JP2012061656A - Ink suction system and ink suction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink suction system or the like that can not only form an appropriate meniscus but also shorten a time needed for suction processing.SOLUTION: There are included: a head interior pressurizing device 78 that gives positive pressure into an ink jet head 51 via an ink supply device 10 that supplies ink into the ink jet head 51; and a suction device 14 that gives negative pressure into a suction cap 71a disjunctively contact closely with a nozzle face 57 to suck the ink from the ink jet head 51. After driving the head interior pressurizing device 78 and the suction device 14 to start the suction processing including giving positive pressure into the ink jet head 51 and sucking the ink from the ink jet head 51, the control device 13 performs continuous control to continue the drive of the head interior pressurizing device 78 until a difference between the pressure in the suction cap 71a and the atmospheric pressure reaches a predetermined value after the drive of the suction device 14 is stopped when the suction process finishes.

Description

  The present invention relates to an ink suction system and an ink suction method for sucking ink from an ink jet head connected to an ink supply means through a cap that is in close contact with the nozzle surface so as to be detachable.

2. Description of the Related Art Conventionally, an ink suction device including a suction cap that is mounted so as to cover the nozzle surface of a recording head and a suction pump that sucks ink from the recording head by applying a negative pressure in the suction cap is known. (See Patent Document 1).
In this ink suction device, the operation of the suction pump is started, and the output of the suction pump is controlled to a target output value lower than the maximum target output value during the period from the middle of the suction period to the end of the operation. After a predetermined period of time, the suction cap is detached from the recording head after the pressure in the suction cap returns to atmospheric pressure.

JP 2004-034663 A

Immediately after the suction pump is stopped, the suction cap in close contact with the nozzle surface is at a negative pressure. If the suction cap is pulled away from the nozzle surface in this state, ink is drawn into the nozzle due to a sudden pressure change, and the ink liquid level (meniscus) in the nozzle cannot be properly maintained. In an ink jet recording head, the meniscus after the suction process tends to be maintained even after the start of ejection for recording. For this reason, it is very important to appropriately form the meniscus after the suction treatment.
Therefore, in the above-described ink suction device, suction is performed by lowering the output of the suction pump in the middle of the suction period so that the pressure in the suction cap does not become too low at the end of the operation, thereby returning to the atmospheric pressure. The time until the removal of the suction cap is shortened.

  However, in the conventional ink suction device described above, since the output of the suction pump is reduced in the middle of the suction period, an appropriate meniscus can be formed, but there is a problem that the time required for suction is extended. Further, in the case of highly viscous ink, it is necessary to wait for a predetermined period until the suction cap is removed after the suction pump is stopped. For this reason, there has been a problem that the time required for a series of suction processes from the close-up of the suction cap to the separation increases.

  An object of the present invention is to provide an ink suction system and an ink suction method capable of forming an appropriate meniscus and reducing the time required for suction processing.

  An ink suction system according to the present invention includes an ink supply unit that supplies ink to an inkjet head, an in-head pressurizing unit that applies positive pressure to the head of the inkjet head via the ink supply unit, and a nozzle surface of the inkjet head A cap that is in close contact with the cap, a suction unit that communicates with the cap, applies a negative pressure to the cap of the close cap, and sucks ink from the inkjet head, and controls the pressure unit and the suction unit in the head Control means, and the control means drives the in-head pressurizing means and the suction means to start a suction process consisting of applying a positive pressure into the head and sucking ink from the inkjet head, and then performs the suction process. At the end of the operation, after stopping the driving of the suction means, until the pressure difference between the pressure in the cap and the atmospheric pressure becomes a predetermined value, Which comprises carrying out the continuous control to continue driving of the head in the pressurizing means.

  The ink suction method of the present invention is an ink suction method for sucking ink through a cap that is in close contact with the nozzle surface of the ink jet head with respect to the ink jet head connected to the ink supply means. And a suction step of applying a negative pressure to the cap of the ink jet and sucking the ink from the ink jet head at a predetermined timing. After starting the suction processing step that is started in conjunction with, at the end of the suction processing step, after finishing the suction step, until the pressure difference between the pressure in the cap and the atmospheric pressure reaches a predetermined value, The pressurizing step is continued.

