JP2018094835A - Device for ejecting liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for ejecting liquid, capable of effectively removing droplets adhering to a nozzle face even at a wiping direction downstream side of a wiping member, in which the wiping member gets dirty by wiped droplets.SOLUTION: A device for ejecting liquid includes: a wiping unit 100 which has a recording head 34 having a nozzle 38 ejecting liquid, a cap member having a nip part abutting on the recording head 34 so as to surround the nozzle 38, a wiping member 101 wiping the nozzle face of the recording head 34, and a winding member 103 winding the wiping member 101; and a movement means which moves relatively the recording head 34 and the wiping unit 100 in a state of abutting the wiping member 101 on the nozzle face of the recording head 34. When wiping with the wiping member 101, a place on which the nip part of the cap member abuts, on the nozzle face of the recording head 34 while moving relatively the recording head 34 and the wiping unit 100 with the movement means, a control of wiping the wiping member 101 with the winding member 103 is performed.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an apparatus for discharging a liquid.

  In general, an ink jet recording apparatus forcibly sucks and discharges ink from a nozzle of a liquid ejecting head into the cap in a capping state in which the cap is in contact with the nozzle forming surface so as to surround the nozzle of the liquid ejecting head. A cleaning operation (suction cleaning) can be executed. When suction cleaning is repeatedly performed, the nip portion at the tip of the cap is gradually soiled with ink, and the ink attached to the nip portion of the cap during capping such as suction cleaning is transferred to the nozzle surface. The ink dries and thickens, and is fixed so as to surround the nozzles on the nozzle surface. If accumulation of fixed ink on the nozzle surface progresses, it will rub against the object to be conveyed during printing, resulting in an image failure, or a gap between the nozzle surface and the cap nip during capping, and the moisture retention and suction on the nozzle surface will be correct. I can't do it. Therefore, it is necessary to sufficiently remove the fixed ink when wiping the nozzle surface.

  As a method of wiping the nozzle surface of the recording head of the ink jet recording apparatus, a method of using a wiping sheet that is a wiping member provided on the apparatus main body side to wipe off ink on the nozzle surface is known.

  Japanese Patent Application Laid-Open No. 2004-133830 suppresses the slack of the wiping member when the long wiping member is pressed and brought into contact with the liquid ejection surface of the liquid ejection head to wipe the liquid ejection surface, thereby improving the cleaning performance of the head. Disclosed is a liquid ejection device capable of For this purpose, a slack removing member is disposed on a side portion in front of the relative movement direction of the liquid discharge head, and after removing the slack of the wiping member, the wiping member is brought into contact with the liquid discharge surface of the liquid discharge head. Wipe and clean the liquid discharge surface.

  However, the conventional wiping method cannot sufficiently remove the ink adhered to the nozzle surface on the downstream side in the wiping direction of the wiping sheet, which is soiled by the wiped ink.

  Therefore, the present invention has an object to provide a device for discharging a liquid that can effectively remove droplets adhering to the nozzle surface even on the downstream side in the wiping direction of the wiping member where the wiping member becomes dirty due to the wiped droplets. To do.

  In order to solve this problem, a recording head having a nozzle for discharging a liquid, a cap member having a nip portion that contacts the recording head so as to surround the nozzle, and a wiping member for wiping the nozzle surface of the recording head And a wiping unit that winds up the wiping member, and the recording head and the wiping unit are moved relative to each other in a state where the wiping member is in contact with the nozzle surface of the recording head. When the wiping member wipes the position where the nip portion of the cap member abuts on the nozzle surface of the recording head while moving the recording head and the wiping unit relative to each other by the moving means. And a control means for controlling the wiping member to be taken up by the take-up member. Suggest.

  By transporting the wiping member in the wiping direction at the location within the nozzle surface where liquid droplets thickened due to drying are likely to adhere, the wiping member becomes contaminated by the wiped droplets and also adheres to the nozzle surface downstream of the wiping member. Can be removed sufficiently.

FIG. 6 is a perspective explanatory view of the inkjet recording apparatus 600 as viewed from the front side. It is a side schematic block diagram explaining the whole structure of the mechanism part of the apparatus. It is principal part plane explanatory drawing of the mechanism part. It is block explanatory drawing which shows the outline | summary of the control part of the apparatus. FIG. 5 is a diagram illustrating a mechanism for accumulating fixed ink from a cap 82 to a nozzle surface 37. FIG. 5 is a diagram illustrating a mechanism for accumulating fixed ink from a cap 82 to a nozzle surface 37. It is a figure which shows the wiping unit which concerns on embodiment of this invention. It is a figure which shows the wiping operation | movement of the wiping unit 100. FIG. It is a figure which shows the operation | movement which winds up a fixed amount of wiping sheets 101 immediately after completion | finish of wiping operation | movement. It is a figure which shows the washing | cleaning liquid application | coating mechanism which concerns on embodiment of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory perspective view of an ink jet recording apparatus 600 as an apparatus for discharging a liquid according to the present invention as seen from the front side.
The ink jet recording apparatus 600 has an apparatus main body 1, a supply tray 2 for loading an object to be transported attached to the apparatus main body 1, and a detachable attachment to the apparatus main body 1 to record (form) an image. And a discharge tray 3 for stocking the objects to be conveyed. Furthermore, a cartridge loading unit 4 for loading an ink cartridge is provided at one end side (side of the supply / discharge tray unit) of the front surface of the apparatus main body 1, and the upper surface of the cartridge loading unit 4 has an operation button and a display. The operation / display unit 5 is provided with a device.

