 15a.

[0023] In addition, a maintenance unit 19 and a cap unit 20 are disposed below the second transport unit 12. When performing purging, the maintenance unit 19 moves horizontally below the recording unit 9, wipes off ink extruded from the ink ejection ports of the recording head, and collects the wiped ink. Purging refers to the operation of forcibly pushing ink out of the ink ejection ports of the recording head in order to expel thickened ink, foreign matter, and air bubbles from the ink ejection ports. When capping the ink ejection surface of the recording head, the cap unit 20 moves horizontally below the recording unit 9 and then moves upward to be attached to the underside of the recording head.

[0024] FIG. 2 is a plan view of the recording unit 9. The recording unit 9 includes a head housing 10 and line heads 11Y, 11M, 11C, and 11K. The line heads 11Y to 11K are held in the head housing 10 at a height that forms a predetermined gap (for example, 1 mm) with respect to the conveyance surface of an endless first conveyor belt 8 that is stretched over multiple rollers including a drive roller 6a, a driven roller 6b, and tension rollers 7a and 7b (see FIG. 3). The drive roller 6a drives the first conveyor belt 8 in the conveyance direction of the paper P (the direction of arrow A). The drive of this drive roller 6a is controlled by a main control unit 110a of the control device 110 (see FIG. 5).

[0025] Each of the line heads 11Y to 11K has a plurality of (three in this example) recording heads 17a to 17c. The recording heads 17a to 17c are arranged in a staggered pattern along the paper width direction (arrow BB' direction), which is perpendicular to the paper transport direction (arrow A direction). Each of the recording heads 17a to 17c has a plurality of ink ejection orifices 18 (nozzles). The ink ejection orifices 18 are arranged at equal intervals along the width direction of the recording head, that is, the paper width direction (arrow BB' direction). From the line heads 11Y to 11K, inks of yellow (Y), magenta (M), cyan (C), and black (K) are ejected via the ink ejection orifices 18 of the recording heads 17a to 17c toward the paper P transported by the first transport belt 8.

[0026] The recording heads 17a to 17c constituting the line heads 11Y to 11K are supplied with ink of four colors (yellow, cyan, magenta, and black) stored in ink tanks (not shown) for each of the line heads 11Y to 11K.

[0027] Each of the recording heads 17a to 17c ejects ink from ink ejection orifices 18 toward the paper P, which is adsorbed and held on the conveying surface of the first conveyor belt 8 and conveyed, in accordance with image data received from an external computer in response to a control signal from the control device 110 (see FIG. 5). As a result, a color image is formed on the paper P on the first conveyor belt 8, with inks of four colors, yellow, cyan, magenta, and black, superimposed on top of each other.

[0028] In the printer 100, in order to clean the ink ejection surfaces of the recording heads 17a to 17c, when printing starts after a long period of inactivity and between printing operations, ink is extruded (purged) from the ink ejection ports 18 of all recording heads 17a to 17c, and a recovery operation is performed for the recording heads 17a to 17c in which ink ejected from the ink ejection surfaces is wiped off with a wiper (not shown) in preparation for the next printing operation.

[0029] [2. Configuration of the static eliminator and its peripherals] FIG. 3 is a side cross-sectional view of the first belt transport unit 5 and the recording unit 9 and their surroundings of the printer 100 of this embodiment.

[0030] 3, a charging roller 20 is in contact with the tension roller 7b via the first conveyor belt 8. An attraction voltage power supply 21 is connected to the charging roller 20. The attraction voltage power supply 21 charges the first conveyor belt 8 by applying a predetermined voltage to the charging roller 20 based on a control signal sent from the paper attraction control unit 110b.

[0031] An attraction roller 30 is disposed upstream of the recording unit 9 in the paper transport direction and at a position facing the upstream end of the first transport belt 8. The attraction roller 30 rotates in contact with the transport surface of the first transport belt 8 or the paper P that is electrostatically attracted to the transport surface and transported. The attraction roller 30 is grounded (earthed).