  According to these configurations, in the suction process (step), the pressurization in the head and the depressurization in the cap are performed at the same time, so the flow rate (or flow rate) of the ink passing through the head is high. Increase. Thereby, ink can be sucked in a short time. In addition, since the outflow of ink from the inkjet head to the cap is continued by continuing the pressurization in the head even after the driving of the suction means is stopped (suction process is finished), the inside of the cap The pressure rises from the negative pressure state and quickly becomes substantially equal to the atmospheric pressure. Accordingly, it is possible to shorten the time from the end of ink suction (stop of driving of the suction means or the end of the suction process) to the removal of the cap, and to appropriately form the meniscus in the nozzle when the cap is removed. Can do. Thus, a series of suction processes can be performed in a short time.

  In this case, an in-cap pressurizing unit for applying a positive pressure to the cap is further provided, and the control unit stops driving the suction unit and drives the in-cap pressurization unit at the end of the suction process, and then It is preferable that continuous control for continuing driving of the pressure unit in the head and driving of the pressure unit in the cap is performed until the pressure difference between the pressure in the cap and the atmospheric pressure reaches a predetermined value. .

  In this case, the suction processing step further includes an in-cap pressurizing step for applying a positive pressure in the cap, and upon completion of the suction processing step, the suction step is ended and the in-cap pressurizing step is started. It is preferable to continue the in-head pressurization step and the in-cap pressurization step until the pressure difference between the pressure in the cap and the atmospheric pressure reaches a predetermined value.

  According to these configurations, even after the driving of the suction means is stopped (suction process is completed), the pressure in the head is continued, the ink outflow from the inkjet head is continued, and the pressure in the cap is applied. Since the pressure is started, the pressure in the cap immediately becomes equal to the atmospheric pressure from the negative pressure state. Thereby, a series of suction processes can be performed in a shorter time.

  In this case, it is preferable that the control means has a control table that stores a recovery time until the pressure difference reaches a predetermined value, and performs continuous control based on the control table.

  According to this configuration, it is possible to recognize by simple control that the pressure in the cap has become atmospheric pressure, and it is possible to perform a stable suction process capable of forming an appropriate meniscus in a short time.

  In this case, it is preferable to further include an in-cap pressure detecting means for detecting the pressure in the cap, and the control means preferably performs continuous control based on the detection result of the in-cap pressure detecting means.

  In this case, it is preferable that a head internal pressure detecting means for detecting the pressure in the head is further provided, and the control means performs continuous control based on the detection result of the head internal pressure detecting means.

  According to these structures, it can detect reliably that the pressure in a cap became atmospheric pressure, and formation of a favorable meniscus and reliable suction processing can be implemented in a short time.

(A) of a recording device is a top view, (b) is a side view. It is a top view of a head unit. (A) is a perspective view of an inkjet head, (b) is a perspective sectional view schematically showing the structure of a head body. It is a side view of a suction device. It is a piping system diagram of a suction device. It is the side view which showed typically the ink supply apparatus and suction device which concern on 1st Embodiment. 3 is a flowchart of an ink suction method according to the first embodiment. In the ink suction method according to the first embodiment, (a) is a diagram showing the relationship between the pressure in the cap and time, (b) is a diagram showing the relationship between the output of the ejector and time, and (c) is the inside of the head. It is a figure which shows the relationship between the output of a pressurizing means, and time. It is the side view which showed typically the ink supply apparatus and suction device which concern on 2nd Embodiment. 6 is a flowchart of an ink suction method according to a second embodiment. In the ink suction method according to the second embodiment, (a) is a diagram showing the relationship between the pressure in the cap and time, (b) is a diagram showing the relationship between the output of the ejector and time, and (c) is the inside of the head. The figure which shows the relationship between the output of a pressurizing means, and time, (d) is a figure which shows the relationship between the output of the pressurizing means in a cap, and time. (A) is a side view schematically showing the ink supply device and suction device according to the third embodiment, and (b) is a side view schematically showing the ink supply device and suction device according to the fourth embodiment. is there.

