JP2008105351A - Liquid ejector and control method of liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejector which can be made inexpensive and compact, has no variation of a response speed, and can carry out feeding of an optimum ink by enabling correct opening and closing control. <P>SOLUTION: The liquid ejector is equipped with an opening and closing lever 57 and a holder 58 which can shut tubes 72 connected to atmosphere communication openings of sub tanks 50a-50d, and with valve shafts 55a which open and close openings for flowing out the ink stored in first liquid chambers of the sub tanks 50a-50d towards second liquid chambers. The opening and closing lever 57 (atmosphere communication valve) and the valve shafts 55a (pressure regulating valves) are operatively connected with each other by a mechanically common valve driving mechanism 80 (a cam shaft 81 and a driving motor 83). Rotation in one direction of the cam shaft 81 gives a transition in the order that the atmosphere communication valve is opened with the pressure regulating valve shut, the atmosphere communication valve is shut with the pressure regulating valve opened, and the atmosphere communication valve is opened with the pressure regulating valve opened. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention opens and closes an air communication valve that opens and closes an air communication port of a first liquid chamber capable of storing liquid, and an opening for allowing the liquid stored in the first liquid chamber to flow out toward the second liquid chamber The present invention relates to a liquid ejecting apparatus having a pressure adjusting valve and a method for controlling the liquid ejecting apparatus, and more specifically, the discharge recovery operation of the liquid ejecting head is performed by opening or closing the pressure adjusting valve and the air communication valve. It is about technology.

  2. Description of the Related Art Conventionally, as an example of a liquid ejecting apparatus, an ink jet printer that transports a recording medium such as recording paper to a liquid ejecting head and ejects ink (liquid) from a nozzle of the liquid ejecting head to form an image is known. Yes. As a method for supplying ink to the liquid discharge head, a “head integrated type” in which ink is arranged and supplied integrally with the liquid discharge head, and an ink cartridge separate from the liquid discharge head are used in the ink jet printer. There is a “head-separated type” that is mounted and supplies the ink in the ink cartridge to the liquid discharge head.

  Here, in a color-compatible inkjet printer, generally, four colors of ink of yellow (Y), magenta (M), cyan (C), and black (K) are used. In the case of a printer, each color ink is contained in an ink cartridge, and is easy to handle. When the ink cartridge is mounted on the ink jet printer, the ink of each color stored in the ink cartridge is supplied to the liquid ejection head through an ink flow path such as a tube by a supply pump.

  In addition, in the “head-separated type” ink jet printer, the ink discharged from the liquid discharge head is temporarily stored in the ink flow path so that stable ink supply is possible, and the liquid discharge head is used as necessary. A liquid supply means that can supply ink is provided. This liquid supply means has functions such as a negative pressure adjustment function that applies a constant negative pressure to the ink of the liquid discharge head and prevents the ink from leaking from the nozzles, the remaining amount of ink is detected, and the ink is circulated. Therefore, it is possible to grasp and adjust the state of the ink jet printer. Therefore, the liquid supply means has a pressure adjustment valve for making the pressure of the ink supplied to the liquid discharge head substantially constant, an atmosphere communication port for communicating the interior in which the liquid is stored to the atmosphere, and an atmosphere communication port. An air communication valve or the like that opens and closes is provided, and is configured so as to be able to optimally supply ink according to the state of the ink jet printer.

As such a technique, for example, a configuration in which a circulation pump is connected to a sub-tank (liquid supply means) provided with an atmosphere communication valve is known. That is, the liquid discharge head and the sub tank constitute a circulation flow path, and the circulation pump is driven with the atmospheric communication valve closed to circulate the ink in the sub tank into the common liquid chamber of the liquid discharge head to perform the circulation operation. Is a technique in which the air communication valve is opened immediately after the circulation pump is stopped. Then, the pressure difference between the common liquid chamber and the sub tank is eliminated, the meniscus is not moved, and ink leakage from the nozzle and air drawing-in are prevented. Furthermore, a switching valve is also installed in the circulation channel, and is opened and closed in accordance with the operation of the air communication valve according to the ink circulation mode and the pressure recovery mode (see, for example, Patent Document 1).
JP 2005-306005 A

In addition, regarding a configuration in which ink supply control is performed by opening and closing various valves, the liquid discharge head is moved to the first position or the second position in accordance with various recovery operations (large recovery and small recovery) of the liquid discharge head, A technique is also known in which the opening and closing of the valve is switched depending on the movement position (see, for example, Patent Document 2).
Japanese Patent No. 2825241

  However, the technique disclosed in Patent Document 1 uses a solenoid on-off valve (solenoid valve) that uses a solenoid as a drive source for switching the valve. This solenoid on-off valve has the advantage that it can be electrically controlled, has a simple configuration, has a high degree of freedom in installation location, and can be controlled independently, but is expensive and has a large volume of parts. There is a problem of being big.

  In particular, in the case of a color compatible ink jet printer, a sub tank is required for each of the four colors of yellow (Y), magenta (M), cyan (C), and black (K). If the on-off valve is provided, the ink jet printer becomes large and expensive. Moreover, it is difficult to make the response speeds of solenoid open / close valves uniform in response due to individual variations during manufacturing, changes over time, and the installation environment of the ink jet printer, and the timing of opening and closing cannot be accurately adjusted. .

  On the other hand, in the technique of the above-mentioned Patent Document 2, the solenoid opening / closing valve is not used, and the valve is opened / closed by using the moving operation of the liquid discharge head, which can be configured relatively inexpensively, but the installation location is limited. There is a problem that. Further, when considering the pressure regulating valve and the atmospheric communication valve, the opening / closing sequence of the two valves and the combination thereof are structurally limited. Furthermore, it cannot be applied to a line head type ink jet printer having a configuration in which the liquid discharge head is not moved.

  Therefore, the problem to be solved by the present invention is that it is inexpensive and can be reduced in size, and there is no variation in response speed as in the case of using a plurality of solenoid on-off valves, enabling accurate control, It is to be able to supply the optimum ink according to the state regardless of the configuration of the liquid discharge head.

