JP6339968B2 - Liquid ejection apparatus and liquid ejection head adjustment method - Google Patents

Description

  The present invention relates to a liquid discharge apparatus and a liquid discharge head adjustment method, and more particularly to a technique for adjusting the internal pressure of a liquid discharge head.

  An ink jet recording apparatus including an ink jet head is known as a liquid discharge apparatus including a liquid discharge head. Inkjet heads achieve stable ejection by keeping the internal pressure constant when ejecting liquid.

  Patent Document 1 is a serial type ink jet recording apparatus, in which the pressure of ink is detected at the end of the scanning range of the carriage, and the detected pressure of the ink is compared with a predetermined appropriate pressure range. A configuration is described that warns of an error when the ink pressure is not within the proper pressure range.

  In addition, the ink jet recording apparatus described in Patent Document 1 describes a configuration in which when an error is warned, the acceleration of the carriage is delayed to detect the ink pressure. The term “detection” in this specification corresponds to the term “detection” in Patent Document 1.

  Patent Document 2 discloses a serial type ink jet recording apparatus. When an ink jet head having a small allowable internal pressure range of the ink jet head is mixed, the acceleration / deceleration control of the carriage is gently performed to suppress the pressure fluctuation. A configuration is described in which ink discharge abnormality due to pressure fluctuation is not caused without being reduced as much as possible. Note that the terms “inkjet head”, “internal pressure”, “drawing speed”, and “ejection abnormality” in the present specification correspond to the terms “recording head”, “hydraulic pressure”, “printing speed”, and “ejection failure” in Patent Document 2.

JP 2014-104675 A JP-A-6-099594

  However, an inkjet recording apparatus including a line-type inkjet head in which ejection elements are arranged over a length corresponding to the entire width of the medium moves the inkjet head along the vertical direction when moving from the drawing position to the maintenance position. There are things to do. Further, when the floating of the drawing target medium is detected, the ink jet head may be moved along the vertical direction in order to avoid contact between the liquid ejection surface of the ink jet head and the medium. When the ink jet head is moved along the vertical direction, the internal pressure of the ink jet head may fluctuate due to the acceleration during the movement, and the discharge state may become unstable.

  The ink jet recording apparatuses described in Patent Document 1 and Patent Document 2 each include a serial ink jet head, and the moving direction of the ink jet head is horizontal.

  Since the serial type inkjet head is moved in the horizontal direction and the line type inkjet head is moved in the vertical direction, conditions such as the weight of the inkjet head, the weight of the ink, and the moving speed are different. Therefore, it is difficult to apply a pressure adjustment technique applied to a serial inkjet head to a line-type inkjet head.

  The present invention has been made in view of such circumstances, and provides a liquid discharge apparatus and a liquid discharge head adjustment method that realize a stable discharge state when the liquid discharge head is moved in a direction including a vertical component. The purpose is to do.

  In order to achieve the above object, the following invention aspects are provided.

  A liquid ejection apparatus according to a first aspect is a liquid ejection head including an ejection element that ejects a liquid, and includes an individual channel that communicates with the ejection element, and a liquid ejection head that includes an internal channel that communicates with the individual channel. An individual channel opening / closing unit that switches between opening and closing of the individual channel, the individual channel opening / closing unit provided in the individual channel, and a first head moving unit that moves the liquid discharge head in a first direction having a vertical component And whether or not the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction by the first head moving means. When the determination means and the determination means determine that the pressure in the internal flow path of the liquid ejection head has a fluctuation that falls outside a predetermined allowable range, the individual flow is linked with the operation of the first head moving means. Road opening and closing means The individual flow path switch control means for closing the individual channels to control the operation, a liquid ejection apparatus comprising a.

  According to the first aspect, when the liquid discharge head is moved in the first direction, the individual flow path communicating with the discharge element is closed in conjunction with the movement of the liquid discharge head. The pressure fluctuation in the internal flow path of the liquid discharge head communicating with the individual flow path during the movement is suppressed within an allowable range.

  During the movement of the liquid discharge head in the first direction by the first head moving means, not only the period during which the liquid discharge head is actually moving in the first direction, but also the liquid discharge using the first head moving means. The period from the start of the head movement control to the actual movement of the liquid discharge head in the first direction, and the movement control of the liquid discharge head using the first head moving means after the liquid discharge head stops. A period until it is stopped may be included.

  The second aspect is the liquid ejection apparatus according to the first aspect, wherein the individual flow path opening / closing control means determines that the determination means has a variation in which the pressure of the internal flow path of the liquid ejection head is outside the allowable range. Before the first head moving means moves the liquid discharge head in the first direction, the individual flow path opening / closing means is operated to close the individual flow path, and the first head moving means moves the liquid discharge head in the first direction. When the operation is stopped, the individual channel opening / closing means can be operated to open the individual channel.

  According to the second aspect, since the individual flow path is closed during the movement of the liquid ejection head in the first direction, the liquid ejection head communicated with the individual flow path when the liquid ejection head is moved in the first direction. The pressure fluctuation in the internal flow path is suppressed.

  The third aspect predicts pressure fluctuations in the internal flow path of the liquid discharge head during the movement of the liquid discharge head in the first direction by the first head moving means in the liquid discharge apparatus of the first aspect or the second aspect. Pressure fluctuation predicting means, and the judging means determines whether the pressure of the internal flow path of the liquid discharge head is moved by the first head moving means in the first direction based on the prediction result of the pressure fluctuation predicting means. It can be configured to determine whether or not there is a fluctuation that falls outside the allowable range.

  In the third aspect, it is possible to predict the pressure fluctuation of the internal flow path of the liquid discharge head during the movement of the liquid discharge head in the first direction based on the operation parameter of the first head moving means.

  As the operation parameter of the first head moving means, the operating frequency of the actuator in an aspect in which the first head moving means is provided with an actuator can be applied.

  According to a fourth aspect, in the liquid ejection apparatus according to the first aspect, the liquid ejection apparatus includes an acceleration measurement unit that measures the acceleration of the liquid ejection head during the movement of the liquid ejection head in the first direction by the first head moving unit. Based on the measurement result of the acceleration measuring means, the pressure in the internal flow path of the liquid discharge head falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction by the first head moving means. The individual flow path opening / closing control means determines whether or not there is a fluctuation, and the individual flow path opening / closing control means determines that the individual flow path opening / closing control means has a fluctuation that the pressure of the internal flow path of the liquid discharge head is outside the allowable range. The individual flow path is closed by operating the means, and when the movement of the liquid ejection head in the first direction is stopped by the first head moving means, the individual flow path opening / closing means is operated to open the individual flow path. Can

  According to the fourth aspect, during the movement of the liquid discharge head in the first direction by the first head moving means, it is determined that the pressure of the internal flow path of the liquid discharge head has a fluctuation that is outside the allowable range. Until the movement of the liquid ejection head in the first direction is stopped, the individual flow path communicating with the ejection element is closed, so that it communicates with the individual flow path when the liquid ejection head is moved in the first direction. Pressure fluctuation in the internal flow path of the liquid discharge head is suppressed.

  The period from when the liquid discharge head is actually stopped until the movement control of the liquid discharge head using the first head moving means is stopped until the movement of the liquid discharge head in the first direction is stopped. May be included.

  According to a fifth aspect, in the liquid ejection apparatus according to the first aspect, there is provided pressure measurement means for measuring the pressure of the internal flow path of the liquid ejection head during the movement of the liquid ejection head in the first direction by the first head movement means. The determination means is based on the measurement of the pressure measurement means, and the pressure of the internal flow path of the liquid discharge head is determined within a predetermined allowable range during the movement of the liquid discharge head in the first direction by the first head moving means. The individual flow path opening / closing control means determines whether the pressure in the internal flow path of the liquid ejection head has a fluctuation that falls outside the allowable range. Operate the flow path opening / closing means to close the individual flow path, and if the determination means determines that the pressure of the internal flow path of the liquid ejection head has a variation that falls within the allowable range, operate the individual flow path opening / closing means. Structure to open individual flow path It can be.

  According to the fifth aspect, the individual flow path communicating with the ejection element is closed during the period when the pressure of the internal flow path of the liquid ejection head is determined to have a fluctuation that is outside the allowable range. Pressure fluctuations in the internal flow path of the liquid discharge head communicating with the individual flow path when the discharge head is moved are suppressed.

  According to a sixth aspect, in the liquid ejection device according to any one of the first to fifth aspects, the individual flow path is a supply-side individual flow path that supplies the liquid to the ejection element, and a recovery that collects the liquid from the ejection element. The individual flow path opening / closing means includes a supply side individual flow path opening / closing means provided in the supply side individual flow path, and a recovery side individual flow path opening / closing means provided in the recovery side individual flow path. can do.

  According to the sixth aspect, even in a liquid ejection apparatus including a supply-side flow path system and a recovery-side flow path system, by applying any one of the first to fifth aspects to both, Pressure fluctuation in the internal flow path of the liquid discharge head communicating with the individual flow path when the liquid discharge head is moved in one direction is suppressed.

  According to a seventh aspect, in the liquid ejection device according to the fifth aspect, the individual flow path includes a supply-side individual flow path for supplying the liquid to the ejection element and a recovery-side individual flow path for recovering the liquid from the ejection element. The path opening / closing means includes a supply side individual flow path opening / closing means provided in the supply side individual flow path, and a recovery side individual flow path opening / closing means provided in the recovery side individual flow path. Supply side temporary storage means for temporarily storing liquid supplied to the element, supply side temporary storage means connected to the supply side individual flow path, and recovery side temporary storage for temporarily storing liquid recovered from the discharge element And a recovery side temporary storage means connected to the recovery side individual flow path, the pressure measuring means is a supply side pressure sensor for detecting the internal pressure of the supply side temporary storage means, and the recovery side temporary storage means Recovery side pressure to detect the internal pressure of It can be configured as a sensor.

  According to the seventh aspect, even in the liquid discharge apparatus including the recovery-side flow path system, the individual flow path communicating with the discharge element is closed based on the measurement by the pressure measuring means, so the liquid discharge head in the first direction The pressure fluctuation in the internal flow path of the liquid discharge head communicating with the individual flow path when moving the liquid is suppressed.

  A liquid discharge apparatus according to an eighth aspect includes a discharge element that discharges liquid, an individual flow path that communicates with the discharge element, a liquid discharge head that includes an internal flow path that communicates with the individual flow path, and an internal flow of the liquid discharge head. An internal pressure adjusting means for adjusting the pressure of the passage, a first head moving means for moving the liquid discharge head in a first direction having a vertical component, and the pressure in the internal flow path of the liquid discharge head is the first head moving means Determining means for determining whether or not there is a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction, and the pressure in the internal flow path of the liquid discharge head is determined in advance by the determination means. When it is determined that the fluctuation is outside the determined allowable range, the proportional control parameter applied to the internal pressure adjusting means is changed in conjunction with the operation of the first head moving means to sense the pressure fluctuation. A proportional control parameter changing means for increasing a, which is a liquid ejecting apparatus comprising a.

  According to the eighth aspect, during the movement of the liquid discharge head in the first direction by the first head moving means, the proportional control parameter is changed in conjunction with the movement of the liquid discharge head to increase the sensitivity to pressure fluctuation. Therefore, the pressure fluctuation in the internal flow path of the liquid discharge head communicating with the individual flow path during the movement of the liquid discharge head in the first direction by the first head moving means is suppressed.

  During the movement of the liquid discharge head in the first direction by the first head moving means, not only the period during which the liquid discharge head is actually moving in the first direction, but also the liquid discharge using the first head moving means. The period from the start of the head movement control to the actual movement of the liquid discharge head in the first direction, and the movement control of the liquid discharge head using the first head moving means after the liquid discharge head stops. A period until it is stopped may be included.

  According to a ninth aspect, in the liquid ejection apparatus according to the eighth aspect, when the proportional control parameter changing unit determines that the determination unit has a variation in which the pressure of the internal flow path of the liquid ejection head is outside the allowable range, Before the one head moving means moves the liquid ejection head in the first direction, the proportional control parameter applied to the internal pressure adjusting means is changed to increase the sensitivity to pressure fluctuation, and the first head moving means moves in the first direction. When the movement of the liquid discharge head is stopped, the proportional control parameter can be restored before being changed.

  According to the ninth aspect, during the movement of the liquid discharge head in the first direction by the first head moving means, the proportional control parameter is appropriately changed, so that the liquid discharge head in the first direction by the first head moving means is moved. Fluctuation in the internal flow path of the liquid discharge head communicating with the individual flow path during the movement of the liquid is suppressed.