  Hereinafter, a recording apparatus provided with a suction device (ink suction system) according to a first embodiment of the present invention will be described with reference to the accompanying drawings. In this recording apparatus, for example, an ultraviolet curable ink (UV ink) is ejected by an inkjet head onto a thin film workpiece to be discharged in a so-called reel-to-reel format, thereby obtaining a desired image or the like. It is something to print. In the following description, the workpiece feed direction is the X-axis direction, the direction orthogonal to the X-axis direction is the Y-axis direction, the direction orthogonal to the X-axis direction and the Y-axis direction is the Z-axis direction, and the workpiece The direction of rotation in the parallel plane is defined as the θ direction.

  As shown in FIG. 1, the recording apparatus 1 includes a machine base 2, a feeding device 3 that feeds out a long workpiece W wound in a roll shape, a winding device 4 that winds up a printed workpiece W, A work stage 5 disposed on the machine base 2 for sucking and setting the supplied work W, and an X axis extending in the X-axis direction and intermittently feeding the work W in the X-axis direction via the work stage 5 The Y-axis table 8 includes a table 7, a Y-axis table 8 spanned in the Y-axis direction so as to straddle the X-axis table 7, and a plurality of inkjet heads 51 that eject ink and print on the workpiece W. The carriage unit 9 is movably mounted on the vehicle.

  In addition, the recording apparatus 1 performs overall control of the ink supply apparatus 10 for supplying ink to each inkjet head 51, the maintenance apparatus 11 for maintaining and recovering the function of each inkjet head 51, and the recording apparatus 1. And a control device 13. The maintenance device 11 is disposed in a maintenance area that is deviated in the Y-axis direction from the printing area where the X-axis table 7 and the Y-axis table 8 intersect, and performs maintenance of the inkjet head 51 facing the maintenance area.

  In this recording apparatus 1, after the work W fed by the feeding apparatus 3 is attracted by the work stage 5, the work W is intermittently fed (sub-scanned) in the X-axis direction via the work stage 5 by the X-axis table 7. Then, printing is performed by ejecting ink from the inkjet head 51 while reciprocating (main scanning) the carriage unit 9 with respect to the print area of the work W held by suction.

  The feeding device 3 includes a feeding motor 22 that feeds and rotates a feeding reel 21 around which the workpiece W is wound, and bends the fed workpiece W in a “V” shape in the Z-axis direction, and applies a light back tension to the workpiece W. A feeding-side buffer mechanism 23 to be applied, and is disposed upstream in the feed direction (X-axis direction) of the workpiece W.

  The winding device 4 includes a winding motor 25 that winds and rotates a winding reel 24 that winds the workpiece W, and bends the wound workpiece W into a “V” shape in the Z-axis direction. A winding-side buffer mechanism 26 that applies a light forward tension, and is disposed downstream of the workpiece W in the feeding direction (X-axis direction).

  The work stage 5 sucks the work W sent from the feeding device 3 through a plurality of holes (not shown) formed on the surface thereof. A feeding roller 28 and a feeding roller 29 are respectively attached to the upstream end and the downstream end of the work stage 5 in the conveyance (X-axis) direction. Although not described in detail, the plurality of holes formed in the work stage 5 communicate with a vacuum suction facility (not shown) and a compressed air supply facility 76 (see FIG. 5), respectively.

  The feeding roller 28 and the feeding roller 29 are free-rotating nip rollers provided so as to be movable up and down, and are arranged side by side in the X-axis direction, sandwiching the workpiece W and facing the workpiece W on the upper surface of the workpiece stage 5. I will. Then, the work stage 5 is intermittently fed in the X-axis direction (from the upstream side to the downstream side) by the X-axis table 7 in a state where the work W is attracted.

  The X-axis table 7 is disposed on the machine base 2 and has a pair of X-axis guide rails 31 extending in the X-axis direction, and a motor drive that supports the work stage 5 slidably along the X-axis guide rails 31. X-axis slider 32. The X-axis table 7 stops when the carriage unit 9 moves forward (or backward), and sends the workpiece W to the downstream side in the X-axis direction by the printing width (return) until the next backward movement (or forward movement). Feed).