The present invention solves the above-described problems by the following means.
According to a first aspect of the present invention, a liquid discharge head for forming an image by discharging liquid from a nozzle, a liquid to be discharged, and a liquid supplied to the liquid discharge head A liquid ejecting apparatus including a liquid supply unit capable of storing a liquid therein, the first liquid chamber being capable of storing liquid therein and having an atmosphere communication port for communicating the inside and the atmosphere; An atmosphere communication valve for opening and closing the atmosphere communication port; a second liquid chamber having a discharge port for supplying liquid stored therein to the liquid discharge head; the first liquid chamber and the second liquid chamber; A partition wall for partitioning, an opening for allowing the liquid stored in the first liquid chamber to flow out toward the second liquid chamber, and a pressure adjustment for opening and closing the opening A pressure adjusting valve And the atmospheric communication valve are interlocked by a mechanically common valve driving mechanism, the pressure adjustment valve is closed, the atmospheric communication valve is opened, the pressure adjustment valve is opened, and the atmospheric communication valve is opened. The valve is closed, the pressure regulating valve is opened, and the atmospheric communication valve is opened in order.

  Moreover, the invention according to claim 4, which is another one of the present invention, is capable of storing a liquid therein, and has a first liquid chamber having an atmosphere communication port for communicating the inside and the atmosphere, Between the first liquid chamber and the second liquid chamber, an air communication valve for opening and closing the air communication port, a second liquid chamber having a discharge port for supplying the liquid stored therein to the liquid discharge head, and A partition wall for partitioning, an opening for allowing the liquid stored in the first liquid chamber to flow out toward the second liquid chamber, and a pressure adjusting valve for opening and closing the opening A liquid supply unit comprising: a liquid supply unit including: a liquid supply unit that supplies liquid stored in the liquid supply unit to a liquid discharge head, and discharges the liquid from a nozzle of the liquid discharge head to form an image. With a mechanically common valve drive mechanism. The pressure adjustment valve and the atmospheric communication valve are interlocked, the pressure adjustment valve is closed, the atmospheric communication valve is opened, the pressure adjustment valve is opened, and the atmospheric communication valve is closed, The pressure adjusting valve is opened, and the transition is made in the order in which the atmospheric communication valve is opened.

(Function)
According to the first and fourth aspects of the present invention, the air communication valve that opens and closes the air communication port of the first liquid chamber and the partition wall that partitions the first liquid chamber and the second liquid chamber are formed. And a pressure adjusting valve for opening and closing the opening. The pressure adjustment valve and the atmosphere communication valve are mechanically linked by a common valve drive mechanism, the pressure adjustment valve is closed, the atmosphere communication valve is opened, the pressure adjustment valve is opened, and the atmosphere communication valve is opened. While the valve is closed, the pressure adjustment valve is opened, and the atmospheric communication valve is opened. Therefore, by operating a common valve drive mechanism, both the pressure adjustment valve and the atmosphere communication valve are opened and closed in a predetermined order (the order in accordance with the progress of the discharge recovery operation for optimal ink supply). be able to.

  According to the above invention, since the pressure regulating valve and the atmospheric communication valve are mechanically linked by a common valve driving mechanism, if one valve driving mechanism is operated, both the pressure regulating valve and the atmospheric communication valve are operated. Can be opened and closed. Therefore, it is not necessary to provide separate and separate operating mechanisms (multiple solenoid valves and multiple motors) for the pressure adjustment valve and the atmospheric communication valve, and it is possible not only to reduce the cost and size, but also to adjust the pressure. Variations in the response speed of the valve and the atmosphere communication valve can be eliminated.

  In addition, since the pressure adjustment valve and the atmosphere communication valve open and close in a predetermined order according to the progress of the ink discharge recovery operation, the liquid discharge head is in a cleaned state (the state where bubbles are removed), It becomes possible to always supply optimal ink to the liquid discharge head.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the following embodiments, as an example of the liquid ejecting apparatus of the present invention, an ink jet printer 10 that forms an image by ejecting ink (liquid) from a nozzle 28 of a liquid ejecting head described later is given as an example.

  The ink jet printer 10 of the present embodiment is compatible with “head-separated type” color, and a sub tank 50 (corresponding to the liquid supply means in the present invention) between the liquid discharge head and the ink cartridge 30. The supply pump 40 is installed via the ink supply pump, and ink is supplied from the ink cartridge 30 to the liquid discharge head by the supply pump 40.

  Furthermore, the ink jet printer 10 of this embodiment is of a line head type including a line head 20 as the liquid discharge head of the present invention. In the line head 20, nozzles 28 for ejecting ink are linearly arranged at a predetermined pitch over the length in the sheet width direction of the maximum size recording sheet that can be printed. For this reason, a carriage for moving the liquid ejection head in the paper width direction is not required, and noise and vibration during the printing operation are unlikely to occur. During printing, the recording paper moves at a constant speed without being stopped by the conveying means, and ink is continuously ejected from the line head 20 in synchronization therewith, so that the printing time can be shortened. It is.

FIG. 1 is a conceptual diagram showing a line head type ink jet printer 10 of the present embodiment.
As shown in FIG. 1, the inkjet printer 10 includes a line head 20, an ink cartridge 30, a supply pump 40, a sub tank 50, and a suction pump 60. The ink cartridge 30 is arranged separately from the line head 20. In addition, the ink supply system is a “head-separated type” in which ink is supplied through the tube 70. That is, the ink passes through the ink cartridge 30, the supply pump 40, and the sub tank 50 before the ink is supplied to the line head 20.

  Here, as will be described later, the line head 20 has a plurality of head chips arranged on the inner surface of the nozzle sheet 27 on which the nozzles 28 are formed. The head chips discharge energy to the ink in the ink liquid chamber 22. And the ink can be ejected from the nozzles 28. That is, in order to print on a recording sheet using such a line head 20, ink is ejected from the nozzles 28 by the head chip based on a command from the control unit. At the same time, the recording paper is continuously conveyed while maintaining a position away from the nozzle sheet 27 by a predetermined distance. Then, the ejected ink lands on a predetermined position on the recording paper and printing is performed.

  The ink cartridge 30 is a container that contains four colors of ink, yellow (Y), magenta (M), cyan (C), and black (K). The ink cartridge 30 can be easily detached from the ink jet printer 10. Therefore, the user of the inkjet printer 10 can quickly replace the ink cartridge 30 with a new one when the ink in the ink cartridge 30 is insufficient.

  The ink of each color of the ink cartridge 30 attached to the ink jet printer 10 is sent to the sub tank 50 by the supply pump 40 installed for each color. That is, each supply pump 40 can inhale ink of a corresponding color from the ink cartridge 30 as necessary, and can discharge the ink toward the sub tank 50. Therefore, when each supply pump 40 is driven, each color ink is supplied from the ink cartridge 30 to the sub tank 50.

