Liquid ejection device

Abstract

To enable miniaturization of a device.SOLUTION: A liquid discharge device includes: an inkjet head having nozzles for discharging ink; a solenoid valve for selectively taking any one of a communication state where an ink storage chamber for storing ink and an atmosphere communication path for communicating the ink storage chamber and outside are communicated with each other, and a cut-off state where the atmosphere communication path is cut off; a power source 6 for generating a voltage; a power source line 8a connected to the power source 6; and a voltage supply part 90 for supplying the voltage that is generated by the power source 6 and input through the power source line 8a, to the inkjet head and the solenoid valve. The voltage supply part 90 can switch a supply destination of the voltage between the inkjet head and the solenoid valve.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a liquid ejection device having an electrically driven valve capable of selectively taking 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 shut-off state in which the air communication passage is shut off.

Background Art

[0002] Patent Document 1 describes an inkjet recording apparatus in which ink supplied from an ink tank is stored in an ink buffer, and recording operation is performed by ejecting the ink from a print head on a carriage onto a recording medium. In this inkjet recording apparatus, during ink supply in which ink in the ink tank is supplied into the ink buffer, an air release electromagnetic valve that controls communication between the upper air layer in the ink buffer and the atmosphere is open. Thereby, at the time of ink supply, it becomes possible to release the air in the upper part of the ink buffer, and the ink in the ink buffer is not pressurized. Further, in this inkjet recording apparatus, at the time of purging, the air release electromagnetic valve is closed, and pressurized ink is supplied from the ink tank, and a purging operation is performed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, Patent Document 1 describes an inkjet recording apparatus having an electromagnetic valve for atmosphere release. However, Patent Document 1 does not describe details regarding the power source that generates the voltage supplied to the electromagnetic valve for atmosphere release and the print head, and the power supply line that supplies the voltage generated by the power source to the electromagnetic valve for atmosphere release and the print head. For example, the voltage supplied to the electromagnetic valve for atmosphere release and the voltage supplied to the print head are usually generated by separate power sources and supplied to the electromagnetic valve for atmosphere release and the print head via separate power supply lines. In this case, there is a problem that space is required to install a plurality of power sources and a plurality of power supply lines, and the apparatus becomes large-sized.

[0005] Therefore, an object of the present invention is to provide a liquid ejection apparatus capable of miniaturizing the apparatus.

Means for Solving the Problems

[0006] The liquid ejection apparatus of the present invention includes a liquid ejection head having a nozzle for ejecting a liquid, a liquid storage chamber for storing the liquid, an atmosphere communication path for communicating the liquid storage chamber with the outside, and an electrically driven valve capable of selectively taking either a communication state in which the atmosphere communication path is communicated or a shut-off state in which the atmosphere communication path is shut off. A liquid storage unit, a liquid flow path that connects the liquid ejection head and the liquid storage chamber so that the liquid can flow, a power source that generates a voltage, The main board on which the power supply is mounted, the sub-board to which the liquid ejection head and the valve are connected, the control unit mounted on the main board, and the signal line connected to the control unit, a power supply line connected to the power source, and a supply unit that supplies the voltage generated by the power source and input via the power supply line to the liquid ejection head and the valve. The supply unit is capable of switching the voltage supply destination. wherein the power supply line is formed on a flexible cable, the supply unit is mounted on the sub-board, and a voltage is input via the power supply line, and has a switching circuit for switching the voltage supply destination between the liquid ejection head and the valve, the control unit generates a switching signal for instructing the switching circuit to switch the voltage supply destination, and the switching circuit switches the voltage supply destination based on the switching signal generated by the control unit and input via the signal line is. From another perspective, the liquid ejection device of the present invention includes a liquid ejection head having a nozzle for ejecting 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 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, a power source that generates a voltage, a power line connected to the power source, and a supply unit that supplies the voltage generated by the power source and input via the power line to the liquid ejection head and the valve. The supply unit is capable of switching the voltage supply destination. Further, the supply unit includes a wiring connected to an end portion of the power line opposite to the side connected to the power source, a first branch wiring formed by branching of the wiring and connected to the liquid ejection head, and a second branch wiring formed by branching of the wiring and connected to the valve, a first connection line connecting an intermediate point on the second branch wiring and the ground, a capacitor provided on the first connection line and charged by the voltage input to the second branch wiring via the power line, a switching circuit provided between the intermediate point and the valve in the second branch wiring and capable of switching between a state in which a voltage is supplied to the valve and a state in which a voltage is not supplied to the valve, and a second connection line connecting the first branch wiring and the switching circuit. The switching circuit switches to a state in which no voltage is supplied to the valve when a voltage is generated by the power source and the voltage is input to the switching circuit via the power line, the wiring, the first branch wiring, and the second connection line, and switches to a state in which a voltage is supplied to the valve by the discharge of the capacitor when no voltage is generated by the power source and no voltage is input to the switching circuit via the power line, the wiring, the first branch wiring, and the second connection line. From another perspective, the liquid ejection device of the present 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 capable of selectively taking either a communication state in which the air communication passage is communicated or a cutoff 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 power source that generates a voltage, a power line connected to the power source, and a supply unit that supplies the voltage generated by the power source and input via the power line to the liquid ejection head and the valve. The supply unit can switch the voltage supply destination. The power source generates a voltage of a magnitude necessary to drive the liquid ejection head, and the supply unit has a voltage conversion circuit that changes the voltage input via the power line to a magnitude necessary to drive the valve.

