Liquid ejection device

Abstract

To control opening / closing of an electrically driven valve in consideration of a relation between the valve and other electrically driven devices.SOLUTION: A control part executes: valve opening / closing processing (S6) of switching a solenoid valve from a cut-off state to a communication state, and then returning the solenoid valve to the cut-off state; and opening / closing propriety determination processing (S3) of determining propriety of execution of the valve opening / closing processing. The control part determines that the valve opening / closing processing can be executed when ink is not discharged from nozzles, and determines that the valve opening / closing processing cannot be executed when the ink is discharged from the nozzles, in the opening / closing propriety determination processing. The control part permits the valve opening / closing processing when it is determined by the opening / closing propriety determination processing that the valve opening / closing processing can be executed (S3:YES), and does not permit the valve opening / closing processing when it is determined that the valve opening / closing processing cannot be executed (S3:NO).SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a liquid ejection device having an electrically driven valve that can selectively adopt either a communication state in which an air communication passage for communicating a liquid storage chamber communicating with a liquid ejection head with the outside is communicated, or a blocking state in which the air communication passage is blocked.

Background Art

[0002] Patent Document 1 discloses a printer (liquid ejection device) that ejects ink supplied from an ink cartridge (liquid storage unit) mounted on a carriage to perform printing. The ink cartridge mounted on such a printer has an ink storage unit (liquid storage chamber) for storing ink, an ink supply unit for supplying the ink stored in the storage unit to a print head unit of the printer, an air chamber into which external air is introduced, and an atmosphere valve for introducing the air in the air chamber into the ink storage unit.

[0003] The atmosphere valve becomes an open valve state when the ink in the ink storage unit is supplied to the printer and the pressure difference between the air chamber and the ink storage unit increases. Then, when air is introduced into the ink storage unit and the pressure difference between the air chamber and the ink storage unit decreases, it returns to the closed valve state. As a result, the pressure in the ink storage unit is maintained within an appropriate pressure range, so that poor ink supply due to an excessive increase in the negative pressure in the ink storage unit is suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, when an air valve that opens and closes according to the pressure difference between the air chamber and the ink storage section is employed as a means for adjusting the negative pressure in the ink storage chamber, the valve cannot be opened and closed at an arbitrary timing that has nothing to do with the pressure difference between the air chamber and the ink storage section. Therefore, it is conceivable to employ a valve that is driven electrically instead of the air valve. When a valve that is driven electrically is employed, it is necessary to control the driving of the valve in consideration of its relationship with other devices that are driven electrically.

[0006] Therefore, an object of the present invention is to provide a liquid ejection device capable of controlling the opening and closing of a valve that is driven electrically while considering its relationship with other devices that are driven electrically.

Means for Solving the Problems

[0007] The liquid ejection device according to the first invention includes a liquid ejection head having a nozzle for ejecting a liquid, a liquid storage chamber for storing the liquid, an air communication passage for communicating the liquid storage chamber with the outside, and a liquid storage section having an electrically driven valve capable of selectively taking either a communicating state in which the air communication passage is communicated or a blocking state in which the air communication passage is blocked, a liquid flow path that connects the liquid ejection head and the liquid storage chamber so that the liquid can flow therethrough, and a control unit. The control unit executes a valve opening / closing process of switching the valve from the blocking state to the communicating state and then returning it to the blocking state, and an opening / closing permission determination process of determining whether the valve opening / closing process can be executed. In the opening / closing permission determination process, it is determined that the valve opening / closing process can be executed when the liquid is not being ejected from the nozzle, and it is determined that the valve opening / closing process cannot be executed when the liquid is being ejected from the nozzle. When it is determined by the opening / closing permission determination process that the valve opening / closing process can be executed, the valve opening / closing process is permitted, and when it is determined that the valve opening / closing process cannot be executed, the valve opening / closing process is not permitted.

[0008] The liquid ejection device according to the second invention includes a liquid ejection head having a nozzle for ejecting a liquid, a liquid storage chamber for storing the liquid, an air communication passage for communicating the liquid storage chamber with the outside, and a liquid storage unit having an electrically driven valve that can selectively take either a communicating state in which the air communication passage is communicated or a blocking state in which the air communication passage is blocked, a liquid flow path that connects the liquid ejection head and the liquid storage chamber so that the liquid can flow, a motor, and a control unit. The control unit performs a valve opening / closing process of returning the valve from the blocking state to the communicating state and then back to the blocking state, a driving state determination process of determining whether the motor is in a first state or a second state in which the driving load is greater than that in the first state, and in the driving state determination process, when it is determined that the motor is in the first state, it is determined that the valve opening / closing process can be executed, and when it is determined that the motor is in the second state, it is determined that the valve opening / closing process cannot be executed. The control unit executes an opening / closing permission determination process of permitting the valve opening / closing process when it is determined in the opening / closing permission determination process that the valve opening / closing process can be executed, and not permitting the valve opening / closing process when it is determined that the valve opening / closing process cannot be executed.

Advantages of the Invention

[0009] If the valve opening / closing process is executed while the liquid is being ejected from the nozzle, the supply power to the liquid ejection head may be insufficient due to voltage fluctuations caused by the valve opening / closing process, which may affect the ejection of the liquid from the nozzle. According to the liquid ejection device according to the first invention, since the valve opening / closing process is not executed when the liquid is being ejected from the nozzle of the liquid ejection head, it is possible to avoid affecting the ejection of the liquid from the nozzle. Therefore, it is possible to control the opening and closing of the valve while considering the relationship with the liquid ejection head.

[0010] When the valve opening / closing process is executed during the driving of the motor, the driving load of the valve is added to the driving load of the motor, and there is a risk that the load exceeds the usage limit of the device. According to the liquid ejection device according to the second invention, when the driving load of the motor is relatively large, the valve opening / closing process is not executed, so that an excessive load can be avoided. Therefore, the opening and closing of the valve can be controlled while considering the relationship with the motor.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0012] (First Embodiment) Hereinafter, the printer 1 according to the first embodiment of the present invention will be described. The printer 1 is installed and used in the state shown in FIG. 1. In the present embodiment, the three directions indicated by the arrows in FIG. 1 are the vertical direction A1, the front-rear direction A2, and the left-right direction A3. FIGS. 2 to 6 also show the three directions shown in FIG. 1.

