JP2013215901A - Cleaning method, cleaning device, and ink-jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head cleaning method having a better nozzle cleaning effect.SOLUTION: A head cleaning method includes an immersion process for immersing a surface with a head nozzle in a cleaning solution and a vibration process for discharging a liquid from the nozzle by giving vibrations to a pressure chamber through the use of a vibration means which gives vibrations to the pressure chamber in a head communicating with the nozzle while the surface is immersed in the cleaning solution.

Description

  The present invention relates to a head cleaning method, a cleaning apparatus, and an ink jet recording apparatus that discharge liquid such as ink.

  Patent Document 1 describes an inkjet head cleaning device for cleaning the nozzle surface of an inkjet head. This apparatus injects the cleaning liquid onto the nozzle surface from the parent nozzle blade and the child nozzle blade in which the cleaning liquid injection hole is formed.

JP 2011-51281 A (published March 17, 2011)

  When ink or dust having a high viscosity adheres to the head of the ink jet printer, the ink ejection performance from the head deteriorates. Such dirt may clog the nozzles of the head, resulting in non-ejection nozzles. It is conceivable to use the apparatus described in Patent Document 1 as a method for cleaning such a head.

  The apparatus described in Patent Document 1 performs cleaning by retracting a head during printing to a maintenance station and spraying a cleaning liquid.

  However, even if the cleaning liquid is jetted onto the head on which the meniscus is formed, if air remains in the nozzle, the cleaning liquid may not enter the nozzle and the nozzle may not be sufficiently cleaned.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a head cleaning method and the like having a higher nozzle cleaning effect.

  The cleaning method according to the present invention is a method for cleaning a head that discharges liquid from a nozzle, and includes a dipping step of immersing the surface of the head provided with the nozzle in a cleaning liquid, and the surface immersed in the cleaning liquid. A vibration step of ejecting the liquid from the nozzle by applying vibration to the pressure chamber by a vibration means that vibrates the pressure chamber in the head in communication with the nozzle. It is said.

  The cleaning device according to the present invention is a cleaning device for a head that discharges liquid from a nozzle, and a cleaning liquid storage tank that stores a cleaning liquid for immersing the surface of the head provided with the nozzle, and the nozzle Vibration control means for controlling the vibration to apply vibration to the pressure chamber in a state where the surface is immersed in the cleaning liquid. It is a feature.

  With the nozzle immersed in the cleaning liquid, the pressure chamber is vibrated and the liquid is discharged from the pressure chamber through the nozzle, so that air accumulated in the nozzle is pushed out of the nozzle, and the nozzle is in the cleaning liquid and the head. Filled with fresh liquid. Further, since the pressure applied to the liquid in the nozzle is increased and decreased by vibration, the cleaning liquid reciprocates in the nozzle. As a result, foreign matter in the nozzle and ink with increased viscosity can be discharged. Therefore, the cleaning effect of the nozzle becomes higher.

  In the cleaning method according to the present invention, the supply pressure is raised by the supply pressure control means for controlling the supply pressure of the liquid supplied to the head before or while the surface is immersed in the cleaning liquid. More preferably, it includes a pressure raising step.

  The pressure in the head during printing is kept at a slightly negative pressure rather than atmospheric pressure. On the other hand, it is preferable that the cleaning liquid does not enter the inside of the head from the nozzle during cleaning. Therefore, by increasing the supply pressure of the liquid supplied to the head by the supply pressure control means, it is possible to prevent the cleaning liquid from entering the nozzle. Further, if the supply pressure is increased to such an extent that liquid is oozed out from the nozzle before the nozzle is immersed in the cleaning liquid, the air in the nozzle can be immersed in the cleaning liquid in a state where the air is discharged by the liquid. Thereby, since it will be in the state where the washing | cleaning liquid enters a nozzle easily, a cleaning effect can be made higher.

  More preferably, the cleaning method according to the present invention includes a jetting step of jetting the cleaning liquid in a state where the surface is immersed in the cleaning liquid by jet means for jetting the cleaning liquid toward the surface.

  The cleaning effect can be further enhanced by spraying the cleaning liquid by the jet means toward the direction opposite to the direction in which the liquid is discharged from the nozzle, that is, toward the surface where the nozzle is provided. At this time, it is more preferable to perform vibration by the vibration means. Accordingly, it is possible to prevent the liquid from being discharged from the nozzle and the cleaning liquid from entering the upstream of the nozzle more than necessary.

  In the cleaning method according to the present invention, after the head is cleaned a predetermined number of times, at least a part of the cleaning liquid is discharged by a cleaning liquid discharging unit that discharges the cleaning liquid from the cleaning liquid storage tank that stores the cleaning liquid. It is more preferable to include a cleaning liquid replacement step of supplying the cleaning liquid to the cleaning liquid storage tank by a cleaning liquid supply unit that supplies a cleaning liquid to the cleaning liquid storage tank.