  The Y-axis table 8 includes a pair of Y-axis guide rails 34 laid across the machine base 2 in the Y-axis direction, a bridge plate 35 in which the carriage unit 9 is suspended, and the bridge plate 35 in the Y-axis direction. And a motor-driven Y-axis slider 36 that is slidably supported. The Y-axis table 8 reciprocates the ink-jet head 51 in the Y-axis direction during printing via the carriage unit 9 and causes the ink-jet head 51 to face the maintenance device 11.

  The carriage unit 9 includes a carriage body 43 that is suspended from the bridge plate 35 and a head unit 44 that is suspended from the carriage body 43 and includes a plurality of inkjet heads 51. As shown in FIG. 2, the head unit 44 has a plurality of inkjet heads 51 arranged and fixed to the head plate 50 in a predetermined pattern, and a pair of ultraviolet rays is provided at both ends of the head plate 50 in the Y-axis direction. A lamp 45 is mounted.

  As shown in FIG. 3A, the inkjet head 51 is a so-called two-unit type, and an ink introduction part 52 having two connection needles 55, a two-head head substrate 53 that is continuous with the ink introduction part 52, and A pump unit 54 is provided below the ink introduction unit 52 and has an in-head flow path filled with ink, and a nozzle plate 58 having a nozzle surface 57 in which a large number of ejection nozzles 56 are opened. .

  As schematically shown in FIG. 3B, the pump unit 54 is installed on the adhesive film 54a, and joins the piezoelectric element 54b corresponding to each discharge nozzle 56, the adhesive film 54a, and the nozzle plate 58. And a silicon cavity 54c constituting a pressure chamber 54d corresponding to each discharge nozzle 56. In addition, the pump unit 54 includes a common chamber 54e that accumulates functional liquid to be supplied to the pressure chamber 54d and communicates with the connection needles 55, and a supply path 54f that connects the pressure chamber 54d and the common chamber 54e. Is formed. Each pressure chamber 54 d corresponds to each discharge nozzle 56 (piezoelectric element 54 b) and communicates with each discharge nozzle 56. Ink is ejected from each ejection nozzle 56 by applying a drive waveform output from the control device 13 to each piezoelectric element 54b via a cable connected to the head substrate 53. In the claims, “inside the head” refers to the inside of each pressure chamber 54d.

  The ink used in this embodiment is a so-called ultraviolet curable ink, and a pair of ultraviolet lamps 45 mounted on the head unit 44 are turned on to cure and fix the ultraviolet curable ink landed on the workpiece W. The ink is not limited to an ultraviolet curable ink, and may be an infrared curable ink or a visible light curable ink.

  As shown in FIGS. 1 and 6, the ink supply device 10 includes a plurality of ink tanks 61 that respectively store a plurality of colors of ink, and a plurality of ink supply channels that connect the ink tanks 61 and the inkjet heads 51. 62 and an air release channel 63 communicating with the upper space of each ink tank 61. Each ink supply channel 62 is branched into two at the downstream end, and is connected to two connection needles 55, respectively. Each atmosphere opening channel 63 is provided with an atmosphere opening / closing valve 64 for opening and closing the channel. The ink of each color is supplied to each inkjet head 51 at a constant pressure from each ink tank 61 by utilizing the natural head (atmospheric pressure) by opening each atmospheric on-off valve 64. Each ink supply channel 62 is preferably composed of a gas-impermeable tube.

  Next, the maintenance device 11 will be described with reference to FIGS. The maintenance device 11 includes a suction device 14 that forcibly sucks and discharges ink from each inkjet head 51, and a wiping device 15 (see FIG. 1) that wipes the nozzle surface 57 after suction.

  The suction device 14 includes a cap unit 71 on which a plurality of suction caps 71a closely contacting each inkjet head 51 are mounted, an elevating mechanism 72 that moves the cap unit 71 up and down via the support structure 72a, and a waste liquid that stores the sucked ink. A tank 73, a suction channel system 74 for communicating each suction cap 71 a and the waste liquid tank 73, an ejector 75 (suction means) interposed in the suction channel system 74, and each ink tank 61 of the ink supply device 10. And an in-head pressurizing device 78 communicating with the head. Further, the suction device 14 includes a compressed air supply facility 76 that supplies compressed air for control to the ejector 75, and an exhaust facility 77 for exhausting air from each part.