[0013] <Overview of Printer 1> As shown in FIG. 1, Printer 1 has a housing 11 generally in the shape of a rectangular parallelepiped. An opening 12 is formed substantially at the center of the front wall 11a of the housing 11. A paper feed tray 15 and a paper discharge tray 16 are provided in two upper and lower stages in the opening 12. The paper feed tray 15 is configured to be insertable and removable in the front-rear direction A2 from the opening 12, that is, detachable from the housing 11. Paper P of a desired size (for example, A4 size) is placed on the paper feed tray 15. Printer 1 can be connected to an external device such as a personal computer (hereinafter referred to as a PC). Then, a recording operation is executed based on recording data from a PC or the like.

[0014] As shown in FIG. 1, an operation unit 13 is provided at the upper part of the front wall 11a. The operation unit 13 is composed of buttons operated for various settings, a liquid crystal display on which various information is displayed, and the like. In the present embodiment, the operation unit 13 is composed of a touch panel having the functions of both a button and a liquid crystal display.

[0015] As shown in FIGS. 1 and 2, the housing 11 has an opening / closing cover 14 that constitutes the ceiling portion thereof. The opening / closing cover 14 is configured to be rotatable about a rotation axis (not shown) along the left-right direction A3 at the rear end portion. By opening the opening / closing cover 14, an ink tank 61 (described later) disposed in the housing 11 is exposed, and it becomes possible to inject and replenish ink into the ink tank 61.

[0016] <Internal Structure of Printer 1> Next, the internal structure of Printer 1 will be described. As shown in FIG. 2, Printer 1 includes a feeding unit 20, a pair of conveyance rollers 35, a recording unit 40, a pair of paper discharge rollers 36, an ASF (Auto Sheet Feed) motor 20M (see FIG. 6), a PF (Paper Feed) motor 30M (see FIG. 6), a CR (carriage) motor 70M (see FIG. 6), and a control unit 5 (see FIG. 6).

[0017] As shown in Fig. 2, the paper feeding unit 20 feeds the paper P placed on the paper feed tray 15 to the conveyance path 25. The pair of conveyance rollers 35 conveys the paper P fed by the paper feeding unit 20 to the recording unit 40. The recording unit 40 has, for example, an inkjet recording system configuration, and records an image on the paper P conveyed by the pair of conveyance rollers 35. The pair of discharge rollers 36 discharges the paper P recorded by the recording unit 40 to the discharge tray 16.

[0018] <Paper feeding unit 20> As shown in Fig. 2, the paper feeding unit 20 is provided above the paper feed tray 15. The paper feeding unit 20 has a paper feed roller 21 and an arm 22. The paper feed roller 21 is pivotally supported at the tip of the arm 22. The arm 22 is rotatably supported by a support shaft 22a. The arm 22 is biased by a spring or the like in the direction in which the paper feed roller 21 contacts the paper feed tray 15 (in the direction of rotating downward). Further, the arm 22 is configured to be retractable upward when attaching and detaching the paper feed tray 15. The power of the ASF motor 20M is transmitted to the paper feed roller 21 via a transmission mechanism (not shown), causing the paper feed roller 21 to rotate. Thereby, the paper P stacked in the paper feed tray 15 is fed to the conveyance path 25.

[0019] <Paper feed tray 15> As shown in Fig. 2, the paper feed tray 15 has an inclined wall portion 15a. The inclined wall portion 15a guides the paper P placed on the paper feed tray 15 to the conveyance path 25 when the paper P is fed by the paper feed roller 21.

[0020] <Conveyance path 25> The conveyance path 25 is formed inside the housing 11, and as shown in Fig. 2, it bends upward from the rear end of the paper feed tray 15 and then to the front side of the printer 1. The paper P fed from the paper feed tray 15 is guided by the conveyance path 25 to make a U-turn from below to above and reaches the recording unit 40.

[0021] <Pair of conveyance rollers 35 and pair of discharge rollers 36> The conveying roller pair 35 has a conveying roller 35a arranged on the lower side and a pinch roller 35b arranged on the upper side. The conveying roller 35a is rotated by the power of the PF motor 30M transmitted through a transmission mechanism (not shown). The pinch roller 35b rotates along with the rotation of the conveying roller 35a. The conveying roller 35a and the pinch roller 35b rotate while sandwiching the sheet P from the vertical direction A1, and convey the sheet P to the recording unit 40.

[0022] The paper discharge roller pair 36 has a paper discharge roller 36a arranged on the lower side and a boosting roller 36b arranged on the upper side. The paper discharge roller 36a is rotated by the power of the PF motor 30M transmitted through a transmission mechanism (not shown). The boosting roller 36b rotates along with the rotation of the paper discharge roller 36a. The paper discharge roller 36a and the boosting roller 36b rotate while sandwiching the sheet P from the vertical direction A1, and convey the sheet P to the paper discharge tray 16.

[0023] <Recording unit 40> As shown in FIGS. 2 and 3, the recording unit 40 has an inkjet head 41, an ink tank 61, a carriage 70, a moving mechanism 71, and a platen 17. The carriage 70 reciprocates in the scanning direction (the left - right direction A3, which is perpendicular to the conveyance direction of the sheet P). The inkjet head 41 and the ink tank 61 are supported by the carriage 70. That is, the printer 1 in the present embodiment is a so - called on - carriage type in which the ink tank 61 and the inkjet head 41 are mounted on the carriage 70. In the present embodiment, the entire ink tank 61 is located above the inkjet head 41. However, it is not limited to this, and a part of the ink tank 61 may be located above the upper surface of the inkjet head 41 and the remaining part may be located below the upper surface.

[0024] <Ink tank 61> As shown in Fig. 3, the ink tank 61 has a tank body 62, a cap 63, and an electromagnetic valve 64. The tank body 62 has a substantially rectangular parallelepiped shape, and an ink storage chamber 62a for storing ink is formed inside. Black ink is stored in the ink storage chamber 62a.

[0025] As shown in Fig. 3, a through hole 62c penetrating the upper wall 62b of the tank body 62 is formed in the tank body 62. The through hole 62c is located at the center of the upper wall 62b in the left - right direction A3 and is slightly forward. A cylindrical body 66 is fitted into the through hole 62c. The cylindrical body 66 has an ink injection port 67 at its upper end. The ink injection port 67 is an opening that opens upward (i.e., to the outside). The inner peripheral surface of the cylindrical body 66 defines an ink supply path 66a leading from the ink injection port 67 to the ink storage chamber 62a. The ink injection port 67 communicates the ink storage chamber 62a with the outside.