  In the cleaning apparatus according to the present invention, the cleaning liquid discharging means for discharging the cleaning liquid from the cleaning liquid storage tank, the cleaning liquid supply means for supplying a new cleaning liquid to the cleaning liquid storage tank, and the cleaning of the head are performed a predetermined number of times. Thereafter, the cleaning liquid discharging means and the cleaning liquid supply means are controlled so that at least a part of the cleaning liquid is discharged by the cleaning liquid discharging means and a new cleaning liquid is supplied to the cleaning liquid storage tank by the cleaning liquid supply means. And a cleaning liquid exchange control means.

  The use of the cleaning liquid a plurality of times may contaminate the cleaning liquid and reduce the cleaning effect. However, the high cleaning effect can be maintained by replacing the cleaning liquid.

  In the cleaning apparatus according to the present invention, it is more preferable that the cleaning liquid supply unit further includes a cleaning liquid surface height adjusting unit that maintains the height of the surface of the cleaning liquid in the cleaning liquid storage tank at a predetermined height.

  By adjusting the height of the surface of the cleaning liquid in the cleaning liquid storage tank, it is possible to prevent the cleaning liquid from entering the head more than necessary.

  Further, an ink jet recording apparatus according to the present invention comprises the cleaning apparatus according to the present invention, a wiping means for wiping off deposits on the surface provided with the nozzle, and a capping means for covering and protecting the surface. It is characterized by providing.

  Since the cleaning apparatus according to the present invention is provided, the nozzle can be cleaned with a higher cleaning effect. Further, the head can be more efficiently cleaned by wiping and capping.

  According to the present invention, the nozzle can be cleaned with a higher cleaning effect.

It is a figure which shows the structure of the washing | cleaning apparatus 20 which is one Embodiment of the washing | cleaning apparatus which concerns on this invention. It is a figure which shows the structure of the inkjet recording device 1 provided with the cleaning apparatus 20 which is one Embodiment of the cleaning apparatus which concerns on this invention.

  Hereinafter, an embodiment of a cleaning method and a cleaning apparatus according to the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a configuration of a cleaning device 20 which is an embodiment of a cleaning device according to the present invention. FIG. 2 is a diagram illustrating a configuration of the inkjet recording apparatus 1 including the cleaning device 20.

<Configuration of head 10>
The cleaning device 20 is for cleaning the head 10. First, the configuration of the head 10 will be described. The head 10 includes a pressure chamber 11, a nozzle 12, a vibration element (vibration means) 13, and an ink supply chamber 15.

  The pressure chamber 11 is in the head 10 and communicates with a nozzle 12 that ejects ink.

  The nozzle 12 is a hole for ejecting ink. When vibration is applied to the pressure chamber 11 by the vibration element 13, the pressure applied to the ink in the pressure chamber 11 rises and falls, thereby ejecting ink in droplets.

  The vibration element 13 is for ejecting ink from the nozzle 12 by vibrating. When cleaning the surface of the head on which the nozzle is provided (hereinafter referred to as “nozzle surface” for convenience of description), the vibration element 13 applies vibration to the pressure chamber 11 to eject ink from the nozzle 12. Flushing is performed. In addition, when ink is ejected to the medium 100 illustrated in FIG. 2, the ink is ejected from the nozzle 12 by the vibration of the vibration element 13.

  In addition, an ink supply pipe is connected to the head 10, and a supply pressure adjusting unit 14 that adjusts the supply pressure of ink supplied to the head 10 is provided in the supply pipe. The supply pressure by the supply pressure adjusting unit 14 is controlled by a supply pressure control unit 31 described later.

  The ink supply chamber 15 is for supplying ink supplied from the outside to the pressure chamber 11. The supply pressure of the ink to the ink supply chamber 15 is adjusted by the supply pressure adjusting unit 14.

<Configuration of cleaning device 20>
The cleaning device 20 includes a cleaning liquid storage tank 21, an ultrasonic oscillator (jet unit) 22, a cleaning liquid supply unit (cleaning liquid supply unit) 23, a cleaning liquid discharge unit (cleaning liquid discharge unit) 26, a circulation pump 27, and a control unit 30. Yes.

  The cleaning liquid storage tank 21 is a tank for storing a cleaning liquid for immersing the nozzle surface. When cleaning the nozzle surface, the nozzle surface is immersed in the cleaning liquid stored in the cleaning liquid storage tank 21.

  The ultrasonic oscillating device 22 corresponds to the jet means provided in the cleaning device according to the present invention, and is for jetting the cleaning liquid toward the nozzle surface by ultrasonic waves. Thereby, a cleaning effect can be made higher. It is more preferable to perform flushing while jetting the cleaning liquid with ultrasonic waves. As a result, it is possible to prevent ink from being ejected from the nozzle and the cleaning liquid from entering the upstream of the nozzle more than necessary.