  The tenth aspect predicts pressure fluctuations in the internal flow path of the liquid ejection head during the movement of the liquid ejection head in the first direction by the first head moving means in the liquid ejection apparatus of the eighth aspect or the ninth aspect. Pressure fluctuation predicting means, and the judging means determines whether the pressure of the internal flow path of the liquid discharge head is moved by the first head moving means in the first direction based on the prediction result of the pressure fluctuation predicting means. It can be configured to determine whether or not there is a fluctuation that falls outside the allowable range.

  In the tenth aspect, predicting the pressure fluctuation in the internal flow path of the liquid ejection head during the movement of the liquid ejection head in the first direction by the first head moving means based on the operation parameter of the first head moving means. Is possible.

  An eleventh aspect is the liquid ejection apparatus according to the eighth aspect, further comprising acceleration measuring means for measuring the acceleration of the liquid ejection head during the movement of the liquid ejection head in the first direction by the first head moving means, Based on the measurement result of the acceleration measuring means, the pressure in the internal flow path of the liquid discharge head falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction by the first head moving means. The proportional control parameter changing means determines whether the internal pressure adjusting means determines that the pressure in the internal flow path of the liquid ejection head is outside the allowable range. By changing the applied proportional control parameter to increase the sensitivity to pressure fluctuation and stopping the movement of the liquid ejection head in the first direction by the first head moving means, the proportional control parameter It may be configured to return before the change.

  According to the eleventh aspect, during the movement of the liquid discharge head in the first direction by the first head moving means, it is determined that the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside the allowable range. Until the movement of the liquid discharge head in the first direction is stopped, the pressure of the internal flow path of the liquid discharge head is controlled based on the changed proportional control parameter. Pressure fluctuations in the internal flow path of the liquid discharge head communicating with the individual flow path during the movement of the discharge head in the first direction are suppressed.

  A twelfth aspect is the liquid ejection apparatus according to the eighth aspect, comprising pressure measuring means for measuring the pressure of the internal flow path of the liquid ejection head during the movement of the liquid ejection head in the first direction by the first head moving means. The determination means determines whether the pressure of the internal flow path of the liquid discharge head is determined in advance during the movement of the liquid discharge head in the first direction by the first head moving means based on the measurement result of the pressure measurement means. The proportional control parameter changing means determines whether or not the pressure in the internal flow path of the liquid discharge head has a fluctuation that falls outside the allowable range. The proportional control parameter applied to the pressure adjusting means is changed to increase the sensitivity to pressure fluctuation, and the judging means determines that the pressure in the internal flow path of the liquid discharge head has a fluctuation that falls within an allowable range. If it may be configured to return before the change proportional control parameter.

  According to the twelfth aspect, since the proportional control parameter is changed during the period in which the pressure of the internal flow path of the liquid discharge head is determined to have a fluctuation that is outside the allowable range, the liquid discharge head by the first head moving unit is changed. Pressure fluctuation in the internal flow path of the liquid discharge head communicating with the individual flow path during the movement in the first direction is suppressed.

  A thirteenth aspect is the liquid ejection device according to any one of the eighth aspect to the twelfth aspect, wherein the individual flow path is a supply-side individual flow path that supplies the liquid to the ejection element, and recovery that collects the liquid from the ejection element It can be set as the structure containing a side separate flow path.

  According to the thirteenth aspect, even in a liquid ejection apparatus including a supply-side flow path system and a recovery-side flow path system, by applying any one of the eighth to twelfth aspects to both, Pressure fluctuation in the internal flow path of the liquid discharge head communicating with the individual flow path when the liquid discharge head is moved in one direction is suppressed.

  According to a fourteenth aspect, in the liquid ejection device according to the fifth aspect or the twelfth aspect, the internal flow path of the liquid ejection head includes a temporary storage unit that temporarily stores the liquid supplied to the ejection element, and the pressure measurement unit includes: It can be set as the structure which is a pressure sensor which detects the internal pressure of a temporary storage means.

  According to the fourteenth aspect, it is possible to suppress pressure fluctuations in the internal flow path of the liquid discharge head communicating with the individual flow path when the liquid discharge head is moved in the first direction based on the internal pressure of the temporary storage unit. it can.

  According to a fifteenth aspect, in the liquid ejection device according to the twelfth aspect, the individual flow path includes a supply-side individual flow path for supplying the liquid to the discharge element and a recovery-side individual flow path for recovering the liquid from the discharge element. The internal flow path of the head is a supply-side temporary storage means for temporarily storing the liquid supplied to the discharge element, the supply-side temporary storage means connected to the supply-side individual flow path, and the liquid recovered from the discharge element Is a recovery-side temporary storage means that temporarily stores the recovery-side temporary storage means connected to the recovery-side individual flow path, and the pressure measurement means detects the internal pressure of the supply-side temporary storage means. It can be set as the structure which is a collection | recovery side pressure sensor which detects the internal pressure of a sensor and a collection | recovery side temporary storage means.

  According to the fifteenth aspect, when the recovery-system flow path is provided, the liquid ejection head is moved in the first direction based on the internal pressure of the supply-side temporary storage unit and the internal pressure of the recovery-side temporary storage unit. Fluctuations in the internal flow path of the liquid discharge head communicating with the individual flow paths can be suppressed.

  According to a sixteenth aspect, in the liquid ejection device according to any one of the first to fifteenth aspects, the liquid ejection head may be configured to include a second head moving unit that moves the liquid ejection head in the horizontal direction.

  According to the sixteenth aspect, even when the liquid discharge head is moved in the first direction and the horizontal direction, the internal flow path of the liquid discharge head communicated with the individual flow path when the liquid discharge head is moved in the first direction. The pressure fluctuation can be suppressed.

  A liquid discharge head adjustment method according to a seventeenth aspect is a method for adjusting a liquid discharge head comprising: a discharge element that discharges liquid; an individual flow path that communicates with the discharge element; and an internal flow path that communicates with the individual flow path. Determining whether or not the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction including the vertical component. In conjunction with the movement of the liquid ejection head in the first direction when it is determined that the pressure of the internal flow path of the liquid ejection head has a fluctuation that falls outside a predetermined allowable range by the process and the determination process, The liquid discharge head adjustment method includes an individual flow path closing process for closing the individual flow path and a moving process for moving the liquid discharge head in the first direction.

  According to the 17th aspect, the same effect as the 1st aspect can be obtained.

  In the seventeenth aspect, matters similar to those specified in the second aspect to the seventh aspect and the fourteenth aspect to the sixteenth aspect can be appropriately combined. The elements of the processing and operation means specified in the liquid ejection apparatus can be grasped as processes having corresponding processing and functions.

  A liquid discharge head adjustment method according to an eighteenth aspect is a method for adjusting a liquid discharge head comprising: a discharge element that discharges liquid; an individual flow path that communicates with the discharge element; and an internal flow path that communicates with the individual flow path. A determination step of determining whether or not the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction including the vertical component. If the determination process determines that the pressure in the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range, the liquid discharge head moves in the first direction and moves the liquid. And a proportional control parameter changing step for changing the proportional control parameter applied to the adjustment of the internal pressure of the discharge head to increase sensitivity to pressure fluctuation.

  According to the 18th aspect, the same effect as the 8th aspect can be obtained.

  In the seventeenth aspect, matters similar to the matters specified in the ninth to sixteenth aspects can be appropriately combined. The elements of the processing and operation means specified in the liquid ejection apparatus can be grasped as processes having corresponding processing and functions.

  According to the present invention, when the liquid discharge head is moved in the first direction, the individual flow path communicating with the discharge element is closed in conjunction with the movement of the liquid discharge head, so that the liquid discharge head is moved in the first direction. Pressure fluctuations in the internal flow path of the liquid discharge head communicating with the individual flow paths during the movement are suppressed within an allowable range.

FIG. 1 is an overall configuration diagram showing a schematic configuration of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective plan view of the liquid ejection surface of the inkjet head. FIG. 3 is a perspective view of the head module including a partial cross-sectional view. FIG. 4 is a plan perspective view of the liquid ejection surface in the head module. FIG. 5 is a cross-sectional view showing the internal structure of the head module. FIG. 6 is a perspective view showing the structure of the internal flow path of the inkjet head. FIG. 7 is a block diagram showing the configuration of the internal flow path of the inkjet head and the configuration of the ink supply system. FIG. 8 is a schematic diagram schematically showing a schematic configuration of the first head moving unit. FIG. 9 is a block diagram showing a configuration of a control system of the ink jet recording apparatus shown in FIG. FIG. 10 is an explanatory diagram of a technical problem associated with the vertical movement of the inkjet head. FIG. 11 is a flowchart showing a control flow of the inkjet head adjustment method according to the first embodiment of the present invention. FIG. 12 is an explanatory diagram of the effect of the ink jet head adjustment method according to the first embodiment of the present invention. FIG. 13 is a block diagram showing a configuration of a control system of the ink jet recording apparatus according to the first modification of the first embodiment. FIG. 14 is a flowchart showing the flow of control of the inkjet head adjustment method according to the first modification of the first embodiment of the present invention. FIG. 15 is a flowchart showing a control flow of the inkjet head adjustment method according to the second modification of the first embodiment of the present invention. FIG. 16 is a block diagram showing the configuration of the control system of the ink jet recording apparatus according to the second embodiment of the present invention. FIG. 17 is an explanatory diagram of an inkjet head adjustment method according to the second embodiment of the present invention. FIG. 18 is a flowchart showing a control flow of the inkjet head adjustment method according to the second embodiment of the present invention. FIG. 19 is a flowchart showing a control flow of the ink jet head adjustment method according to the first modification of the second embodiment of the present invention. FIG. 20 is a flowchart showing a control flow of the inkjet head adjustment method according to the second modification of the second embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First embodiment]
<Overall configuration of inkjet recording apparatus>
FIG. 1 is an overall configuration diagram showing a schematic configuration of an ink jet recording apparatus according to a first embodiment of the present invention. An ink jet recording apparatus 10 illustrated in FIG. 1 is an image forming apparatus that draws ink on a medium 100 using an ink jet method. In addition, the ink jet recording apparatus 10 illustrated in FIG. 1 is an embodiment of a liquid ejection apparatus. Ink is an aspect of liquid.

  Hereinafter, the configuration of each part of the inkjet recording apparatus 10 of the present embodiment will be described in detail.

<Media supply unit>
The medium supply unit 17 takes out the medium 100 from the stocker 17D, and delivers the taken-out medium 100 to the drawing unit 60. The medium supply unit 17 includes a stocker 17D that stores the medium 100, a posture adjustment unit 17B that adjusts the posture of the medium 100 one by one and transfers the medium 100 to the transfer cylinder 17A, and a transfer cylinder 17A that transfers the medium to the drawing unit 60 in the subsequent stage. I have.

  The transfer cylinder 17A includes a transfer cylinder main body 17C formed of a frame, and a gripper 17G provided in the transfer cylinder main body 17C. The transfer cylinder 17A is formed corresponding to the maximum width of the medium 100, and is rotated by being driven by a motor (not shown).

The maximum width of the medium is the maximum length of the medium 100 in the direction orthogonal to the conveyance direction of the medium 100. The maximum width of the media is indicated by a reference sign L _max in Fig. In the following description, the conveyance direction of the medium 100 may be described as the medium conveyance direction.

  The direction orthogonal to the medium conveyance direction is illustrated with reference numeral X in FIG. Further, the medium conveyance direction is illustrated by adding a symbol Y in FIG.

  In the present specification, the terms orthogonal or vertical are substantially the same as the case of crossing at 90 degrees out of the case of crossing at an angle of more than 90 degrees or of less than 90 degrees. Orthogonal or vertical.

  In addition, the term “parallel” in this specification includes substantial parallelism having the same effect as parallel, although the two directions are not parallel. Further, the same term in the present specification includes substantially the same, although there is a difference, which can obtain the same effect as the same.

  The transfer cylinder 17A rotates clockwise in FIG. Thereby, the gripper 17G rotates on the same circumference. The medium 100 is conveyed with its tip end gripped by the gripper 17G. In FIG. 1, the rotation direction of the transfer cylinder 17A is indicated by an arrow line.

  The gripper 17G is a direction orthogonal to the medium conveyance direction, and includes a plurality of claws, a claw base disposed along the rotation axis direction of the transfer cylinder 17A, and a claw opening / closing unit that collectively opens and closes the plurality of claws. . The gripper 17G fixes the medium 100 by sandwiching the tip of the medium 100 between the nail and the nail base.

  The medium 100 is supplied to the drawing unit 60 by the medium supply unit 17 shown in FIG.