Effects of the Invention

[0007] According to the liquid ejection device of the present invention, a voltage generated by one power supply and input to the supply unit via one power supply line can be supplied to the liquid ejection head and the valve. Therefore, the number of power supplies and the number of power supply lines can be reduced, enabling miniaturization of the device.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] (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.

[0010] <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.

[0011] 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.

[0012] As shown in FIGS. 1 and 2, the housing 11 has an opening / closing cover 14 that constitutes its ceiling portion. 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, which will be described later, disposed inside the housing 11 is exposed, and it becomes possible to inject and replenish ink into the ink tank 61.

[0013] <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. 8), an LF (Line Feed) motor 30M (see FIG. 8), a control unit 5 (see FIG. 8), and a power supply 6 (see FIGS. 6 and 8).

[0014] 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 conveyance roller pair 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 conveyance roller pair 35. The paper discharge roller pair 36 discharges the paper P recorded by the recording unit 40 to the paper discharge tray 16.

[0015] <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. As a result, the paper P stacked in the paper feed tray 15 is fed to the conveyance path 25.

[0016] <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.

[0017] <Conveyance path 25> The conveyance path 25 is formed inside the housing 11 and, as shown in Fig. 2, bends upward from the rear end of the paper feed tray 15 and toward 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 reach the recording unit 40.

[0018] <Conveyance roller pair 35 and paper discharge roller pair 36> The conveying roller pair 35 has a conveying roller 35a disposed on the lower side and a pinch roller 35b disposed on the upper side. The power of the LF motor 30M is transmitted to the conveying roller 35a via a transmission mechanism (not shown) to cause rotation. 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 in the vertical direction A1, and convey the sheet P to the recording unit 40.

[0019] The paper discharge roller pair 36 has a paper discharge roller 36a disposed on the lower side and a boosting roller 36b disposed on the upper side. The power of the LF motor 30M is transmitted to the paper discharge roller 36a via a transmission mechanism (not shown) to cause rotation. 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 in the vertical direction A1, and convey the sheet P to the paper discharge tray 16.

[0020] <Recording unit 40> As shown in FIGS. 2 and 3, the recording unit 40 includes an inkjet head 41, an ink tank 61, a relay substrate 80 (the "substrate" of the present invention), 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 conveying 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 thereto, 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.

[0021] <Ink tank 61> As shown in FIG. 3, the ink tank 61 includes 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.

[0022] As shown in FIG. 3, a through hole 62c penetrating the upper wall 62b 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 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.

[0023] 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 when the cap 63 is removed from the cylindrical body 66 to inject ink into the ink storage chamber 62a.

[0024] As shown in FIG. 3(b), an air communication path 62e is formed in the tank body 62, penetrating the rear side wall 62d and communicating the ink storage chamber 62a with the outside. The air communication path 62e is arranged near the upper end of the rear side wall 62d.

[0025] As shown in Fig. 3(b), the electromagnetic valve 64 is a known two-way electromagnetic valve, which has a valve part 64a and a solenoid part 64b. The electromagnetic valve 64 is fixed to the upper wall 62b. The valve part 64a is disposed in the ink storage chamber 62a, and has an internal flow path (not shown) that communicates with the atmosphere communication path 62e and the ink storage chamber 62a, and a valve (not shown) that opens and closes the internal flow path. The solenoid part 64b is disposed on the upper wall 62b and opens and closes the valve of the valve part 64a.

[0026] When no voltage is supplied to the solenoid part 64b, the electromagnetic valve 64 is in a blocking state (i.e., the valve closes the internal passage) that blocks the communication between the atmosphere communication path 62e and the ink storage chamber 62a. When the voltage generated by the power source 6 (Figs. 6 and 8) is supplied to the solenoid part 64b, the valve part 64a is in a communicating state (i.e., the valve opens the internal passage) that allows the atmosphere communication path 62e and the ink storage chamber 62a to communicate with each other. That is, the electromagnetic valve 64 selectively takes either the blocking state or the communicating state. By setting the electromagnetic valve 64 to the communicating state, the negative pressure in the ink storage chamber 62a can be released.

[0027] As a modification, the valve part 64a of the electromagnetic valve 64 may be connected to the atmosphere communication path 62e and the outside so as to be communicable outside the ink tank 61. In this case, it is possible to selectively take a communicating state in which the atmosphere communication path 62e communicates with the outside and a blocking state in which communication with the outside is blocked. Further, the entire electromagnetic valve 64 may be disposed in the ink storage chamber 62a. Further, if the internal flow path of the valve part 64a is connected to be communicable with the atmosphere communication path 62e, the electromagnetic valve 64 may be fixed and installed on at least any one of the front, rear, left, and right side walls other than the upper wall 62b of the tank body 62.