[0032] A static eliminator 40 is disposed between the recording unit 9 and the attraction roller 30. The static eliminator 40 has a static eliminator brush 41, a duct 42, and a scraper 43. The static eliminator brush 41 is a roll-shaped brush made of a conductive material. A brush drive motor 60 (see FIG. 5) is connected to the rotation shaft of the static eliminator brush 41. The static eliminator brush 41 is earthed to the ground.

[0033] When a printing operation is performed, the paper P is transported from the registration roller pair 13 to the first belt transport unit 5 at a predetermined timing. The paper P transported to the first belt transport unit 5 is pressed against the transport surface of the first transport belt 8 by the attraction roller 30, and then passes below the static eliminator 40. At this time, the static eliminator brush 41 comes into contact with the paper P while rotating in the forward direction (clockwise in FIG. 3) relative to the movement direction of the first transport belt 8, thereby removing the charge on the paper P and electrostatically attracting the paper P to the first transport belt 8.

[0034] By using a roll-shaped brush as the de-ionization brush 41 and rotating it in the forward direction relative to the movement direction of the first conveyor belt 8, friction on the surface of the paper P is suppressed compared to when the de-ionization brush 41 is fixed, thereby suppressing the generation of paper dust.

[0035] Duct 42 covers the side (upper side) of discharging brush 41 opposite to first conveyor belt 8. A paper dust suction flow path 53 (see FIG. 4) is connected to duct 42. Paper dust generated by contact between discharging brush 41 and paper P passes through paper dust suction flow path 53 and is collected in waste ink collection container 52 (see FIG. 4). Scraper 43 protrudes from the inner surface of duct 42, and scrapes off foreign matter such as paper dust adhering to discharging brush 41 by coming into contact with the brush part when discharging brush 41 rotates.

[0036] 4 is a schematic diagram showing the configuration of the static eliminator 40 of the printer 100 and the suction path of the suction pump 55 connected to the cap 50 attached to the recording head 17. In the following description, the recording heads 17a to 17c will be simply referred to as the recording head 17.

[0037] A cap 50 is attached to the recording head 17. The cap 50 is supported by a cap unit 20 (see FIG. 1), and is attached to the ink ejection surface (nozzle surface) 171 of the recording head 17 when printing processing is not performed for a certain period of time or longer. By attaching the cap 50, the ink ejection surface 171 of the recording head 17 is kept sealed. An ink discharge flow path 51 is connected to the cap 50.

[0038] The ink discharge flow path 51 communicates between the inside of the cap 50 and the waste ink collection container 52. A paper dust suction flow path 53 is connected to the junction 51a of the ink discharge flow path 51. The paper dust suction flow path 53 communicates between the inside of the duct 42 of the static eliminator 40 and the ink discharge flow path 51.

[0039] A suction pump 55 is connected downstream of the junction 51a in the ink discharge direction (the direction from the recording head 17 toward the waste ink collection container 52) of the ink discharge flow path 51. A first on-off valve 56 is disposed between the recording head 17 and the junction 51a. The first on-off valve 56 opens and closes the ink discharge flow path 51 between the recording head 17 and the suction pump 55 in response to a control signal from the control device 110 (see FIG. 5).

[0040] A second on-off valve 57 is disposed between the static eliminator 40 and the junction 51a. The second on-off valve 57 opens and closes the paper dust suction passage 53 in response to a control signal from the control device 110.

[0041] In the printer 100, in order to remove dried or thickened ink and foreign matter from inside the ink ejection ports 18 (see FIG. 2) of the recording head 17, when starting printing after a long period of inactivity and between printing operations, with the cap 50 attached to the ink ejection surface 171, the suction pump 55 is used to suck air from the space (sealed space) between the ink ejection surface 171 and the cap 50, thereby performing a suction purge process to forcibly suck ink from all of the ink ejection ports 18 of the recording head 17, in preparation for the next printing operation. The ink sucked into the cap 50 from the recording head 17 (purged ink) is discharged outside the cap 50 by the suction pump 55 and then collected in the waste ink collection container 52 via the ink discharge flow path 51.