  The sub tank 50 temporarily stores ink. However, the sub tank 50 is not a mere storage tank. As will be described later, an open / close valve 55d for adjusting the flow rate of ink supplied to the line head 20 and the remaining amount of ink. A liquid amount sensor 51c for detection, a filter 51d for removing bubbles and foreign matters mixed in the ink, and the like are incorporated. For this reason, functions such as pressure adjustment in the line head 20, detection of the remaining amount of ink, removal of bubbles and foreign matters, and the like are provided. For example, a liquid amount sensor 51c provided so as to come into contact with the ink in the sub tank 50. When a decrease in ink is detected by this, ink is supplied from the ink cartridge 30 to the sub tank 50 by the supply pump 40 corresponding to the ink of that color. Therefore, in the inkjet printer 10 of the present embodiment, the various states of the line head 20 can be best maintained by stably supplying ink from the sub tank 50 to the line head 20.

  The sub tank 50 is installed at a position lower than the line head 20 so that the meniscus of the nozzles 28 that eject ink can be maintained. That is, by setting the ink ejection surface of the line head 20 (the surface of the nozzle sheet 27 on the ink ejection side) to be higher in the vertical direction than the sub tank 50, the ink in the ink liquid chamber 22 is not affected by the water head difference. Based on the given negative pressure. For this reason, it is possible to prevent ink from leaking from the nozzles 28 and to always maintain a state where ink can be ejected.

  Further, the suction pump 60 is for sucking ink from the line head 20 at the time of initial filling of ink or maintenance. In other words, the ink is supplied to the line head 20 from the supply port 21a, but each ink containing bubbles and foreign matter can be maintained so that the bubbles and foreign matters in the line head 20 can be removed and normal ink ejection can be maintained. A suction pump 60 is connected to the discharge port 21b opposite to the supply port 21a in order to suck from the line head 20 and discharge it.

  Here, the ink discharging operation by the suction pump 60 is set to be performed arbitrarily or periodically, so that the cleaning in the line head 20 can be executed efficiently. In addition, the suction pump 60 is installed for each color in the same manner as the supply pump 40. Therefore, it is possible to select and drive only the suction pump 60 corresponding to the ink having a problem such as mixing of bubbles, so that wasteful ink consumption due to cleaning can be reduced.

  As described above, the inkjet printer 10 according to the present embodiment supplies the line head 20, the ink cartridge 30, and the supply for each of the four colors of Y (yellow), M (magenta), C (cyan), and K (black). A pump 40, a sub tank 50, and a suction pump 60 are provided, and are connected by four tubes 70 corresponding to each color. Each tube 70 is made of silicon rubber or the like and has appropriate elasticity.

FIG. 2 is a perspective view and a sectional view partially showing the line head 20 in the ink jet printer 10 of the present embodiment shown in FIG.
As shown in FIG. 2, the line head 20 is configured by laminating a barrier layer 26 on a semiconductor substrate 25 and bonding a nozzle sheet 27 on which nozzles 28 are formed to the barrier layer 26. A plurality of heating resistors 23 are deposited in one direction at regular intervals on the semiconductor substrate 25, and the ink liquid chamber 22 is formed by the semiconductor substrate 25 surrounding the heating resistors 23, the barrier layer 26, and the nozzle sheet 27. Has been. The ink liquid chamber 22 has an opening region that communicates with the ink flow path 24, and ink is supplied into the ink liquid chamber 22 from the opening region.

  Here, the semiconductor substrate 25 is made of silicon, glass, ceramics, or the like, and the heating resistor 23 is deposited on one surface of the semiconductor substrate 25 by using a fine processing technique for manufacturing a semiconductor or an electronic device. Is formed. The heating resistor 23 is electrically connected to an external circuit through a conductor portion (not shown) formed on the semiconductor substrate 25.

  The barrier layer 26 is laminated on the side of the heating resistor 23 of the semiconductor substrate 25. That is, the barrier layer 26 applies a photosensitive resin to the entire upper surface of the semiconductor substrate 25 and emits light having a wavelength band that is optimal for exposing the photosensitive resin through a photomask having a pattern with an appropriate shape. Then, the exposed photosensitive resin layer is developed with a predetermined developer, and unexposed portions are removed, thereby patterning on the semiconductor substrate 25 excluding the periphery of the heating resistor 23. Is formed. The heating chip 23, the semiconductor substrate 25, and the barrier layer 26 constitute a head chip.

  Furthermore, the nozzle sheet 27 is formed by, for example, an electroforming technique using Ni (nickel), and the nozzle sheet 27 is provided with a plurality of nozzles 28. As shown in FIG. 2, the head chip (the heating resistor 23, the semiconductor substrate 25, and the barrier layer 26) is arranged so that the position of each nozzle 28 and the position of each heating resistor 23 are aligned. The nozzles 28 are precisely positioned so that the nozzles 28 are opposed to the respective heating resistors 23, and are bonded onto the nozzle sheet 27 with the barrier layer 26 facing down.

  Therefore, as shown in FIG. 2A, the ink liquid chamber 22 is constituted by the semiconductor substrate 25, the barrier layer 26, and the nozzle sheet 27 so as to surround the heating resistor 23. That is, the semiconductor substrate 25 and the heating resistor 23 constitute the upper wall of the ink liquid chamber 22 in FIG. 2A, the barrier layer 26 constitutes the three side walls of the ink liquid chamber 22, and the nozzle sheet 27. Constitutes the lower wall of the ink liquid chamber 22.

  The ink liquid chamber 22 has an opening area in the lower right direction in FIG. 2A, and this opening area communicates with a common ink flow path 24. That is, as shown in FIG. 2B, a common flow path member 29 is disposed on the upper side of the semiconductor substrate 25, and the common ink flow path 24 formed by the common flow path member 29 is used for all the inks. It communicates with the liquid chamber 22. Therefore, the ink in the ink cartridge 30 (see FIG. 1) is supplied to all the ink liquid chambers 22 through the common ink flow path 24.

  Then, in a state where the ink liquid chamber 22 is filled with ink, when a pulse current is passed through the heating resistor 23 for a short time (for example, for 1 to 3 μsec) by a command from a control unit (not shown), The heating resistor 23 is heated rapidly. As a result, an ink bubble is generated at a portion in contact with the heating resistor 23, and a predetermined volume of ink is pushed away by the expansion of the bubble (the ink boils). Then, this becomes an ejection pressure, and an ink having a volume equivalent to the pushed ink is ejected as ink droplets from the nozzle 28 and landed on the recording paper to form an image.