  In the present embodiment, when the operation of the recording apparatus 1 is stopped, the carriage unit 9 is moved to the position of the suction device 14 by the Y-axis table 8, the cap unit 71 is raised by the lifting mechanism 72, and all the inkjet heads 51 are So-called capping (head maintenance) is performed. On the other hand, when the operation is started, the ejector 75 is driven in a capped state to perform the suction process on each inkjet head 51, and then the wiping device 15 performs the wiping process. Then, the carriage unit 9 moves onto the workpiece W set on the workpiece stage 5.

  As shown in FIG. 4, the cap unit 71 has a plurality of suction caps 71 a mounted on the cap plate 71 b so as to have the same arrangement as the plurality of inkjet heads 51 mounted on the head unit 44 and the same inclination posture. Configured.

  The lifting mechanism 72 has a lifting drive mechanism 72b that lifts and lowers the cap unit 71 in the vertical direction via the support structure 72a. The elevating mechanism 72 is lowered to a close position where it is in close contact with the nozzle surface 57 of each inkjet head 51, a spaced position slightly spaced from the nozzle surface 57, and a position where consumables of the head unit 44 and the cap unit 71 can be replaced. The cap unit 71 is moved up and down in three stages between the two replacement positions.

  As shown in FIG. 5, each suction flow path system 74 includes a plurality of cap side flow paths 74a connected to each cap unit 71, a manifold 74b connected to the downstream end of each cap side flow path 74a, and a manifold 74b. A tank-side flow path 74c that communicates with the waste liquid tank 73. Each cap-side channel 74a and tank-side channel 74c is provided with an open / close valve 74d for opening and closing each channel. In addition, it is preferable that each cap side flow path 74a and the tank side flow path 74c are comprised with the gas-impermeable tube.

  The ejector 75 introduces compressed air pressure-adjusted by the electropneumatic regulator 79 from the compressed air supply equipment 76 to the primary side, and connects the secondary side to the upper space of the waste liquid tank 73, Reduce pressure. The control device 13 controls the electropneumatic regulator 79 so that the pressure of the waste liquid tank 73 becomes an appropriate suction pressure based on the number of open / close valves 74d.

  Note that a plurality of waste liquid tanks 73 may be provided for each suction cap 71 a and each cap-side flow path 74 a may be communicated with each waste liquid tank 73. In this case, the manifold 74b and the tank side flow path 74c can be omitted, and the sucked ink can be individually collected for each color. Thereby, the reusability of ink can be improved. In this case, an ejector 75 may be provided for each suction cap 71a (waste liquid tank 73), and ink may be individually sucked for each color. In place of the ejector 75, a suction pump such as a tube pump may be used.

  As shown in FIG. 6, each in-head pressurizing device 78 is a so-called pressurizing pump, and communicates with an upper space of each ink tank 61 serving as an ink supply source via a head pressurizing flow path 78a. . A head pressurization on / off valve 78b that opens and closes the flow path is interposed in the head pressurization flow path 78a. Each in-head pressurizing device 78 pressurizes the inside of each ink tank 61, pushes the ink to the ink jet head 51 through the ink supply channel 62, and indirectly pressurizes the inside of the pressure chamber 54d. The in-head pressurizing device 78 may be communicated with a compressed air supply facility to introduce compressed air instead of the pressurizing pump. In this case, driving of each in-head pressurizing device 78 is started / stopped by opening / closing the head pressurizing on / off valve 78b.

  Next, an ink suction method (“suction process step” in the claims) by the control device 13 will be described with reference to FIGS. In order to simplify the description, the description will be given focusing on one inkjet head 51 and one suction cap 71a.

  The control device 13 drives the elevating mechanism 72 to raise the cap unit 71 to the close position, and closely attach each suction cap 71a to the nozzle surface 57 of each inkjet head 51 (step S1).