[0042] [3. Printer control path] 5 is a block diagram showing an example of a control path of the printer 100 of this embodiment. In addition to the above configuration, the printer 100 further includes an operation panel 27, a storage unit 28, a communication unit 29, and a brush drive motor 60.

[0043] The operation panel 27 is an operation unit for accepting various setting inputs. For example, the user can operate the operation panel 27 to input information about the size of the paper P to be set in the paper feed cassette 2a or the manual paper feed tray 2b, that is, the size of the paper P to be transported by the first transport belt 8. The user can also operate the operation panel 27 to input the number of sheets of paper P to be printed and to instruct the start of a print job. The operation panel 27 also functions as a notification device that notifies the user about the operating status of the printer 100.

[0044] The storage unit 28 is a memory that stores the operation program of the control device 110 and also stores various types of information, and is configured to include a ROM (Read Only Memory), a RAM (Random Access Memory), a non-volatile memory, etc. Information set by the operation panel 27 is stored in the storage unit 28.

[0045] The communication unit 29 is a communication interface for sending and receiving information to and from an external device (for example, a personal computer). For example, when a user operates a PC and sends a print command (print instruction) along with image data to the printer 100, the image data and print command are input to the printer 100 via the communication unit 29. In the printer 100, the main control unit 110a controls the recording heads 17a to 17c based on the image data to eject ink, thereby recording an image on the paper P.

[0046] The brush drive motor 60 rotates the static elimination brush 41 (see FIG. 3) at a predetermined rotation speed based on a control signal sent from the main control unit 110a.

[0047] The printer 100 of this embodiment also includes a control device 110. The control device 110 includes, for example, a CPU (Central Processing Unit) and a memory. Specifically, the control device 110 includes a main control unit 110a, a paper suction control unit 110b, a paper supply control unit 110b, and a maintenance control unit 110d.

[0048] The main control unit 110a controls the operation of each unit of the printer 100. For example, the main control unit 110a controls the driving of each roller inside the printer 100, the ejection of ink from the recording heads 17a to 17c when recording an image, etc. The main control unit 110a also drives the suction device 70 to remove paper dust from the paper P being transported to the recording unit 9.

[0049] The paper adsorption control unit 110b electrostatically adsorbs the paper P to the first conveyor belt 8 by sending a control signal to the adsorption voltage power supply 21 to apply a voltage to the charging roller 20.

[0050] The paper supply control unit 110c is a recording medium supply control unit that controls the pair of registration rollers 13 as a recording medium supply unit. For example, the paper supply control unit 110c controls the timing of conveying the succeeding paper P by controlling the pair of registration rollers 13 based on the timing of detection of the rear end of the paper P by a paper detection sensor (not shown).

[0051] The maintenance control unit 110d controls the recording heads 17a to 17c to perform the above-mentioned purge, which forcibly expels ink from each ink ejection nozzle 18. When the maintenance control unit 110d causes the recording heads 17a to 17c to perform the purge, it also controls the driving of the above-mentioned maintenance unit 19 (for example, the downward movement and retraction of the recording unit 9).

[0052] The control device 110 may further include a calculation unit that performs necessary calculations and a timer unit that measures time. Also, the main control unit 110a may function as both the calculation unit and the timer unit.

[0053] [4. Static electricity removal performed when the printer is printing] As described above, when the static elimination brush 41 is rotated and brought into contact with the paper P to eliminate static electricity, the static elimination brush 41 rubs against the surface of the paper P, generating paper dust. This paper dust clogs the ink ejection ports 18 of the recording head 17, causing ink ejection problems (missing pins) from the ink ejection ports 18, resulting in a decrease in image quality.

[0054] Therefore, in the printer 100 of this embodiment, the suction pump 55 used for the suction purge process of the recording head 17 is connected to the duct 42 of the static eliminator 40, and the paper dust generated in the static eliminator 40 is sucked and removed by the suction pump 55. In addition, the rotation speed of the static eliminator brush 41 is controlled to suppress the generation of paper dust.