  Here, the line head 20 is in a state in which the ink liquid chamber 22 is always filled with ink so that the ink can be ejected at all times. Therefore, it is necessary to prevent ink in the ink liquid chamber 22 from leaking from the nozzles 28. Therefore, the ink jet printer 10 of the present embodiment applies a constant negative pressure to the ink of the line head 20 by the sub tank 50 to prevent ink leakage.

FIG. 3 is a cross-sectional view showing the sub tank 50 in the inkjet printer 10 of the present embodiment shown in FIG.
As shown in FIG. 3, the sub tank 50 includes a first liquid chamber 51 that can store ink therein, a second liquid chamber 52 that can discharge ink stored therein, and a first liquid chamber 51. A partition wall 53 that partitions the second liquid chamber 52, an opening 54 formed in the partition wall 53, and a pressure adjustment valve 55 that opens and closes the opening 54 are provided.

  Here, the first liquid chamber 51 includes a supply port 51a that receives ink supplied by the supply pump 40 (see FIG. 1), and an air communication port 51b for communicating the inside of the first liquid chamber 51 and the atmosphere. The liquid amount sensor 51c detects the remaining amount of ink in the first liquid chamber 51, and the filter 51d removes bubbles and foreign matters mixed in the ink. A tube 71 from the supply pump 40 is connected to the supply port 51a, a tube 72 having the other end opened is connected to the atmosphere communication port 51b, and the atmosphere communication valve 56 is in the middle of the tube 72. Is attached.

  In normal times, the atmosphere communication valve 56 is open, and the pressure in the first liquid chamber 51 is kept equal to the atmospheric pressure. Further, the ink fed from the supply pump 40 (see FIG. 1) flows through the supply port 51 a and is stored in the first liquid chamber 51. Since the electrode of the liquid amount sensor 51c is exposed on the top surface of the first liquid chamber 51 and the liquid level of the stored ink can be detected, the ink in the first liquid chamber 51 is reduced by the liquid amount sensor 51c. Is detected, ink is supplied from the ink cartridge 30 (see FIG. 1) to the first liquid chamber 51 by the supply pump 40 corresponding to the ink of that color.

  Further, a filter 51d is installed in an intermediate portion in the first liquid chamber 51, and all ink passes through the filter 51d from the top to the bottom. Therefore, bubbles and foreign matters mixed in the ink are removed by the filter 51d, so that the ink can be stably ejected by the line head 20 (see FIG. 2).

  On the other hand, the second liquid chamber 52 is partitioned from the first liquid chamber 51 by a partition wall 53 provided on the downstream side of the filter 51 d in the first liquid chamber 51. The partition wall 53 is formed with an opening 54 through which the ink stored in the first liquid chamber 51 flows out toward the second liquid chamber 52. Therefore, the ink from which bubbles and foreign matters are removed in the first liquid chamber 51 can flow into the second liquid chamber 52 through the opening 54.

  Thus, the ink that flows into the second liquid chamber 52 through the opening 54 and is stored is sent out toward the line head 20 (see FIG. 2). That is, the second liquid chamber 52 has a discharge port 52a for discharging the ink stored in the second liquid chamber 52 toward the line head 20, and a tube 73 directed to the line head 20 is provided in the discharge port 52a. It is connected. Therefore, the ink in the second liquid chamber 52 is supplied to the ink liquid chamber 22 of the line head 20, and ink can be ejected.

Incidentally, a pressure adjusting valve 55 that opens and closes the opening 54 is installed in the opening 54 formed in the partition wall 53 that partitions the first liquid chamber 51 and the second liquid chamber 52. The pressure adjustment valve 55 is constituted by a valve shaft 55a, an opening / closing spring 55b, a diaphragm 55c, and an opening / closing valve 55d, and adjusts the flow rate of ink discharged from the discharge port 52a of the second liquid chamber 52 to thereby adjust the line head. It plays a role of making the ink pressure in the 20 ink liquid chambers 22 (see FIG. 2) substantially constant.
Next, the pressure adjustment valve 55 will be described in detail.

FIG. 4 is a cross-sectional view showing a normal state of the pressure regulating valve 55 in the sub tank 50 shown in FIG.
FIG. 5 is a cross-sectional view showing a state during operation of the pressure adjustment valve 55 in the sub tank 50 shown in FIG.
As shown in FIGS. 4 and 5, the pressure regulating valve 55 includes a valve shaft 55a that vertically penetrates the opening portion 54 of the second liquid chamber 52 and the partition wall 53, and an open / close spring that biases the valve shaft 55a upward. A diaphragm 55c that constitutes the second liquid chamber 52 between 55b and the partition wall 53; an on-off valve 55d that is attached to the lower end of the valve shaft 55a and that can contact the partition wall 53 around the opening 54; It has.

  Therefore, the opening / closing valve 55d of the pressure adjusting valve 55 is urged toward the partition wall 53 by the opening / closing spring 55b. In a normal state, as shown in FIG. The part 54 is closed. Further, the urging force of the opening / closing spring 55b is the ink pressure in the second liquid chamber 52 at the normal time, that is, in the ink liquid chamber 22 (see FIG. 2) of the line head 20 at the standby time when ink is not discharged. The ink pressure is set to be balanced with the ink pressure. Furthermore, an elastic diaphragm 55c is attached to the valve shaft 55a urged upward by the open / close spring 55b, and the diaphragm 55c undulates in response to fluctuations in the ink pressure in the second liquid chamber 52. It is like that.

  Here, when ink is ejected from the line head 20 (see FIG. 2), the ink pressure in the ink liquid chamber 22 decreases, and accordingly, the ink liquid chamber 22 and the tube 73 communicate with each other. The ink pressure in the second liquid chamber 52 of the sub tank 50 also decreases. Then, due to the pressure drop in the second liquid chamber 52, the diaphragm 55c constituting the partition wall of the second liquid chamber 52 is recessed downward as shown in FIG.