  The cartridge loading unit 4 contains a plurality of recording liquids (inks) that are different color materials, such as black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. Ink cartridges (main tanks) 10k, 10c, 10m, and 10y (referred to as “ink cartridge 10” when colors are not distinguished) are inserted from the front side of the apparatus main body 1 toward the rear side. A front cover (cartridge cover) 6 that is opened when the ink cartridge 10 is attached or detached is provided on the front side of the cartridge loading portion 4 so as to be openable and closable. Further, the ink cartridges 10k, 10c, 10m, and 10y are configured to be loaded side by side in a vertical state.

  Further, the operation / display unit 5 has the remaining amounts of the ink cartridges 10k, 10c, 10m, and 10y of each color at the arrangement positions corresponding to the mounting positions (arrangement positions) of the ink cartridges 10k, 10c, 10m, and 10y of each color. The remaining amount display portions 11k, 11c, 11m, and 11y for each color for displaying the near end and the end are arranged. Further, the operation / display unit 5 is also provided with a power button 12, a transported object feed / print resume button 13, and a cancel button 14.

Next, the mechanism part of the ink jet recording apparatus 600 will be described with reference to FIGS. 2 is a schematic side view illustrating the outline of the mechanism, and FIG. 3 is an explanatory plan view of the main part.
A carriage 33 is slidably held in the main scanning direction by a main guide rod 31 and a sub guide rod 32 which are main guide members horizontally mounted on the left and right side plates 21A and 21B constituting the frame 21. The moving scanning is performed in the direction indicated by the arrow (carriage main scanning direction) in FIG.

  As described above, the carriage 33 includes a recording head 34 including four droplet discharge heads that discharge ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk). A plurality of ink ejection openings are arranged in a direction crossing the main scanning direction (conveyed object feeding direction), and the ink droplet ejection direction is directed downward. Note that it is also possible to employ one or a plurality of head configurations having nozzle rows that eject liquids of the respective colors.

  As an inkjet head constituting the recording head 34, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. It is possible to use a shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as pressure generating means for generating a pressure for discharging a liquid.

  The carriage 33 is equipped with a head tank 35 for each color for supplying each color ink to each recording head 34. As described above, each color head tank 35 is supplementarily supplied with ink of each color from the ink cartridge 10 of each color mounted in the cartridge loading unit 4 via the supply tube 36 having flexibility of each color. The cartridge loading unit 4 is provided with a supply pump unit 24 which is a liquid feeding means for feeding ink in the ink cartridge 10.

  On the other hand, as the supply unit for supplying the transported object 42 loaded on the transported object stacking part (pressure plate) 41 of the supply tray 2, the transported object 42 is separated and fed one by one from the transported object stacking part 41. Opposite the half-moon roller (supply roller) 43 and the supply roller 43, a separation pad 44 made of a material having a large friction coefficient is provided, and this separation pad 44 is urged toward the supply roller 43 side.

  In order to send the object to be conveyed 42 supplied from the supply unit to the lower side of the recording head 34, a guide 45 for guiding the object to be conveyed 42, a counter roller 46, a conveyance guide member 47, and a tip pressurization. A holding member 48 having a roller 49 and a conveying belt 51 which is a conveying means for electrostatically attracting the conveyed conveyed object 42 and conveying it at a position facing the recording head 34 are provided.

  The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction). Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51. Further, a guide member 57 is disposed on the back side of the conveyor belt 51 in correspondence with a printing area by the recording head 34.

  The transport belt 51 rotates in the belt transport direction of FIG. 3 when the transport roller 52 is rotationally driven by the sub-scanning motor 504 with timing.

  Further, as a discharge unit for discharging the transported object 42 recorded by the recording head 34, a separation claw 61 for separating the transported object 42 from the transport belt 51, a discharge roller 62, and a discharge roller 63 are provided. The discharge tray 3 is provided below the discharge roller 62.

  A duplex unit 71 is detachably mounted on the back surface of the apparatus body 1. The duplex unit 71 takes in the object to be conveyed 42 returned by the reverse rotation of the conveyor belt 51, reverses it, and supplies it again between the counter roller 46 and the conveyor belt 51. The upper surface of the duplex unit 71 is a manual feed tray 72.

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 81 including a recovery means for maintaining and recovering the state of the nozzles of the recording head 34 is arranged in the non-printing area on one side of the carriage 33 in the scanning direction. Yes.

  The maintenance and recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a to 82d (hereinafter referred to as “caps 82” when not distinguished from each other) for capping each nozzle surface of the recording head 34, and thickening. In order to discharge the recorded recording liquid, an empty discharge receiver 84 for receiving droplets when performing empty discharge for discharging droplets that do not contribute to recording, a suction pump 508, and the like are provided. Here, the cap 82a is a suction and moisture retention cap, and the other caps 82b to 82d are moisture retention caps.

  Then, the waste liquid of the recording liquid generated by the maintenance and recovery operation by the maintenance and recovery mechanism 81, the ink discharged to the cap 82, and the ink discharged to the empty discharge receiver 94 are discharged to the waste liquid tank 506 and stored therein.