  Further, the jet means provided in the cleaning device according to the present invention is not limited to the one that generates jets by ultrasonic waves, and may be constituted by, for example, a liquid pumping device such as a pump.

  The cleaning liquid supply unit 23 is for supplying a new cleaning liquid to the cleaning liquid storage tank 21. The cleaning liquid supply unit 23 includes a preliminary cleaning liquid tank 24 and a cleaning liquid surface level adjustment tank (cleaning liquid surface height adjusting means) 25.

  The preliminary cleaning liquid tank 24 is a container for storing new cleaning liquid to be supplied to the cleaning liquid storage tank 21.

  The cleaning liquid surface level adjustment tank 25 is a tank for keeping the height of the surface of the cleaning liquid in the cleaning liquid storage tank 21 at a predetermined height. The cleaning liquid surface level adjustment tank 25 is connected to the cleaning liquid storage tank 21 by a pipe. The cleaning liquid storage tank 21 and the cleaning liquid surface level adjustment tank 25 have the same height of the surface of the cleaning liquid therein. Therefore, by adjusting the height of the surface of the cleaning liquid in the cleaning liquid surface level adjustment tank 25 and adjusting the height of the surface of the cleaning liquid in the cleaning liquid storage tank 21, it can be maintained at a predetermined height. The “predetermined height” may be an arbitrary height set by the user or a height necessary for immersing the nozzle surface determined by the control unit. By adjusting the height of the surface of the cleaning liquid in the cleaning liquid storage tank 21, the cleaning liquid can be prevented from entering the head 10 more than necessary.

  The cleaning liquid surface height adjusting means provided in the cleaning apparatus according to the present invention is not limited to means for adjusting the water level like the cleaning liquid surface level adjusting tank 25. For example, the cleaning liquid surface height adjusting means is an electronic device using a flow sensor, a water level sensor or the like. It may be a means for adjusting the height of the surface of the cleaning liquid by control.

  The cleaning liquid discharge unit 26 is for discharging the cleaning liquid from the cleaning liquid storage tank 21. In this embodiment, it is constituted by a valve, and the cleaning liquid in the cleaning liquid storage tank 21 is discharged by opening the valve.

  After the head 10 is cleaned a predetermined number of times, the cleaning liquid supply unit 23 and the cleaning liquid discharge unit 26 discharge at least a part of the cleaning liquid and supply a new cleaning liquid, whereby the cleaning liquid in the cleaning liquid storage tank 21 is supplied. Can be exchanged. The use of the cleaning liquid a plurality of times may contaminate the cleaning liquid and reduce the cleaning effect. However, the high cleaning effect can be maintained by replacing the cleaning liquid.

  The circulation pump 27 circulates the cleaning liquid in the cleaning liquid storage tank 21. Since the cleaning liquid is jetted toward the nozzle surface by the ultrasonic oscillator 22, it is necessary to supply the cleaning liquid to the lower side of the ultrasonic oscillator 22. Therefore, the cleaning liquid is circulated by the circulation pump 27 so that the cleaning liquid is drawn from a location away from the ultrasonic oscillator 22 and supplied to the lower side of the ultrasonic oscillator 22. It may be said that the circulation pump 27 constitutes a part of jet means provided in the cleaning device according to the present invention.

  The control unit 30 is for controlling each part of the head 10 and the cleaning apparatus 20 when cleaning the head including the nozzle surface.

  The control unit 30 includes a supply pressure control unit (supply pressure control unit) 31, a vibration control unit (vibration control unit) 32, a jet flow control unit (jet flow control unit) 33, and a cleaning liquid exchange control unit (cleaning liquid exchange control unit) 34. ing.

  The supply pressure control unit 31 is for controlling the supply pressure of ink supplied to the head 10. Specifically, the supply pressure of the ink supplied to the head 10 is controlled by adjusting the supply pressure adjusting unit 14.

  When cleaning the nozzle surface, the supply pressure control unit 31 increases the supply pressure before or while the nozzle surface is immersed in the cleaning liquid. The ink internal pressure in the head during printing is kept at a slightly negative pressure rather than atmospheric pressure. On the other hand, it is preferable that the cleaning liquid does not enter the inside of the head 10 from the nozzle during cleaning. Therefore, by increasing the supply pressure of the ink supplied to the head 10 by the supply pressure control unit 31, it is possible to prevent the cleaning liquid from entering the nozzle 12. Further, if the supply pressure is increased to such an extent that ink is oozed out from the nozzle 12 before the nozzle 12 is immersed in the cleaning liquid, the air in the nozzle 12 can be immersed in the cleaning liquid in a state where the air is discharged by the ink. Thereby, since it will be in the state where the washing | cleaning liquid enters the nozzle 12 easily, a cleaning effect can be made higher.