[0026] The cap 63 shown in Fig. 3 is made of, for example, a flexible resin. The cap 63 is detachable from the upper end of the cylindrical body 66 by a user operation and closes or opens the ink injection port 67. The ink injection port 67 is normally closed by the cap 63 and is opened by removing the cap 63 from the cylindrical body 66 when injecting ink into the ink storage chamber 62a.

[0027] As shown in Fig. 3(b), an air communication path 62e that penetrates the rear side wall 62d of the tank body 62 and communicates the ink storage chamber 62a with the outside is formed in the tank body 62. The air communication path 62e is arranged near the upper end of the rear side wall 62d.

[0028] As shown in FIG. 3(b), the electromagnetic valve 64 is a known two-way electromagnetic valve, having a valve portion 64a and a solenoid portion 64b. The electromagnetic valve 64 is fixed to the upper wall 62b. The valve portion 64a is disposed in the ink storage chamber 62a, and has an internal flow path (not shown) that communicates with the atmosphere communication passage 62e and the ink storage chamber 62a, and a valve (not shown) that opens and closes the internal flow path. The solenoid portion 64b is disposed on the upper wall 62b and opens and closes the valve of the valve portion 64a.

[0029] Under the control of the control unit 5, the electromagnetic valve 64 selectively assumes either a blocking state in which the solenoid portion 64b is driven to block the communication between the atmosphere communication passage 62e and the ink storage chamber 62a (i.e., the state where the valve closes the internal passage), or a communicating state in which the atmosphere communication passage 62e and the ink storage chamber 62a are communicated (i.e., the state where the valve opens the internal passage). By setting the electromagnetic valve 64 to the communicating state, the negative pressure in the ink storage chamber 62a can be released.

[0030] As a modification, the valve portion 64a of the electromagnetic valve 64 may be connected to the atmosphere communication passage 62e and the outside in a communicable manner outside the ink tank 61. In this case, it is possible to selectively assume a communicating state in which the atmosphere communication passage 62e communicates with the outside and a blocking state in which communication with the outside is blocked. Also, the entire electromagnetic valve 64 may be disposed in the ink storage chamber 62a. Further, if the internal flow path of the valve portion 64a is connected to the atmosphere communication passage 62e in a communicable manner, the electromagnetic valve 64 may be fixed and installed on at least one of the front, rear, left, and right side walls other than the upper wall 62b of the tank body 62.

[0031] Further, in the tank body 62, an outlet 62h is formed that penetrates the bottom wall 62g and allows the ink in the ink storage chamber 62a to flow out to the ink jet head 41. The outlet 62h is located at the center of the bottom wall 62g in the left-right direction A3 and near the front end portion.

[0032] <Ink jet head 41> The inkjet head 41 is supplied with black ink from the ink tank 61. Further, the inkjet head 41 discharges ink from a plurality of nozzles 42 formed on the nozzle surface 41a (see FIG. 5) which is the lower surface thereof. More specifically, as shown in FIG. 4, the plurality of nozzles 42 form a nozzle row in the front-rear direction A2 along the conveyance direction of the paper P. Black ink is discharged from the plurality of nozzles 42. As shown in FIGS. 4 and 5, the inkjet head 41 has a flow path unit 43 and a piezoelectric actuator 50.

[0033] <Flow path unit 43> As shown in FIG. 5, the flow path unit 43 is formed by laminating four plates 43a to 43d in order from above. As shown in FIGS. 4 and 5, a plurality of nozzles 42 are formed in the plate 43d. A plurality of pressure chambers 45 are formed in the plate 43a. Further, the pressure chambers 45 are provided for each nozzle 42, and the right end portion overlaps the nozzle 42 in the vertical direction A1.

[0034] As shown in FIGS. 4 and 5, circular through holes 46a are formed in the plate 43b at portions overlapping the left end portions of the respective pressure chambers 45 in the vertical direction A1. Also, circular through holes 46b are formed in the plate 43b at portions overlapping the right end portions of the respective pressure chambers 45 and the nozzle 42 in the vertical direction A1.

[0035] As shown in FIGS. 4 and 5, a manifold flow path 47 is formed in the plate 43c. The manifold flow path 47 extends in the front-rear direction A2 (conveyance direction) and overlaps the left side portions of the plurality of pressure chambers 45 in the vertical direction A1. Thereby, each pressure chamber 45 communicates with the manifold flow path 47 through the through hole 46a. Also, as shown in FIG. 4, a supply port 48 is provided at the downstream end portion of the manifold flow path 47 in the conveyance direction. The supply port 48 opens on the upper surface of the flow path unit 43 (that is, the upper surface of the plate 43a).

[0036] As shown in FIG. 3, the inkjet head 41 is connected to the ink tank 61 via a connection member 69. A communication passage 69a (the "liquid flow path" of the present invention) that connects the outlet 62h and the supply port 48 is formed in the connection member 69. Thereby, the ink in the ink storage chamber 62a of the ink tank 61 is supplied to the manifold flow path 47 via the supply port 48.

[0037] Also, as shown in FIGS. 4 and 5, circular through-holes 49 are formed in the plate 43c at portions that overlap the respective through-holes 46b and nozzles 42 in the vertical direction A1. Thereby, each nozzle 42 communicates with the pressure chamber 45 via the through-holes 46b and 49.

[0038] In the flow path unit 43, individual flow paths 44 are formed by the nozzles 42, the pressure chambers 45, the through-holes 46b and 49 that connect the nozzles 42 and the pressure chambers 45, and the through-holes 46a that connect the pressure chambers 45 to the manifold flow path 47. A plurality of individual flow paths 44 are formed corresponding to the plurality of nozzles 42.

[0039] <Piezoelectric actuator 50> As shown in FIG. 5, the piezoelectric actuator 50 has a diaphragm 51, a piezoelectric layer 52, a common electrode 53, and a plurality of individual electrodes 54. The diaphragm 51 is made of a piezoelectric material mainly composed of lead zirconate titanate, is disposed on the upper surface of the flow path unit 43, and covers the plurality of pressure chambers 45. Note that the diaphragm 51 may be made of an insulating material other than the piezoelectric material, unlike the piezoelectric layer 52.