  The ink jet recording apparatus 600 includes a wiping unit 100 between the maintenance / recovery mechanism 81 and the transport belt 51 in the scanning direction of the carriage 33. The wiping unit 100 contacts the nozzle surface 37 of the recording head 34 with the cloth-like wiping sheet 101 and wipes and cleans the nozzle surface 37. The wiping unit 100 moves in the sub-scanning direction when wiping the nozzle surface 37 of the recording head 34.

  Further, as shown in FIG. 3, in the non-printing area on the other side in the scanning direction of the carriage 33, idle discharge is performed to discharge liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An empty discharge receiver 88 for receiving the liquid droplets at the time is disposed, and the empty discharge receiver 88 is provided with an opening 89 along the nozzle row direction of the recording head 34.

  In the ink jet recording apparatus 600 configured as described above, the objects to be conveyed 42 are separated and supplied one by one from the supply tray 2, and the objects to be conveyed 42 supplied substantially vertically upward are guided by the guide 45, It is sandwiched between the counter roller 46 and conveyed, and further, the leading end is guided by the conveying guide member 47 and pressed against the conveying belt 51 by the leading end pressing roller 49, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately repeated from the AC bias supply unit of the control unit provided in the apparatus to the charging roller 56, that is, an alternating voltage is applied, and the conveying belt 51 is alternately charged. In the voltage pattern, that is, in the sub-scanning direction which is the rotation direction, plus and minus are alternately charged in a band shape with a predetermined width. When the object to be conveyed 42 is fed onto the conveying belt 51 that is alternately charged with plus and minus, the object to be conveyed 42 is attracted to the conveying belt 51, and the object to be conveyed 42 is sub-scanned by the circumferential movement of the conveying belt 51. Conveyed in the direction.

  Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped transported object 42 to record one line, and the transported object 42 is placed in place. After the quantitative transport, record the next line. By receiving a recording end signal or a signal that the rear end of the transported object 42 has reached the recording area, the recording operation is terminated and the transported object 42 is discharged to the discharge tray 3.

  Further, during printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 81 side, and the recording head 34 is capped by the cap 82 to keep the nozzles in a wet state, thereby preventing ejection failure due to ink drying. . In addition, the recording liquid is sucked from the nozzle by the suction pump 508 in a state where the recording head 34 is capped by the cap 82 (referred to as “nozzle suction” or “head suction”) to recover the thickened recording liquid or bubbles. Perform the action. In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. As a result, the stable ejection performance of the recording head 34 is maintained.

Next, an outline of a control unit of the apparatus for discharging the liquid will be described with reference to FIG. This figure is an overall block diagram of the control unit.
The control unit controls the entire apparatus that discharges the liquid. The main control unit 301 as a control unit composed of a microcomputer that also functions as a unit for performing control according to the present invention, and a microcomputer that controls printing. And a print control unit 302 configured as described above.

  Then, the main control unit 301 performs main scanning on the main scanning motor 500 that moves the carriage 33 in the main scanning direction in order to form an image on the transported object 42 based on the print processing information input from the communication circuit 300. The sub-scanning motor 504 that feeds the transported object 42 is controlled to be driven via the sub-scanning motor driving circuit 304 via the motor driving circuit 303, and printing data is sent to the printing control unit 302. Do.

  The main control unit 301 receives a detection signal from a carriage position detection circuit 305 that detects the position of the carriage 33, and the main control unit 301 controls the movement position and movement speed of the carriage 33 based on the detection signal. To do. Further, the main control unit 301 controls the movement position and movement speed of the wiping unit 100 described later, the rotation amount of the take-up roller 103, and the like. The main control unit 301 controls the opening and closing of the valve 403 of the cleaning liquid application mechanism 400 shown in FIG. The carriage position detection circuit 305 detects the position of the carriage 33 by, for example, reading and counting the number of slits of the encoder sheet 512 arranged in the scanning direction of the carriage 33 with the photosensor 510 mounted on the carriage 33. The main scanning motor drive circuit 303 rotates the main scanning motor 500 according to the carriage movement amount input from the main control unit 301 to move the carriage 33 to a predetermined position at a predetermined speed.

  Further, the main control unit 301 receives a detection signal from a conveyance amount detection circuit 306 that detects the movement amount of the conveyance belt 51, and the main control unit 301 moves the movement amount and movement speed of the conveyance belt 51 based on the detection signal. To control. The carry amount detection circuit 306 detects the carry amount by, for example, reading and counting the number of slits of the rotary encoder sheet 516 attached to the rotation shaft of the carry roller 52 with the photo sensor 518. The sub-scanning motor driving circuit 304 rotates the sub-scanning motor 504 according to the conveyance amount input from the main control unit 301, and rotationally drives the conveyance roller 52 to move the conveyance belt 51 to a predetermined position at a predetermined speed. Move with.

  The main control unit 301 rotates the supply roller 43 once by giving a sheet feeding roller driving command to the sheet feeding roller driving circuit 307. The main control unit 301 rotates the motor of the maintenance / recovery mechanism 81 via the maintenance / recovery mechanism drive motor drive circuit 308, thereby moving the cap 82 up and down and driving the suction pump 508 as described above.

  The main control unit 301 controls the drive motor (supply motor) 514 for driving the pump of the supply pump unit 24 via the supply pump drive circuit 311, and controls the ink cartridge 10 loaded in the cartridge loading unit 4. Ink is replenished and supplied (filled) to the head tank 35. At this time, the main control unit 301 controls replenishment supply (filling operation) based on a detection signal from the head tank full tank sensor 312 that detects that the head tank 35 is full. In this case, there are an open air filling in which filling is performed with the open air mechanism of the head tank 35 being opened, and a normal filling in which filling is performed with the open air mechanism being closed.