<Drawing part>
The drawing unit 60 draws color inks of cyan, magenta, yellow, and black on the drawing surface of the medium 100 to draw a color image on the drawing surface of the medium 100. The drawing unit 60 presses the drawing cylinder 61 that conveys the medium 100, and the drawing surface of the medium 100 that is conveyed by the drawing cylinder 61, so that the surface opposite to the drawing surface of the medium 100 becomes the outer peripheral surface 61 </ b> A of the drawing cylinder 61. The sheet pressing roller 63 to be in close contact, the ink jet heads 21C, 21M, 21Y, and 21K that eject inks of cyan, magenta, yellow, and black on the medium 100, and the inline sensor 64 are configured.

  The ink jet heads 21C, 21M, 21Y, and 21K are one mode of the liquid discharge head. The drawing cylinder 61 is an aspect of the medium transport unit. The term “droplet ejection” in this specification can be treated as a synonym for ejection.

  The drawing cylinder 61 receives the medium 100 from the transfer cylinder 17A, and rotates counterclockwise in FIG. The medium 100 is conveyed while being sucked and held on the outer peripheral surface 61 </ b> A of the drawing cylinder 61. In FIG. 1, the rotation direction of the drawing cylinder 61 is illustrated by an arrow line. Note that the support of the medium 100 to the outer peripheral surface 61A of the drawing cylinder 61 is not limited to vacuum suction. Electrostatic adsorption or the like can also be applied.

  A gripper 61 </ b> G is provided on the outer peripheral surface 61 </ b> A of the drawing cylinder 61. The medium 100 is conveyed with the tip end gripped by the gripper 61G. The drawing cylinder 61 shown in FIG. 1 is provided with grippers 61G at two locations on the outer peripheral surface 61A, and the two grippers 61G are arranged at symmetrical positions with the rotation shaft 61B of the drawing cylinder 61 in between. The drawing cylinder 61 is configured to be able to transport two sheets of paper with one rotation.

  The basic structure of the gripper 61G provided in the drawing cylinder 61 is the same as that of the gripper 17G provided in the transfer cylinder 17A. In the direction orthogonal to the medium conveyance direction, the arrangement of the plurality of claws of the gripper 61G of the drawing cylinder 61 corresponds to the position between the plurality of claws of the gripper 17G of the transfer cylinder 17A.

  When the medium 100 is transferred from the transfer cylinder 17A to the drawing cylinder 61 at the medium receiving position of the drawing cylinder 61, the tip of the medium 100 gripped by the gripper 17G of the transfer cylinder 17A is gripped by the gripper 61G of the drawing cylinder 61, When the gripper 17G of the transfer cylinder 17A opens the medium 100, the medium 100 is transferred from the transfer cylinder 17A to the drawing cylinder 61.

  In the medium 100, an arc-shaped surface defined by the outer peripheral surface 61 </ b> A of the drawing cylinder 61 in the region from the medium receiving position of the drawing cylinder 61 to the medium receiving position of the chain transport unit 72 is a medium transport surface. Is conveyed through a medium conveyance path set on the top. The medium conveyance path passes through the center of the drawing cylinder 61 in the direction orthogonal to the medium conveyance direction, and is set corresponding to the maximum width of the medium 100.

  The sheet pressing roller 63 is installed in the vicinity of the medium receiving position of the drawing cylinder 61, and is pressed against and brought into contact with the outer peripheral surface 61A of the drawing cylinder 61 by applying a pressing force by a pressing mechanism (not shown). The medium 100 transferred from the transfer cylinder 17A to the drawing cylinder 61 is nipped by passing between the sheet pressing roller 63 and the outer peripheral surface 61A of the drawing cylinder 61, and the surface opposite to the drawing surface of the medium 100 is formed. The drawing cylinder 61 is in close contact with the outer peripheral surface 61A.

  Ink-jet heads 21C, 21M, 21Y, and 21K that eject inks of cyan, magenta, yellow, and black are arranged at regular intervals along the medium conveyance path. The inkjet heads 21 </ b> C, 21 </ b> M, 21 </ b> Y, and 21 </ b> K are line type heads corresponding to the maximum width of the medium 100 and eject ink toward the medium 100 from a plurality of nozzle portions formed on the liquid ejection surface.

  The liquid discharge surfaces of the inkjet heads 21C, 21M, 21Y, and 21K (not shown in FIG. 1) are surfaces that face the outer peripheral surface 61A of the drawing cylinder 61 of the inkjet heads 21C, 21M, 21Y, and 21K, and are liquid discharges that discharge ink. A surface that functions as a surface.

  A color image is drawn on the drawing surface of the medium 100 by ink ejected from the inkjet heads 21C, 21M, 21Y, and 21K.

  The inline sensor 64 functions as a reading unit that reads the drawing surface of the medium 100 on which the color image is drawn. The ink jet recording apparatus 10 can detect an ejection abnormality of the ink jet heads 21C, 21M, 21Y, and 21K based on the reading result of the inline sensor 64.

<Recovery Department>
The collection unit 70 collects the medium 100 that has undergone a series of drawing processes by stacking it on the stacker 71. The collection unit 70 includes a stacker 71 that collects the medium 100, a chain conveyance unit 72 that receives the medium 100 from the drawing unit 60 and discharges the medium 100 to the stacker 71, and a guide 73 that supports the medium 100 conveyed by the chain conveyance unit 72. And is configured.

  The chain transport unit 72 includes two chains 72A arranged along a direction orthogonal to the medium transport direction. The endless chain 72A is wound around two sprockets 72B and 72C. The chain transport unit 72 causes the chain 72A to travel by rotating the sprocket 72B or the sprocket 72C in the clockwise direction in FIG.

  The chain 72A is provided with a plurality of grippers 72G along the medium conveyance direction. In FIG. 1, only one of the two chains 72A is shown. The gripper 72G is supported by a gripper support member (not shown) spanned between the two chains 72A. Since the basic structure and operation of the gripper 72G are the same as those of the gripper 17G of the transfer cylinder 17A and the gripper 61G of the drawing cylinder 61, description thereof will be omitted.

  In the chain transport section 72, a plurality of grippers 72G are arranged along the traveling direction of the chain 72A. The arrangement interval of the plurality of grippers 72G corresponds to the maximum length of the medium 100 in the medium conveyance direction.

  A guide 73 is disposed below the chain conveyance unit 72 in FIG. The medium 100 delivered from the drawing unit 60 to the chain conveyance unit 72 is gripped at the leading end by the gripper 72G of the chain 72A, is supported by the guide 73 at the trailing end, and passes between the chain 72A and the guide 73. The medium 100 transported by the chain transport unit 72 is collected by the stacker 71.

  The configuration of the inkjet recording apparatus 10 is not limited to the present embodiment. For example, a mode in which a pre-processing unit that performs pre-processing on the drawing surface of the medium 100 before drawing is also possible in front of the drawing unit 60. Examples of the pretreatment include application of a treatment liquid that aggregates or insolubilizes the color material contained in the ink, a drying treatment of the treatment liquid, and a heat treatment of the medium 100.

  In addition, a mode in which a post-processing unit that performs post-processing at the subsequent stage of the drawing unit 60 is also possible. Examples of post-processing include fixing processing of the medium 100 after drawing, drying processing of the medium 100 after drawing, and the like.

<Inkjet head structure>
FIG. 2 is a perspective plan view showing an example of the structure of the inkjet head. In the following description, the same components as those described above are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  Since the inkjet heads 21C, 21M, 21Y, and 21K shown in FIG. 1 have the same structure, when it is not necessary to distinguish the inkjet heads 21C, 21M, 21Y, and 21K, the inkjet head is represented by reference numeral 21. To do.

  The ink jet head 21 shown in FIG. 2 has a structure in which a plurality of head modules 200 are connected in a direction orthogonal to the medium conveyance direction. The plurality of head modules 200 shown in FIG. 2 have the same structure and the same function. The head module 200 can function alone as an ink jet head.

The ink jet head 21 illustrated in FIG. 2 has a structure in which a plurality of head modules 200 are arranged in a line along a direction orthogonal to the medium transport direction, over a length corresponding to the maximum width L _max of the medium 100. This is a line-type inkjet head in which a plurality of nozzle portions are arranged. The line-type inkjet head is sometimes called a full-line inkjet head.

  The nozzle part is an aspect of the ejection element. The ejection element is a unit that ejects liquid as droplets. Details of the structure and function of the ejection element will be described later. In FIG. 2, the illustration of the ejection element is omitted.

  In the present embodiment, the inkjet head 21 having a structure in which a plurality of head modules 200 are arranged in a line along a direction orthogonal to the medium conveyance direction is exemplified, but the plurality of head modules 200 is orthogonal to the medium conveyance direction. May be arranged in a zigzag pattern, or a plurality of head modules 200 may be integrated.

  FIG. 3 is a perspective view of the head module including a partial cross-sectional view. The head module 200 has an ink supply unit including an ink supply chamber 232 and an ink circulation chamber 236 on the upper side in FIG. 3, which is the opposite side of the liquid ejection surface 277 of the nozzle plate 275.

  The ink supply chamber 232 is connected to an ink tank (not shown) via a supply-side individual flow path 252, and the ink circulation chamber 236 is connected to a collection tank (not shown) via a recovery-side individual flow path 256. The supply side individual flow path 252 and the recovery side individual flow path 256 are one mode of the individual flow paths.

  FIG. 4 is a plan perspective view of the liquid ejection surface of the head module. In FIG. 4, the number of nozzle openings 280 arranged on the liquid ejection surface 277 is omitted, but a plurality of nozzle openings 280 are arranged on the liquid ejection surface 277 of one head module 200 by a two-dimensional arrangement. ing.

  The head module 200 has an end face on the long side along the V direction having an inclination of an angle β with respect to a direction orthogonal to the medium conveyance direction, and a W direction having an inclination of the angle α with respect to the medium conveyance direction. It has a parallelogram planar shape having an end surface on the short side, and a plurality of nozzle openings 280 are arranged in a matrix in the row direction along the V direction and the column direction along the W direction.

  The arrangement of the nozzle openings 280 is not limited to the aspect illustrated in FIG. 4, and a plurality of nozzle openings 280 are arranged along a row direction along a direction orthogonal to the medium conveyance direction and a column direction obliquely intersecting the direction orthogonal to the medium conveyance direction. Nozzle openings 280 may be arranged.

  The matrix arrangement of the nozzle openings 280 is a medium conveyance direction in which a plurality of nozzle openings 280 are projected in a direction orthogonal to the medium conveyance direction, and the plurality of nozzle openings 280 are arranged along a direction orthogonal to the medium conveyance direction. In the projection nozzle row 280A in the orthogonal direction, the nozzle openings 280 are arranged at uniform intervals between the nozzle openings 280 and the inter-nozzle distance.

  In the projection nozzle row 280A in the direction orthogonal to the medium conveyance direction, the nozzle openings 280 belonging to one head module 200 and the nozzle openings 280 belonging to the other head module 200 are mixed in a connecting portion between adjacent head modules 200. ing.

  When there is no attachment position error in each head module 200, the nozzle openings 280 belonging to one head module 200 and the nozzle openings 280 belonging to the other head module 200 in the connecting region are projected in a direction perpendicular to the medium transport direction. Since the nozzle rows are arranged at the same position in the nozzle row, the nozzle openings 280 are evenly arranged in the connection region.

  FIG. 5 is a cross-sectional view showing the internal structure of the inkjet head. Reference numeral 214 is an ink supply path, reference numeral 218 is a pressure chamber, reference numeral 216 is an individual supply path connecting each pressure chamber 218 and the ink supply path 214, and reference numeral 220 is a nozzle communication path connecting the pressure chamber 218 to the nozzle opening 280, reference numeral 226. Is a circulation individual flow path connecting the nozzle communication path 220 and the circulation common flow path 228. The pressure chamber 218 may be referred to as a liquid chamber.

  A vibration plate 266 is provided on the flow path structure 210 constituting the flow path portions 214, 216, 218, 220, 226, and 228. A piezoelectric element 230 having a laminated structure of a lower electrode 265, a piezoelectric layer 231, and an upper electrode 264 is disposed on the vibration plate 266 via an adhesive layer 267. The lower electrode 265 may be referred to as a common electrode, and the upper electrode 264 may be referred to as an individual electrode.

  The upper electrode 264 is an individual electrode patterned corresponding to the shape of each pressure chamber 218, and a piezoelectric element 230 is provided for each pressure chamber 218.

  The ink supply path 214 is connected to the ink supply chamber 232 shown in FIG. 3, and ink is supplied from the ink supply path 214 to the pressure chamber 218 via the individual supply path 216. By applying a driving voltage to the upper electrode 264 of the piezoelectric element 230 provided in the corresponding pressure chamber 218 according to the input image data, the piezoelectric element 230 and the diaphragm 266 are deformed, and the volume of the pressure chamber 218 is increased. The ink droplets are ejected from the nozzle openings 280 through the nozzle communication passages 220 due to the pressure change accompanying the change.