  When the supply pressure is increased before the nozzle surface is immersed in the cleaning liquid, the supply pressure control unit 31 separately receives an instruction to start cleaning by user input or the like and before the nozzle surface is immersed in the cleaning liquid. Control to increase supply pressure. For example, the supply pressure control unit 31 or another control unit controls whether or not the nozzle surface is immersed in the cleaning liquid, and the supply pressure control unit 31 increases the supply pressure before performing control so that the nozzle surface is immersed. You may control.

  Further, when the supply pressure control unit 31 increases the supply pressure in a state where the nozzle surface is immersed in the cleaning liquid, the supply pressure control unit 31 recognizes whether the nozzle surface is immersed in the cleaning liquid and supplies the supply pressure. Whether the pressure is increased may be controlled, and the nozzle surface is immersed in the cleaning liquid from a mechanism for adjusting the height of the head 10, a mechanism for adjusting the height of the cleaning liquid storage tank 21, or a control unit thereof. It may be controlled to increase the supply pressure after receiving a signal indicating that the operation has been performed. When the supply pressure control unit 31 recognizes whether or not the nozzle surface is immersed in the cleaning liquid and controls whether or not to increase the supply pressure, whether or not the nozzle surface is immersed in the cleaning liquid. The recognition may be performed by detecting that the nozzle surface has come into contact with the cleaning liquid using a separately provided sensor or the like. The mechanism for adjusting the height of the head 10 and / or the height of the cleaning liquid storage tank 21 may be adjusted. The information indicating the height of the head 10 and / or the cleaning liquid storage tank 21 may be received from the mechanism that performs the processing.

  Here, the supply pressure control unit 31 will be described for the purpose of controlling the supply pressure adjustment unit 14 when the head 10 is cleaned. The supply pressure adjusting unit 14 needs to be operated to supply ink to the head 10 when printing is performed by ejecting ink onto the medium 100 shown in FIG. Control of the supply pressure adjusting unit 14 at the time of printing may be performed by the supply pressure control unit 31 or may be performed by a control unit of the supply pressure adjusting unit 14 provided in the inkjet recording apparatus 1 separately.

  The vibration control unit 32 controls the vibration element 13. When cleaning the nozzle surface, the vibration control unit 32 controls the vibration element 13 so as to apply vibration to the pressure chamber 11 while the nozzle surface is immersed in the cleaning liquid. In the state where the nozzle 12 is immersed in the cleaning liquid, the pressure chamber 11 is vibrated and the liquid is discharged from the pressure chamber 11 through the nozzle 12, whereby the air accumulated in the nozzle 12 is pushed out of the nozzle 12, and the nozzle 12 Is filled with cleaning liquid and ink. Further, since the pressure applied to the ink in the nozzle 12 is increased and decreased by the vibration, the cleaning liquid reciprocates in the nozzle 12. That is, by performing flushing, foreign matter in the nozzle 12 and ink with increased viscosity can be discharged. Therefore, the cleaning effect of the nozzle 12 becomes higher.

  As a method for recognizing whether or not the nozzle surface is immersed in the cleaning liquid, the vibration control unit 32 may recognize the same as the supply pressure control unit 31, for example, from another control unit or the like. You may receive and recognize the signal which shows that the nozzle surface was immersed in the washing | cleaning liquid. Then, for example, immediately after the nozzle surface is immersed in the cleaning liquid or at the same time as the operation of the ultrasonic oscillator 22 starts, the vibration element 13 starts to vibrate in accordance with a predetermined timing that is input in advance. .

  Here, the vibration control unit 32 is described as being intended to control the vibration element 13 when the head 10 is cleaned. The vibration element 13 needs to vibrate when printing is performed by discharging ink to the medium 100 shown in FIG. Vibration control during printing may be performed by the vibration control unit 32 or may be performed by a vibration element control unit provided in the inkjet recording apparatus 1 separately.

  The jet control unit 33 controls the jet of cleaning liquid by the ultrasonic oscillator 22. The jet control unit 33 controls the ultrasonic oscillator 22 so that the cleaning liquid is jetted toward the nozzle surface while the nozzle surface is immersed in the cleaning liquid. By spraying the cleaning liquid toward the nozzle surface, the cleaning effect can be further enhanced. At this time, it is more preferable to perform flushing together. Thereby, the cleaning effect is improved by the cleaning liquid reciprocating the nozzle 12 due to the pressure fluctuation of the pressure chamber 11.