  Further, the main control unit 301 takes in information stored in the nonvolatile memory 316 which is a storage unit provided in each ink cartridge 10 mounted on the cartridge loading unit 4 through the cartridge communication circuit 314, and performs a necessary process. And stored in a non-volatile memory (for example, EEPROM) 315 which is a main body storage means.

  Further, the main control unit 301 receives a detection signal from an environmental sensor 313 that detects environmental temperature and environmental humidity.

  The print control unit 302 generates pressure for ejecting droplets of the recording head 34 based on the signal from the main control unit 301 and the carriage position and conveyance amount from the carriage position detection circuit 305 and the conveyance amount detection circuit 306. Data for driving the means is generated. The print control unit 302 transfers the above-described image data as serial data to the head driving circuit 310, and also transfers a transfer clock, a latch signal, and a droplet control signal (mask signal) necessary for transferring the image data and confirming the transfer. ) And the like are output to the head drive circuit 310. Further, the print control unit 302 supplies the drive signal pattern data stored in the ROM to a drive waveform generation unit and a head driver including a D / A converter, a voltage amplifier, a current amplifier, and the like that perform D / A conversion. Drive waveform selection means is included. The print control unit 302 generates a drive waveform including one drive pulse (drive signal) or a plurality of drive pulses (drive signal) and outputs the drive waveform to the head drive circuit 310.

  The head drive circuit 310 selectively selects a drive signal constituting a drive waveform supplied from the print control unit 302 based on image data corresponding to one row of the print head 34 that is input serially. The recording head 34 is driven by applying it to a driving element (for example, a piezoelectric element as described above) that generates energy for discharging the ink. At this time, by selecting a driving pulse constituting the driving waveform, for example, dots having different sizes such as large droplets (large dots), medium droplets (medium dots), and small droplets (small dots) can be distinguished. it can.

Next, an example of this embodiment will be described in detail.
First, with reference to FIGS. 5 and 6, a mechanism for depositing fixed ink from the cap 82 to the nozzle surface 37 will be described. Although FIG. 5 is described on the assumption that the cap 82 moves with respect to the recording head 34, the cap 82 or the recording head 34 may actually move. A suction pump 508 for sucking ink from the nozzles 38 of the recording head 34 is disposed under the cap 82.

  During the maintenance / recovery operation (maintenance) of the recording head, the cap 82 separated from the nozzle surface 37 of the recording head 34 rises and comes into contact with the nozzle surface 37 for capping (FIG. 5A). Ink 90 is sucked from the nozzle 38 (FIG. 5B). Next, the cap 82 moves downward to a position away from the nozzle surface 37, wipes the nozzle surface 37 with the wiping sheet 101, and then the ink 90 in the cap is discharged (FIG. 5C). Even after the ink 90 is discharged, the ink 90 adheres to the nip portion 83 that is the portion of the cap 82 that contacts the nozzle surface 37. If capping is performed in this state, the ink 90 comes into contact with the nozzle surface 37 again (FIG. 5D), and the ink 90 is transferred to the nozzle surface 37 even after the cap 82 is separated from the nozzle surface 37 (FIG. 5). 5 (e)).

  With the above deposition mechanism, the ink 90 adheres to the nozzle surface 37 so as to surround the nozzle 38 (FIG. 6). FIG. 6 is a bottom view of the recording head 34 and it can be seen that the ink 90 is deposited on the nozzle surface 37 in a rectangular shape. This is because the nip portion 83 of the cap 82 has a rectangular shape so as to surround the nozzle 38. However, the nip portion 83 is not limited to a rectangular shape, and may have another shape.

Next, a wiping unit according to an embodiment of the present invention will be described with reference to FIG.
The wiping unit (wiping unit) 100 is for wiping the ink 90 or foreign matter adhering to the nozzle surface 37 of the recording head 34 with the wiping sheet 101 during maintenance.

  The wiping unit 100 includes a wiping sheet 101 that is a planar and roll wiping member that wipes the nozzle surface 37 of the recording head 34, a supply roller 102 that supplies the wiping sheet 101, and a pressing device that presses the wiping sheet 101 against the nozzle surface 37. A contact member 104; a winding roller 103 that is a winding member that winds the supplied wiping sheet 101; a compression spring 106 for pressing the pressing member 104; a pedestal 105 for fixing the compression spring; Yes. The width of the wiping sheet 101 in the direction orthogonal to the wiping direction is set so that the nozzle surface 37 of the recording head 34 can be wiped at once. The pressing member 104 is connected to the pedestal 105 by a compression spring 106 so as to press against the nozzle surface 37 of the recording head 34 with a constant pressure. The recording head 34 and the wiping unit 100 can move relative to each other. The inkjet recording apparatus 600 includes a recording head 34 having a nozzle 38 that ejects ink that is droplets, a cap member 82 having a nip portion 83 that can contact the recording head 34 so as to surround the nozzle 38, and The wiping unit 100 is provided.