[0040] The piezoelectric layer 52 is made of a piezoelectric material and is disposed on the upper surface of the diaphragm 51. As shown in FIG. 4, the piezoelectric layer 52 extends continuously over the plurality of pressure chambers 45. The common electrode 53 is disposed between the diaphragm 51 and the piezoelectric layer 52 and extends continuously over the plurality of pressure chambers 45. The common electrode 53 is connected to a power source (not shown) and is held at a ground potential.

[0041] As shown in FIG. 4, the plurality of individual electrodes 54 individually correspond to the plurality of pressure chambers 45. The individual electrode 54 has an elliptical planar shape that is slightly smaller than the pressure chamber 45, is disposed on the upper surface of the piezoelectric layer 52, and overlaps the central portion of the pressure chamber 45 in the vertical direction A1. Each of the plurality of individual electrodes 54 is connected to a driver IC (not shown), and either a ground potential or a driving potential (for example, about 20 V) is selectively applied by the driver IC.

[0042] Also, portions sandwiched between the common electrode 53 and each individual electrode 54 of the piezoelectric layer 52 are polarized in the vertical direction A1, respectively. In the piezoelectric actuator 50, portions of the diaphragm 51, the piezoelectric layer 52, and the common electrode 53 that overlap the respective pressure chambers 45 in the vertical direction and portions formed by the individual electrodes 54 each serve as a driving element 55 that applies pressure to the ink in the pressure chamber 45.

[0043] Here, a method of driving the piezoelectric actuator 50 to eject ink from the nozzle 42 will be described. In the piezoelectric actuator 50, all the individual electrodes 54 are previously held at the same ground potential as the common electrode 53. When ejecting ink from a certain nozzle 42, the potential of the individual electrode 54 in the driving element 55 corresponding to that nozzle 42 is switched from the ground potential to the driving potential. Then, due to the potential difference between the individual electrode 54 and the common electrode 53, the portions of the diaphragm 51 and the piezoelectric layer 52 that overlap the pressure chamber 45 in the vertical direction A1 are deformed so as to be convex toward the pressure chamber 45 as a whole. As a result, the volume of the pressure chamber 45 decreases, the pressure of the ink in the pressure chamber 45 increases, and the ink is ejected from the nozzle 42 communicating with the pressure chamber 45.

[0044] <Platen 17> The platen 17 is disposed below the inkjet head 41 and supports the paper P conveyed by the pair of conveyance rollers 35. The platen 17 is disposed in a portion through which the paper P passes within the reciprocating movement range of the carriage 70. Since the width of the platen 17 is sufficiently larger than the maximum width of the paper P that can be conveyed, the paper P conveyed through the conveyance path 25 always passes over the platen 17.

[0045] <Moving mechanism 71> As shown in FIG. 2, the moving mechanism 71 includes a pair of guide rails 72 and a belt transmission mechanism (not shown). The pair of guide rails 72 are arranged at a distance in the front-rear direction A2 and extend parallel to each other in the left-right direction A3. The carriage 70 is arranged so as to straddle the pair of guide rails 72. The carriage 70 is connected to a CR motor 70M (see FIG. 6) via a belt transmission mechanism. When the CR motor 70M is driven, the belt transmission mechanism is driven. As a result, the carriage 70 moves in the scanning direction (left-right direction A3) along the pair of guide rails 72 together with the ink tank 61 and the inkjet head 41.

[0046] The inkjet head 41 ejects ink from the nozzles 42 under the control of the control unit 5 based on the recording data. That is, as the carriage 70 reciprocates in the left-right direction A3, the inkjet head 41 scans the paper P, and by ejecting ink from the nozzles 42, an image is recorded on the paper P conveyed on the platen 17.

[0047] <Control unit 5> As shown in FIG. 6, the control unit 5 has a CPU (Central Processing Unit) 131, an ASIC (Application Specific Integrated Circuit) 135, and a memory 140. The CPU 131, the ASIC 135, and the memory 140 are connected by an internal bus 137. The memory 140 includes a ROM (Read Only Memory) 132, a RAM (Random Access Memory) 133, and an EEPROM (Electrically Erasable Programmable Read-Only Memory) 134. Programs for controlling various operations of the printer 1 and the like are stored in the ROM 132. The CPU 131 executes programs while using the RAM 133 and the EEPROM 134.

[0048] ASIC 135 outputs control signals to the ASF motor 20M, PF motor 30M, CR motor 70M, inkjet head 41, electromagnetic valve 64, etc., and controls their operations.

[0049] For example, based on the recording data transmitted from an external device (e.g., a PC or smartphone), the control unit 5 controls the ASF motor 20M, PF motor 30M, CR motor 70M, inkjet head 41, etc., to record an image on the paper P. The recording of the image is performed by alternately performing a conveyance process of conveying the paper P by a predetermined distance in the conveyance direction and a scanning process of discharging ink from a plurality of nozzles 42 of the inkjet head 41 while moving the carriage 70 in the scanning direction.

[0050] Also, the control unit 5 controls the drive of the electromagnetic valve 64 and executes a valve opening / closing process of switching the electromagnetic valve 64 from a blocked state to a communicating state and then back to the blocked state.

[0051] Furthermore, the control unit 5 executes an opening / closing permission determination process for determining whether the valve opening / closing process can be executed. Then, when the control unit 5 determines that the valve opening / closing process can be executed by the opening / closing permission determination process, it permits the valve opening / closing process, and when it determines that the valve opening / closing process cannot be executed, it does not permit the valve opening / closing process.

[0052] Here, both the inkjet head 41 and the electromagnetic valve 64 are devices driven by electricity. If the valve opening / closing process is executed while ink is being discharged from the nozzles 42, the supply power to the inkjet head 41 will be insufficient due to voltage fluctuations caused by the valve opening / closing process, which may affect the discharge of ink from the nozzles 42 and result in a deterioration of the image quality of the formed image.

[0053] Therefore, in the opening / closing permission determination process, the control unit 5 determines that the valve opening / closing process can be executed when ink is not being discharged from the nozzles 42. Also, when ink is being discharged from the nozzles 42, it determines that the valve opening / closing process cannot be executed.