[0028] In addition, an outlet 62h is formed in the tank body 62, which 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.

[0029] <Inkjet 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.

[0030] <Flow path unit 43> As shown in FIG. 5, the flow path unit 43 is formed by stacking 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 thereof overlaps with the nozzle 42 in the vertical direction A1.

[0031] As shown in FIGS. 4 and 5, circular through holes 46a are formed in the plate 43b at portions overlapping with 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 with the right end portions of the respective pressure chambers 45 and the nozzle 42 in the vertical direction A1.

[0032] 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 with 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).

[0033] As shown in FIG. 3, the inkjet head 41 is connected to the ink tank 61 via the 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.

[0034] 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.

[0035] 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-hole 46a that connects the pressure chamber 45 to the manifold flow path 47. A plurality of individual flow paths 44 are formed corresponding to the plurality of nozzles 42.

[0036] <Piezoelectric actuator 50> As shown in FIG. 5, the piezoelectric actuator 50 includes 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.

[0037] 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 across a plurality of pressure chambers 45. As shown in FIG. 5, the common electrode 53 is disposed between the diaphragm 51 and the piezoelectric layer 52 and extends continuously across the plurality of pressure chambers 45. The common electrode 53 is connected to the power supply 6 via wiring members (FPC (Flexible Printed Circuits) 96, COF (Chip On Film) 95, etc.) described later and is held at the ground potential.

[0038] A plurality of individual electrodes 54 individually correspond to the plurality of pressure chambers 45 as shown in FIG. 4. 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. Further, the left end of the individual electrode 54 extends to a position where it does not overlap the pressure chamber 45 in the vertical direction A1. The left end of the individual electrode 54 serves as a connection terminal 54a to which the COF 95 described later is connected. The individual electrode 54 is connected to a driver IC 59 (see FIG. 8) mounted on the COF 95. Then, either the ground potential or a predetermined driving potential (for example, about 20 V) is selectively applied to the plurality of individual electrodes 54 individually by the driver IC 59.

[0039] Also, the 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, the 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 the portions formed by the individual electrodes 54 serve as driving elements 55 that apply pressure to the ink in the pressure chambers 45, respectively.

[0040] Here, a method for 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 portion of the diaphragm 51 and the piezoelectric layer 52 that overlaps the pressure chamber 45 in the vertical direction A1 is deformed so that the whole becomes convex toward the pressure chamber 45 side. 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.

[0041] <Platen 17> The platen 17 is disposed below the inkjet head 41 and supports the paper P conveyed by the pair of conveying rollers 35. The platen 17 is disposed in the portion where 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 conveyable paper P, the paper P conveyed on the conveyance path 25 always passes over the platen 17.

[0042] <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 spaced apart in the front-rear direction A2 and extend parallel to each other in the left-right direction A3. The carriage 70 is disposed so as to straddle the pair of guide rails 72. The carriage 70 is connected to a carriage motor 70M (see FIG. 8) via a belt transmission mechanism, and when the carriage 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.

[0043] 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 is scanned with respect to the paper P, and by ejecting ink from the nozzles 42, an image is recorded on the paper P conveyed on the platen 17.

[0044] <Relay substrate 80> As shown in FIG. 6, the relay substrate 80 is connected to the control substrate 7 (the "main substrate" of the present invention) on which the control unit 5 and the power supply 6 are mounted via an FFC (Flexible Flat Cable) 8. Thereby, as will be described in detail later, the control signal generated by the control unit 5 and the voltage generated by the power supply 6 can be input to the relay substrate 80 via the FFC 8. Note that the connection between the relay substrate 80 and the control substrate 7 may be made by an FPC (Flexible Printed Circuits) or other connection members.

[0045] Also, the relay substrate 80 is supported by the carriage 70 and is arranged behind the ink tank 61 in a state of standing upright along the vertical direction A1 as shown in FIG. 3(b). The relay substrate 80 has a rectangular planar shape as shown in FIG. 6. The relay substrate 80 is provided with three connection parts 82 - 84, a voltage supply part 90, and a signal wiring 88.

[0046] <Connection parts 82 - 84> As shown in FIG. 6, the connection part 82 is arranged near the center of the right end of the relay substrate 80. One end of the FFC 8 is connected to the connection part 82. The connection part 83 is arranged near the center of the lower end of the relay substrate 80. As shown in FIG. 3(b), an FPC 96 connected to a COF 95 connected to the piezoelectric actuator 50 of the inkjet head 41 is connected to the connection part 83. The connection part 84 is arranged near the center of the upper end of the relay substrate 80. As shown in FIG. 3(b), a wiring 97 connected to the electromagnetic valve 64 is connected to the connection part 84.

[0047] <Voltage supply unit 90> The voltage supply unit 90 supplies the voltage input via the power line 8a of the FFC8, which will be described later, to the inkjet head 41 and the electromagnetic valve 64. As shown in FIG. 6, the voltage supply unit 90 includes a power wiring 91 (the "wiring" of the present invention), a head wiring 91a (the "first branch wiring" of the present invention), a valve wiring 91b (the "second branch wiring" of the present invention), a drive circuit 92, and a connection line 93 (the "second connection line" of the present invention).