  When the diaphragm 55c is recessed downward, the on-off valve 55d is opened. That is, the diaphragm 55c is attached to the valve shaft 55a biased by the opening / closing spring 55b. Since the urging force of the open / close spring 55b is in equilibrium with the ink pressure in the second liquid chamber 52 at the normal time shown in FIG. 4, if the ink pressure in the second liquid chamber 52 decreases, the diaphragm 55c The opening and closing spring 55b is pushed in while being recessed downward. Then, the valve shaft 55a descends and pushes down the on-off valve 55d attached to the lower end, so that the on-off valve 55d is separated from the partition wall 53 and opened. As will be described later, the on-off valve 55d can be forcibly opened by applying an external force to the top of the valve shaft 55a to push in the valve shaft 55a.

  When the on-off valve 55d is opened, the opening 54 of the partition wall 53 is exposed. At this time, since the ink pressure in the second liquid chamber 52 is low, the ink in the first liquid chamber 51 flows into the second liquid chamber 52 through the opening 54. When ink flows in until the ink pressure in the second liquid chamber 52 becomes the original pressure, the urging force of the opening / closing spring 55b pushes the valve shaft 55a, the diaphragm 55c, and the opening / closing valve 55d upward, and FIG. As shown, the opening / closing valve 55d comes into contact with the partition wall 53 around the opening 54 again to close the opening / closing valve 55d, and the opening 54 is closed.

  As described above, in the sub tank 50 in the ink jet printer 10 of this embodiment, the opening / closing valve 55d is automatically operated by the pressure adjusting valve 55 shown in FIGS. 4 and 5, and the opening 54 is opened and closed. Therefore, it is possible to cause ink to flow from the first liquid chamber 51 to the second liquid chamber 52 or to dam it as necessary.

  Further, in the case of maintenance of the ink jet printer 10 or the initial filling of the ink to the line head 20, it is necessary to supply a large amount of ink to the line head 20. In addition, the air communication port 56 must be forcibly closed by the air communication valve 56.

  This point will be described in detail. For example, in order to remove bubbles and foreign matters existing in the line head 20, it is necessary to eject ink from the nozzles 28 at a pressure higher than that during normal printing. Therefore, during such maintenance, more ink than usual must be supplied to the line head 20. In particular, as in the inkjet printer 10 of the present embodiment, a line head type in which a large number of nozzles 28 are arranged in the width direction of the recording paper requires more than three times the amount of ink as usual. Moreover, maintenance needs to be performed periodically or arbitrarily.

Therefore, during maintenance or the like, the opening 54 must be forcibly opened by the pressure adjustment valve 55 so that a large amount of ink can smoothly flow and pass through the sub tank 50. Further, the atmosphere communication port 51b must be forcibly closed by the atmosphere communication valve 56 so that the ink supply pressure by the supply pump 40 is maintained up to the line head 20.
Therefore, forcible opening / closing of the pressure adjusting valve 55 and the atmospheric communication valve 56 by the valve driving mechanism 80 of the present invention will be described in detail.

FIG. 6 is a perspective view showing the valve drive mechanism 80 attached to the sub tank 50 shown in FIG.
As shown in FIG. 6, the valve drive mechanism 80 includes a camshaft 81, a gear 82, a drive motor 83, and a lever case 84. 6 shows the top of the valve shaft 55a of the pressure adjusting valve 55 (see FIG. 3), and the open / close lever 57 and the holder 58 correspond to the atmospheric communication valve 56 shown in FIG. ing.

  Further, the sub tank 50 corresponds to a sub tank 50a corresponding to yellow (Y) ink, a sub tank 50b corresponding to magenta (M) ink, a sub tank 50c corresponding to cyan (C) ink, and black (K) ink. Corresponding sub tanks 50d are aligned in a horizontal line and are integrated as a unit.

  Therefore, each of the sub tanks 50a to 50d has the first liquid chamber 51 and the second liquid chamber 52 shown in FIG. 3, and a plurality of the first liquid chambers 51 and the second liquid chambers 52 are arranged in parallel. ing. In addition, respective atmospheric communication valves 56 (open / close levers 57 in FIG. 6) for opening and closing the respective atmospheric communication ports 51b of the respective first liquid chambers 52 are arranged in line with each other. Each pressure regulating valve 55 that opens and closes each opening 54 between the second liquid chamber 52 is also arranged in a line.

  Then, as shown in FIG. 6, four flexible tubes 72 are connected to the atmospheric communication ports 51b (see FIG. 3) of the sub tanks 50a to 50d, and the tubes 72 are arranged in one row. The holder 58 is held in an aligned state. In addition, the four valve shafts 55a of each pressure regulating valve 55 (see FIG. 3) are aligned and protruded from one of the sub tanks 50a to 50d.

  Each valve shaft 55a of such a sub tank 50 can be mechanically pushed down by a camshaft 81 disposed on the upper part thereof. That is, four push cams 81a are formed on the camshaft 81, and each push cam 81a is aligned in a row corresponding to the four valve shafts 55a. Therefore, if the camshaft 81 is rotated, an external force acts on the top of each valve shaft 55a by each push cam 81a, and each valve shaft 55a moves up and down.

  Here, the camshaft 81 is connected to the drive motor 83 via a gear 82 disposed on the side of the sub tank 50. Further, the rotational position of each pressing cam 81 a of the camshaft 81 is detected by a position detection sensor (not shown) installed at the end of the camshaft 81. Therefore, if the drive motor 83 is driven by a signal from a control unit (not shown), the camshaft 81 rotates, and each push-down cam 81a can be stopped at a predetermined position.

  On the other hand, each tube 72 of the sub tank 50 can be mechanically closed by an open / close lever 57 and a holder 58 corresponding to the atmosphere communication valve 56 (see FIG. 3). That is, the upper part of the open / close lever 57 is in contact with the top surface of the lever case 84, and the lower part of the open / close lever 57 is in contact with the surface of the tubes 72 held in the holder 58 and aligned in a row. When the lever case 84 is lowered, each tube 72 is crushed via the opening / closing lever 57.

  Here, the camshaft 81 is formed with a lowering cam 81 b described later, and the lowering cam 81 b is disposed in the lever case 84. Therefore, if the cam shaft 81 is rotated by the drive motor 83, the lever case 84 moves up and down via the descending cam 81b, and the open / close lever 57 is operated accordingly. The lever case 84 stops at a predetermined position when the position of the descending cam 81b is detected by a position detection sensor (not shown).