  By controlling the driving of the piezoelectric element 230 corresponding to each nozzle opening 280 according to the dot arrangement data generated from the input image data, ink can be ejected from the nozzle opening 280.

  A desired image can be recorded on the medium 100 by controlling the ink droplet ejection timing from each nozzle opening 280 according to the transport speed while transporting the medium 100 in the medium transport direction at a constant speed. it can.

  The pressure chamber 218 provided corresponding to each nozzle opening 280 has a substantially square planar shape, and an outlet to the nozzle opening 280 is provided at one of the diagonal corners, and the other is provided at the other. An individual supply path 216 serving as an inlet for the supply ink is provided. Illustration of the planar shape of the pressure chamber 218 is omitted.

  The planar shape of the pressure chamber is not limited to a square. The planar shape of the pressure chamber may have various forms such as a square such as a rhombus and a rectangle, a pentagon, a hexagon and other polygons, a circle and an ellipse.

  A circulation outlet is formed in the nozzle portion 281 including the nozzle opening 280 and the nozzle communication path 220, and the nozzle portion 281 communicates with the circulation individual flow path 226 via the circulation outlet. Of the ink in the nozzle communication path 220 and the nozzle opening 280, ink that is not used for droplet ejection is collected into the circulation common flow path 228 via the circulation individual flow path 226.

  The circulation common flow path 228 is connected to the ink circulation chamber 236 shown in FIG. 3, and the ink is always collected to the circulation common flow path 228 through the circulation individual flow path 226, so that the nozzle at the time of non-droplet ejection The thickening of the ink in the vicinity of the opening 280 is prevented.

  As an example of the inkjet head 21 described above, there is a configuration in which 17 head modules 200 are arranged in a line along a direction orthogonal to the medium conveyance direction. Further, as an example of the head module 200, a configuration including 2048 ejection elements can be given.

  The ejection element in the head module 200 shown in FIG. 5 includes one nozzle portion 281, a flow path such as a pressure chamber 218 communicating with the nozzle portion 281, and a piezoelectric element 230 corresponding to the nozzle portion 281.

  As an example of the piezoelectric element 230, the piezoelectric element 230 having a structure separated individually corresponding to the nozzle opening 280 of FIG. Of course, a structure in which the piezoelectric layer 231 is integrally formed with respect to the plurality of nozzle portions 281, individual electrodes are formed corresponding to the respective nozzle portions 281, and an active region is formed for each nozzle portion 281 is applied. Also good.

  A heater is provided in the pressure chamber 218 as a pressure generating element instead of a piezoelectric element, and a drive voltage is supplied to the heater to generate heat, and ink in the pressure chamber 218 is ejected from the nozzle opening 280 using a film boiling phenomenon. A thermal method may be applied.

  As an aspect of the ejection element, a configuration including the nozzle portion 281, the flow path such as the pressure chamber 218, and the piezoelectric element 230 illustrated in FIG. 5 can be employed. The ejection element communicates with the supply-side individual flow path 252 shown in FIG. 3 through a supply flow path structure such as the ink supply path 214. Further, the discharge element communicates with the recovery-side individual flow channel 256 shown in FIG. 3 via a circulation flow channel structure such as the circulation individual flow channel 226 shown in FIG.

<Description of ink supply system>
FIG. 6 is a perspective view showing the structure of the internal flow path of the inkjet head. FIG. 7 is a block diagram showing the configuration of the internal flow path of the inkjet head and the configuration of the ink supply system. 6 is a cover for protecting the ink supply system shown in FIG. 7 and a control circuit board (not shown).

  As shown in FIG. 6, the inkjet head 21 has a structure in which a plurality of head modules 200 are arranged in a line along a direction orthogonal to the medium conveyance direction. The plurality of head modules 200 provided in the inkjet head 21 are supported by the frame 300. A lifting support member 302 that supports the inkjet head 21 when the inkjet head 21 is lifted up and down is attached to both ends of the frame 300 in a direction orthogonal to the medium transport direction.

  The supply side individual flow path 252 of each head module 200 is connected to the supply side manifold 308 via the supply side damper 304 and the supply side valve 306. Further, the collection-side individual flow path 256 of each head module 200 is connected to the collection-side manifold 318 via a collection-side damper 314 and a collection-side valve 316.

  The supply side manifold 308 has a flow path structure common to the head modules 200 in the ink jet head 21 in which the ink supplied to the head module 200 is temporarily stored. The collection side manifold 318 has a flow path structure common to the head modules 200 in which the ink collected from the head module 200 is temporarily stored inside the inkjet head 21.

  The supply-side valve 306 corresponds to supply-side individual flow path opening / closing means. The collection side valve 316 corresponds to a collection side individual channel opening / closing means. The supply side individual flow path opening / closing means and the recovery side individual flow path opening / closing means are one mode of the individual flow path opening / closing means.

  The supply side manifold 308 corresponds to supply side temporary storage means. The collection side manifold 318 corresponds to a collection side temporary storage means. The supply-side temporary storage unit and the recovery-side temporary storage unit are one mode of the temporary storage unit.

  A supply-side pressure sensor 320 is attached as a means for measuring the pressure of the liquid in the supply-side manifold 308. The recovery side manifold 318 is provided with a recovery side pressure sensor 322 as means for measuring the pressure of the liquid in the recovery side manifold 318.

  The supply side pressure sensor 320 corresponds to a supply side pressure measurement sensor. The recovery side pressure sensor 322 corresponds to a recovery side pressure measurement sensor. The supply side pressure measurement sensor and the recovery side pressure measurement sensor are one aspect of the pressure measurement means.

  The collection side manifold 318 is connected to the supply side manifold 308 via the first bypass flow path valve 330 and the first bypass flow path 332. The supply side manifold 308 is connected to the recovery side manifold 318 via the second bypass flow path valve 334 and the second bypass flow path 336.

  The individual flow path opening / closing means may include a first bypass flow path valve 330 and a second bypass flow path valve 334.

  The supply side manifold 308 is connected to the supply back pressure tank 342 shown in FIG. The supply back pressure tank 342 has a hermetically sealed structure and has a structure in which the inside is partitioned into a gas chamber 342B and a liquid chamber 342C by an elastic film 342A.

  The gas chamber 342 </ b> B of the supply back pressure tank 342 is connected to the supply air tank 348 via the first gas flow path valve 344 and the first gas flow path 346. The supply air tank 348 is connected to a first atmosphere release channel 352 to which a first atmosphere release valve 350 is attached. The supply air tank 348 is opened to the atmosphere by opening the first atmosphere release valve 350.

  The collection side manifold 318 is connected to the collection back pressure tank 362 shown in FIG. The recovery back pressure tank 362 has a sealed structure and has a structure in which the inside is partitioned into a gas chamber 362B and a liquid chamber 362C by an elastic film 362A.

  The elastic film 342A of the supply back pressure tank 342 and the elastic film 362A of the recovery back pressure tank 362 function as a damper that smoothes the pulsating flow of ink.

  The gas chamber 362B of the recovery back pressure tank 362 is connected to the recovery air tank 368 via the second gas flow path valve 364 and the second gas flow path 366. The recovery air tank 368 is connected to a second atmosphere release channel 372 to which a second atmosphere release valve 370 is attached. The recovery air tank 368 is opened to the atmosphere by opening the second atmosphere release valve 370.

  The liquid chamber 342 </ b> C of the supply back pressure tank 342 is connected to the first supply flow path 374. A first supply flow path valve 376 is attached to the first supply flow path 374. The liquid chamber 362C of the recovery back pressure tank 362 is connected to the recovery flow path 375. The recovery channel 375 is provided with a second supply channel valve 378. The first supply channel 374 and the recovery channel 375 have a structure that merges with one end of the common channel 377.

  The other end of the common flow path 377 is connected to the direction switching valve 329. A second supply channel 309 is connected to the first output port 329A of the direction switching valve 329. A second recovery channel 319 is connected to the second output port 329B of the direction switching valve 329.

  The second supply channel 309 is connected to the supply tank 311 through the supply pump 313. The second recovery channel 319 is connected to the recovery tank 321 via the recovery pump 323.

  The supply tank 311 and the recovery tank 321 communicate with each other via a pump 325.

  The direction switching valve 329 switches whether the second supply channel 309 is connected to the common channel 377 or the second recovery channel 319 is connected. Switching by the direction switching valve 329 enables switching between ink supply from the supply tank 311 to the inkjet head 21 and ink recovery from the inkjet head 21 to the recovery tank 321.

  The ink supply system shown in FIG. 7 is appropriately provided with a filter that captures foreign matter, a deaeration device that removes bubbles in the ink, a check valve that prevents backflow of ink, and the like.

  The internal flow path of the ink jet head 21 in the present embodiment includes at least the supply side manifold 308 shown in FIGS. 6 and 7. Further, a mode in which the recovery side manifold 318 is included as an internal flow path of the inkjet head 21 is also possible.

<Description of movement of inkjet head>
FIG. 8 is a schematic diagram schematically showing a schematic configuration of the first head moving unit. The first head moving unit 400 illustrated in FIG. 8 is means for moving the inkjet head 21 in the vertical direction. In FIG. 8, the moving direction of the inkjet head 21 is illustrated using an arrow line.

  The first head moving unit 400 is disposed outside the both ends of the inkjet head 21 in a direction orthogonal to the medium conveyance direction. The first head moving unit 400 includes a head support member 402 that supports the elevation support member 302 of the inkjet head 21 and an actuator 404 that raises and lowers the head support member 402 along the vertical direction.

  The actuator 404 includes a lifting mechanism and a driving source for the lifting mechanism. A ball screw or the like can be applied to the lifting mechanism. A rotary motor can be applied to the drive source. A linear motor in which an elevating mechanism and a drive source are integrated may be applied.

  In the present embodiment, the first head moving unit 400 that raises and lowers the inkjet head 21 along the vertical direction is shown. However, the first head moving unit 400 moves the inkjet head 21 in an oblique first direction having a vertical component. It may be moved.

  8 illustrates the first head moving unit 400 that raises and lowers one inkjet head 21, but the first head moving unit 400 is used when the four inkjet heads 21C, 21M, 21Y, and 21K shown in FIG. May apply a configuration in which the four inkjet heads 21C, 21M, 21Y, and 21K are moved up and down collectively, or may apply a configuration in which the four inkjet heads 21C, 21M, 21Y, and 21K are moved up and down individually. Good.

  The ink jet recording apparatus 10 is a direction orthogonal to the medium conveyance direction when the ink jet heads 21C, 21M, 21Y, and 21K shown in FIG. 1 are retracted from the drawing position directly above the drawing cylinder 61. A second head moving unit for moving in the horizontal direction is provided. The second head moving unit is shown in FIG. 9 with reference numeral 420, and the detailed configuration is not shown.

  A configuration example of the second head moving unit includes a support member that supports the inkjet head 21 and a moving mechanism that moves the inkjet head 21.

  When the inkjet head 21 is moved from the drawing position to the maintenance position, the first head moving unit 400 is used to move the inkjet head 21 located at the drawing position vertically upward, and the second head moving unit is used to perform drawing. The inkjet head 21 that has been moved upward is moved in the horizontal direction in a direction perpendicular to the medium transport direction.

  Further, when the floating of the medium 100 is detected and the inkjet head 21 is retracted, the inkjet head 21 is moved vertically upward using the first head moving unit 400.

  The first head moving unit 400 corresponds to first head moving means. The second head moving unit 420 shown in FIG. 9 corresponds to second head moving means.

<Description of control system>
FIG. 9 is a block diagram showing a configuration of a control system of the ink jet recording apparatus shown in FIG. As shown in FIG. 9, each part of the inkjet recording apparatus 10 is comprehensively controlled by a system controller 12.

  The system controller 12 sends a command signal to the communication unit 14, the medium supply control unit 16, the conveyance control unit 18, the discharge control unit 20, and the like, and controls the operation of each unit of the apparatus. The system controller 12 may employ a configuration including a central processing unit, a storage device, and device drivers corresponding to various functions.

  The system controller 12 has a function as a memory controller that controls reading of information from a storage unit such as the image memory 22, the parameter storage unit 30, and the program storage unit 32 and writing of information to the storage unit. Yes.

  The system controller 12 acquires an input signal sent from the operation unit 24 and a setting signal representing a setting inputted from the setting unit 28, and a command signal to the corresponding configuration based on the contents of the input signal or the setting signal And send a command signal to the corresponding configuration. Further, the setting information represented by the setting signal is stored in a predetermined storage unit.