  It is preferable that an elastic member such as rubber is provided on the surface of the pressing member 104 so as not to damage the nozzle surface 37 of the recording head 34. The pressing member 104 is a rotatable roller member, and when the wiping sheet 101 is wound up by the winding roller 103, the pressing member 104 is caused by a frictional force acting between the pressing member 104 and the wiping sheet 101. It is preferable to carry around. By configuring the pressing member 104 with a rotatable roller, the wiping sheet 101 and the pressing member 104 can be smoothly moved during the wiping operation without sliding.

  The ink jet recording apparatus 600 includes a moving unit 530 as a moving unit that moves the wiping unit 100 in the sub-scanning direction. The moving unit 530 is connected to the connection unit 532 of the wiping unit 100, and includes a belt 520 that is wound around the roller 526 and a motor 524 that drives the roller 526. By driving the motor 524 and rotating the roller 526, the wiping unit 100 connected to the belt 520 and the belt 520 is moved in the sub-scanning direction.

  The wiping unit 100 comes into contact with the cam 534 via the engaging portion 536. By rotating the cam 534, the wiping unit 100 can be moved in the vertical direction.

  A rotary encoder 109 is attached to the winding roller 103, and the winding distance of the wiping sheet 101 can be measured by the photo sensor 107 of the rotary encoder 109. The wiping unit 100 includes a drive motor 108 that rotationally drives the take-up roller 103, and the rotation speed of the drive motor 108 is controlled by the main control unit 301.

Next, the wiping operation of the wiping unit 100 will be described with reference to FIGS.
First, the wiping operation when the fixed ink is deposited on the nozzle surface 37 so as to surround the nozzle 38 of the nozzle surface 37 by the transfer from the nip portion 83 will be described with reference to FIG. 8A is a bottom view of the recording head 34, and below that, a side view of the recording head 34 and the wiping unit 100 are shown.

  After the wiping operation is requested, the wiping unit 100 is raised by the control of the main control unit 301 (FIG. 4) until the upper end of the pressing member 104 is positioned above the nozzle surface 37 of the recording head 34 to be wiped. (FIG. 8A). The vertical distance A between the height position of the upper end of the pressing member 104 and the height position of the nozzle surface of the recording head 34 at this time is a compression spring that connects the pressing member 104 and the base 105 when wiping the nozzle surface. 106 equal to the amount of shrinkage. For this reason, the vertical distance A needs to be increased enough to obtain a desired pressing pressure. Further, by changing the spring constant or natural length of the compression spring 106, the nozzle surface 37 of the recording head 34 can be wiped with the wiping sheet 101 by an arbitrary pressing load. At this time, the nozzle surface 37 of the recording head 34 is wiped by moving the recording head 34 and the wiping unit 100 relative to each other while the winding roller 103 is fixed.

  When the wiping sheet 101 abutted against the nozzle surface 37 by the moving unit 530 is moved to the position of the fixed ink 90 attached to the upstream side in the wiping direction on the nozzle surface 37 of the recording head 34, the wiping sheet 101 and the recording head While the relative movement of 34 is continued, the winding roller 103 is rotated by a certain amount to run the wiping sheet 101 in the wiping direction (FIG. 8B). At this point, the short side position B in the direction orthogonal to the wiping direction of the fixed ink 90 surrounding the nozzle 38 has already been wiped off. In addition, since the wiping sheet 101 is run in the wiping direction, ink adheres to the wiping sheet 101 as illustrated in FIG. The ink stain C adheres to the wiping sheet 101 in the width direction of the wiping sheet 101, and the width of the stain C corresponds to the length of the rectangular fixed ink 90 in the short side direction. The right view of FIG. 8B is a view when the left view of FIG. 8B is viewed from the right side (the view when viewed in the direction opposite to the wiping direction).

  Thereafter, the wiping operation and the relative movement are continued with the take-up roller 103 fixed for a while (FIG. 8C), and both sides of the two nozzles 38 of the rectangular fixed ink 90 attached to the nozzle surface 37 are placed on both sides. The fixed ink on the two sides in the long side direction adhered to the surface is wiped off by the wiping sheet 101, and the ink adheres to two places E on the wiping sheet 101. Further, the ink adheres to the two places F on the wiping sheet 101 by wiping the two rows of nozzles 38. Due to the ink E adhering to the wiping sheet 101, linear stains along the traveling direction of the wiping sheet 101 remain on the wiping sheet 101. By performing the wiping operation and the relative movement while the winding roller 103 is fixed, the length of dirt on this line can be shortened. The right view of FIG. 8C is a view when the left view of FIG. 8C is viewed from the right side (the view when viewed in the direction opposite to the wiping direction).

  Further, the wiping operation and the relative movement are continued with the winding roller 103 fixed, and the position D (here, the center of the fixed ink 90) of the fixed ink 90 adhered to the nozzle surface 37 of the recording head 34 on the downstream side in the wiping direction. When the wiping sheet 101 moves to the vicinity), the recording roller 34 and the wiping unit 100 continue to move relative to each other, and the winding roller 103 is rotated by a certain amount to wind the wiping sheet 101 in the wiping direction. The sheet 101 is caused to travel (FIG. 8D). The right view of FIG. 8D is a view when the left view of FIG. 8D is viewed from the right side (the view when viewed in the direction opposite to the wiping direction).