As described above, the valve drive mechanism 80 shown in FIG. 6 includes the camshaft 81 for operating the opening / closing lever 57 (atmospheric communication valve 56 shown in FIG. 3) and the valve shaft 55a (pressure adjusting valve 55 shown in FIG. 3). And a drive motor 83 for rotating the camshaft 81. Therefore, the opening / closing lever 57 (atmospheric communication valve 56 shown in FIG. 3) and the valve shaft 55a (pressure adjusting valve 55 shown in FIG. 3) are mechanically linked by a common valve drive mechanism 80.
Next, the atmosphere communication valve 56 will be described in detail.

FIG. 7 is a perspective view showing an opening / closing lever 57 and a holder 58 corresponding to the atmosphere communication valve 56 shown in FIG.
The four tubes 72 are collected on the holder 58 shown in FIG. The open / close lever 57 is provided corresponding to the four tubes 72, and four lever portions 57a that respectively contact the top surface of the lever case 84 (see FIG. 6) and the lever portions 57a are deformed downward. Four elastically deformable portions 57b, four protrusions 57c for pressing the surface of each tube 72 and locally crushing, and individually closing each tube 72, and a holder 58 are rotatably supported. The shaft portion 57d is integrally formed with a comb tooth shape.

  And each lever part 57a, each elastic deformation part 57b, and each projection part 57c are provided for every four tubes 72, and each is aligned so that it may become substantially parallel to the corresponding tubes 72. Yes. Therefore, the shaft portion 57d on one end side rotating with respect to the holder 58 serves as a common fulcrum, and the lever portions 57a on the other end side on which the lever case 84 (see FIG. 6) abuts serves as a lever point. Each protrusion 57c that presses the tube 72 is a lever action point.

8A and 8B are a front view and a cross-sectional view showing an open / close state of the tube 72 by the open / close lever 57 shown in FIG. 7, and FIG. 8A shows a normal state (open state), and FIG. Indicates a state during operation (blocking state).
As shown in FIG. 8, the four tubes 72 are held by the holder 58 in a state of being aligned in a row. The open / close lever 57 has four lever portions 57 a in contact with the top surface 84 a of the lever case 84, and four protrusions 57 c in contact with the surface of each tube 72.

  A descending cam 81b of the camshaft 81 is disposed in the window 84b of the lever case 84. Therefore, when the camshaft 81 is rotated in the normal state shown in FIG. 8A, the window 84b is pushed down following the shape of the descending cam 81b as shown in FIG. 8B. Then, the lever case 84 is displaced downward, and each lever portion 57a (power point) of the open / close lever 57 that is in contact with the top surface 84a swings about the shaft portion 57d (fulcrum), and each projection portion 57c ( The action point) crushes each tube 72. As a result, each tube 72 is closed, and communication between the interior of the sub tank 50a to the sub tank 50d (see FIG. 6) and the atmosphere is blocked.

  As described above, the lever principle is used for the open / close lever 57, and the projections 57c can be surely crushed even if the force applied to the levers 57a (power points) is small. (Leverage point) and lever ratio are set. Further, since the open / close lever 57 has a comb-teeth shape, even if the lever portions 57a are not pushed down evenly due to the hardness of the tubes 72 or the backlash of the lever case 84, the amount of movement of the lever portions 57a varies. Does not affect the adjacent tube 72. Furthermore, each elastic deformation portion 57b (see FIG. 7) absorbs stress in the operation direction (vertical direction) of each lever portion 57a, prevents fatigue breakage, and varies the hardness of each tube 72 and the lever case. 84 looseness and the like are absorbed.

  Therefore, even if all the lever portions 57a are pushed down simultaneously by one lever case 84, it becomes possible to apply a pressing force to each tube 72 independently, and the difference in hardness of each tube 72 and the lever case Even if there is 84 backlash or the like, the tube 72 does not vary in the degree of crushing, and the operation reliability can be improved.

  When a large amount of ink is supplied to the line head 20 (see FIG. 2) during maintenance or initial ink filling, the inside of the sub tank 50a to the sub tank 50d (see FIG. 6) and the atmosphere are simply shut off. In addition, it is necessary to open the pressure adjustment valves 55 (see FIG. 3) of the sub tanks 50a to 50d. However, in the ink jet printer 10 of the present embodiment, the open / close lever 57 (atmospheric communication valve 56 shown in FIG. 3) and The valve shaft 55a (pressure adjusting valve 55 shown in FIG. 3) is mechanically interlocked by a common valve drive mechanism 80 (see FIG. 6).

  That is, as shown in FIG. 6, the camshaft 81 of the valve drive mechanism 80 is provided with an opening / closing lever 57 (aside from the push-down cam 81a for operating the valve shaft 55a (the pressure adjusting valve 55 shown in FIG. 3)). A lowering cam 81b for operating the atmospheric communication valve 56) shown in FIG. 3 is formed. Therefore, when the camshaft 81 is rotated by one drive motor 83, the valve shaft 55a is operated to open the pressure adjusting valve 55 (see FIG. 3), and at the same time, the open / close lever 57 is operated to crush the tube 72. The inside of the sub tank 50a to the sub tank 50d is shut off from the atmosphere.

  Accordingly, in the inkjet printer 10 of the present embodiment, it is not necessary to provide each of the pressure adjustment valves 55 and the atmospheric communication valves 56 of the sub tanks 50a to 50d with a drive motor and a solenoid, and both of them are used with a minimum number of drive sources. Can be operated simultaneously. In particular, even when the ink color is added and the sub tank 50 is added, it is possible to cope with the same configuration, and it can be made small and inexpensive.

  Further, in the inkjet printer 10 of the present embodiment, the combination of the open / close state of the pressure adjustment valve 55 and the open / close state of the atmospheric communication valve 56 depends on the cam profile of the pressing cam 81a and the descending cam 81b of the camshaft 81. A plurality of types are prepared, and when the camshaft 81 rotates once in one direction, a combination of opening and closing the two is obtained in a predetermined order. The order is determined so that the open / close state of the pressure adjustment valve 55 and the open / close state of the air communication valve 56 are in a predetermined combination according to the type of the discharge recovery operation of the line head 20. In synchronism with the progress of the discharge recovery operation, the opening / closing combination suitable for the discharge recovery operation for optimal ink supply can be obtained in order by simply rotating the camshaft 81 once in one direction. ing.

  Here, the ejection recovery operation is executed when the inkjet printer 10 shifts from a normal state (during printing or standby) to a maintenance state. That is, maintenance is appropriately performed before and after the start of printing, and the supply pump 40 and the suction pump 60 are driven to cause ink to flow. Then, bubbles and foreign matters inside the line head 20 are removed from the ink liquid chamber 22 and the ink flow path 24.