  For the operation unit 24, operation members such as operation buttons, a keyboard, and a mouse can be applied.

  The system controller 12 functions as a display driver that controls display of information on the display unit 26. A display device can be applied to the display unit 26. It is also possible to use the operation unit 24 and the display unit 26 by using a touch panel display device.

  The communication unit 14 is an input interface to which various data such as discharge data sent from the host computer 15 is input. The communication form between the communication unit 14 and the host computer 15 may be wired communication or wireless communication. The communication unit 14 may be connected to the host computer 15 via a network.

  The medium supply control unit 16 controls the operation of the medium supply unit 17 based on a command signal sent from the system controller 12. A medium to be drawn is supplied from the medium supply unit 17. The operation of the medium supply unit 17 includes taking out the medium from the stocker 17D shown in FIG. 1 and adjusting the posture of the medium by the posture adjusting unit 17B.

  The transport control unit 18 illustrated in FIG. 9 starts, stops, and transports a transport unit 19 that transports a medium supplied via the medium supply unit 17 based on a command signal sent from the system controller 12. Control speed etc.

  The transport control unit 18 controls the transport pitch of the medium according to the image forming resolution in the medium transport direction. Further, the conveyance control unit 18 controls the medium conveyance speed in accordance with the image forming resolution and the ejection frequency of the inkjet head 21.

  The ejection control unit 20 controls ink ejection by the inkjet head 21. When color image formation using a plurality of colors of ink is performed, the inkjet head 21 illustrated in FIG. 9 includes the inkjet heads 21C, 21M, 21Y, and 21K for each color illustrated in FIG.

  The ejection control unit 20 includes an image processing unit (not shown) and a drive voltage generation unit (not shown). The image processing unit generates dot data representing dot arrangement or dot size or the number of dots per pixel from input image data sent from the host computer 15 via the communication unit 14. .

  Examples of input image data sent from the host computer 15 include raster data in which the density value of each pixel is represented by a digital value from 0 to 255. The image processing unit performs color separation processing, color conversion processing, correction processing, and halftone processing on the input image data to generate dot data in which the size of the dot position for each color is defined.

  Based on the dot data generated by the image processing unit, the discharge timing and discharge volume for each pixel position are determined. The discharge volume in this specification is a liquid that forms one dot, and when one dot is formed by multiple discharges at a high frequency, the total of the multiple discharge volumes is the discharge volume. The discharge volume may be referred to as a discharge amount.

  A mode of forming one dot at a time or a mode of forming one dot at a plurality of times may be applied to ejection in the present specification. A dot is a constituent unit of dot data after halftone processing. In an actually drawn image, a plurality of dots arranged at high density are integrated.

  The drive voltage generation unit generates a drive voltage to be supplied to the inkjet head 21 based on the discharge timing and the discharge volume for each dot position, and supplies the drive voltage to the inkjet head 21. A configuration example of the drive voltage generation unit includes a drive waveform storage unit that stores a drive waveform, an amplification unit that amplifies the drive waveform, and a drive voltage output unit that outputs the drive voltage.

  The image memory 22 temporarily stores input image data sent from the host computer 15 via the communication unit 14. The input image data temporarily stored in the image memory 22 is subjected to image processing by an image processing unit (not shown).

  The setting unit 28 performs various settings for the inkjet recording apparatus 10. Examples of setting by the setting unit 28 include setting of operation parameters of the first head moving unit 400 and setting of proportional control parameters. As an operation parameter of the first head moving unit 400, an operation frequency of the actuator 404 shown in FIG.

  The parameter storage unit 30 stores various parameters used in the inkjet recording apparatus 10. Various parameters stored in the parameter storage unit 30 are read out via the system controller 12 and set in each unit of the apparatus. Examples of parameters stored in the parameter storage unit 30 include an operation parameter of the first head moving unit 400 or a proportional control parameter.

  The program storage unit 32 stores a program used for each unit of the inkjet recording apparatus 10. Various programs stored in the program storage unit 32 are read out via the system controller 12 and executed in each unit of the apparatus.

  Examples of the program stored in the program storage unit 32 include a program that causes the computer to function as an internal pressure suppression control unit that suppresses fluctuations in the internal pressure of the inkjet head 21. The internal pressure of the inkjet head 21 in this specification is a concept including the back pressure of the inkjet head 21. The back pressure is a pressure common to a plurality of ejection elements.

  The head movement control unit 40 controls the operations of the first head moving unit 400 shown in FIGS. 8 and 9 and the second head moving unit 420 shown in FIG. 9 based on a command from the system controller 12. . The head movement control unit 40 may include a first head movement control unit that controls the operation of the first head movement unit 400 and a second head movement control unit that controls the operation of the second head movement unit 420.

  The valve control unit 50 controls opening and closing of the valve 422 based on a command from the system controller 12. 9 includes the supply side valve 306, the recovery side valve 316, the first bypass passage valve 330, the second bypass passage valve 334, the first gas passage valve 344, the second gas flow shown in FIG. A passage valve 364, a first atmosphere release valve 350, a second atmosphere release valve 370, a first supply flow path valve 376, and a second supply flow path valve 378 are included. The valve control unit 50 corresponds to an individual flow path opening / closing control unit.

  The pump control unit 52 illustrated in FIG. 9 controls the operation of the pump 424 based on a command from the system controller 12. The pump 424 shown in FIG. 9 includes the supply pump 313, the recovery pump 323, and the circulation pump 325 shown in FIG. The supply pump 313 and the recovery pump 323 shown in FIG. 7 are one mode of the internal pressure adjusting means.

  The pressure fluctuation prediction unit 54 is a means for predicting the pressure in the internal flow path of the inkjet head 21 while the inkjet head 21 is moved in the vertical direction. The prediction result of the pressure fluctuation prediction unit 54 is sent to the determination unit 56 via the system controller 12. The pressure fluctuation prediction unit 54 corresponds to pressure fluctuation prediction means.

  While moving the inkjet head 21 in the vertical direction, not only the period during which the inkjet head 21 is actually moving in the vertical direction but also the inkjet head 21 using the first head moving unit 400 by the head movement control unit 40. Ink jet head using the first head moving unit 400 by the head moving control unit 40 after the movement control is started and until the inkjet head 21 actually moves in the vertical direction and after the inkjet head 21 stops. A period until 21 movement control is stopped may be included.

  When the determination unit 56 acquires the prediction result of the pressure fluctuation prediction unit 54, the determination unit 56 compares the prediction result with a preset pressure threshold value, and the pressure threshold value with which the pressure in the internal flow path of the inkjet head 21 is set in advance. It is judged whether or not. A signal representing the determination result of the determination unit 56 is sent to the system controller 12.

  When the system controller 12 acquires a signal representing the determination result of the determination unit 56, the system controller 12 sends a command signal to the valve control unit 50 according to the determination result. The determination unit 56 corresponds to a determination unit.

  Based on the command signal sent from the system controller 12, the valve control unit 50 includes the supply side valve 306, the recovery side valve 316, the first bypass flow path valve 330, and the second bypass among the valves 422. The flow path valve 334 is opened and closed.

[Description of adjusting method of inkjet head]
<Overall configuration>
Next, the inkjet head adjustment method according to the first embodiment will be described in detail.

  FIG. 10 is an explanatory diagram of a technical problem associated with the vertical movement of the inkjet head. FIG. 10 is a graph showing the pressure in the internal flow path of the inkjet head 21 shown in FIG.

  The horizontal axis of the graph shown in FIG. 10 is the period. The unit of the horizontal axis of the graph shown in FIG. 10 is second. The vertical axis of the graph shown in FIG. 10 is the pressure in the internal flow path of the inkjet head 21. The unit of the vertical axis of the graph shown in FIG. 10 is Pascal.

The graph shown in FIG. 10 shows the inside of the inkjet head 21 when the inkjet head 21 is moved vertically from the drawing position, stopped at a stop position above the drawing position, and moved vertically downward from the stop position. It represents the pressure in the flow path. Note that the pressure in the internal flow path of the inkjet head 21 shown in FIG. 10 represents a tendency of pressure change based on the pressure measurement value of the supply-side pressure sensor 320 shown in FIG. Instead of the pressure measurement value of the supply side pressure sensor 320, the pressure measurement value of the recovery side pressure sensor 322 may be used.

  The pressure in the internal flow path of the inkjet head 21 shown in FIG. 10 was measured with the supply side valve 306 and the recovery side valve 316 shown in FIG. 6 open. Further, ten types of acceleration were measured using the acceleration of the inkjet head 21 as a parameter. The moving distance of the inkjet head 21 was fixed to 20 millimeters, and the moving speed of the inkjet head 21 was changed according to the set acceleration of the inkjet head 21. A plurality of types of moving distances of the inkjet head 21 were set in the range of 1 mm or more and 20 mm or less, and the same measurement was performed.

The range of acceleration of the inkjet head 21 is 1 millimeter per square second or more and 6000 millimeters per square second. The range of the moving speed of the inkjet head 21 is 1 millimeter / second or more and 10 millimeter / second or less. FIG. 10 shows pressure fluctuations when the period from t ₁ to t ₂ , the period from t ₂ to t ₃ , and the period from t ₃ to t ₄ are each 1 second.

The inkjet head 21 is moved in the vertically upward direction at t ₁ is started, is stopped at the upper stop position of the drawing position in t _2, the movement of the vertically downward direction by t ₃ is started, back into the drawing position t ₄ It is.

  Since the four inkjet heads 21C, 21M, 21Y, and 21K shown in FIG. 1 have the same structure and the same movement parameters, the pressure measurement shown in this embodiment is shown in FIG. Of the four inkjet heads 21C, 21M, 21Y, and 21K, one arbitrary inkjet head 21 was used.

  As the ink, the black ink described in Example 6 of Japanese Patent Application Laid-Open No. 2014-141053 was used. Since the ink described in Example 6 of Japanese Patent Application Laid-Open No. 2014-141053 is different in color material and has the same composition, the measurement results of cyan ink, magenta ink, and yellow ink are the same as those of the black ink. Can be predicted. In addition, the ink described in Example 6 of Japanese Patent Application Laid-Open No. 2014-141053 is an ink jet head adjustment method according to the present embodiment, considering that a composition such as a coloring material is contained in an aqueous solvent. It can be handled as a general water-based ink applied to the head.

  When the ink-jet head 21 is moved in the vertical direction, as shown in FIG. 10, the pressure in the internal flow path of the ink-jet head 21 fluctuates in response to a change in the position of the ink-jet head 21 in the vertical direction. This is because when the inkjet head 21 is moved in the vertical direction, the acceleration accompanying the movement acts on the ink inside the nozzle portion 281, and the ink inside the nozzle portion 281 is subjected to pressure fluctuation.

  The upper broken line among the two broken lines parallel to the horizontal axis in the graph of FIG. 10 is the pressure upper limit value of the internal flow path of the inkjet head 21 that adversely affects the image quality. That is, when the inkjet head 21 is moved in the vertical direction, the ink ejection state may fluctuate due to pressure fluctuations in the internal flow path, which may adversely affect image quality.

  Note that the lower broken line of the two broken lines parallel to the horizontal axis in the graph of FIG. 10 is the pressure lower limit value of the internal flow path of the inkjet head 21 that adversely affects the image quality. The permissible range of the pressure of the internal flow path of the ink jet head 21 defined by the upper pressure limit value and the lower limit value of the internal flow path of the ink jet head 21 is the temperature of the ink in the internal flow path of the ink jet head 21 and the type of ink. , And drawing conditions.

  In the present embodiment, the pressure in the internal flow path of the inkjet head 21 is the pressure on the supply side manifold 308 measured by the supply side pressure sensor 320 or the recovery side measured by the recovery side pressure sensor 322 shown in FIG. Manifold 318 pressure can be applied. As an example of the allowable range of the pressure in the internal flow path of the inkjet head 21, a range of minus 200 Pascals or more and 200 Pascals or less can be given. The pressure adjustment range of the internal flow path of the inkjet head 21 is made narrower than the allowable range of the pressure of the internal flow path of the inkjet head 21.

  The inkjet recording apparatus 10 shown in the present embodiment suppresses fluctuations in the internal pressure of the inkjet head 21 in conjunction with the vertical movement of the inkjet head 21 while moving the inkjet head 21 along the vertical direction. It has a function to maintain image quality.

  The interlock includes a response before the inkjet head 21 starts to move in the vertical direction and a response when the inkjet head 21 moves in the vertical direction.

  FIG. 11 is a flowchart showing a control flow of the inkjet head adjustment method according to the first embodiment of the present invention. The ink jet head adjustment method corresponds to the liquid discharge head adjustment method.