[0048] One end of the power wiring 91 is connected to the connection portion 82. That is, the power wiring 91 is connected to the power line 8a of the FFC8 connected to the connection portion 82. The head wiring 91a and the valve wiring 91b are respectively formed by branching the ends on the side opposite to the side connected to the connection portion 82 of the power wiring 91.

[0049] The end of the head wiring 91a on the side opposite to the power wiring 91 side is connected to the connection portion 83. That is, the head wiring 91a is connected to the inkjet head 41 via the connection portion 83, the FPC 96, and the COF 95.

[0050] The end of the valve wiring 91b on the side opposite to the power wiring 91 side is connected to the connection portion 84. A drive circuit 92 is disposed in the middle of the valve wiring 91b. That is, the valve wiring 91b is connected to the electromagnetic valve 64 via the drive circuit 92, the connection portion 84, and the wiring 97.

[0051] As shown in FIG. 7, the drive circuit 92 includes a connection line 94 (the "first connection line" of the present invention), a capacitor 85, a switching circuit 86, and a diode 87.

[0052] The connection line 94 connects the midpoint 94a on the valve wiring 91b to the ground. The capacitor 85 is provided on the connection line 94. The capacitor 85 is charged by the voltage input to the valve wiring 91b via the power line 8a, the connection portion 82, and the power wiring 91.

[0053] The switching circuit 86 is provided between the intermediate point 94a and the connection part 84 in the valve wiring 91b. The part of the valve wiring 91b on the power supply wiring 91 side with respect to the switching circuit 86 is defined as the first part 91b1, and the part of the valve wiring 91b on the connection part 84 side with respect to the switching circuit 86 is defined as the second part 91b2. The connection wire 93 connects the intermediate point 93a on the head wiring 91a and the switching circuit 86. The configuration of the switching circuit 86 will be described in detail later.

[0054] The diode 87 is provided between the power supply wiring 91 and the intermediate point 94a in the first part 91b1 of the valve wiring 91b. The diode 87 prevents the flow of electricity from the intermediate point 94a to the power supply wiring 91.

[0055] Here, the switching circuit 86 will be described in more detail. The switching circuit 86 can switch between a state in which a voltage is supplied to the electromagnetic valve 64 and a state in which no voltage is supplied to the electromagnetic valve 64. The switching circuit 86 is a transistor or an LDO (Low Drop Out).

[0056] To the VDD terminal of the switching circuit 86, the end on the side opposite to the end on the power supply wiring 91 side in the first part 91b1 of the valve wiring 91b is connected. To the VOUT terminal of the switching circuit 86, the end on the side opposite to the end on the connection part 84 side in the second part 91b2 of the valve wiring 91b is connected. To the CE terminal of the switching circuit 86, the end on the side opposite to the end on the intermediate point 93a side in the connection wire 93 is connected. To the CE terminal of the switching circuit 86, the voltage generated by the power supply 6 is input via the power supply line 8a of the FFC8, the power supply wiring 91, the head wiring 91a, and the connection wire 93.

[0057] The switching circuit 86 functions as a transformer circuit that changes the voltage input via the VDD terminal to a magnitude (=V2) necessary to drive the solenoid valve 64. Here, in the present embodiment, the power supply 6 generates a voltage (=V1) of a magnitude necessary to drive the inkjet head 41. And it is assumed that V1 > V2. The switching circuit 86 steps down the voltage (=V1) input via the VDD terminal to V2. In the case where V1 < V2, the switching circuit 86 steps up the voltage (=V1) input via the VDD terminal to V2.

[0058] When the voltage is generated by the power supply 6 and a voltage is input to the CE terminal, the switching circuit 86 switches to a state where no voltage is supplied to the solenoid valve 64. Also, when the voltage is not generated by the power supply 6 and no voltage is input to the CE terminal, the switching circuit 86 switches to a state where a voltage is supplied to the solenoid valve 64 by the discharge of the capacitor 85.

[0059] <Signal wiring 88> Returning to FIG. 6, one end of the signal wiring 88 is connected to the connection portion 82. The signal wiring 88 is connected to a signal line 8b (described later) of the FFC 8 connected to the connection portion 82. The other end of the signal wiring 88 is connected to the connection portion 83. That is, the signal wiring 88 is connected to the inkjet head 41 via the connection portion 83, the FPC 96, and the COF 95.

[0060] <ffc8> On FFC8, as shown in FIG. 6, a power line 8a and a signal line 8b are formed, one end of each being connected to the connection portion 7a of the control board 7 and the other end being connected to the connection portion 82 of the relay board 80. The other end of the power line 8a is connected to the power distribution line 91 via the connection portion 82. Also, the other end of the signal line 8b is connected to the signal wiring 88 via the connection portion 82. The power line 8a inputs the voltage generated by the power supply 6 to the voltage supply unit 90. The signal line 8b transmits the control signal from the control unit 5 to the inkjet head 41.