  Thereafter, in step S2, the drive of the ejector 75 and the in-head pressurizing device 78 is started simultaneously with the atmospheric on-off valve 64 closed and the head pressurization on-off valve 78b opened (see “Suction Step” and “ “In-head pressurization process”). When driving of the in-head pressurizing device 78 is started, the pressure in each pressure chamber 54d increases (becomes positive pressure). On the other hand, when driving of the ejector 75 is started, the pressure in the suction cap 71a in close contact with the nozzle surface 57 is reduced (becomes negative pressure (see FIG. 8A)). Therefore, the ink supplied from the ink supply device 10 via the ink supply flow path 62 is discharged to the waste liquid tank 73 via the suction cap 71a and the suction flow path system 74. As described above, since the pressurization in each pressure chamber 54d and the decompression in the suction cap 71a are performed at the same time, the flow velocity (or flow rate) of the ink passing through each pressure chamber 54d and the discharge nozzle 56 is obtained. Will increase. Thereby, ink can be sucked in a short time.

  In this embodiment, the drive of the ejector 75 and the in-head pressurizing device 78 is started at the same time. However, if the drive of the ejector 75 and the in-head pressurizing device 78 is started at a predetermined timing, the drive is started. Good. That is, the drive start of the in-head pressurizing device 78 may be preceded, and the drive of the ejector 75 may be started after a lapse of a predetermined time, or vice versa.

  The control device 13 stores in advance the time required for the suction process (referred to as “suction time”). In step S3, when the suction time has elapsed since the start of step S2, the drive of the ejector 75 is stopped ( (Refer FIG.8 (b)). At this time, the control device 13 performs control (continuous control) so as to continue the driving of the in-head pressurizing device 78 (see FIG. 8C). Then, since the ink is continuously pumped to the inkjet head 51 by driving the in-head pressurizing device 78, the ink flows out from each discharge nozzle 56 into the suction cap 71a even when the ejector 75 is stopped. Will continue. For this reason, the pressure in the suction cap 71a quickly rises from the negative pressure state and becomes substantially the same pressure as the atmospheric pressure (see FIG. 8A). Such continuation control of the in-head pressurizing device 78 is particularly effective when ink having a high viscosity (30 to 50 poise) is used so that the outflow of ink by the natural water head cannot be continued after the drive of the ejector 75 is stopped. It is valid.

  In addition to the above-described suction time, the control device 13 stores the time (referred to as “recovery time”) required for the pressure in the suction cap 71a to be substantially equal to the atmospheric pressure after the drive of the ejector 75 is stopped. It has a control table. In step S4, based on this control table, when the recovery time has elapsed, the driving (continuous control) of the in-head pressurizing device 78 is stopped. Then, the atmospheric on / off valve 64 is opened, and the head pressurizing on / off valve 78b is closed. The pressure difference between the pressure in the suction cap 71a and the atmospheric pressure is ideally zero (zero), but continues when the pressure in the suction cap 71a is slightly lower than the atmospheric pressure. Control may be stopped. That is, it is sufficient that the pressure difference is such that the ink level (meniscus) in the discharge nozzle 56 can be properly maintained when the suction cap 71a is separated in the next step S5.

  In step S <b> 5, the elevating mechanism 72 is driven to lower the cap unit 71 to the separation position, and the suction cap 71 a is separated from the nozzle surface 57 of each inkjet head 51. In this case, since the inside of the suction cap 71 a that is in close contact with the nozzle surface 57 is at a pressure equivalent to the atmospheric pressure, the suction cap 71 a can be separated from the nozzle surface 57 without difficulty, and suddenly with respect to each discharge nozzle 56. Therefore, the ink is not drawn into the discharge nozzle 56 because it does not give a change in pressure. Thereby, the meniscus of the ink in the discharge nozzle 56 can be appropriately maintained.

  According to the above configuration, the ink suction time can be shortened, and proper meniscus formation in each discharge nozzle 56 when the suction caps 71a are removed is ensured, and the suction caps 71a have a proper meniscus formation. The pressure recovery time can be shortened. Thereby, a series of suction processing steps can be performed in a short time.