  In the inkjet head adjustment method according to the first embodiment described below, the inkjet head 21 is closed by closing the supply side valve 306 and the recovery side valve 316 shown in FIG. 6 and the like before the inkjet head 21 starts to move in the vertical direction. 21 fluctuations in internal pressure are suppressed. The first bypass passage valve 330 and the second bypass passage valve 334 may be closed.

  As shown in FIG. 11, when a movement start instruction for the inkjet head 21 including movement along the vertical direction of the inkjet head 21 is given in the movement start instruction step S10, the operation parameters of the inkjet head 21 are set in the operation parameter setting step S12. Is set.

  In the present embodiment, the operating frequency of the actuator 404 shown in FIG. 8 is set as the setting of the operating parameter of the inkjet head 21. The setting unit 28 shown in FIG. 9 is applied to set the operating frequency of the actuator 404.

  Examples of setting the operating frequency of the actuator 404 shown in FIG. 8 include a mode of reading the operating parameters stored in the parameter storage unit 30 and a mode of inputting the operating parameters from the outside using the operation unit 24.

  When the operation parameter of the inkjet head 21 is set in the operation parameter setting step S12 of FIG. 11, the pressure variation of the internal flow path of the inkjet head 21 is predicted in the pressure variation prediction step S14. The pressure fluctuation prediction unit 54 shown in FIG. 9 is applied to the prediction of the pressure fluctuation in the internal flow path of the inkjet head 21.

  As an example of the prediction of the pressure fluctuation of the internal flow path of the ink jet head 21 by the pressure fluctuation prediction unit 54, the mode predicted by calculation based on the operation parameter set in the operation parameter setting step S 12, the operation parameter and the pressure fluctuation in advance There is a mode in which the correlation is obtained and stored, and pressure fluctuation information corresponding to the set operation parameter is read out.

  If the pressure fluctuation in the internal flow path of the inkjet head 21 is predicted in the pressure fluctuation prediction step S14 of FIG. 11, the pressure fluctuation in the internal flow path of the ink jet head 21 is determined in advance in the pressure fluctuation determination step S16. Whether it is within the allowable range or not. The determination as to whether or not the pressure fluctuation in the internal flow path of the inkjet head 21 is within a predetermined allowable range can be determined using the upper limit value and the lower limit value of the allowable range as pressure threshold values. A value within an allowable range may be applied as the pressure threshold. The threshold in FIG. 11 is a pressure threshold.

  When the curve representing the pressure of the internal flow path of the ink jet head 21 shown in FIG. 10 is applied as the predicted value of the pressure fluctuation of the internal flow path of the ink jet head 21, the pressure fluctuation determining step S16 shows the pressure fluctuation shown in FIG. Whether the curve representing the pressure in the internal flow path of the inkjet head 21 exceeds the upper limit value or the lower limit value shown in FIG. 10 is determined.

  When the predicted value of the pressure fluctuation in the internal flow path of the ink jet head 21 exceeds the pressure threshold and is outside the allowable range of the pressure fluctuation in the internal flow path of the ink jet head 21, which is determined as YES in the pressure fluctuation determination step S <b> 16 of FIG. 11. Advances to the valve closing step S18, and the plurality of supply side valves 306 shown in FIG. 6 and the plurality of recovery side valves 316 shown in FIG. 6 are collectively closed.

  The predicted value of the pressure fluctuation in the internal flow path of the inkjet head 21 that is NO in the pressure fluctuation determination step S16 of FIG. 11 is equal to or less than the pressure threshold, and is within the allowable range of the pressure fluctuation in the internal flow path of the inkjet head 21. In this case, the process proceeds to the head movement start process S20, and the movement start process of the inkjet head 21 is executed.

  When the movement of the inkjet head 21 is started in the head movement start process S20, the process proceeds to the head movement monitoring process S22, and it is determined whether or not the inkjet head 21 has reached the target position.

  When the inkjet head 21 reaches the target position, which is YES in the head movement monitoring process S22, the process proceeds to the head movement stop process S24, and the movement stop process of the inkjet head 21 is executed.

  When the inkjet head 21 has not reached the target position, which is NO in the head movement monitoring step S22, monitoring whether the inkjet head 21 has reached the target position is continued in the head movement monitoring step S22.

  When the movement stop process of the inkjet head 21 is completed in the head movement stop process S24, the process proceeds to the valve opening / closing determination process S26, and the supply side valve 306 and the recovery side shown in FIG. 7 are the valves closed in the valve closing process S18. It is determined whether the valve 316 is closed.

  If the supply side valve 306 and the recovery side valve 316 shown in FIG. 7 are closed in the valve opening / closing determination step S26, the process proceeds to the valve opening step S28, and the supply side valve 306 and the recovery side valve 316 are Opened, the process proceeds to the head movement end step S30 of FIG.

  If the supply side valve 306 and the recovery side valve 316 shown in FIG. 7 are opened, which is determined to be NO in the valve opening / closing determination step S26, the process proceeds to the head movement end step S30.

  In the head movement end process S30, a head movement end process is executed. The processes from the head movement start process S20 to the head movement end process S30 correspond to the movement process. The pressure fluctuation determination step S16 corresponds to a determination step. The valve closing step S18 corresponds to an individual channel closing step.

  FIG. 12 is an explanatory diagram of the effect of the ink jet head adjustment method according to the first embodiment of the present invention. The curve shown by the solid line in FIG. 12 is the pressure fluctuation in the internal flow path of the inkjet head 21 when the inkjet head adjustment method shown in FIG. 11 is applied and the inkjet head 21 is moved in the vertical direction. The conditions for measuring the pressure in the internal flow path of the inkjet head 21 shown in FIG. 12 are the same as the conditions for measuring the pressure in the internal flow path of the inkjet head 21 shown in FIG.

  As shown in FIG. 12, the pressure fluctuation in the internal flow path of the inkjet head 21 can be within an allowable range defined by the upper limit value and the lower limit value. That is, a supply-side valve 306 provided in the supply-side individual flow path 252 that supplies ink from the supply-side manifold 308 to each head module 200, and a recovery-side individual flow path that recovers ink from the head movement end step S30 to the recovery-side manifold 318. The recovery-side valve 316 provided at 256 is closed, and the inkjet head 21 is moved vertically upward or vertically downward, so that the inkjet head 21 is moving vertically upward or vertically downward. The pressure fluctuation in the internal flow path is suppressed.

  That is, by closing the supply side valve 306 and the like, the communication state between each nozzle provided in the inkjet head 21 and the supply side manifold 308 and the recovery side manifold 318 is blocked, and the internal flow path of the inkjet head 21 is blocked. Is blocked from the atmosphere, so that the acceleration caused by the movement of the ink jet head 21 in the vertical upward direction or the vertical downward direction does not act on the ink in the internal flow path of the ink jet head 21, and the inside of the ink jet head 21. The pressure fluctuation in the flow path is suppressed.

  In addition, the curve illustrated using the dashed line in FIG. 12 indicates the internal flow path of the inkjet head 21 when the inkjet head 21 is moved in the vertical direction without applying the inkjet head adjustment method illustrated in FIG. It is a pressure fluctuation, and is a pressure fluctuation in the internal flow path of the inkjet head 21 shown in FIG.

  In FIG. 12, the pressure fluctuation of the internal flow path of the inkjet head 21 based on an arbitrary pressure measurement value as the pressure of the internal flow path of the inkjet head 21 to which the inkjet head adjustment method according to the first embodiment of the present invention is applied. showed that.

  The acceleration range of the inkjet head 21 and the speed range of the inkjet head 21 described above are a practical acceleration range and a speed range of the inkjet head 21. For the practical acceleration range and speed range of the inkjet head 21, when the inkjet head adjustment method according to the first embodiment of the present invention is applied, the pressure fluctuation in the internal flow path of the inkjet head 21 is set to the upper limit value, In addition, it was confirmed that the allowable range defined by the lower limit value can be accommodated.

  The movement parameters of the inkjet head, the upper limit value of pressure fluctuation in the internal flow path of the inkjet head, and the lower limit value of pressure fluctuation depend on the structure of the inkjet head, usage conditions, etc., so consider the usage conditions for each inkjet head. By determining the relationship between the upper limit value of pressure fluctuation in the internal flow path of the ink jet head, the lower limit value of pressure fluctuation, and the movement parameter of the ink jet head, the ink jet head adjustment method according to this embodiment can be applied to various ink jets. Can be widely applied to.

  According to the ink jet recording apparatus and the ink jet head adjustment method according to the first embodiment configured as described above, when the ink jet head 21 is moved in the vertical direction, the pressure fluctuation in the internal flow path of the ink jet head 21 is predicted. If the pressure in the internal flow path of the ink jet head 21 is predicted to exceed a predetermined pressure threshold, the nozzle portion 281 shown in FIG. 4 and the inside of the ink jet head 21 shown in FIG. By moving the inkjet head 21 after blocking communication with the flow path, pressure fluctuations in the internal flow path of the inkjet head 21 are suppressed, and the ejection state of the inkjet head 21 is stably maintained.

  This embodiment may be applied when the inkjet head is moved in the first direction during a non-drawing period and a non-ejection period in which the inkjet head 21 does not perform the ejection operation. By suppressing the pressure fluctuation in the internal flow path of the inkjet head 21 during the non-drawing period and the non-ejection period when the inkjet head 21 does not perform the ejection operation, a stable ejection state is realized from the start of the ejection operation.

<First modification>
FIG. 13 is a block diagram showing a configuration of a control system of the ink jet recording apparatus according to the first modification of the first embodiment. In FIG. 13, the same components as those in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. An ink jet recording apparatus 10A according to a first modification of the first embodiment described below includes means for monitoring the acceleration of the ink jet head 21, and the supply side valve shown in FIG. Controls opening and closing of 306 and the like.

  The ink jet recording apparatus 10A illustrated in FIG. 13 includes an acceleration sensor 58 instead of the pressure fluctuation prediction unit 54 illustrated in FIG. The acceleration sensor 58 is attached to the inkjet head 21 shown in FIG. 1 and the like, and measures the acceleration of the inkjet head 21 when the inkjet head 21 is moved in the vertical direction.

  Examples of the acceleration sensor include a capacitance type acceleration sensor, a piezoresistive type acceleration sensor, and a gas temperature distribution type acceleration sensor. That is, the acceleration sensor 58 shown in FIG. 13 is adapted to output an output signal corresponding to the acceleration of the inkjet head 21. The acceleration sensor 58 is an aspect of acceleration measuring means.

  An output signal representing the measurement result of the acceleration sensor 58 is sent to the determination unit 56 via the system controller 12. The determination unit 56 determines whether or not the acceleration of the inkjet head 21 when moving the inkjet head 21 in the vertical direction based on the output signal of the acceleration sensor 58 exceeds a predetermined acceleration threshold value, and represents the determination result. A signal is sent to the system controller 12.

  When the system controller 12 acquires a signal representing the determination result of the determination unit 56, the system controller 12 sends a command signal to the valve control unit 50 according to the determination result.

  The valve control unit 50 opens and closes the supply side valve 306 shown in FIG. 7 among the valves 422 based on the command signal sent from the system controller 12.

  FIG. 14 is a flowchart showing the flow of control of the inkjet head adjustment method according to the first modification of the first embodiment of the present invention. 14, the same steps as those in FIG. 11 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. Note that the threshold in FIG. 14 is an acceleration threshold.

  The flowchart shown in FIG. 14 measures the acceleration of the inkjet head 21 using the acceleration sensor 58 shown in FIG. 13 instead of the operation parameter setting step S12, the pressure fluctuation prediction step S14, and the pressure fluctuation judgment step S16 in FIG. And an acceleration determination step S21 for determining whether or not the measured acceleration exceeds a predetermined acceleration threshold value.

  That is, the movement start process of the inkjet head 21 is performed in the movement start instruction step S10, and when the movement of the inkjet head 21 is started in the head movement start step S20, the acceleration of the inkjet head 21 is measured in the acceleration measurement step S15. The Then, in the acceleration determination step S21, it is determined whether or not the measured acceleration exceeds a predetermined acceleration threshold value.

  If the measured acceleration exceeds the predetermined acceleration threshold value, which is determined as YES in the acceleration determination step S21, the process proceeds to the valve closing step S18, and the supply side valve 306 and the recovery side valve 316 shown in FIG. 7 are closed. .

  If the measured acceleration is equal to or less than a predetermined acceleration threshold value, which is NO in the acceleration determination step S21, the process proceeds to the head movement monitoring step S22. When the inkjet head 21 reaches the target position, which is YES in the head movement monitoring step S22, the steps after the valve opening / closing determination step S26 are executed.