[0054] When the ink ejection operation and the valve opening / closing operation are executed simultaneously, the magnitude of the influence on ink ejection varies depending on the model of the printer 1. Therefore, whether or not to limit the simultaneous execution of the ink ejection operation and the valve opening / closing operation is determined for each model of the printer 1. That is, in models where the influence on ink ejection when the ink ejection operation and the valve opening / closing operation are executed simultaneously is relatively large, a limit on the simultaneous execution of the ink ejection operation and the valve opening / closing operation is provided. Also, in models where the influence on ink ejection when the ink ejection operation and the valve opening / closing operation are executed simultaneously is relatively small, no limit on the simultaneous execution of the ink ejection operation and the valve opening / closing operation is provided.

[0055] The EEPROM 134 stores an opening / closing permission determination table as shown in FIG. 7. As shown in FIG. 7, in models where a limit on the simultaneous execution of the ink ejection operation and the valve opening / closing operation is provided, when the "ink ejection status" is "non-ejection", the "valve opening / closing process" is "permissible", and when the "ink ejection status" is "ejection", the "valve opening / closing process" is "not permissible". Also, in models where no limit on the simultaneous execution of the ink ejection operation and the valve opening / closing operation is provided, the "valve opening / closing process" is "permissible" whether the "ink ejection status" is "non-ejection" or "ejection". The control unit 5 determines whether or not to execute the valve opening / closing process in the opening / closing permission determination process based on the opening / closing permission determination table in FIG. 7.

[0056] In addition, the control unit 5 has a function as a measurement unit that measures the negative pressure in the ink storage chamber 62a. Specifically, the control unit 5 cumulatively counts the number of dots of the image formed by the ink ejected from the nozzles 42 of the ink jet head 41 during the period when the electromagnetic valve 64 is in the blocked state. Then, based on the counted number of dots, the amount of ink used during the period when the electromagnetic valve 64 is in the blocked state is calculated, and based on this, the negative pressure in the ink storage chamber 62a is measured. When the valve opening / closing process is executed, the cumulative count of the number of dots is reset.

[0057] Further, the control unit 5 executes a negative pressure determination process for determining whether or not the negative pressure in the ink storage chamber 62a measured based on the cumulative count of the number of dots is equal to or greater than a threshold value. The negative pressure determination process includes a first determination process for determining whether or not the negative pressure in the ink storage chamber 62a is equal to or greater than a first threshold value, and a second determination process for determining whether or not the negative pressure in the ink storage chamber 62a is equal to or greater than a second threshold value that is higher than the first threshold value.

[0058] In the first determination process, when the control unit 5 determines that the negative pressure in the ink storage chamber 62a is equal to or greater than the first threshold value, it executes an open / close determination process. Then, in the open / close determination process, when it is determined that the valve opening / closing process cannot be executed, the second determination process is executed.

[0059] Further, in the second determination process, when the control unit 5 determines that the negative pressure in the ink storage chamber 62a is equal to or greater than the second threshold value, it executes a stop process for stopping the recording of an image. In the stop process, the driving of the PF motor 30M, the CR motor 70M, and the inkjet head 41 is stopped, and the conveyance process of the paper P and the scanning process of moving the carriage 70 and discharging ink from the nozzles 42 are stopped. Note that the stop process is executed after the image recording on the paper P on which the image recording is being performed has ended when it is determined in the second determination process that the negative pressure is equal to or greater than the second threshold value, and before the image recording on the next paper P is started. After executing the stop process, the control unit 5 executes the valve opening / closing process.

[0060] Note that the control unit 5 of the present embodiment has one CPU and one ASIC each. However, the control unit 5 may include only one ASIC, and this one ASIC may perform all the necessary processes at once, or may include a plurality of ASICs, and these plurality of ASICs may share the necessary processes.

[0061] <Operation of Printer 1> Next, with reference to the flowchart shown in FIG. 8, an example of the operations performed by the printer 1 will be described. First, the control unit 5 cumulatively counts the number of dots of the image formed by the ink ejected from the nozzles 42 of the inkjet head 41 (S1). Then, it is determined whether or not the negative pressure level in the ink reservoir chamber 62a measured based on the number of dots counted in S1 is equal to or higher than a first threshold value (S2). If it is determined that the negative pressure level is not equal to or higher than the first threshold value (S2: NO), the process returns to S1.

[0062] On the other hand, if it is determined that the negative pressure level is equal to or higher than the first threshold value (S2: YES), the control unit 5 determines whether or not to execute the valve opening / closing process based on the opening / closing determination table of FIG. 7 (S3). If it is determined that the valve opening / closing process can be executed (S3: YES), the control unit 5 permits the valve opening / closing process and proceeds to S6 described later.

[0063] If it is determined that the valve opening / closing process cannot be executed (S3: NO), the control unit 5 does not permit the valve opening / closing process. Then, the control unit 5 determines whether or not the negative pressure level in the ink reservoir chamber 62a measured based on the number of dots counted in S1 is equal to or higher than a second threshold value (S4). If it is determined that the negative pressure level is not equal to or higher than the second threshold value (S4: NO), the process returns to S1.

[0064] On the other hand, if it is determined that the negative pressure level is equal to or higher than the second threshold value (S4: YES), the control unit 5 executes a stop process to stop the recording of the image (S5). After that, the control unit 5 executes a valve opening / closing process of switching the electromagnetic valve 64 from the blocked state to the communicating state and then returning it to the blocked state (S6). Finally, the control unit 5 resets the cumulative count of the number of dots (S7).

[0065] The above operations are repeated while the power of the printer 1 is on. Therefore, after executing the process of S7, the process returns to S1.

[0066] <Features of the First Embodiment> As described above, in the printer 1 of the above-described embodiment, the control unit 5 executes a valve opening / closing process of switching the electromagnetic valve 64 from a closed state to a communicating state and then returning it to the closed state, and an opening / closing permission determination process of determining whether or not the valve opening / closing process can be executed. In the opening / closing permission determination process, the control unit 5 determines that the valve opening / closing process can be executed when ink is not being ejected from the nozzle 42, and determines that the valve opening / closing process cannot be executed when ink is being ejected from the nozzle 42. When the control unit 5 determines that the valve opening / closing process can be executed by the opening / closing permission determination process, it permits the valve opening / closing process, and when it determines that the valve opening / closing process cannot be executed, it does not permit the valve opening / closing process.