(Second Embodiment)
A recording apparatus 1 to which the ink suction system according to the second embodiment is applied will be described with reference to FIGS. As shown in FIG. 9, the suction device 14 of the recording apparatus 1 includes an in-cap pressure device 81 that applies a positive pressure to each suction cap 71a. Each in-cap pressurizing device 81 is a so-called pressurizing pump, and communicates with the internal space of each suction cap 71a via a cap pressurizing flow path 81a. In the cap pressurizing channel 81a, a cap pressurizing on / off valve 81b for opening and closing the channel is opened. Each in-cap pressurizing device 81 pressurizes each suction cap 71a. Since the other configuration of the recording apparatus 1 is the same as that of the first embodiment, the description thereof is omitted. The in-cap pressurizing device 81 may be communicated with a compressed air supply facility instead of the pressurizing pump to introduce the compressed air. In this case, driving of each in-cap pressurizing device 81 is started / stopped by opening / closing the cap pressurizing on / off valve 81b.

  In the ink suction method by the control device 13 according to the second embodiment, Step S1, Step S2, and Step S5 described in the first embodiment are the same, and Step S3 and Step S4 (referred to as Step S13 and Step S14). Are different (see FIG. 10). Therefore, in the following description, the same description as that according to the first embodiment is omitted, and only different points are shown.

  After the above-described Step S1 and Step S2, in Step S13, when the suction time has elapsed from the start of Step S2, the drive of the ejector 75 is stopped (see FIG. 11B) and the cap pressurization on-off valve 81b is opened. Then, the in-cap pressurizing device 81 is driven (see FIG. 11D). Then, the control device 13 performs control (continuous control) so as to continue driving the in-head pressurizing device 78 and the in-cap pressurizing device 81 until the pressure in the suction cap 71a becomes atmospheric pressure. (See FIGS. 11C and 11D). Thus, as in the first embodiment, the outflow of ink from each ejection nozzle 56 by driving the in-head pressurizing device 78 is continued, and the inside of the suction cap 71a is added by the in-cap pressurizing device 81. Therefore, the pressure in the suction cap 71a immediately rises from the negative pressure state, and becomes substantially the same pressure as the atmospheric pressure (see FIG. 11A).

  The control table of the control device 13 stores a recovery time in consideration of driving of the in-head pressurizing device 78 and the in-cap pressurizing device 81 from the stop of the drive of the ejector 75. The recovery time is set so that the pressure in the suction cap 71a does not become higher than the atmospheric pressure. In step S14, after the recovery time has elapsed, the driving (continuous control) of the in-head pressurizing device 78 and the in-cap pressurizing device 81 is stopped simultaneously, and the cap pressurization on-off valve 81b is closed. Then, the atmospheric on / off valve 64 is opened, and the head pressurizing on / off valve 78b is closed. The driving stop of the in-head pressurizing device 78 and the in-cap pressurizing device 81 may be performed in conjunction with each other at a predetermined timing. That is, the drive of the in-head pressurizing device 78 may be stopped first, and the drive of the in-cap pressurizing device 81 may be stopped after a predetermined time has elapsed, or vice versa.

  After step S14, step S5 described above is performed, and the series of suction processing steps is completed. Thereby, a series of suction processing steps can be performed in a shorter time.

(Third embodiment)
A recording apparatus 1 to which the ink suction system according to the third embodiment is applied will be described with reference to FIG. The suction device 14 of the recording apparatus 1 includes an in-cap pressure detecting means 82 for detecting the pressure in the suction cap 71a. In addition, the control device 13 omits the recovery time stored in the control table, and performs continuous control based on the detection result of the in-cap pressure detection means 82. That is, in the above-described step S4, when the in-cap pressure detecting means 82 detects that the pressure in the suction cap 71a has become atmospheric pressure (or a predetermined pressure difference from atmospheric pressure), the in-head pressure device 78. Is stopped (continuous control). Since the other configuration of the recording apparatus 1 is the same as that of the first embodiment, the description thereof is omitted.

  The control device 13 (ink suction method) according to the third embodiment may be applied to the device according to the second embodiment. That is, in step S14, the drive (continuous control) of the in-head pressurizing device 78 and the in-cap pressurizing device 81 may be stopped using the detection result of the in-cap pressure detecting means 82.

  According to this configuration, it is possible to reliably detect that the pressure in each suction cap 71a has become atmospheric pressure, and good meniscus formation and reliable suction processing can be performed in a short time.