  As a method for recognizing whether or not the nozzle surface is immersed in the cleaning liquid, the jet flow control unit 33 may recognize, for example, in the same manner as the supply pressure control unit 31 or the vibration control unit 32. A signal indicating that the nozzle surface is immersed in the cleaning liquid may be received and recognized from the control unit or the like. Then, for example, immediately after the nozzle surface is immersed in the cleaning liquid, or at the same time as the flushing starts, the ultrasonic oscillation device 22 starts to vibrate in accordance with a predetermined timing input in advance.

  The cleaning liquid replacement control unit 34 controls the cleaning liquid supply unit 23 and the cleaning liquid discharge unit 26. Specifically, after cleaning the head 10 a predetermined number of times, the cleaning liquid replacement control unit 34 discharges at least a part of the cleaning liquid by the cleaning liquid discharge unit 26, and supplies the cleaning liquid storage tank 21 by the cleaning liquid supply unit 23. The cleaning liquid supply unit 23 and the cleaning liquid discharge unit 26 are controlled so as to supply a new cleaning liquid.

  The cleaning liquid replacement control unit 34 recognizes that the head 10 has been cleaned a predetermined number of times and replaces the cleaning liquid. How the cleaning liquid replacement control unit 34 counts the number of cleanings can be set as appropriate. For example, the time from when the head 10 is immersed in the cleaning liquid to when the head 10 comes out of the cleaning liquid may be counted as one time, and the time from when the user inputs an instruction to start cleaning to when the user inputs an instruction to end cleaning It may be counted, or it may be counted as one time from when the user inputs an instruction to start cleaning until the completion of all the preset steps. The use of the cleaning liquid a plurality of times may contaminate the cleaning liquid and reduce the cleaning effect. However, the high cleaning effect can be maintained by replacing the cleaning liquid.

  The cleaning device 20 may further include a wiper that wipes the nozzle surface. After cleaning with the cleaning liquid, the nozzle surface is wet. If it moves on the medium 100 in a wet state, the cleaning liquid drips on the medium 100. If the wiper for wiping the nozzle surface to remove the cleaning liquid from the nozzle surface is provided, it is possible to prevent the cleaning liquid from contaminating the medium 100.

<Configuration of Inkjet Recording Apparatus 1>
The ink jet recording apparatus 1 includes a head 10, a cleaning device 20, a maintenance station 40, and a guide mechanism 50. The ink jet recording apparatus 1 is for performing printing by ejecting ink onto the medium 100.

  The head 10 scans on the medium 100 by reciprocating along the arrow X direction which is the direction defined by the guide mechanism 50.

  The maintenance station 40 is a mechanism for performing maintenance of the head 10, and includes a wiper (wiping means) and a lid (capping means). Specifically, operations such as flushing, capping, wiping, and purging are performed at the maintenance station 40. For example, these operations are performed when cleaning the slightly contaminated head 10 that does not require cleaning with a cleaning liquid.

  As described above, the flushing is an operation of cleaning the nozzle 12 by ejecting ink that has been thickened by ejecting ink by vibrating the vibration element 13. To do this, it is more preferable to provide a container for receiving ink by flushing under the nozzle surface.

  Capping is to cover the nozzle surface of the head 10 so that the ink near the nozzle 12 does not harden when printing is not performed. Therefore, it is more preferable that the maintenance station 40 includes a lid of the head 10. Further, it is more preferable to provide a suction function for suctioning the nozzle surface by setting the inside of the lid to a negative pressure.

  Wiping is an operation of wiping off ink (adhered matter) adhering to the nozzle surface with a wiper. Therefore, it is more preferable that the maintenance station 40 includes a wiper.

  Purge is an operation of cleaning the nozzle 12 by discharging ink from the nozzle 12 by increasing the supply pressure when supplying ink to the head 10 without using the vibration element 13. Purge is suitably performed by raising the supply pressure to, for example, atmospheric pressure or higher. Therefore, it is more preferable that the maintenance station 40 includes a container that collects the ink coming out of the nozzles 12 by purging.

  The guide mechanism 50 is a mechanism for defining the direction in which the head 10 moves. The head 10 is attached to the guide mechanism 50 so as to be movable in a direction defined by the guide mechanism 50 (arrow X direction).

  The cleaning device 20 is provided under one end of the guide mechanism 50, and the maintenance station 40 is provided at the other end. After performing printing to some extent, the head 10 moves to the maintenance station 40 and receives maintenance such as flushing, wiping, and purging. Further, when printing is not performed, the head 10 is protected by capping. When the nozzle surface is further contaminated by performing more printing, the nozzle moves to the cleaning device 20 and is cleaned.

  Thus, by providing the cleaning device 20 and the maintenance station 40 at both ends of the guide mechanism 50, the space can be used effectively. That is, if both the cleaning device 20 and the maintenance station 40 are provided at one end, the structure on the end side of the inkjet recording apparatus 1 becomes too large. Also, the space at the other end is wasted. By providing the cleaning device 20 using the space that should be wasted, the device can be further space-saving.