[0055] 6 is a flowchart showing the static elimination operation and paper dust removal operation executed during printing by the printer 100 of this embodiment. The operations of the suction pump 55, first on-off valve 56, and second on-off valve 57 during printing by the printer 100 will be described along the steps of FIG. 6, with reference to FIGS. 1 to 5 as needed.

[0056] First, the control device 110 determines whether the communication unit 29 has received a print command from a host device such as a personal computer (step S1). If the communication unit 29 has not received a print command (No in step S1), the control device 110 continues to wait for printing.

[0057] When a print command is received (Yes in step S1), the control device 110 starts a print preparation operation. Specifically, the control device 110 starts rotating the first conveyor belt 5 in response to a control signal from the main control unit 110a. Then, the control signal from the paper suction control unit 110b applies a predetermined voltage from the suction voltage power source 21 to the charging roller 20, thereby charging the first conveyor belt 8.

[0058] Next, the main control unit 110a separates the cap 50 from the recording head 17 (step S2). Then, the first on-off valve 56 is closed and the second on-off valve 57 is opened (step S3) to open the paper dust suction passage 53. In this state, the suction pump 55 is turned on (step S4) to rotate the charge removal brush 41 at the same speed as the first conveyor belt 5 (step S5).

[0059] Next, the main control unit 110a starts the printing operation (step S6). Specifically, the paper P is conveyed from the registration roller pair 13 to the first belt conveying unit 5 at a predetermined timing in response to a control signal from the paper supply control unit 110c. The main control unit 110a ejects ink from the recording head 17 onto the paper P passing below the recording unit 9, based on the image data received together with the print command, to record an image.

[0060] Next, the main control unit 110a determines whether printing has finished (step S7). If printing is continuing (No in step S7), the main control unit 110a repeats the printing operation described above. If printing has finished (Yes in step S7), the main control unit 110a attaches the cap 50 to the recording head 17 (step S8).

[0061] Next, the control device 110 starts the paper dust removal operation on the first conveyor belt 5. Specifically, the charge removal brush 41 is rotated at a higher speed than the first conveyor belt 8 (step S9), causing the charge removal brush 41 to scrape off the paper dust adhering to the first conveyor belt 8 (foreign matter removal operation). The paper dust adhering to the charge removal brush 41 is scraped off by the scraper 43. The paper dust scraped off from the first conveyor belt 8 and the charge removal brush 41 is sucked by the suction pump 55 and collected in the waste ink collection container 52 via the duct 42 and the paper dust suction passage 53. The rotation of the first conveyor belt 5 and the charge removal brush 41 stops after a predetermined time has elapsed.

[0062] Thereafter, the suction pump 55 is turned off (step S10), and the first on-off valve 56 is opened and the second on-off valve 57 is closed in preparation for the suction purge process (step S11).

[0063] 6, by rotating the charge removal brush 41 at the same speed as the first transport belt 8 during the printing operation, rubbing of the charge removal brush 41 against the surface of the paper P is suppressed. As a result, it is possible to remove static electricity from the paper P without generating unnecessary paper dust. Furthermore, by performing a paper dust removal operation in which the charge removal brush 41 rotates at a speed faster than the first transport belt 8 after the printing operation is completed, it is possible to efficiently remove paper dust adhering to the transport surface of the first transport belt 8.

[0064] Furthermore, paper dust generated by the friction between the charge removal brush 41 and the paper P, and paper dust removed from the first conveyor belt 8 by the charge removal brush 41, are sucked up using a suction pump 55 that performs a suction purge process on the recording head 17. This eliminates the need to provide a separate pump for sucking up paper dust, which contributes to reducing the number of parts and costs of the printer 100.

[0065] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, an example was described in which the printer 100 that records color images using four color inks was used as the inkjet recording apparatus, but the present invention is equally applicable to a monochrome printer that records monochrome images using black ink.