[0061] <Control unit 5> As shown in FIG. 8, the control unit 5 includes a CPU (Central Processing Unit) 131, an ASIC (Application Specific Integrated Circuit) 135, and a memory 140. These CPU 131, ASIC 135, and memory 140 are mounted on the control board 7 (see FIG. 6). As shown in FIG. 6, the signal wirings 7b, 7c provided on the control board 7 are connected to the ASIC 135, respectively. The end of the signal wiring 7b on the side opposite to the ASIC 135 side is connected to the power supply 6. The end of the signal wiring 7c on the side opposite to the ASIC 135 side is connected to the connection portion 7a of the control board 7.

[0062] Returning to FIG. 8, the CPU 131, ASIC 135, and 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 EEPROM 134. Note that at least one of the CPU 131 and the memory 140 may be provided separately without being mounted on the control board 7.

[0063] ASIC 135 outputs control signals to the ASF motor 20M, LF motor 30M, carriage motor 70M, inkjet head 41, power supply 6, etc., and controls the operations of these components. For example, the control unit 5 controls the inkjet head 41, ASF motor 20M, LF motor 30M, carriage motor 70M, etc. based on the recording data transmitted from an external device (e.g., a PC or smartphone), alternately executes the conveyance process and the recording process, and records an image or the like on the paper P. Further, the control unit 5 controls the on / off of the power supply 6. For example, the control unit 5 controls the on / off of the power supply 6 in units of recording jobs. That is, the control unit 5 keeps the power supply 6 on while the image for one recording job is being recorded, and turns off the power supply 6 when the recording of the image for one recording job is completed.

[0064] Note that the ASIC 135 in the present embodiment is connected to the ASF motor 20M, LF motor 30M, and carriage motor 70M by individual wirings (not shown) and controls these motors 20M, 30M, and 70M.

[0065] Note that the control unit 5 in the present embodiment has one CPU and one ASIC, but the control unit 5 may include only one ASIC, and this one ASIC may perform all the necessary processes collectively, or may include a plurality of ASICs, and these plurality of ASICs may share and perform the necessary processes.

[0066] <Power supply 6> As shown in FIG. 6, the power supply 6 is mounted on the control board 7. The power supply 6 is a regulator or the like, and generates a voltage of a magnitude necessary to drive the inkjet head 41 from the voltage supplied from an external power source. The power supply 6 is connected to the ASIC 135 of the control unit 5 by a signal wiring 7b. Further, the other end of a power supply wiring 7d, one end of which is connected to the connection portion 7a, is connected to the power supply 6. That is, the power supply 6 is connected to the power supply line 8a of the FFC 8 via the power supply wiring 7d and the connection portion 7a. The end of the power supply line 8a opposite to the side connected to the power supply 6 is connected to the power supply wiring 91 via the connection portion 82.

[0067] <Operation of Voltage Supply Unit 90> Here, with reference to FIG. 7, the operation of the voltage supply unit 90 will be described. When the power supply 6 is turned on under the control of the control unit 5, as shown in FIG. 7(a), the voltage generated by the power supply 6 is input to the power supply wiring 91 of the voltage supply unit 90 via the connection portion 82 of the relay substrate 80. The voltage input to the power supply wiring 91 is supplied to the head wiring 91a and the valve wiring 91b, respectively.

[0068] The voltage supplied to the head wiring 91a is supplied to the inkjet head 41 via the connection portion 83 of the relay substrate 80. Also, the voltage supplied to the head wiring 91a is input to the CE terminal of the switching circuit 86 via the connection line 93. When a voltage is input to the CE terminal, the switching circuit 86 is in a state where no voltage is supplied to the electromagnetic valve 64.

[0069] On the other hand, the voltage supplied to the valve wiring 91b is charged to the capacitor 85. As described above, at this time, the switching circuit 86 is in a state where no voltage is supplied to the electromagnetic valve 64, so the voltage supplied to the valve wiring 91b is not supplied to the electromagnetic valve 64 via the connection portion 84.

[0070] When the power supply 6 is turned off under the control of the control unit 5, as shown in FIG. 7(b), the input of the voltage from the power supply 6 stops and the capacitor 85 discharges. At this time, the diode 87 prevents the flow of electricity from the intermediate point 94a to the power supply wiring 91. Also, since no voltage is input to the CE terminal of the switching circuit 86, the switching circuit 86 is in a state where a voltage is supplied to the electromagnetic valve 64 due to the discharge of the capacitor 85. Therefore, due to the discharge of the capacitor 85, a voltage is supplied to the electromagnetic valve 64 via the connection portion 84.

[0071] In this way, the voltage supply unit 90 can switch the destination of the voltage generated by the power supply 6. Specifically, when the power supply 6 is on, the voltage supply unit 90 supplies voltage to the inkjet head 41, and when the power supply 6 is off, it supplies voltage to the electromagnetic valve 64. The voltage supply unit 90 switches the destination of the voltage exclusively. That is, the voltage supply unit 90 does not supply voltage to both the inkjet head 41 and the electromagnetic valve 64 simultaneously.

[0072] <Features of the First Embodiment> As described above, the printer 1 of the above-described embodiment includes a power supply 6 that generates voltage, a power supply line 8a connected to the power supply 6, and a voltage supply unit 90 that supplies the voltage generated by the power supply 6 and input via the power supply line 8a to the inkjet head 41 and the electromagnetic valve 64. The voltage supply unit 90 can switch the destination of the voltage.