[0067] If the valve opening / closing process is executed when ink is being ejected from the nozzle 42, the supply power to the inkjet head 41 may become insufficient due to voltage fluctuations caused by the valve opening / closing process, and the ejection of ink from the nozzle 42 may be affected. According to the above-described configuration, since the valve opening / closing process is not executed when ink is being ejected from the nozzle 42 of the inkjet head 41, it is possible to avoid affecting the ejection of ink from the nozzle 42. Therefore, it is possible to control the opening and closing of the electromagnetic valve 64 while considering the relationship with the electrically driven inkjet head 41.

[0068] Also, in the printer 1 of the above-described embodiment, the control unit 5 measures the negative pressure in the ink storage chamber 62a based on the cumulative count of the number of dots. Then, the control unit 5 executes a negative pressure determination process of determining whether or not the negative pressure in the ink storage chamber 62a is equal to or greater than a threshold value, and in the negative pressure determination process, when it is determined that the negative pressure in the ink storage chamber 62a is equal to or greater than the threshold value, it executes the opening / closing permission determination process. Therefore, when the negative pressure in the ink storage chamber 62a increases, it is possible to control the opening and closing of the electromagnetic valve 64 while considering the relationship with the inkjet head 41.

[0069] Furthermore, in the printer 1 of the above-described embodiment, the negative pressure determination process includes a first determination process for determining whether or not the negative pressure in the ink storage chamber 62a is equal to or greater than a first threshold value, and a second determination process for determining whether or not the negative pressure in the ink storage chamber 62a is equal to or greater than a second threshold value that is higher than the first threshold value. When the control unit 5 determines in the first determination process that the negative pressure in the ink storage chamber 62a is equal to or greater than the first threshold value, the control unit 5 executes the open / close determination process, and when it is determined in the open / close determination process that the valve opening / closing process cannot be executed, the control unit 5 executes the second determination process. Then, when it is determined in the second determination process that the negative pressure in the ink storage chamber 62a is equal to or greater than the second threshold value, the control unit 5 executes a stop process for stopping the recording of an image, and after executing the stop process, the control unit 5 executes the valve opening / closing process. Therefore, the electromagnetic valve 64 can be appropriately controlled according to the magnitude of the negative pressure in the ink storage chamber 62a.

[0070] (Second Embodiment) Next, with reference to FIG. 9, a printer according to a second embodiment of the present invention will be described. The content of the open / close determination process executed by the control unit 5 in this embodiment is mainly different from that of the printer 1 of the first embodiment. Hereinafter, components having the same configuration as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0071] In this embodiment, the control unit 5 executes a drive state determination process for determining the drive states of a PF motor 30M for driving a conveyance roller 35a that is a drive roller of the conveyance roller pair 35 and a discharge roller 36a that is a drive roller of the discharge roller pair 36, and a CR motor 70M for driving a movement mechanism 71 that moves the carriage 70. Specifically, the control unit 5 determines, for each of the PF motor 30M and the CR motor 70M, whether it is in a first state or a second state in which the drive load is greater than the first state. In this embodiment, it is determined that the motor is in the first state when it is not driving, and it is determined that the motor is in the second state when it is driving.

[0072] Here, the PF motor 30M, the CR motor 70M, and the electromagnetic valve 64 are all electrically driven devices. When the valve opening / closing process is executed during the driving of the PF motor 30M and the CR motor 70M, the driving load of the electromagnetic valve 64 is added to the driving loads of the PF motor 30M and the CR motor 70M, and there is a risk that the load exceeds the load rating which is the usage limit of the printer 1.

[0073] Therefore, in the opening / closing permission determination process, when the control unit 5 determines in the driving state determination process that at least one of the PF motor 30M and the CR motor 70M is in the first state (non - driving state), it determines that the valve opening / closing process can be executed. Also, when it is determined in the driving state determination process that both the PF motor 30M and the CR motor 70M are in the second state (driving state), it determines that the valve opening / closing process cannot be executed. Then, when the control unit 5 determines that the valve opening / closing process can be executed by the opening / closing permission determination process, it permits the valve opening / closing process, and when it determines that the valve opening / closing process cannot be executed, it does not permit the valve opening / closing process.

[0074] The load rating of the printer 1 varies for each model of the printer 1. Therefore, whether or not to limit the simultaneous execution of the driving of the PF motor 30M and the CR motor 70M and the valve opening / closing operation is determined for each model of the printer 1. That is, for models with a relatively small load rating, a limit on the simultaneous execution of the driving of the PF motor 30M and the CR motor 70M and the valve opening / closing operation is provided. Also, for models with a relatively large load rating, no limit on the simultaneous execution of the driving of the PF motor 30M and the CR motor 70M and the valve opening / closing operation is provided.

[0075] The EEPROM 134 stores an open / close permission determination table as shown in FIG. 9. As shown in FIG. 9, in models where restrictions are provided on the simultaneous execution of the driving of the PF motor 30M and the CR motor 70M and the valve opening / closing operation, when both the “driving status of the PF motor” and the “driving status of the CR motor” are “driving”, the “valve opening / closing process” is “not permitted”, and when at least one of the “driving status of the PF motor” and the “driving status of the CR motor” is “not driving”, the “valve opening / closing process” is “permitted”. Also, in models where no restrictions are provided on the simultaneous execution of the driving of the PF motor 30M and the CR motor 70M and the valve opening / closing operation, in any situation, the “valve opening / closing process” is “permitted”. The control unit 5 determines whether to execute the valve opening / closing process in the open / close permission determination process based on the open / close permission determination table in FIG. 9.

[0076] <Features of the Second Embodiment> As described above, in the present embodiment, the control unit 5 performs a driving state determination process for determining whether the motors (PF motor 30M and CR motor 70M) driven electrically are in the first state or the second state in which the driving load is greater than the first state, and in the driving state determination process, when it is determined that the motor is in the first state, it is determined that the valve opening / closing process can be executed, and when it is determined that the motor is in the second state, it is determined that the valve opening / closing process cannot be executed. Then, in the open / close permission determination process, when it is determined that the valve opening / closing process can be executed, the valve opening / closing process is permitted, and when it is determined that the valve opening / closing process cannot be executed, the valve opening / closing process is not permitted.

[0077] When the valve opening / closing process is executed during the driving of the motor, the driving load of the valve is added to the driving load of the motor, and there is a risk that the load will exceed the usage limit of the device. According to the above configuration, by preventing the valve opening / closing process from being executed when the driving load of the motor is relatively large, it is possible to avoid an excessive load. Therefore, it is possible to control the opening and closing of the electromagnetic valve 64 while considering the relationship with the motors (PF motor 30M and CR motor 70M).