  In the inkjet printer 10 of the present embodiment, such a discharge recovery operation is configured by a head pressurization process, a head suction process, and the like. In the head pressurization process, the pressure adjustment valve 55 is opened and the air communication valve 56 is opened. In this state, the pressure of the ink in the line head 20 is increased and the ink is pushed out from the nozzles 28 by operating only the supply pump 40. On the other hand, in the head suction process, the pressure adjustment valve 55 is opened and the air communication valve 56 is also opened. In this state, only the suction pump 60 is operated, whereby the ink pushed onto the surface of the nozzle sheet 27 is ejected from the nozzle 28. Suck back from.

FIG. 9 is a table showing the discharge recovery operation of the line head 20 in the inkjet printer 10 of the present embodiment.
FIG. 10 is a perspective view showing a state in the line head 20 corresponding to the discharge recovery operation shown in FIG.
As shown in FIG. 9, the discharge recovery operation is divided into a plurality of operation steps. And by performing each operation | movement process in predetermined order, as shown in FIG. 10, the bubble etc. in the line head 20 are removed.

The first stage (sequence No. 1) of the ejection recovery operation shown in FIG. 9 is an ink supply process.
In the ink replenishment step, the rotation angle of the camshaft 81 is set to 0 ° or 360 °, whereby the pressure adjustment valve 55 is closed and the atmosphere communication valve 56 is opened (valve mode A). In this state, only the supply pump 40 is driven (the supply pump 40 is turned on and the suction pump 60 is turned off), and the ink is supplied from the ink cartridge 30 to the sub tank 50.

  If the ink is replenished until the sub tank 50 becomes full in such an ink replenishment process, the next stage (sequence No. 2) is a head pressurization process. That is, as shown in FIG. 10A, fine bubbles may be mixed in the ink liquid chamber 22 and the ink flow path 24 in the line head 20, and the ink is discharged from the nozzles 28 as it is. Therefore, discharge recovery operation (removal of bubbles) is performed.

  In the head pressurizing step, the camshaft 81 is rotated by 90 ° in one direction and the rotation angle is set to 270 °, whereby the pressure adjusting valve 55 is opened and the atmospheric communication valve 56 is closed (valve mode B). To be. In this valve mode B, even if the pressure adjustment valve 55 is opened, the atmosphere communication valve 56 is closed at the same time, so that ink does not naturally leak from the nozzle 28. In this state, pressurization is performed by driving only the supply pump 40 (turning on the supply pump 40 and turning off the suction pump 60).

  When pressure is applied by the supply pump 40 in the valve mode B, the pressure of the ink in the line head 20 increases, and the old ink (ink containing bubbles) filled in the vicinity of the nozzles 28 is pushed out. This old ink is eventually pushed out of the nozzle 28 and overflows the surface of the nozzle sheet 27 as shown in FIG. 10 (b). However, the valve mode B (the pressure adjustment valve 55 is opened and the air communication valve is opened). 56 is closed), there is no natural leakage of ink from the nozzles 28, so that the supply pump 40 can be accurately driven and controlled (pressurized) to the extent that ink does not drip. When the fine bubbles in the ink liquid chamber 22 are discharged to the surface of the nozzle sheet 27 together with the overflowed ink, the bubbles are exposed to the outside air and disappear. Therefore, air bubbles in the ink liquid chamber 22 can be removed by this head pressurizing step.

  After executing such a head pressurizing process for a predetermined time, the process proceeds to the head suction process in the next stage (sequence No. 3). That is, as shown in FIG. 10C, since air bubbles that could not be removed in the head pressurization process remain in the ink flow path 24 of the line head 20, the head pressurization is performed to remove the air bubbles. A head suction process is performed after the process.

  In the head suction process, the camshaft 81 is further rotated by 90 ° in the same direction as the head pressurization process, the rotation angle is 180 °, thereby opening the pressure adjustment valve 55 and opening the air communication valve 56 (Valve mode C). In this valve mode C, the atmosphere in the sub-tank 50 is returned to atmospheric pressure by opening the atmosphere communication valve 56, whereby the head pressurization process can be instantaneously switched to the head suction process. In this state, only the suction pump 60 is driven (the supply pump 40 is turned off and the suction pump 60 is turned on), and the ink overflowing on the surface of the nozzle sheet 27 is sucked back from the nozzles 28.

  When suction by the suction pump 60 is performed in the valve mode C, bubbles remaining in the ink flow path 24 of the line head 20 are removed. That is, in the head suction process, as shown in FIG. 10C, the bubbles are sucked while shaking the bubbles by creating the ink flow opposite to the ejection, and the bubbles in the ink flow path 24 are removed. In the valve mode C (the pressure adjustment valve 55 is opened and the atmosphere communication valve 56 is also opened), the inside of the sub tank 50 is returned to atmospheric pressure, so that the drive control (suction) of the suction pump 60 is facilitated, and the meniscus is applied to the nozzle 28. So that the pressure of the ink in the line head 20 can be accurately managed.

After the bubbles in the ink flow path 24 are also removed by such a head suction process, the process proceeds to the standby process in the final stage (sequence No. 4).
In the standby step, the camshaft 81 is further rotated 180 ° in the same direction as the head pressurization step and the head suction step (total 360 °), the rotation angle is 0 °, and the valve mode A (the pressure adjustment valve 55 is closed, The air communication valve 56 is returned to the open state. Then, neither the supply pump 40 nor the suction pump 60 is driven (the supply pump 40 is turned off and the suction pump 60 is also turned off). Therefore, as shown in FIGS. 4 and 5, the pressure adjusting valve 55 automatically activates the opening / closing valve 55d, and the ink pressure in the line head 20 is kept substantially constant. That is, it is possible to stand by in a state where high quality printing is possible.

  As described above, the ink jet printer 10 according to the present embodiment is an extremely simple operation in which the camshaft 81 is rotated once by a predetermined angle, and the pressure adjustment valve 55 and the atmosphere communication valve 56 are in a predetermined order (optimum ink). Are opened and closed in an order according to the progress of the discharge recovery operation for supplying the water. That is, since the opening and closing of the pressure adjustment valve 55 and the atmosphere communication valve 56 follows a set cam profile, there is no variation in response speed that is a concern when opening and closing with a plurality of electromagnetic valves or motors. In addition, the time required for switching between opening and closing of the pressure adjustment valve 55 and the atmosphere communication valve 56 is shortened, and temporary internal pressure fluctuations of the line head 20 during the discharge recovery operation due to the rapid switching can be eliminated.