<Operation of Cleaning Device 20>
Next, the operation of the cleaning device 20 will be described.

  First, the control unit 30 receives a cleaning start instruction. This instruction may be input by the user, for example, or may be automatically started after printing a predetermined amount.

  Next, the control unit 30 sends an instruction to move the head 10 over the cleaning device 20 to the control unit that controls the movement of the head 10. As a result, the head 10 moves onto the cleaning device 20. In addition, you may comprise so that the movement part of the head 10 may be sent by the control part 30. FIG.

  Next, the supply pressure control unit 31 determines whether to increase the supply pressure before the nozzle surface is immersed in the cleaning liquid. This determination is based on, for example, a setting by the user. When the supply pressure is set to increase before the nozzle surface is immersed in the cleaning liquid, the supply pressure control unit 31 controls the supply pressure adjustment unit 14 to increase the ink supply pressure (supply pressure increasing step). If the nozzle surface is set to increase the supply pressure before immersing it in the cleaning liquid, then it is not set to increase the supply pressure after increasing the supply pressure before the nozzle surface is immersed in the cleaning liquid. The supply pressure control unit 31 does not control the supply pressure adjustment unit 14 and proceeds to the dipping process.

  In the dipping process, the nozzle surface is dipped in the cleaning liquid. Specifically, the position of the head 10 is lowered and moved to the cleaning liquid in the cleaning liquid storage tank 21, or the cleaning liquid storage tank 21 is raised to a position higher than the position where the cleaning liquid covers the nozzle surface. Both the head 10 and the cleaning liquid storage tank 21 may be moved.

  Whether the nozzle surface is immersed in the cleaning liquid may be recognized by detecting that the nozzle surface is in contact with the cleaning liquid by a separately provided sensor or the like as described above. Information indicating the height of the head 10 and / or the cleaning liquid storage tank 21 may be received and recognized from a mechanism for adjusting and / or a mechanism for adjusting the height of the cleaning liquid storage tank 21, another control unit, or the like. A signal indicating that the nozzle surface is immersed in the cleaning liquid may be received and recognized.

  Next, in a state where the nozzle surface is immersed in the cleaning liquid, the vibration element 13 applies vibration to the pressure chamber 11 to discharge ink from the nozzle 12 and start flushing (vibration process).

  By the vibration process, air accumulated in the nozzle is pushed out from the nozzle, and the nozzle is filled with the cleaning liquid and the liquid in the head. Further, the cleaning liquid reciprocates in the nozzle, so that foreign matter in the nozzle and ink with increased viscosity can be discharged.

  Further, the supply pressure control unit 31 controls the supply pressure adjusting unit 14 to increase the supply pressure in a state where the nozzle surface is immersed in the cleaning liquid (supply pressure increasing step). The supply pressure increasing step for increasing the supply pressure while the nozzle surface is immersed in the cleaning liquid may be performed before the above vibration step is started. Alternatively, the supply pressure raising step may be started after the vibration step is started. Further, although it may be performed after the vibration process is completed, it is more preferable to perform the supply pressure increasing process while performing the vibration process, that is, performing the flushing. The cleaning effect in the nozzle 12 is further improved. Further, the supply pressure raising step may be performed before, after, or at any timing while performing the jet step described later.

  It should be noted that the degree of increase in the supply pressure in the supply pressure increase process may be such that ink is ejected from the nozzle 12, and more preferably a small amount of ink oozes out.

  Further, the jet flow control unit 33 controls the ultrasonic oscillator 22 to jet the cleaning liquid toward the nozzle surface while the nozzle surface is immersed in the cleaning liquid (jet process). The jet process may be performed before the vibration process is started, the jet process may be started simultaneously with the start of the vibration process, or the jet process may be started after the vibration process is started. Moreover, although it may be performed after the vibration process is completed, it is more preferable to perform the jet process while performing the vibration process, that is, performing the flushing. This is because the cleaning liquid can be prevented from entering the nozzle 12 more than necessary. Further, the jet flow process may be performed before, after, or at any timing while performing the jet flow process.

  Finally, the control unit 30 receives a signal indicating the end of cleaning of the head 10 and terminates the supply pressure increasing process, the vibration process, and the jet process in the supply pressure control unit 31, the vibration control unit 32, and the jet flow control unit 33, respectively. Let A signal indicating the end of cleaning of the head 10 may be set as appropriate. For example, it may be a signal indicating that at least one of the vibration process, the supply pressure increasing process and the jet flow process has been performed for a predetermined time, or a signal indicating an instruction to end the cleaning input by the user. Good.