[0078] Also, in the present embodiment, the control unit 5 determines that it is in the first state when the motor is not driving in the driving state determination process, and determines that it is in the second state when the motor is driving. Therefore, by preventing the valve opening / closing process from being executed when the motor is driving, it is possible to avoid an excessive load.

[0079] Furthermore, in the present embodiment, in the driving state determination process, for each of the PF motor 30M and the CR motor 70M, it is determined whether it is in the first state or the second state. In the opening / closing permission determination process, when it is determined that at least one of the PF motor 30M and the CR motor 70M is in the first state in the driving state determination process, it is determined that the valve opening / closing process can be executed, and when it is determined that both the motors of the PF motor 30M and the CR motor 70M are in the second state, it is determined that the valve opening / closing process cannot be executed. Therefore, by preventing the valve opening / closing process from being executed when the driving loads of the two motors of the PF motor 30M and the CR motor 70M both become large, it is possible to avoid an excessive load.

[0080] As described above, the embodiments of the present invention have been described with reference to the drawings, but the specific configuration should be considered not to be limited to these embodiments. The scope of the present invention is shown not by the description of the above embodiments but by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

[0081] For example, in the above-described second embodiment, the case where it is determined that it is in the first state when the motor is not driving and it is determined that it is in the second state when the motor is driving in the driving state determination process has been described, but it is not limited thereto. That is, it may be determined that it is in the first state when the motor is not driving and when the motor is not accelerating, and it may be determined that it is in the second state when the motor is accelerating.

[0082] Also, in the above-described second embodiment, in the opening / closing permission determination process, when it is determined in the drive state determination process that at least one of the two motors, the PF motor 30M and the CR motor 70M, is in the first state, it is determined that the valve opening / closing process can be executed, and when it is determined in the drive state determination process that both of the two motors, the PF motor 30M and the CR motor 70M, are in the second state, it is determined that the valve opening / closing process cannot be executed. However, the present invention is not limited to this. That is, in the opening / closing permission determination process, when it is determined in the drive state determination process that both of the two motors, the PF motor 30M and the CR motor 70M, are in the first state, it is determined that the valve opening / closing process can be executed, and when it is determined in the drive state determination process that at least one of the two motors, the PF motor 30M and the CR motor 70M, is in the second state, it may be determined that the valve opening / closing process cannot be executed. Further, the opening / closing permission determination process may be based on only the drive state of either one of the PF motor 30M and the CR motor 70M, and when the motor is in the first state, it may be determined that the valve opening / closing process can be executed, and when the motor is in the second state, it may be determined that the valve opening / closing process cannot be executed. Furthermore, the opening / closing permission determination process may be executed in consideration of not only the drive states of the PF motor 30M and the CR motor 70M but also the drive state of, for example, the ASF motor 20M.

[0083] Furthermore, in the above-described embodiment, the case where the control unit 5 measures the negative pressure in the ink storage chamber 62a based on the cumulative count of the number of dots has been described. However, the present invention is not limited to this. That is, the negative pressure in the ink storage chamber 62a may be measured by a pressure sensor.

[0084] Also, in the above-described embodiment, the case where the negative pressure determination process includes the first determination process of determining whether the negative pressure in the ink storage chamber 62a is equal to or greater than the first threshold value and the second determination process of determining whether the negative pressure in the ink storage chamber 62a is equal to or greater than the second threshold value that is higher than the first threshold value has been described. However, the present invention is not limited to this. The negative pressure determination process may be performed with respect to only one threshold value.

[0085] In addition, in the above-described embodiment, the case where the opening / closing determination process is executed when it is determined that the negative pressure in the ink storage chamber 62a is equal to or higher than the threshold value has been described, but the present invention is not limited to this. For example, during continuous printing, the opening / closing determination process may be executed at predetermined time intervals.

[0086] Furthermore, in the above-described embodiment, the case where the stop process is executed after the image recording on the sheet P on which the image recording is being performed has ended and before the start of the image recording on the next sheet P when it is determined in the second determination process that the negative pressure is equal to or higher than the second threshold value has been described, but the present invention is not limited to this. For example, the stop process may be executed immediately when it is determined in the second determination process that the negative pressure is equal to or higher than the second threshold value.

[0087] In addition, in the above-described embodiment, the present invention is adopted in a monochrome printer, but the present invention may also be adopted in a color printer.

[0088] Also, in the above-described embodiment, the case where the ink tank 61 is provided with an ink inlet 67 that communicates the ink tank 61 with the outside has been described, but the ink inlet 67 may not be provided in the ink tank 61.

[0089] In addition, in the above-described embodiment, the case where the ink tank 61 includes an electromagnetic valve 64 has been described, but the present invention is not limited to this. That is, the valve provided in the ink tank 61 may be any valve that is driven electrically. For example, an electric valve driven by a motor may be adopted instead of the electromagnetic valve 64.

[0090] Furthermore, in the above-described embodiment, the case where the ink tank 61 and the inkjet head 41 are of an on-carriage type mounted on the carriage 70 has been described, but the present invention is not limited to this. That is, the present invention can also be adopted in a line-type inkjet head in which the carriage 70 is not provided and the inkjet head is fixed.

[0091] Furthermore, it is also possible to apply the present invention to a liquid ejection apparatus having a liquid ejection head that ejects a liquid other than ink. Further, the ejection target is not limited to the paper P, and may be, for example, cloth, a substrate, or the like. Also, it is possible to adopt an ejection energy imparting means other than the piezoelectric actuator 50. In this case, for example, a thermal type ejection energy imparting means may be adopted in which a heating element heats the liquid ink in the nozzle to generate bubbles and the ink is pushed out from the nozzle for recording.