(Fourth embodiment)
A recording apparatus 1 to which the ink suction system according to the fourth embodiment is applied will be described with reference to FIG. The recording apparatus 1 further includes in-head pressure detection means 83 for detecting the pressure in each pressure chamber 54d in addition to the in-cap pressure detection means 82 provided in the suction device 14 according to the third embodiment. Yes. The in-head pressure detecting means 83 is interposed in the ink supply channel 62 in the vicinity of the inkjet head 51.

  Further, the control device 13 performs continuous control based on the detection results of the cap internal pressure detecting means 82 and the head internal pressure detecting means 83. That is, in step S4 described above, the detection result of the cap internal pressure detection means 82 and the detection result of the head internal pressure detection means 83 are compared, and the pressure difference is within a predetermined range stored in advance in the control table. In some cases, the driving (continuous control) of the in-head pressurizing device 78 is stopped. Since the other configuration of the recording apparatus 1 is the same as that of the first embodiment, the description thereof is omitted.

  The control device 13 (ink suction method) according to the fourth embodiment may be applied to the device according to the second embodiment. That is, in step S14, the drive (continuous control) of the in-head pressurizing device 78 and the in-cap pressurizing device 81 is stopped using the detection results of the in-cap pressure detecting means 82 and the in-head pressure detecting means 83, respectively. It may be.

  DESCRIPTION OF SYMBOLS 10: Ink supply apparatus, 13: Control apparatus, 51: Inkjet head, 78: In-head pressurization apparatus, 71a: Suction cap, 75: Ejector, 81: In-cap pressurization apparatus, 82: In-cap pressure detection means, 83 : In-head pressure detection means

Claims (7)

Ink supply means for supplying ink to the inkjet head;
In-head pressurizing means for applying a positive pressure in the head of the inkjet head via the ink supply means;
A cap that comes into close contact with the nozzle surface of the inkjet head in a freely detachable manner;
A suction unit that communicates with the cap and sucks ink from the inkjet head by applying a negative pressure in the cap of the cap that is in close contact;
Control means for controlling the pressure means in the head and the suction means, and
The control means includes
After driving the in-head pressurizing means and the suction means to start suction processing consisting of applying positive pressure into the head and sucking ink from the inkjet head,
At the end of the suction process, after the drive of the suction means is stopped, the drive of the pressure means in the head is continued until the pressure difference between the pressure in the cap and the atmospheric pressure reaches a predetermined value. An ink suction system characterized by performing control. A cap in-cap means for applying a positive pressure in the cap;
The control means includes
Upon completion of the suction process, the driving of the suction unit is stopped and the pressure unit in the cap is driven,
Thereafter, until the pressure difference between the pressure in the cap and the atmospheric pressure reaches a predetermined value, the control of the in-head pressurizing unit and the continuous control to continue the drive of the in-cap pressurizing unit are performed. The ink suction system according to claim 1, wherein: The control means includes
A control table storing a recovery time until the pressure difference reaches a predetermined value;
The ink suction system according to claim 1, wherein the continuous control is performed based on the control table. A cap internal pressure detecting means for detecting the pressure in the cap;
The ink suction system according to claim 1, wherein the control unit performs the continuous control based on a detection result of the in-cap pressure detection unit. A head internal pressure detecting means for detecting the pressure in the head;
The ink suction system according to claim 4, wherein the control unit performs the continuous control based on a detection result of the in-head pressure detection unit. An ink suction method for sucking ink through a cap that is in close contact with the nozzle surface of the ink jet head with respect to the ink jet head connected to the ink supply means,
An in-head pressurizing step for applying a positive pressure in the head of the ink jet head via the ink supply means, and a suction step for applying an negative pressure in the cap of the cap and sucking ink from the ink jet head. And starting a suction processing step that starts in conjunction with a predetermined timing,
At the end of the suction processing step, after the suction step is finished, the in-head pressurization step is continued until the pressure difference between the pressure in the cap and the atmospheric pressure reaches a predetermined value. Ink suction method. The suction treatment step further includes an in-cap pressurizing step for applying a positive pressure in the cap,
Upon completion of the suction processing step, the suction step is completed and the in-cap pressurization step is started.
7. The ink according to claim 6, wherein the in-head pressurizing step and the in-cap pressurizing step are continued until the pressure difference between the pressure in the cap and the atmospheric pressure reaches a predetermined value. Suction method.

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