[0066] Furthermore, in the above embodiment, a line head type printer 100 was described as an inkjet recording device that performs recording using line heads 11C to 11K equipped with recording heads 17a to 17c in which a large number of ink ejection nozzles 18 are arranged along the width direction of the sheet, but the present invention can equally well be applied to a serial type inkjet recording device in which recording is performed by scanning the recording head 17 across the sheet. [Industrial Applicability]

[0067] The present invention can be used in an inkjet recording device that performs recording by ejecting ink from ink ejection nozzles provided in a recording head, and by using the present invention, it is possible to provide an inkjet recording device that can effectively prevent nozzle clogging and conveyor belt contamination caused by paper dust generated when conveying paper using an electrostatic adsorption method. [Explanation of symbols]

[0068] 5 First belt conveyor (conveyor) 8. First conveyor belt (conveyor belt) 9 Recording section 17, 17a to 17c recording head 171 Ink ejection surface 18 Ink outlet 20 Charging roller 30 suction roller 40 Static eliminator 41 Anti-static brush 42 Duct 43 Scraper 50 caps 51 Ink discharge channel 52 Waste ink collection container 53 Paper powder suction channel (foreign matter suction channel) 55 Suction pump 56 First shut-off valve 57 Second shut-off valve 60 brush drive motor 100 Printers (inkjet recording devices) 110 Control device (control unit) P paper

Claims

1. a conveying unit that conveys paper by electrostatically adsorbing it to an endless conveying belt; a recording unit having a recording head disposed opposite to a conveying surface of the conveyor belt, the recording head discharging ink from ink discharge ports onto the paper conveyed by the conveyor belt; a cap attached to an ink ejection surface of the recording head and forming a sealed space between the cap and the ink ejection surface; a suction pump that sucks air from inside the cap; an ink discharge flow path that discharges the liquid sucked into the inside of the cap by the suction pump; a static eliminator disposed upstream of the recording unit in the paper transport direction, for eliminating charges from the paper; a control unit that controls operations of the conveying unit, the recording unit, the suction pump, and the static eliminator; In an inkjet recording apparatus comprising: The static eliminator is a roll-shaped anti-static brush disposed opposite to the conveyor belt across the entire width direction of the conveyor belt, the brush being in contact with the paper conveyed by the conveyor belt; a brush drive motor that rotates the charge removal brush in a forward direction relative to the moving direction of the conveyor belt; a duct that covers the side of the anti-static brush opposite to the conveyor belt and that sucks in foreign matter generated by contact between the anti-static brush and the paper or the conveyor belt; a scraper that protrudes from the inner surface of the duct so as to come into contact with the static elimination brush and scrapes off the foreign matter adhering to the static elimination brush; and an inkjet recording apparatus including a foreign matter suction passage that communicates the duct with the suction pump, and recovering the foreign matter in the duct using the suction pump and the foreign matter suction passage;

2. the foreign matter suction flow path joins the ink discharge flow path upstream of the suction pump in a discharge direction of the liquid, a first opening / closing valve that opens and closes the ink discharge flow path between the cap and the suction pump; a second on-off valve that opens and closes the foreign matter suction flow path between the duct and the suction pump; Equipped with The control unit during image recording on the paper, the first on-off valve is closed and the second on-off valve is opened while the suction pump is driven to collect the foreign matter in the duct; 2. The inkjet recording device according to claim 1, wherein the cap is attached to the ink ejection surface when an image is not being recorded on the paper, the first on-off valve is opened, and the second on-off valve is closed, and then the suction pump is driven to perform a suction purge process for sucking air from the sealed space.

3. 2. The inkjet recording apparatus according to claim 1, wherein the control unit controls the drive of the brush drive motor to rotate the charge removal brush at a speed equal to the moving speed of the conveyor belt when recording an image on the paper.

4. The inkjet recording device according to claim 1, characterized in that the control unit controls the driving of the brush drive motor to perform a foreign matter removal operation by rotating the anti-static brush at a speed faster than the moving speed of the conveying belt after image recording on the paper is completed.

5. 5. The inkjet recording apparatus according to claim 1, further comprising an attraction roller disposed upstream of the static eliminator in the transport direction, for pressing the paper against the transport belt.

Images