[0073] According to the above configuration, the voltage generated by one power supply 6 and input to the voltage supply unit 90 via one power supply line 8a can be supplied to the inkjet head 41 and the electromagnetic valve 64. Therefore, the number of power supplies 6 and the number of power supply lines 8a can be reduced, enabling the miniaturization of the device.

[0074] Further, the printer 1 of the above-described embodiment further includes a control board 7 on which the power supply 6 is mounted and a relay board 80 to which the inkjet head 41 and the electromagnetic valve 64 are connected, and the power supply line 8a is formed on the FFC8. In this embodiment, the number of power supplies 6 and the number of power supply lines 8a can be reduced, and the size of the control board 7 and the width of the FFC8 can be decreased.

[0075] Furthermore, in the printer 1 of the above-described embodiment, the voltage supply unit 90 includes a power supply wiring 91 connected to the power supply 6 of the power supply line 8a, head wiring 91a formed by branching of the power supply wiring 91 and connected to the inkjet head 41, and valve wiring 91b connected to the electromagnetic valve 64, a connection line 94 connecting an intermediate point 94a of the valve wiring 91b and the ground, a capacitor 85 provided in the connection line 94, a switching circuit 86 provided in the valve wiring 91b and capable of switching between a state where a voltage is supplied to the electromagnetic valve 64 and a state where no voltage is supplied to the electromagnetic valve 64, and a connection line 93 connecting the head wiring 91a and the switching circuit 86. When a voltage is generated by the power supply 6 and the voltage is input to the switching circuit 86 via the connection line 93, the switching circuit 86 switches to a state where no voltage is supplied to the electromagnetic valve 64. When no voltage is generated by the power supply 6 and no voltage is input to the switching circuit 86 via the connection line 93, the switching circuit 86 switches to a state where a voltage is supplied to the electromagnetic valve 64 by the discharge of the capacitor 85. Therefore, the voltage supply unit 90 does not require a control signal for switching the voltage supply destination, so a signal line for supplying the control signal is unnecessary, and further miniaturization of the device is possible.

[0076] In addition, in the printer 1 of the above-described embodiment, a diode 87 for preventing the flow of electricity from the intermediate point 94a toward the power supply wiring 91 side is provided between the power supply wiring 91 and the intermediate point 94a in the valve wiring 91b. Therefore, when the capacitor 85 is discharged, it is possible to prevent a voltage from being supplied to the inkjet head 41 due to the flow of electricity through the valve wiring 91b from the intermediate point 94a toward the power supply wiring 91 side.

[0077] Also, in the printer 1 of the above-described embodiment, the power supply 6 generates a voltage of a magnitude necessary to drive the inkjet head 41, and the switching circuit 86 of the voltage supply unit 90 has a function as a voltage conversion circuit that changes the voltage input via the power supply line 8a to a magnitude necessary to drive the electromagnetic valve 64. Therefore, a voltage of an appropriate magnitude can be supplied to the electromagnetic valve 64.

[0078] (Second Embodiment) Next, with reference to FIG. 9, a printer according to a second embodiment of the present invention will be described. The configuration of the voltage supply unit 290 provided on the relay substrate 280 of this embodiment is mainly different from that of the printer 1 of the first embodiment. Hereinafter, for components having the same configuration as those in the first embodiment, the same reference numerals will be given and their descriptions will be omitted as appropriate.

[0079] On the control board 207 of this embodiment, two signal wirings 7c1 and 7c2 are provided, one end of which is connected to the ASIC 135 and the other end of which is connected to the connection portion 7a. Also, on the FFC 208, a power line 8a and two signal lines 8b1 and 8b2 are provided, one end of each of which is connected to the connection portion 7a of the control board 7 and the other end of which is connected to the connection portion 82 of the relay board 80. The signal line 8b1 is connected to the signal wiring 7c1 via the connection portion 7a of the control board 207. The signal line 8b2 is connected to the signal wiring 7c2 via the connection portion 7a of the control board 207. The signal line 8b2 is connected to the other end of a signal wiring 88 whose one end is connected to the connection portion 83 on the relay board 280.

[0080] The voltage supply unit 290 has a switching circuit 286 mounted on the relay substrate 280. The switching circuit 286 switches the supply destination of the input voltage between the inkjet head 41 and the electromagnetic valve 64. The switching circuit 286 exclusively switches the supply destination of the voltage. Also, the switching circuit 286 has a function as a voltage conversion circuit.

[0081] The other end of a power supply wiring 291, one end of which is connected to the connection portion 82, is connected to the switching circuit 286. The power supply wiring 291 is connected to the power line 8a of the FFC 8 connected to the connection portion 82. Thereby, the voltage generated by the power supply 6 is input to the switching circuit 286 via the power supply wiring 7d, the power line 8a, the connection portion 82, and the power supply wiring 291.