  At this point, the entire fixed ink surrounding the nozzle 38 has already been wiped off. Further, since the wiping sheet 101 is run again in the wiping direction, the ink adheres to the two places C and D on the wiping sheet 101 as shown in FIG. The ink stain D adheres to the wiping sheet 101 over the width direction of the wiping sheet 101, and the width of the stain D corresponds to the length of the rectangular fixed ink 90 in the short side direction. Finally, the wiping operation is completed by lowering the wiping unit 100 and returning the relative position between the recording head 34 and the wiping unit 100 to the original position. The position at which the wiping sheet 101 starts to be wound may not be the time when the fixed ink 90 is reached, but is the time before the fixed ink 90 is reached, that is, when the position near the fixed ink 90 is reached. Also good.

  As described above, the wiping sheet 101 is brought into contact with the nozzle surface 37 of the recording head 34, and the ink is wiped by moving the recording head 34 and the wiping unit 100 relative to each other. During this wiping operation, at least a part of the contact area where the nip 83 at the tip of the cap 82 and the nozzle surface 37 of the recording head 34 abut on the nozzle surface 37 of the recording head 34, particularly the nozzle surface 37 of the recording head 34. The wiping sheet 101 is wound up in the wiping direction by the take-up roller 103 when the rectangular fixed ink 90 adhering to the wiping direction is wiped off at the upstream side in the wiping direction and on the downstream side in the wiping direction. Thus, even if the wiping sheet is soiled with the fixing ink 90 by wiping the short side C of the rectangular fixing ink 90 attached to the nozzle surface 37, the wiping sheet 101 is taken up by the take-up roller 103 even if the wiping sheet becomes dirty. By wiping the short side D on the downstream side in the wiping direction of the fixed ink 90 with the new surface (the surface on which ink has not yet adhered), the inks C and D adhering to the nozzle surface 37 can be effectively removed.

  In the wiping operation shown in FIGS. 8B and 8D, the wiping sheet 101 is wound up and traveled in the wiping direction while continuing the relative movement, so that the wiping out of the fixed ink surrounding the nozzle 38 with a large amount of ink is performed. The short side positions C and D in the direction orthogonal to the direction are always wiped in the unused area of the wiping sheet 101. In other words, during the wiping operation, the wiping sheet 101 is taken up in the wiping direction by the take-up roller 103 at the positions C and D where the ink amount is large among the contact points between the nip portion 83 of the cap 82 and the nozzle surface 37. The wiping sheet 101 does not have to be taken up by the take-up roller 103 at the positions E and F where the amount of ink is small in the contact portion. In this manner, by arbitrarily changing the wiping speed of the wiping sheet 101 and the start and stop of the wiping sheet 101 within the nozzle surface 37, the ink at the locations C and D where there is particularly a large amount of ink stains can be efficiently obtained. It can be removed. Moreover, the water-repellent film formed on the nozzle surface 37 can be protected by not causing the wiping sheet 101 to travel at the locations E and F where the ink stains in the nozzle surface 37 are small or increasing the wiping speed more than necessary. It becomes possible.

  The amount of winding of the wiping sheet 101 executed during the wiping operation, that is, the amount of rotation of the winding roller 103 is determined as follows. The wiping unit 100 comes into contact with the nozzle surface 37 in an unused area that appears due to the winding of the wiping sheet 101, and this unused area is formed on the wiping sheet 101 by the wiping sheet 101 absorbing ink from the nozzle surface 37. The amount of rotation of the take-up roller 103 is adjusted so as to be an area where there is no ink smear spreading or an area sufficiently separated from the area where this smudge exists. Accordingly, the long side positions E and F parallel to the wiping direction of the fixed ink 90 surrounding the nozzle 38 are also wiped by the unused area of the wiping sheet 101, so that the ink absorbing capacity of the wiping sheet 101 is not exceeded. The fixed ink 90 attached to the nozzle surface 37 can be removed (FIG. 8C). Further, by using the unused area of the wiping sheet 101, the fixing ink 90 removed on the short side C on the upstream side in the wiping direction of the fixing ink 90 attached to the nozzle surface 37 is pushed into the nozzle 38. It becomes possible to prevent non-ejection and ejection bending. Further, as described above, the wiping sheet 101 is taken up by the take-up roller 103 at the short side positions C and D of the fixed ink 90 surrounding the nozzle 38, and the nozzle surface is obtained at the short side positions C and D. 37 and the wiping sheet 101 can be wiped with the relative speed larger than the long side positions E and F.

  Next, the wiping operation when the time elapsed from the end of the previous wiping operation to the start of the current wiping operation is equal to or less than a certain time will be described. Here, as an example, an operation of winding a certain amount of the wiping sheet 101 immediately after the wiping operation is completed will be described with reference to FIG.

  After the wiping operation is requested, the wiping unit 100 is raised by the control of the main control unit 301 (FIG. 4) until the upper end of the pressing member 104 is positioned above the nozzle surface 37 of the recording head 34 to be wiped. (FIG. 9A). Then, the nozzle surface 37 of the recording head 34 is wiped by moving the recording head 34 and the wiping unit 100 relative to each other while the take-up roller 103 is fixed (FIG. 9B). Specifically, the wiping sheet 101 is wiped with the wiping sheet 101 by moving the wiping unit 100 in the sub-scanning direction while the wiping sheet 101 is pressed in contact with the nozzle surface 37 of the recording head 34. Next, when the wiping sheet 101 wipes out the entire nozzle surface and the wiping sheet 101 is separated from the nozzle surface 37 (FIG. 9C), the wiping sheet 101 is wound up by a certain amount by the winding roller 103 (FIG. 9 ( d)). In FIG. 9C, since the wiping sheet 101 is not run in the wiping direction, the ink is attached to the wiping sheet 101 corresponding to the position directly above the pressing member 104. In FIG. 9D, since the wiping sheet 101 is run in the wiping direction, the ink on the wiping sheet 101 is also moved in the wiping direction. Finally, the wiping operation is completed by lowering the wiping unit 100 and returning the relative position between the recording head 34 and the wiping unit 100 to the original position.