  The cleaning liquid replacement control unit 34 recognizes the number of cleanings performed after the previous cleaning liquid replacement process from the signal indicating the start and end of cleaning of the head 10. If the cleaning liquid replacement process has not been performed in the past, the cleaning device 20 performs the cleaning for the first time and then recognizes the number of cleanings performed so far.

  The cleaning liquid replacement control unit 34 performs the cleaning liquid replacement process after the recognized number of cleanings reaches a predetermined number. That is, the cleaning liquid replacement control unit 34 discharges at least a part of the cleaning liquid from the cleaning liquid storage tank 21 by the cleaning liquid discharge section 26 and supplies the new cleaning liquid to the cleaning liquid storage tank 21 by the cleaning liquid supply section 23. The discharge unit 26 and the cleaning liquid supply unit 23 are controlled. By keeping the cleaning liquid fresher, the head 10 can be cleaned with a high cleaning effect over a long period of time.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in the embodiments are also included. It is included in the technical scope of the present invention.

<Additional notes>
As described above, one embodiment of the cleaning method according to the present invention is a method for cleaning the head 10 that ejects ink from the nozzles 12, in which the nozzle surface is immersed in the cleaning liquid, and the nozzle surface is immersed in the cleaning liquid. And a vibration step of ejecting ink from the nozzles 12 by applying vibration to the pressure chamber 11 by the vibration element 13.

  The cleaning device 20 is a cleaning device for the head 10 that ejects ink from the nozzles 12. The cleaning device 20 includes a cleaning liquid storage tank 21 that stores cleaning liquid for immersing the nozzle surface, and the vibration element 13. And a vibration control unit 32 that controls the pressure chamber 11 to vibrate when immersed.

  In the state where the nozzle 12 is immersed in the cleaning liquid, the pressure chamber 11 is vibrated, the ink is discharged from the pressure chamber 11 through the nozzle 12 and flushed, whereby the air accumulated in the nozzle 12 is pushed out from the nozzle 12. The nozzle 12 is filled with the cleaning liquid and the ink in the head 10. Further, since the pressure applied to the ink in the nozzle 12 is increased and decreased by the vibration, the cleaning liquid reciprocates in the nozzle 12. As a result, foreign matter in the nozzle 12 and ink with increased viscosity can be discharged. Therefore, the cleaning effect of the nozzle 12 becomes higher.

  In one embodiment of the cleaning method according to the present invention, the supply pressure is controlled before or after the nozzle surface is immersed in the cleaning liquid by the supply pressure control unit 31 that controls the supply pressure of the ink supplied to the head 10. A supply pressure increasing step of increasing the pressure.

  The pressure in the head 10 during printing is kept at a slightly negative pressure rather than atmospheric pressure. On the other hand, it is preferable that the cleaning liquid does not enter the inside of the head 10 from the nozzle during cleaning. Therefore, by increasing the supply pressure of the ink supplied to the head 10 by the supply pressure control unit 31, it is possible to prevent the cleaning liquid from entering the nozzle 12. Further, if the supply pressure is increased to such an extent that ink is oozed out from the nozzle 12 before the nozzle 12 is immersed in the cleaning liquid, the air in the nozzle 12 can be immersed in the cleaning liquid in a state where the air is discharged by the ink. Thereby, since it will be in the state where the washing | cleaning liquid enters the nozzle 12 easily, a cleaning effect can be made higher.

  One embodiment of the cleaning method according to the present invention includes a jetting process in which the cleaning liquid is jetted by the ultrasonic oscillator 22 that jets the cleaning liquid toward the nozzle surface while the nozzle surface is immersed in the cleaning liquid.

  The cleaning effect can be further enhanced by spraying the cleaning liquid by the ultrasonic oscillator 22 in the direction opposite to the direction in which the ink is ejected from the nozzle 12, that is, toward the nozzle surface. At this time, it is more preferable to perform vibration by the vibration element 13 together. As a result, it is possible to prevent ink from being ejected from the nozzles and the cleaning liquid from entering the upstream of the nozzles 12 more than necessary.

  In one embodiment of the cleaning method according to the present invention, after cleaning the head 10 a predetermined number of times, at least a part of the cleaning liquid is discharged by the cleaning liquid discharge unit 26 that discharges the cleaning liquid from the cleaning liquid storage tank 21 that stores the cleaning liquid. Then, a cleaning liquid replacement step of supplying the cleaning liquid to the cleaning liquid storage tank 21 by the cleaning liquid supply unit 23 that supplies a new cleaning liquid to the cleaning liquid storage tank 21 is included.

  In the cleaning apparatus 20, the cleaning liquid discharge unit 26 that discharges the cleaning liquid from the cleaning liquid storage tank 21, the cleaning liquid supply unit 23 that supplies a new cleaning liquid to the cleaning liquid storage tank 21, and the head 10 are cleaned a predetermined number of times. The cleaning liquid is controlled by the cleaning liquid discharge unit 26 and the cleaning liquid supply unit 23 such that at least a part of the cleaning liquid is discharged by the cleaning liquid discharge unit 26 and a new cleaning liquid is supplied to the cleaning liquid storage tank 21 by the cleaning liquid supply unit 23. An exchange control unit 34.