Explanation of Reference Numerals

[0092] 1 Printer (Liquid Ejection Apparatus) 5 Control Unit 35 Pair of Conveyor Rollers (Conveyor Mechanism) 36 Pair of Paper Discharge Rollers (Conveyor Mechanism) 41 Inkjet Head (Liquid Ejection Head) 61 Ink Tank (Liquid Storage Section) 62a Ink Storage Chamber (Liquid Storage Chamber) 62e Atmosphere Communication Path 64 Electromagnetic Valve (Valve) 69a Communication Path (Liquid Flow Path) 70 Carriage 71 Moving Mechanism 30M CR Motor 70M PF Motor

Claims

1. A liquid ejection head having a nozzle for ejecting a liquid, a liquid storage chamber for storing a liquid, an air communication passage for communicating the liquid storage chamber with the outside, and a liquid storage unit having an electrically driven valve capable of selectively taking either a communication state in which the air communication passage is communicated or a shut-off state in which the air communication passage is shut off, a liquid flow path that connects the liquid ejection head and the liquid storage chamber so that the liquid can flow, and a control unit, wherein the control unit executes a valve opening / closing process of switching the valve from the shut-off state to the communication state and then returning it to the shut-off state, and an opening / closing permission determination process for determining whether or not the valve opening / closing process can be executed, in the opening / closing permission determination process, it is determined that the valve opening / closing process can be executed when the liquid is not being ejected from the nozzle, and it is determined that the valve opening / closing process cannot be executed when the liquid is being ejected from the nozzle, and when it is determined by the opening / closing permission determination process that the valve opening / closing process can be executed, the valve opening / closing process is permitted, and when it is determined that the valve opening / closing process cannot be executed, the valve opening / closing process is not permitted. A liquid ejection device characterized by this.

2. A liquid ejection head having a nozzle for ejecting a liquid, a liquid storage chamber for storing a liquid, an air communication passage for communicating the liquid storage chamber with the outside, and a liquid storage unit having an electrically driven valve capable of selectively taking either a communication state in which the air communication passage is communicated or a shut-off state in which the air communication passage is shut off, a liquid flow path that connects the liquid ejection head and the liquid storage chamber so that the liquid can flow, a motor, and a control unit, wherein the control unit executes a valve opening / closing process of switching the valve from the shut-off state to the communication state and then returning it to the shut-off state, a drive state determination process for determining whether the motor is in a first state or a second state in which the drive load is greater than the first state, and in the drive state determination process, an opening / closing permission determination process is executed in which it is determined that the valve opening / closing process can be executed when it is determined that the motor is in the first state, and it is determined that the valve opening / closing process cannot be executed when it is determined that the motor is in the second state. In the opening / closing permission determination process, when it is determined that the valve opening / closing process can be executed, the valve opening / closing process is permitted, and when it is determined that the valve opening / closing process cannot be executed, the valve opening / closing process is not permitted. A liquid ejection device characterized by this.

3. In the drive state determination process, the control unit determines that it is in the first state when the motor is not driving, and determines that it is in the second state when the motor is driving. The liquid ejection device according to claim 2.

4. In the drive state determination process, the control unit determines that it is in the first state when the motor is not driving and when the motor is not accelerating, and determines that it is in the second state when the motor is accelerating. The liquid ejection device according to claim 2.

5. Further provided with a transport mechanism for transporting a recording medium, The motor is for driving the transport mechanism. The liquid ejection device according to any one of claims 2 to 4.

6. The liquid ejection head and a carriage that supports the liquid storage unit, Further provided with a moving mechanism for moving the carriage, The motor is for driving the moving mechanism. The liquid ejection device according to any one of claims 2 to 4.

7. A transport mechanism for transporting a recording medium in a transport direction, The liquid ejection head and a carriage that supports the liquid storage unit, Further provided with a moving mechanism for moving the carriage in a scanning direction intersecting the transport direction, Two motors are provided, one for driving the transport mechanism and the other for driving the moving mechanism, The control unit, In the drive state determination process, for each of the two motors, determines which of the first state and the second state it is in, In the opening / closing permission determination process, when it is determined in the drive state determination process that at least one of the two motors is in the first state, it is determined that the valve opening / closing process can be executed, and when it is determined in the drive state determination process that both of the two motors are in the second state, it is determined that the valve opening / closing process cannot be executed. The liquid ejection device according to any one of claims 2 to 4.

8. Further provided with a measurement unit for measuring the negative pressure in the liquid storage chamber, The control unit further executes a negative pressure determination process for determining whether or not the negative pressure in the liquid storage chamber measured by the measurement unit is equal to or greater than a threshold value. The liquid ejection device according to any one of claims 1 to 7, wherein, in the negative pressure determination process, when it is determined that the negative pressure in the liquid storage chamber is equal to or greater than the threshold value, the open / close permission determination process is executed.

9. The liquid ejection device further includes a measurement unit that measures the negative pressure in the liquid storage chamber. The control unit further executes a negative pressure determination process including a first determination process for determining whether or not the negative pressure in the liquid storage chamber measured by the measurement unit is equal to or greater than a first threshold value, and a second determination process for determining whether or not the negative pressure in the liquid storage chamber measured by the measurement unit is equal to or greater than a second threshold value that is higher than the first threshold value. The control unit In the first determination process, when it is determined that the negative pressure in the liquid storage chamber is equal to or greater than the first threshold value, the open / close permission determination process is executed. In the open / close permission determination process, when it is determined that the valve opening / closing process cannot be executed, the second determination process is executed. In the second determination process, when it is determined that the negative pressure in the liquid storage chamber is equal to or greater than the second threshold value, a stop process for stopping the driving of the liquid ejection head is executed. After executing the stop process, the liquid ejection device according to claim 1, wherein the valve opening / closing process is executed.

10. The liquid ejection device further includes a measurement unit that measures the negative pressure in the liquid storage chamber. The control unit further executes a negative pressure determination process including a first determination process for determining whether or not the negative pressure in the liquid storage chamber measured by the measurement unit is equal to or greater than a first threshold value, and a second determination process for determining whether or not the negative pressure in the liquid storage chamber measured by the measurement unit is equal to or greater than a second threshold value that is higher than the first threshold value. The control unit In the first determination process, when it is determined that the negative pressure in the liquid storage chamber is equal to or greater than the first threshold value, the open / close permission determination process is executed. In the open / close permission determination process, when it is determined that the valve opening / closing process cannot be executed, the second determination process is executed. In the second determination process, when it is determined that the negative pressure in the liquid storage chamber is equal to or greater than the second threshold value, a stop process for stopping the driving of the motor is executed. After executing the stop process, the liquid ejection device according to any one of claims 2 to 7, wherein the valve opening / closing process is executed.

11. The liquid ejection device according to any one of claims 1 to 10, wherein the valve comprises an electromagnetic valve.

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