  The ink jet recording apparatus 600 according to the present embodiment includes time measuring means 540 that measures the time elapsed from the end of the previous wiping operation to the start of the current wiping operation. And when the measurement time of the time measuring means 540 is below a predetermined value, winding and running of the wiping sheet 101 are not performed during the current wiping operation. On the contrary, when the measurement time of the time measuring means 540 is larger than the predetermined value, the wiping sheet 101 is wound and traveled during the current wiping operation. Accordingly, when it is considered that the time has not passed so much since the previous wiping operation and the fixed ink 90 on the nozzle surface 37 is not accumulated so much, the wiping sheet 101 is taken up during the wiping operation of the nozzle surface 37. And the wiping sheet | seat 101 can be saved by not performing driving | running | working.

  Further, as shown in FIG. 9D, when the measurement time measured by the time measuring means 540 is less than or equal to a predetermined value, the recording head is between the end of the wiping operation and the start of the next wiping operation. The wiping sheet 101 is wound up by a winding roller 103 in a state where the nozzle surface 37 of 34 and the wiping sheet 101 are separated from each other. Thereby, it is possible to always wipe the nozzle surface 37 in the unused area of the wiping sheet 101. It is preferable that the user can appropriately set a predetermined value for the measurement time via the operation panel of the inkjet recording apparatus 600 or a personal computer connected to the inkjet recording apparatus 600.

  The length of the wiping sheet 101 to be wound in a state where the pressing member 104 is separated from the nozzle surface 37 is such that the wiping area of the wiping sheet 101 that is supposed to come into contact with the nozzle surface 37 during the next wiping operation is an unused area. It is preferable that the length is as long as possible.

Next, a cleaning liquid application mechanism according to an embodiment of the present invention will be described with reference to FIG.
In addition to the wiping unit 100, the inkjet recording apparatus 600 according to the present embodiment includes a cleaning liquid application mechanism 400 that applies a cleaning liquid 401 to the supplied wiping sheet 101. The cleaning liquid application mechanism 400 includes a cleaning liquid 401 placed in a storage tank 402, a nozzle 404 extending from the storage tank 402 to above the pressing member 104, a valve 403 provided in the nozzle 404, and the like. The cleaning liquid 401 is dropped onto the wiping sheet 101 via the nozzle 404 by opening and closing the valve 403 as necessary by the main control unit 301 (FIG. 4). The tip of the nozzle 404 is positioned at an upper position where it does not contact the wiping sheet 101.

  A highly volatile solvent is used for the cleaning liquid 401, and the ink 90 and foreign matters adhering to the nozzle surface 37 of the recording head 34 can be efficiently removed by the solvent. The cleaning liquid 401 preferably has an action of dissolving ink. It is desirable that the cleaning liquid 401 is covered and sealed with a cover or the like so that the highly volatile cleaning liquid 401 does not come into contact with the atmosphere. If the state in which the cleaning liquid 401 is less likely to volatilize is maintained by being covered with a cover or the like, the wiping sheet 101 is placed in the wiping unit 100 without the need to provide the cleaning liquid coating mechanism 400 in the inkjet recording apparatus 600 or the wiping unit 100. The wiping sheet 101 may be impregnated with the cleaning liquid 401 before being set.

  By wiping the wiping sheet 101 with the cleaning liquid 401 in advance by the cleaning liquid application mechanism 400, the nozzle surface 37 can be wet-wiped with the wiping sheet 101 using the cleaning liquid 401. Therefore, by wiping the nozzle surface 37 with the cleaning liquid applied to the wiping sheet 101, the fixed ink 90 attached to the nozzle surface 37 can be more efficiently removed.

  When the cleaning liquid application mechanism 400 is provided in the inkjet recording apparatus 600 as shown in FIG. 10, the cleaning liquid application mechanism 400 is fixed at a position that does not hinder the movement of the wiping unit 100 above the wiping unit 100, and the wiping sheet is discharged from the nozzle 404. A configuration in which the cleaning liquid 401 is applied to the wiping sheet 101 by dripping the cleaning liquid 401 onto the 101 is preferable. The timing at which the cleaning liquid 401 is applied to the wiping sheet 101 is preferably immediately before the wiping unit 100 performs the wiping operation. Moreover, it is preferable that the range which apply | coats the cleaning liquid 401 to the wiping sheet 101 is the whole area | region of the wiping sheet 101 which will be used by subsequent wiping operation | movement. Therefore, when the relative position of the wiping unit 100 and the cleaning liquid application mechanism 400 is fixed, in the application process of the cleaning liquid 401 to the wiping sheet 101, an amount that the cleaning liquid 401 spreads over the entire area that is scheduled to be used in the subsequent wiping operation. It is necessary to apply. Alternatively, the wiping unit 100 and the cleaning liquid application mechanism 400 may be moved relative to each other during application of the cleaning liquid 401 to the wiping sheet 101, so that the cleaning liquid may be applied to the entire area that is scheduled to be used in the subsequent wiping operation.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, a plotter, or a multifunction machine having these functions, for example, an image forming apparatus (ink jet recording apparatus) of a liquid discharge recording system using a recording head for discharging ink droplets (droplets) )It has been known. Such an ink jet recording apparatus ejects ink droplets from a nozzle of a recording head onto a transported object, and image formation (recording, printing, printing, printing is also synonymous, and images having meanings such as characters and figures are formed. Including not only the application to the medium but also the action of applying an image having no meaning such as a pattern to the medium (simply referred to as droplet ejection or liquid ejection for causing a droplet to land on the medium) 2 3D image (stereoscopic image) as a target). In addition, a liquid discharge head (droplet discharge head) used as a recording head is a functional component that discharges and ejects liquid from nozzles, and a diaphragm is displaced by a piezoelectric actuator or the like to change the volume in the liquid chamber, thereby increasing the pressure. There are known piezoelectric heads that discharge and discharge liquid droplets, and thermal heads that provide a heating element that generates heat when energized in the liquid chamber and increase the pressure in the liquid chamber by bubbles generated by the heating element and discharge liquid droplets. Yes.