  The use of the cleaning liquid a plurality of times may contaminate the cleaning liquid and reduce the cleaning effect. However, the high cleaning effect can be maintained by replacing the cleaning liquid.

  In the cleaning apparatus 20, the cleaning liquid supply unit 23 further includes a cleaning liquid surface level adjustment tank 25 that adjusts the height of the surface of the cleaning liquid in the cleaning liquid storage tank 21.

  By adjusting the height of the surface of the cleaning liquid in the cleaning liquid storage tank 21, the cleaning liquid can be prevented from entering the head 10 more than necessary.

  The ink jet recording apparatus 1 includes a cleaning device 20, a wiper for wiping off deposits on the nozzle surface, and a lid for covering and protecting the nozzle surface.

  Since the cleaning device 20 is provided, the nozzle 12 can be cleaned with a higher cleaning effect. Further, the head 10 can be more efficiently cleaned by wiping and capping.

  The present invention can be used in an inkjet printing apparatus.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 10 Head 11 Pressure chamber 12 Nozzle 13 Vibration element (vibration means)
DESCRIPTION OF SYMBOLS 14 Supply pressure adjustment part 15 Ink supply chamber 20 Cleaning apparatus 21 Cleaning liquid storage tank 22 Ultrasonic oscillation apparatus (jet means)
23. Cleaning liquid supply unit (cleaning liquid supply means)
24 Preliminary cleaning liquid tank 25 Cleaning liquid surface level adjustment tank (cleaning liquid surface height adjustment means)
26 Cleaning liquid discharge part (cleaning liquid discharging means)
27 Circulating pump 30 Control unit 31 Supply pressure control unit (supply pressure control means)
32 Vibration control unit (vibration control means)
33 Jet control section (jet control means)
34 Cleaning liquid replacement control unit (cleaning liquid replacement control means)

Claims (8)

A method of cleaning a head that discharges liquid from a nozzle,
An immersion step of immersing the surface of the head provided with the nozzle in a cleaning liquid;
In a state where the surface is immersed in the cleaning liquid, the liquid is discharged from the nozzle by applying vibration to the pressure chamber by a vibration unit that communicates with the nozzle and that vibrates the pressure chamber in the head. And a vibration process.   A supply pressure control means for controlling the supply pressure of the liquid supplied to the head includes a supply pressure increasing step for increasing the supply pressure before or while the surface is immersed in the cleaning liquid. The cleaning method according to claim 1.   The cleaning according to claim 1, further comprising a jetting step of jetting the cleaning liquid in a state where the surface is immersed in the cleaning liquid by jet means for jetting the cleaning liquid toward the surface. Method.   After the head has been cleaned a predetermined number of times, at least a part of the cleaning liquid is discharged by a cleaning liquid discharging means for discharging the cleaning liquid from the cleaning liquid storage tank for storing the cleaning liquid, and a new cleaning liquid is supplied to the cleaning liquid storage tank. The cleaning method according to claim 1, further comprising a cleaning liquid replacement step of supplying the cleaning liquid to the cleaning liquid storage tank by a supplied cleaning liquid supply unit. A head cleaning device for discharging liquid from a nozzle,
A cleaning liquid storage tank for storing a cleaning liquid for immersing the surface of the head provided with the nozzle;
And vibration control means for controlling vibration means for applying vibration to the pressure chamber in the head communicating with the nozzle so as to apply vibration to the pressure chamber in a state where the surface is immersed in the cleaning liquid. A cleaning apparatus characterized by that. Cleaning liquid discharging means for discharging the cleaning liquid from the cleaning liquid storage tank;
Cleaning liquid supply means for supplying a new cleaning liquid to the cleaning liquid storage tank;
After the head has been cleaned a predetermined number of times, at least a part of the cleaning liquid is discharged by the cleaning liquid discharging means, and the cleaning liquid is supplied to the cleaning liquid storage tank by the cleaning liquid supply means. The cleaning apparatus according to claim 5, further comprising: a cleaning liquid replacement control unit that controls the discharge unit and the cleaning liquid supply unit.   The cleaning apparatus according to claim 6, wherein the cleaning liquid supply unit further includes a cleaning liquid surface height adjusting unit that maintains the height of the surface of the cleaning liquid in the cleaning liquid storage tank at a predetermined height.   A cleaning apparatus according to any one of claims 5 to 7, a wiping means for wiping off deposits on the surface on which the nozzle is provided, and a capping means for covering and protecting the surface. An ink jet recording apparatus.

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