  If the inkjet head 21 has not reached the target position, which is NO in the head movement monitoring step S22, the process returns to the acceleration determination step S21, and the acceleration determination step S21, the valve closing step S18, and the head movement monitoring step S22 are executed. The

  According to the first modification of the first embodiment configured as described above, the acceleration of the inkjet head 21 is monitored when the inkjet head 21 is moved in the vertical direction. Since the supply side valve 306 and the recovery side valve 316 shown in FIG. 7 are closed according to the acceleration of the ink jet head 21, the nozzle portion 281 shown in FIG. 4 and the internal flow path of the ink jet head 21 shown in FIG. By moving the inkjet head 21 in the vertical direction in a state where communication with the inkjet head 21 is blocked, the pressure fluctuation in the internal flow path of the inkjet head 21 is suppressed, and the ejection state of the inkjet head 21 is stably maintained.

<Second modification>
FIG. 15 is a flowchart showing a control flow of the inkjet head adjustment method according to the second modification of the first embodiment of the present invention. In FIG. 15, the same steps as those in FIGS. 11 and 14 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The ink jet recording apparatus according to the second modification of the first embodiment described below includes means for monitoring the pressure of the internal flow path of the ink jet head 21, 7 controls the opening and closing of the supply side valve 306 and the like shown in FIG.

  The control system of the inkjet recording apparatus 10 shown in FIG. 9 is applied to the control system of the inkjet recording apparatus according to the second modification.

  As shown in FIG. 15, the movement start process of the inkjet head 21 is performed in the movement start instruction step S <b> 10, and when the movement of the inkjet head 21 is started in the head movement start step S <b> 20, the inkjet head 21 is detected in the pressure measurement step S <b> 17. The pressure in the internal flow path is measured.

  As means for measuring the pressure in the internal flow path of the inkjet head 21, the supply-side pressure sensor 320 or the recovery-side pressure sensor 322 shown in FIG. 9 can be applied. That is, the pressure of the internal flow path of the inkjet head 21 can be the pressure of the supply side manifold 308 or the pressure of the recovery side manifold 318.

  In the first pressure determination step S23, it is determined whether or not the pressure in the internal flow path of the inkjet head 21 measured in the pressure measurement step S17 exceeds a predetermined first pressure threshold value. In addition, the threshold value in 1st pressure determination process S23 of FIG. 15 is a 1st pressure threshold value.

  When the pressure in the internal flow path of the inkjet head 21 measured in the pressure measurement step S17, which is YES in the first pressure determination step S23, exceeds the predetermined first pressure threshold, the valve closing step S18. Proceed to

  If the pressure in the internal flow path of the inkjet head 21 measured in the pressure measurement step S17, which is No in the first pressure determination step S23, is equal to or lower than a predetermined first pressure threshold value, the head movement monitoring step S22 is performed. move on.

  After the head movement stop process S24, the process proceeds to the valve opening / closing determination process S26. When the valve closed in the valve closing process S18 is determined as YES in the valve opening / closing determination process S26, the second pressure determination process S27 is performed. Proceed to

  In the case where the valve closed in the valve closing step S18 is opened, which is NO in the valve opening / closing determination step S26, the process proceeds to the head movement end step S30.

  In the second pressure determination step S27, it is determined whether or not the pressure in the internal flow path of the inkjet head 21 exceeds a predetermined second pressure threshold value. When the pressure in the internal flow path of the inkjet head 21 that is determined as YES in the second pressure determination step S27 exceeds a predetermined second pressure threshold value, the second pressure determination step S27 is performed via the standby step S29. Is repeatedly executed. Note that the threshold value in the second pressure determination step S27 in FIG. 15 is the second pressure threshold value.

  When the pressure in the internal flow path of the inkjet head 21 that is No in the second pressure determination step S27 is equal to or less than a predetermined second pressure threshold, the process proceeds to the valve opening step S28.

  As the pressure of the internal flow path of the inkjet head 21 applied to the second pressure determination step S27, the means for measuring the pressure of the internal flow path of the inkjet head 21 in the pressure measurement step S17 is applied.

  A mode in which the first threshold value applied to the first pressure determination step S23 and the second threshold value applied to the second pressure determination step S27 are values less than the upper limit value shown in FIG. 10 or values exceeding the lower limit value. Is preferred. That is, by maintaining the internal pressure of the inkjet head 21 within a narrower range than the allowable range of the internal pressure of the inkjet head 21, the internal pressure of the inkjet head 21 is within the allowable range even when sudden pressure fluctuations occur. Is prevented.

  Note that the first pressure threshold applied to the first pressure determination step S23 and the second pressure threshold applied to the second pressure determination step S27 may be the same value or different values.

  According to the second modification configured as described above, the pressure in the internal flow path of the inkjet head 21 is monitored when the inkjet head 21 is moved in the vertical direction. Since the supply side valve 306 and the recovery side valve 316 shown in FIG. 7 are closed according to the pressure in the internal flow path of the ink jet head 21, the nozzle portion 281 shown in FIG. 4 and the ink jet head 21 shown in FIG. By moving the inkjet head 21 in the vertical direction in a state where the communication with the internal flow path is cut off, the pressure fluctuation in the internal flow path of the inkjet head 21 is suppressed, and the ejection state of the inkjet head 21 is stabilized. Can be maintained.

[Second Embodiment]
<Device configuration>
Next, an ink jet recording apparatus and an ink jet head adjustment method according to the second embodiment of the present invention will be described. The overall configuration of the inkjet recording apparatus according to the second embodiment and the configuration of the inkjet head are the same as those of the inkjet recording apparatus 10 according to the first embodiment described with reference to FIGS. 1 to 8, and description thereof is omitted here. To do.

  FIG. 16 is a block diagram showing the configuration of the control system of the ink jet recording apparatus according to the second embodiment of the present invention. In FIG. 16, the same components as those in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the ink jet recording apparatus 10B shown in FIG. 16, a proportional control parameter setting unit 59 is added to the ink jet recording apparatus 10 shown in FIG.

  The proportional control parameter set by the proportional control parameter setting unit 59 is sent to the pump control unit 52 via the system controller 12. The pump control unit 52 controls the operations of the supply pump 313 and the recovery pump 323 shown in FIG. 7 among the pumps 424 based on the proportional control parameter.

  The proportional control parameter can be changed as appropriate. The proportional control parameter setting unit 59 is an aspect of the proportional control parameter changing unit.

<Description of ink jet head adjustment method>
FIG. 17 is an explanatory diagram of an inkjet head adjustment method according to the second embodiment of the present invention. FIG. 17 is a graph showing the pressure in the internal flow path of the inkjet head 21. In FIG. 17, the same parts as those in FIGS. 10 and 12 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The inkjet recording apparatus according to the second embodiment changes the proportional control parameter applied to the pressure control of the internal flow path of the inkjet head 21 to change the inkjet head 21 when moving the inkjet head 21 in the vertical direction. Suppresses pressure fluctuations in the internal flow path.

  The proportional control parameter is an adjustment sensitivity when adjusting the pressure of the internal flow path of the inkjet head 21. When the proportional control parameter is changed to a larger value, the adjustment sensitivity increases, and the period until the pressure target value is reached can be shortened. Further, the actual pressure can be made to follow the pressure fluctuation finely.

  When the set value of the proportional control parameter is increased, the rotation speed of the supply pump 313 and the rotation speed of the recovery pump 323 shown in FIG. 7 are increased, and the ink supply volume per unit time is increased.

  FIG. 18 is a flowchart showing a control flow of the inkjet head adjustment method according to the second embodiment of the present invention. 18, the same steps as those in FIG. 11 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The movement start instructing step S10, the operation parameter setting step S12, and the pressure fluctuation determining step S16 shown in FIG. 18 are the same as those in FIG. If the predicted pressure fluctuation value of the inkjet head 21 exceeds the predetermined pressure threshold value, which is YES in the pressure fluctuation determination step S16, the process proceeds to the proportional control parameter change step S108.

  In the proportional control parameter changing step S108, a proportional control parameter changing process for increasing the value of the proportional control parameter is executed. When the proportional control parameter is changed in the proportional control parameter changing step S108, the process proceeds to the head movement starting step S20.

  When the movement of the inkjet head 21 is stopped in the head movement stop step S24, it is determined in the proportional control parameter determination step S116 whether or not the proportional control parameter has been changed.

  If the proportional control parameter is changed to YES in the proportional control parameter determination step S116, the process proceeds to the proportional control parameter return step S118. In the proportional control parameter return step S118, the changed proportional control parameter is returned to the value before the change.

  If the proportional control parameter is determined to be NO in the proportional control parameter determination step S116, the process proceeds to the head movement end step S30.

  The processes from the head movement start process S20 to the head movement end process S30 correspond to the head movement process. The pressure fluctuation determination step S16 corresponds to a determination step.

  According to the ink jet recording apparatus and the ink jet head adjustment method according to the second embodiment configured as described above, when the ink jet head 21 is moved in the vertical direction, the pressure fluctuation in the internal flow path of the ink jet head 21 is predicted. When the pressure in the internal flow path of the inkjet head 21 is predicted to exceed a predetermined pressure threshold, the proportional control parameter applied to the pressure control in the internal flow path of the inkjet head 21 is changed. Therefore, it is possible to shorten the period until the target pressure is reached with respect to the pressure fluctuation in the internal flow path of the inkjet head 21. Further, the pressure in the internal flow path of the inkjet head 21 can be made to closely follow the pressure fluctuation in the internal flow path of the inkjet head 21, and the pressure fluctuation in the internal flow path of the inkjet head 21 is suppressed. The ejection state of the head 21 is maintained stably.

  This is particularly effective when there is a restriction that the control parameter relating to the movement of the inkjet head 21 in the first direction cannot be changed. As a case where there is a restriction that the control parameter relating to the movement of the inkjet head 21 in the first direction cannot be changed, the floating of the medium 100 may be detected during drawing, and the medium 100 may come into contact with the inkjet head 21. If the acceleration is reduced, the ink jet head 21 cannot be raised in time, and the medium 100 comes into contact with the ink jet head 21.

  This embodiment may be applied when the inkjet head 21 is moved in the first direction during the ejection period.

<First modification>
FIG. 19 is a flowchart showing a control flow of the ink jet head adjustment method according to the first modification of the second embodiment of the present invention. In the ink jet recording apparatus according to the first modification of the second embodiment, a proportional control parameter setting unit 59 shown in FIG. 16 is added to the configuration of the ink jet recording apparatus 10A shown in FIG.

  As in the first modification of the first embodiment, the first modification of the second embodiment includes means for monitoring the acceleration of the inkjet head 21 instead of the configuration for predicting the pressure in the internal flow path of the inkjet head 21. The proportional control parameter is changed according to the acceleration of the inkjet head 21.

  In the inkjet head adjustment method shown in FIG. 19, a proportional control parameter changing step S108 is executed instead of the valve closing step S18 of FIG. Further, a proportional control parameter determination step S116 is executed instead of the valve opening / closing determination step S26 of FIG. Further, a proportional control parameter return step S118 is executed instead of the valve opening step S28 of FIG.

  According to the first modification of the second embodiment configured as described above, the acceleration of the inkjet head 21 is monitored when the inkjet head 21 is moved in the vertical direction. Since the proportional control parameter is changed according to the acceleration of the inkjet head 21, the pressure in the actual internal flow path of the inkjet head 21 can be made to closely follow the pressure fluctuation in the internal flow path of the inkjet head 21, and the inkjet The pressure fluctuation in the internal flow path of the head 21 is suppressed, and the ejection state of the inkjet head 21 is stably maintained.

<Second modification>
FIG. 20 is a flowchart showing a control flow of the inkjet head adjustment method according to the second modification of the second embodiment of the present invention. The configuration of the inkjet recording apparatus 10B illustrated in FIG. 16 is applied to the inkjet recording apparatus according to the second modification of the second embodiment.

  Similar to the second modification example of the first embodiment, the second modification example of the second embodiment replaces the configuration of predicting the pressure of the internal flow path of the inkjet head 21 with the pressure of the internal flow path of the inkjet head 21. Means for monitoring is provided, and the proportional control parameter is changed according to the pressure in the internal flow path of the inkjet head 21.

  In the ink jet head adjustment method shown in FIG. 20, a proportional control parameter changing step S108 is executed instead of the valve closing step S18 of FIG. Further, a proportional control parameter determination step S116 is executed instead of the valve opening / closing determination step S26 of FIG. Further, a proportional control parameter return step S118 is executed instead of the valve opening step S28 of FIG.