  In the present application, the material of the “conveyed object” is not limited to paper, and includes cloth, leather, metal, plastic, glass, wood, ceramics, etc. The term “conveyed object” is used as a general term including what is called paper, recording paper, and the like. The “liquid” discharged from the liquid discharge head is not particularly limited as long as it has a viscosity and surface tension that can be discharged from the head, but the viscosity is 30 mPa · s under normal temperature and normal pressure, or by heating and cooling. The following is preferable. More specifically, “liquid” refers to solvents such as water and organic solvents, colorants such as dyes and pigments, functional compounds such as polymerizable compounds, resins, and surfactants, DNA, amino acids, proteins, calcium These include solutions, suspensions, emulsions, and the like containing biocompatible materials such as natural pigments, edible materials such as natural pigments, etc., and these include, for example, inkjet inks, surface treatment liquids, components of electronic devices and light emitting devices, It can be used in applications such as a liquid for forming an electronic circuit resist pattern and a material liquid for three-dimensional modeling. “Liquid ejection unit” is a collection of parts related to liquid ejection, in which other functional parts and mechanisms are integrated with the liquid ejection head, for example, at least one of a carriage, a head tank, a liquid supply mechanism, and a maintenance and recovery mechanism It is comprised including. The “device for discharging liquid” is a device for driving the liquid discharge head to discharge the liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can be attached, but also an apparatus for ejecting liquid toward air or liquid, and an image forming apparatus In addition to these, there are a three-dimensional modeling apparatus, a treatment liquid coating apparatus, a jet granulating apparatus, and the like.

34 Recording head 37 Nozzle surface 38 Nozzle 82 Cap (cap member)
83 Nip part 100 Wiping unit 101 Wiping sheet (wiping member)
103 Winding roller (winding member)

JP 2013-173244 A

Claims (8)

A recording head having a nozzle for discharging liquid;
A cap member having a nip portion that contacts the recording head so as to surround the nozzle;
A wiping unit having a wiping member for wiping the nozzle surface of the recording head, and a winding member for winding the wiping member;
Moving means for relatively moving the recording head and the wiping unit in a state where the wiping member is in contact with the nozzle surface of the recording head;
The wiping member wipes the portion where the nip portion of the cap member abuts on the nozzle surface of the recording head while the moving unit relatively moves the recording head and the wiping unit. Control means for controlling the winding of the member by the winding member;
Comprising
A device for discharging a liquid characterized by the above.   When the controller wipes the portion of the nozzle surface of the recording head where the nip portion in the short side direction of the cap member abuts with the wiping member, the nozzle surface while winding the winding member The apparatus for discharging a liquid according to claim 1, wherein the liquid is wiped off.   When the wiping member wipes the portion of the nozzle surface of the recording head where the nip portion in the long side direction of the cap member is in contact with the wiping member, the control means stops the winding member and stops the nozzle. The apparatus for discharging a liquid according to claim 1, wherein the surface is wiped off.   During the wiping operation, the wiping member is wound up in the wiping direction by the winding member at a position where the droplet amount is large in the contact portion, and the wiping is performed at a position where the droplet amount is small in the contact portion. The apparatus according to claim 1, wherein the member is not wound by the winding member.   The cleaning liquid application mechanism which applies cleaning liquid to the wiping member is provided, or the cleaning liquid is impregnated in the wiping member before the wiping member is set in the wiping unit. The apparatus which discharges the liquid as described in any one of these.   It further has time measuring means for measuring the time elapsed from the end of the previous wiping operation to the start of the current wiping operation, and when the measurement time of the time measuring means is less than or equal to a predetermined value, during the current wiping operation The device for discharging a liquid according to any one of claims 1 to 5, wherein the wiping member is not wound.   If the measured time measured by the time measuring means is less than or equal to a predetermined value, the nozzle surface of the recording head and the wiping member are separated after the wiping operation is finished and before the next wiping operation is started. The apparatus for ejecting liquid according to claim 6, wherein the wiping member is wound up by a predetermined amount by the winding member in a state where the liquid is discharged. The pressing member for pressing the wiping member against the nozzle surface is further provided, and the pressing member is a rotatable roller member having an elastic member provided on a surface thereof. The apparatus which discharges the liquid as described in any one of these.

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