  Accordingly, it is possible to accurately control and manage the discharge recovery operation of the inkjet printer 10, and the line head 20 is optimally cleaned (the state where bubbles and the like are removed) by the accurate discharge recovery operation. In particular, this is particularly effective for the line head 20 that consumes a large amount of ink. Moreover, an inexpensive and compact configuration can be achieved.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to embodiment mentioned above, For example, the following various deformation | transformation is possible.
(1) In this embodiment, the pressure adjustment valve 55 and the atmospheric communication valve 56 are operated by the camshaft 81. However, the pressure adjustment valve 55 and the atmospheric communication valve 56 are mechanically linked by a common valve drive mechanism. For example, the camshaft 81 is not limited.

  (2) In the present embodiment, the line head type ink jet printer 10 including the line head 20 corresponding to the print width is taken as an example of the liquid ejecting apparatus. However, the liquid ejecting apparatus is not limited to the line head type and moves in the width direction of the recording paper. Alternatively, a serial head method for performing printing may be used. Further, the present invention can be widely applied to other liquid ejecting apparatuses that eject various liquids, and may be, for example, a liquid ejecting apparatus that ejects dye to a dyed product.

1 is a conceptual diagram showing a line head type ink jet printer of an embodiment. FIG. It is the perspective view and sectional drawing which show partially the line head in the inkjet printer of this embodiment. It is sectional drawing which shows the sub tank in the inkjet printer of this embodiment. It is sectional drawing which shows the state at the time of the normal time of the pressure regulation valve in the subtank shown in FIG. It is sectional drawing which shows the state at the time of the operation | movement of the pressure control valve in the subtank shown in FIG. It is a perspective view which shows the valve drive mechanism attached to the sub tank shown in FIG. FIG. 4 is a perspective view showing an opening / closing lever and a holder corresponding to the atmosphere communication valve shown in FIG. 3. It is the front view and sectional drawing which show the opening-and-closing state of the tube by the opening-and-closing lever shown in FIG. It is a table | surface which shows the discharge recovery operation | movement of the line head in the inkjet printer of this embodiment. FIG. 10 is a perspective view showing a state in the line head corresponding to the discharge recovery operation shown in FIG. 9.

Explanation of symbols

10 Inkjet printer (liquid ejection device)
20 line head (liquid discharge head)
40 Supply pump 50, 50a, 50b, 50c, 50d Sub tank (liquid supply means)
51 First liquid chamber 51b Atmospheric communication port 52 Second liquid chamber 52a Discharge port 53 Partition wall 54 Opening portion 55 Pressure adjusting valve 55a Valve shaft 55b Opening spring 55c Diaphragm 55d Opening / closing valve 56 Atmospheric communication valve 57 Opening / closing lever (atmospheric communication valve)
58 Holder (Atmospheric communication valve)
60 Suction pump 80 Valve drive mechanism 81 Camshaft 82 Gear 83 Drive motor 84 Lever case

Claims (5)

A liquid ejection head for ejecting liquid from a nozzle to form an image;
A liquid discharge apparatus comprising: a liquid supply unit capable of storing liquid to be discharged and capable of supplying liquid to the liquid discharge head;
The liquid supply means includes
A first liquid chamber capable of storing a liquid therein and having an atmosphere communication port for communicating the inside and the atmosphere;
An atmospheric communication valve for opening and closing the atmospheric communication port;
A second liquid chamber having a discharge port for supplying the liquid stored therein to the liquid discharge head;
A partition wall that partitions between the first liquid chamber and the second liquid chamber;
An opening formed on the partition wall for allowing the liquid stored in the first liquid chamber to flow out toward the second liquid chamber;
A pressure adjusting valve for opening and closing the opening,
The pressure regulating valve and the atmosphere communication valve are mechanically linked by a common valve driving mechanism,
The pressure regulating valve is closed and the atmosphere communication valve is opened.
A state where the pressure regulating valve is opened and the atmospheric communication valve is closed;
The liquid ejecting apparatus according to claim 1, wherein the pressure adjusting valve is opened and the atmospheric communication valve is opened in order. The liquid ejection apparatus according to claim 1,
The valve drive mechanism is
A camshaft for operating the pressure regulating valve and the atmosphere communication valve;
A liquid ejection apparatus comprising: a drive motor for rotating the camshaft. The liquid ejection apparatus according to claim 1,
A supply pump for supplying liquid to the liquid discharge head;
A suction pump for sucking the liquid supplied to the liquid discharge head, and when the pressure adjustment valve is opened and the atmospheric communication valve is closed, only the supply pump operates,
The liquid ejecting apparatus according to claim 1, wherein only the suction pump operates when the pressure adjusting valve is opened and the atmospheric communication valve is opened. A first liquid chamber capable of storing a liquid therein and having an atmosphere communication port for communicating the inside and the atmosphere;
An atmospheric communication valve for opening and closing the atmospheric communication port;
A second liquid chamber having a discharge port for supplying the liquid stored therein to the liquid discharge head;
A partition wall that partitions between the first liquid chamber and the second liquid chamber;
An opening formed on the partition wall for allowing the liquid stored in the first liquid chamber to flow out toward the second liquid chamber;
A liquid supply means comprising: a pressure adjusting valve that opens and closes the opening;
A method of controlling a liquid ejection apparatus that supplies liquid stored in the liquid supply unit to a liquid ejection head and ejects the liquid from a nozzle of the liquid ejection head to form an image.
The pressure adjusting valve and the atmosphere communication valve that are mechanically linked by a common valve drive mechanism,
The pressure regulating valve is closed and the atmosphere communication valve is opened.
A state where the pressure regulating valve is opened and the atmospheric communication valve is closed;
A control method for a liquid discharge apparatus, wherein the pressure adjusting valve is opened and the atmospheric communication valve is opened in order. In the control method of the liquid ejection device according to claim 4,
In a state where the pressure adjusting valve is opened and the atmospheric communication valve is closed, only a supply pump for supplying liquid to the liquid discharge head is operated,
A control method for a liquid ejection device, wherein, when the pressure adjustment valve is opened and the atmosphere communication valve is opened, only a suction pump for sucking the liquid supplied to the liquid ejection head is operated. .

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