[0082] Further, one end of a signal wiring 289, whose other end is connected to a connection portion 82, is connected to the switching circuit 286. The signal wiring 289 is connected to a signal line 8b1 of an FFC 208 connected to the connection portion 82. As a result, a control signal generated by the ASIC 135 is input to the switching circuit 286 via the signal wiring 7c1, the signal line 8b1, the connection portion 82, and the signal wiring 289.

[0083] One end of a head wiring 291a, whose other end is connected to a connection portion 83, is connected to the switching circuit 286. The head wiring 291a is connected to the inkjet head 41 via the connection portion 83, an FPC 96, and a COF 95. One end of a valve wiring 291b, whose other end is connected to a connection portion 84, is connected to the switching circuit 286. The valve wiring 291b is connected to the electromagnetic valve 64 via the connection portion 84 and a wiring 97.

[0084] As one of the control signals, the ASIC 135 generates a switching signal for instructing the switching circuit 286 to switch the voltage supply destination. The switching signal is a signal for instructing to switch the voltage supply destination to either the inkjet head 41 or the electromagnetic valve 64. For example, while an image for one recording job is being recorded, the switching signal instructs to switch the voltage supply destination to the inkjet head 41, and when the recording of the image for one recording job is completed, the switching signal instructs to switch the voltage supply destination to the electromagnetic valve 64. In the first embodiment, an example in which the power supply 6 is turned on / off by the control unit 5 in units of recording jobs has been described, but in this embodiment, the power supply 6 is continuously turned on during a period in which a plurality of recording jobs are executed.

[0085] A voltage generated by the power supply 6 is input to the switching circuit 286 via a power supply line 8a. Also, a switching signal generated by the ASIC 135 is input to the switching circuit 286 via a signal line 8b1. The switching circuit 286 switches the voltage supply destination based on the switching signal.

[0086] <Features of the Second Embodiment> As described above, in this embodiment, similar to the first embodiment described above, the voltage generated by one power supply 6 and input to the voltage supply unit 290 via one power supply line 8a can be supplied to the inkjet head 41 and the electromagnetic valve 64, so that the apparatus can be miniaturized.

[0087] Also, in this embodiment, it includes an ASIC 135 mounted on the control board 207 and a signal line 8b1 connected to the ASIC 135. The voltage supply unit 290 is mounted on the relay board 280, and a voltage is input via the power supply line 8a, and it has a switching circuit 286 that switches the voltage supply destination between the inkjet head 41 and the electromagnetic valve 64. The ASIC 135 generates a switching signal for instructing the switching circuit 286 to switch the voltage supply destination. The switching circuit 286 switches the voltage supply destination based on the switching signal generated by the ASIC 135 and input via the signal line 8b1. In this embodiment, although a signal line 8b1 for supplying the switching signal is required, since the power supply line for supplying the voltage is thicker than the signal line, the apparatus can be miniaturized compared to the case where a plurality of power supply lines are provided.

[0088] 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 by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope equivalent to the claims.

[0089] Also, in the first and second embodiments described above, the power supply line 8a constitutes the wiring formed on one FFC 8(208), but the power supply line 8a itself may be a single individual wiring.

[0090] Also, in the above-described first and second embodiments, a case has been described in which a voltage is supplied to the inkjet head 41 while an image related to one recording job is being recorded, and a voltage is supplied to the electromagnetic valve 64 when the recording of the image related to one recording job is completed. However, the switching timing of the voltage supply destination is not limited to this. That is, for example, a negative pressure detection means for detecting the negative pressure in the ink storage chamber 62a may be provided, and a voltage may be supplied to the inkjet head 41 when the negative pressure in the ink storage chamber 62a is less than a predetermined value, and a voltage may be supplied to the electromagnetic valve 64 when the negative pressure in the ink storage chamber 62a becomes equal to or more than the predetermined value.

[0091] Furthermore, in the above-described first and second embodiments, a case has been described in which the voltage supply unit 90(290) exclusively switches the voltage supply destination. However, this is not limiting. That is, for example, the voltage supply unit 90(290) may switch between supplying the voltage only to the inkjet head 41 and supplying the voltage to both the inkjet head 41 and the electromagnetic valve 64.

[0092] In addition, in the above-described first and second embodiments, a case has been described in which the switching circuit 86(286) has a function as a transformer circuit. However, this is not limiting. A transformer circuit may be provided separately from the switching circuit 86(286). Also, when the magnitude of the voltage (=V2) required to drive the electromagnetic valve 64 is equal to the magnitude of the voltage (=V1) required to drive the inkjet head 41, a component corresponding to the transformer circuit may not be provided.

[0093] Furthermore, in the above-described first embodiment, a case has been described in which the diode 87 for preventing the backflow of electricity when the capacitor 85 is discharged is provided. However, the diode 87 may not be provided.

[0094] In addition, in the above-described embodiments, the present invention is adopted in a monochrome printer, but the present invention may also be adopted in a color printer.

[0095] In addition, 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. However, the ink tank 61 may not be provided with the ink inlet 67.

[0096] In addition, in the above-described embodiment, the case where the ink tank 61 includes the electromagnetic valve 64 has been described. However, 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 employed instead of the electromagnetic valve 64.