  According to the second modification of the second embodiment configured as described above, the fluctuation of the internal pressure of the inkjet head 21 is monitored when the inkjet head 21 is moved in the vertical direction. Since the proportional control parameter is changed according to the fluctuation of the internal pressure of the inkjet head 21, the actual pressure of the internal flow path of the inkjet head 21 can be made to closely follow the pressure fluctuation of the internal flow path of the inkjet head 21. In addition, the pressure fluctuation in the internal flow path of the inkjet head 21 is suppressed, and the ejection state of the inkjet head 21 is stably maintained.

  In the first embodiment and the second embodiment, the liquid ejecting apparatus including the ink jet head including the circulation system that circulates the ink from the nozzle portion is illustrated, but the liquid ejecting apparatus including the liquid ejecting head that does not include the circulation system. It is also possible to apply to.

[About media]
The medium is called by various terms such as a recording medium, a recording medium, a printing medium, a printing medium, an image forming medium, an image forming medium, an image receiving medium, a discharge medium, a paper, a recording paper, a printing paper, and a substrate. Is included.

[About combinations of embodiments]
It is possible to employ a configuration in which the above-described embodiment and the configuration described as the modification are appropriately combined.

[Example of application to program invention]
It is also possible to constitute a program invention including means corresponding to each part of the apparatus and each process described above. That is, the means corresponding to each process of the inkjet head adjustment method according to the first embodiment and the inkjet head adjustment method according to the second embodiment, or the inkjet recording apparatus according to the first embodiment, and the second embodiment. It is possible to configure an ink jet head adjustment program that includes means corresponding to each part of the ink jet recording apparatus and causes a computer to execute as each means.

  The above-described embodiments and modifications of the present invention can be modified, added, or deleted as appropriate without departing from the spirit of the present invention. The present invention is not limited to the embodiments described above, and many modifications are possible by those having ordinary knowledge in the field within the technical idea of the present invention.

  DESCRIPTION OF SYMBOLS 10, 10A, 10B ... Inkjet recording apparatus, 12 ... System controller, 21, 21C, 21M, 21Y, 21K ... Inkjet head, 28 ... Setting part, 40 ... Head movement control part, 50 ... Valve control part, 52 ... Pump control , 54 ... Pressure fluctuation prediction unit, 56 ... Determination unit, 58 ... Acceleration sensor, 59 ... Proportional control parameter setting unit, 100 ... Medium, 252 ... Supply side individual flow path, 256 ... Recovery side individual flow path, 281 ... Nozzle 306 ... supply side valve, 308 ... supply side manifold, 316 ... recovery side valve, 318 ... recovery side manifold, 320 ... supply side pressure sensor, 322 ... recovery side pressure sensor, 313 ... supply pump, 323 ... recovery pump, 400: first head moving unit, 404: actuator, 420 ... second head moving unit

Claims (18)

A liquid discharge head including a discharge element that discharges a liquid, an individual flow path communicating with the discharge element, a liquid discharge head including an internal flow path communicating with the individual flow path;
Individual channel opening / closing means for switching opening and closing of the individual channel, and individual channel opening / closing means provided in the individual channel;
First head moving means for moving the liquid ejection head in a first direction having a vertical component;
Whether or not the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction by the first head moving means. A judging means for judging
When it is determined by the determination means that the pressure of the internal flow path of the liquid ejection head has a fluctuation that falls outside a predetermined allowable range, the individual head movement means is linked with the operation of the first head movement means. Individual channel opening / closing control means for controlling the operation of the channel opening / closing means to close the individual channels;
A liquid ejection apparatus comprising:   The individual flow path opening / closing control means is configured such that when the determination means determines that the pressure of the internal flow path of the liquid discharge head has a fluctuation that is outside the allowable range, the first head moving means Before moving the liquid discharge head in one direction, the individual flow path opening / closing means is operated to close the individual flow path, and the first head moving means moves the liquid discharge head in the first direction. The liquid ejection device according to claim 1, wherein when stopped, the individual channel opening / closing means is operated to open the individual channel. Pressure fluctuation predicting means for predicting pressure fluctuation of the internal flow path of the liquid discharge head during movement of the liquid discharge head in the first direction by the first head moving means;
The determination means determines whether the pressure of the internal flow path of the liquid discharge head is moved by the first head moving means in the first direction based on the prediction result of the pressure fluctuation prediction means. The liquid ejection apparatus according to claim 1, wherein it is determined whether or not there is a fluctuation that falls outside the allowable range. An acceleration measuring means for measuring an acceleration of the liquid discharge head during the movement of the liquid discharge head in the first direction by the first head moving means;
Based on the measurement result of the acceleration measuring means, the determining means determines that the pressure of the internal flow path of the liquid discharge head is during the movement of the liquid discharge head in the first direction by the first head moving means. To determine whether it has fluctuations that fall outside the predetermined tolerance range,
The individual flow path opening / closing control means operates the individual flow path opening / closing means when the determination means determines that the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside the allowable range. And closing the individual flow path and stopping the movement of the liquid ejection head in the first direction by the first head moving means to operate the individual flow path opening / closing means to open the individual flow path. The liquid discharge apparatus according to 1. Pressure measuring means for measuring the pressure of the internal flow path of the liquid discharge head during the movement of the liquid discharge head in the first direction by the first head moving means;
Based on the measurement result of the pressure measuring unit, the determining unit determines whether the pressure of the internal flow path of the liquid discharge head is moved by the first head moving unit in the first direction of the liquid discharge head. To determine whether it has fluctuations that fall outside the predetermined tolerance range,
The individual flow path opening / closing control means operates the individual flow path opening / closing means when the determination means determines that the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside the allowable range. The individual flow path is closed, and when the determination means determines that the pressure of the internal flow path of the liquid discharge head has a variation that falls within the allowable range, the individual flow path opening / closing means is operated to The liquid ejection apparatus according to claim 1, wherein the individual flow path is opened. The individual flow path includes a supply-side individual flow path for supplying liquid to the ejection element, and a recovery-side individual flow path for collecting liquid from the ejection element,
6. The individual flow path opening / closing means includes a supply side individual flow path opening / closing means provided in the supply side individual flow path, and a recovery side individual flow path opening / closing means provided in the recovery side individual flow path. The liquid discharge apparatus according to any one of the above. The individual flow path includes a supply-side individual flow path for supplying liquid to the ejection element, and a recovery-side individual flow path for collecting liquid from the ejection element,
The individual flow path opening / closing means includes a supply side individual flow path opening / closing means provided in the supply side individual flow path, and a recovery side individual flow path opening / closing means provided in the recovery side individual flow path,
The internal flow path of the liquid discharge head is supply-side temporary storage means for temporarily storing liquid to be supplied to the discharge element, supply-side temporary storage means connected to the supply-side individual flow path, and Recovery-side temporary storage means for temporarily storing the liquid recovered from the discharge element, including recovery-side temporary storage means connected to the recovery-side individual flow path,
The liquid discharge according to claim 5, wherein the pressure measuring unit is a supply side pressure sensor that detects an internal pressure of the supply side temporary storage unit, and a recovery side pressure sensor that detects an internal pressure of the recovery side temporary storage unit. apparatus. A liquid discharge head comprising: a discharge element that discharges liquid; an individual flow path that communicates with the discharge element; and an internal flow path that communicates with the individual flow path;
Internal pressure adjusting means for adjusting the pressure of the internal flow path of the liquid discharge head;
First head moving means for moving the liquid ejection head in a first direction having a vertical component;
Whether or not the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction by the first head moving means. A judging means for judging
When it is determined by the determination means that the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range, in conjunction with the operation of the first head moving means, Proportional control parameter changing means for increasing the sensitivity to pressure fluctuation by changing the proportional control parameter applied to the pressure adjusting means;
A liquid ejection apparatus comprising:   The proportional control parameter changing means is configured such that when the determination means determines that the pressure of the internal flow path of the liquid ejection head has a fluctuation that is outside the allowable range, the first head moving means is the first Before moving the liquid discharge head in the direction, the proportional control parameter applied to the internal pressure adjusting means is changed to increase the sensitivity to pressure fluctuations, and the first head moving means moves the liquid in the first direction. The liquid ejection apparatus according to claim 8, wherein when the movement of the ejection head is stopped, the proportional control parameter is restored before being changed. Pressure fluctuation predicting means for predicting pressure fluctuation of the internal flow path of the liquid discharge head during movement of the liquid discharge head in the first direction by the first head moving means;
The determination means determines whether the pressure of the internal flow path of the liquid discharge head is moved by the first head moving means in the first direction based on the prediction result of the pressure fluctuation prediction means. The liquid ejecting apparatus according to claim 8, wherein it is determined whether or not there is a fluctuation that falls outside the allowable range. An acceleration measuring means for measuring an acceleration of the liquid discharge head during the movement of the liquid discharge head in the first direction by the first head moving means;
Based on the measurement result of the acceleration measuring means, the determining means determines that the pressure of the internal flow path of the liquid discharge head is during the movement of the liquid discharge head in the first direction by the first head moving means. To determine whether it has fluctuations that fall outside the predetermined tolerance range,
The proportional control parameter changing unit is a proportional unit applied to the internal pressure adjusting unit when the determining unit determines that the pressure of the internal flow path of the liquid discharge head has a fluctuation that is outside the allowable range. 9. The proportional control parameter is returned before the change when the control parameter is changed to increase sensitivity to pressure fluctuation and the movement of the liquid ejection head in the first direction is stopped by the first head moving means. The liquid discharge apparatus according to 1. Pressure measuring means for measuring the pressure of the internal flow path of the liquid discharge head during the movement of the liquid discharge head in the first direction by the first head moving means;
Based on the measurement result of the pressure measuring unit, the determining unit determines whether the pressure of the internal flow path of the liquid discharge head is moved by the first head moving unit in the first direction of the liquid discharge head. To determine whether it has fluctuations that fall outside the predetermined tolerance range,
The proportional control parameter changing unit is a proportional unit applied to the internal pressure adjusting unit when the determining unit determines that the pressure of the internal flow path of the liquid discharge head has a fluctuation that is outside the allowable range. The control parameter is changed to increase the sensitivity to pressure fluctuation, and when the judgment means judges that the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls within the allowable range, the proportional control parameter is changed. The liquid ejection device according to claim 8, wherein the liquid ejection device is returned to the front.   The liquid according to any one of claims 8 to 12, wherein the individual flow path includes a supply-side individual flow path for supplying a liquid to the ejection element and a recovery-side individual flow path for recovering the liquid from the ejection element. Discharge device. The internal flow path of the liquid discharge head includes temporary storage means for temporarily storing the liquid supplied to the discharge element,
The liquid ejecting apparatus according to claim 5, wherein the pressure measuring unit is a pressure sensor that detects an internal pressure of the temporary storage unit. The individual flow path includes a supply-side individual flow path for supplying liquid to the ejection element, and a recovery-side individual flow path for collecting liquid from the ejection element,
The internal flow path of the liquid discharge head is supply-side temporary storage means for temporarily storing liquid to be supplied to the discharge element, supply-side temporary storage means connected to the supply-side individual flow path, and Recovery-side temporary storage means for temporarily storing the liquid recovered from the discharge element, including recovery-side temporary storage means connected to the recovery-side individual flow path,
The liquid discharge according to claim 12, wherein the pressure measuring means is a supply-side pressure sensor that detects an internal pressure of the supply-side temporary storage means, and a recovery-side pressure sensor that detects an internal pressure of the recovery-side temporary storage means. apparatus.   The liquid discharge apparatus according to claim 1, further comprising a second head moving unit that moves the liquid discharge head in a horizontal direction. A method for adjusting a liquid ejection head comprising: an ejection element that ejects liquid; an individual channel that communicates with the ejection element; and an internal channel that communicates with the individual channel,
It is determined whether or not the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction including a vertical component. A decision process;
When it is determined by the determination step that the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range, the movement of the liquid discharge head in the first direction is interlocked. An individual channel closing step for closing the individual channel;
A moving step of moving the liquid ejection head in the first direction;
A method for adjusting a liquid ejection head comprising: A method for adjusting a liquid ejection head comprising: an ejection element that ejects liquid; an individual channel that communicates with the ejection element; and an internal channel that communicates with the individual channel,
It is determined whether or not the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range during the movement of the liquid discharge head in the first direction including a vertical component. A decision process;
When it is determined by the determination step that the pressure of the internal flow path of the liquid discharge head has a fluctuation that falls outside a predetermined allowable range, the movement of the liquid discharge head in the first direction is interlocked. A proportional control parameter changing step of changing the proportional control parameter applied to the adjustment of the internal pressure of the liquid discharge head to increase the sensitivity to pressure fluctuation;
A method for adjusting a liquid ejection head comprising:

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