[0097] 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. However, 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.

[0098] In addition, the present invention can also be applied to a liquid ejection device having a liquid ejection head that ejects a liquid other than ink. Furthermore, the ejection target is not limited to the paper P, and may be, for example, cloth, a substrate, or the like. Also, as long as the liquid can be ejected from the nozzle by being driven based on a signal from the control unit 5, a means for imparting ejection energy other than the piezoelectric actuator 50 can also be adopted. In this case, for example, a thermal method for imparting ejection energy may be adopted in which the liquid ink in the nozzle is heated by a heating element to generate bubbles and the ink is extruded from the nozzle for recording.

Explanation of Reference Numerals

[0099] 1 Printer (Liquid Ejection Device) 5 Control Unit 6 Power Supply 7 Control Board (Main Board) 8 FFC (Flexible Cable) 8a Power Supply Line 8b1 Signal Line 35 Conveyor roller pair (conveying 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 80 Relay board (sub-board) 85 Capacitor 86 Switching circuit (transforming circuit) 87 Diode 90 Voltage supply unit (supply unit) 91 Power supply wiring (wiring) 91a Wiring for head (first branch wiring) 91b Wiring for valve (second branch wiring) 93 Connection line (second connection line) 94 Connection line (first connection line) 94a Intermediate point 135 ASIC (control unit) 286 Switching circuit

Claims

1. A liquid ejection head having a nozzle for ejecting a liquid, A liquid storage section having a liquid storage chamber for storing a liquid, an air communication passage for communicating the liquid storage chamber with the outside, and 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 liquid can flow, A power source that generates a voltage, A main board on which the power source is mounted, A sub-board to which the liquid ejection head and the valve are connected, A control section mounted on the main board, A signal line connected to the control section, A power line connected to the power source, A supply section that supplies the voltage generated by the power source and input via the power line to the liquid ejection head and the valve, and is provided with, The supply section is capable of switching the voltage supply destination, The power line is formed on a flexible cable, The supply section is mounted on the sub-board, and has a switching circuit that receives a voltage via the power line and switches the voltage supply destination between the liquid ejection head and the valve, The control section generates a switching signal for instructing the switching circuit to switch the voltage supply destination, The switching circuit switches the voltage supply destination based on the switching signal generated by the control section and input via the signal line. A liquid ejection device characterized by this.

2. A liquid ejection head having a nozzle for ejecting a liquid, A liquid storage section having a liquid storage chamber for storing a liquid, an air communication passage for communicating the liquid storage chamber with the outside, and 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 liquid can flow, A power source that generates a voltage, A power line connected to the power source, A supply section that supplies the voltage generated by the power source and input via the power line to the liquid ejection head and the valve, and is provided with, The supply section is capable of switching the voltage supply destination, Furthermore, the supply section, A wiring connected to an end portion of the power line opposite to the side connected to the power source, Each is formed by the branching of the wiring, and includes a first branched wiring connected to the liquid ejection head and a second branched wiring connected to the valve, a first connection line connecting an intermediate point on the second branched wiring and the ground, a capacitor provided on the first connection line and charged by a voltage input to the second branched wiring via the power line, a switching circuit provided between the intermediate point and the valve in the second branched wiring and capable of switching between a state in which a voltage is supplied to the valve and a state in which no voltage is supplied to the valve, and a second connection line connecting the first branched wiring and the switching circuit, wherein the switching circuit when a voltage is generated by the power supply and the voltage is input to the switching circuit via the power line, the wiring, the first branched wiring, and the second connection line, switches to a state in which no voltage is supplied to the valve, and when no voltage is generated by the power supply and no voltage is input to the switching circuit via the power line, the wiring, the first branched wiring, and the second connection line, switches to a state in which a voltage is supplied to the valve by the discharge of the capacitor. The liquid ejection device is characterized by this.

3. The liquid ejection device according to claim 2, wherein a diode that prevents the flow of electricity from the intermediate point toward the wiring side is provided between the wiring and the intermediate point in the second branched wiring.

4. A liquid ejection head having a nozzle for ejecting liquid, a liquid storage chamber for storing liquid, an air communication path 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 communicating state in which the air communication path is communicated or a blocking state in which the air communication path is blocked, a liquid flow path that connects the liquid ejection head and the liquid storage chamber so that liquid can flow, a power supply that generates a voltage, a power line connected to the power supply, and a supply unit that supplies the voltage generated by the power supply and input via the power line to the liquid ejection head and the valve. The supply unit is provided, wherein the supply unit is capable of switching the voltage supply destination, the power supply generates a voltage of a magnitude necessary to drive the liquid ejection head, and the supply unit has a transformer circuit that changes the voltage input via the power line to a magnitude necessary to drive the valve. The liquid ejection device is characterized by this.

5. A transport mechanism that transports a recording medium in a transport direction, a carriage that supports the liquid ejection head and the liquid storage unit, The liquid ejection device according to any one of claims 1 to 4, further comprising a moving mechanism that moves the carriage in a scanning direction intersecting the transport direction.

6. The liquid ejection device according to any one of claims 1 to 5, wherein the valve is an electromagnetic valve.

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