Liquid discharge device and liquid discharge method

Abstract

To reduce discharge abnormalities.SOLUTION: A liquid discharge device according to one embodiment of the invention comprises: a liquid chamber including a nozzle plate provided with a nozzle hole; supply means which supplies liquid to the liquid chamber; a valve body which is provided in the liquid chamber; and valve body moving means which moves the valve body. The liquid is supplied from the liquid chamber to the nozzle hole both when the liquid is discharged and when the liquid is not discharged. The supply amount of the liquid to the nozzle hole when the liquid is not discharged is smaller than the supply amount of the liquid to the nozzle hole when the liquid is discharged.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device and a liquid ejection method. [Background technology]

[0002] Conventionally, a valve-opening and closing type liquid ejection device is known in which pressurized liquid supplied to a liquid chamber is ejected by opening a nozzle hole provided in the liquid chamber by moving a valve body, and is not ejected by closing the nozzle hole by moving the valve body.

[0003] For example, Patent Document 1 discloses a method for reducing ejection abnormalities by vibrating the liquid surface in the nozzle hole when not ejecting, thereby stirring the thickened liquid within the liquid chamber. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a valve-opening and closing type liquid ejection device, the liquid in the liquid chamber is pressurized, so the liquid surface in the nozzle hole cannot be vibrated when not being ejected. As a result, in a valve-opening and closing type liquid ejection device, the thickened liquid cannot be agitated in the liquid chamber by the method described in Patent Document 1, and ejection abnormalities cannot be reduced.

[0005] An object of the present invention is to reduce ejection abnormalities. [Means for solving the problem]

[0006] A liquid ejection device according to one aspect of the present invention comprises a liquid chamber including a nozzle plate having nozzle holes, a supply means for supplying liquid to the liquid chamber, a valve body provided in the liquid chamber, and a valve body moving means for moving the valve body, and the liquid is supplied from the liquid chamber to the nozzle hole both when the liquid is being ejected and when the liquid is not being ejected, and the amount of liquid supplied to the nozzle hole when the liquid is not being ejected is less than the amount of liquid supplied to the nozzle hole when the liquid is being ejected. [Effects of the Invention]

[0007] According to the present invention, ejection abnormalities can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view showing an example of the overall configuration of a liquid ejection device according to a first embodiment of the present invention. [Figure 2] FIG. 10 is an enlarged view of the periphery of the nozzle hole, showing a state in which the nozzle hole is almost completely closed by the valve body. [Figure 3] FIG. 10 is an enlarged view of the periphery of the nozzle hole, showing a state in which the nozzle hole is not completely closed by the valve body. [Figure 4] FIG. 2 is a block diagram showing the functional configuration of a control unit included in the liquid ejection device according to the first embodiment of the present invention. [Figure 5] FIG. 4 is a diagram showing a driving voltage of a valve body moving means provided in the liquid discharge device according to the first embodiment of the present invention. [Figure 6] 6 is a diagram showing how the end face of the valve body moves in response to the drive voltage in FIG. 5. FIG. [Figure 7] FIG. 10 is a schematic perspective view showing a valve body provided in a liquid discharge device according to a first modified example of the first embodiment of the present invention. [Figure 8] FIG. 10 is a schematic cross-sectional view showing a valve body provided in a liquid discharge device according to a second modified example of the first embodiment of the present invention. [Figure 9] FIG. 10 is a schematic cross-sectional view showing a valve body provided in a liquid discharge device according to a third modified example of the first embodiment of the present invention. [Figure 10] FIG. 10 is a schematic perspective view showing a nozzle plate included in a liquid ejection device according to a fourth modified example of the first embodiment of the present invention. [Figure 11] FIG. 10 is a schematic cross-sectional view showing a nozzle plate included in a liquid ejection device according to a fifth modified example of the first embodiment of the present invention. [Figure 12] FIG. 10 is a schematic diagram showing a nozzle plate included in a liquid ejection device according to a sixth modified example of the first embodiment of the present invention. [Figure 13] FIG. 10 is a schematic cross-sectional view showing a state in which liquid is not being ejected in a liquid ejection device according to a second embodiment of the present invention. [Figure 14] FIG. 10 is a schematic cross-sectional view showing a state in which liquid is being discharged in a liquid discharge device according to a second embodiment of the present invention. [Figure 15] FIG. 10 is a schematic diagram illustrating a configuration of a coating device according to a third embodiment of the present invention. [Figure 16] FIG. 10 is a diagram showing a first example of arrangement of a coating device according to a third embodiment of the present invention on a target object. [Figure 17] FIG. 10 is a diagram showing a second example of arrangement of the coating device according to the third embodiment of the present invention on the target object. [Figure 18] FIG. 13 is a first schematic cross-sectional view showing a nozzle plate included in a liquid ejection device according to a seventh modified example of the present invention. [Figure 19] FIG. 13 is a second schematic cross-sectional view showing a nozzle plate included in a liquid ejection device according to a seventh modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A liquid ejection device and a liquid ejection method according to an embodiment of the present invention will be described in detail below with reference to the drawings. However, the following embodiments are merely illustrative of a liquid ejection device and a liquid ejection method for embodying the technical concept of the present embodiment, and are not limited thereto. Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative positions of components described in the embodiments are merely illustrative examples and are not intended to limit the scope of the present invention. Note that the size, positional relationships, etc. of components shown in each drawing may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate components that are the same or of the same quality, and detailed description will be omitted as appropriate.

[0010] In the figures shown below, the X axis and Y axis may be used to represent directions. The direction in which the X axis extends is the X direction, and the direction in which the Y axis extends is the Y direction. The direction in which the arrow indicating the X axis points is referred to as the +X direction, and the direction opposite to the +X direction is referred to as the -X direction. The direction in which the arrow indicating the Y axis points is referred to as the +Y direction, and the direction opposite to the +Y direction is referred to as the -Y direction. The normal direction of the nozzle plate provided in the liquid ejection device according to an embodiment of the present invention is assumed to be along the Y direction. However, these directional expressions merely describe the relationship between relative positions, orientations, directions, etc., and do not necessarily correspond to the relationship during use.

[0011] In this specification, in order to avoid overly complicated drawings, schematic diagrams may be used in which some parts or components are omitted, or end views showing only the cut surface may be used as cross-sectional views. Parallel may include an error of ±10 degrees or less from 0 degrees. In this specification, perpendicular may include an error of ±10 degrees or less from 90 degrees. "Arranged" does not only mean direct contact, but also includes indirect arrangement, for example, via another component.

[0012] [First embodiment] <Configuration of the liquid ejection device according to the first embodiment of the present invention> (Overall composition) The configuration of a liquid ejection device according to a first embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a schematic cross-sectional view showing an example of the overall configuration of a liquid ejection device 100 according to a first embodiment of the present invention. Figure 1 shows a cross-section of the liquid ejection device 100, including a plurality of nozzle holes 101 provided in the liquid ejection device 100. Figure 2 is an enlarged view of the vicinity of the nozzle hole 101, showing an example of a state in which the nozzle hole 101 is almost completely closed by the valve body 104. Figure 3 is an enlarged view of the vicinity of the nozzle hole 101, showing an example of a state in which the nozzle hole 101 is not completely closed by the valve body 104. Figures 2 and 3 are enlarged views of the area corresponding to area II in Figure 1.

[0013] The liquid ejection device 100 includes a liquid chamber 103 including a nozzle plate 102 with nozzle holes 101 for ejecting liquid, a supply means 110 for supplying pressurized liquid P to the liquid chamber 103, a valve element 104 provided in the liquid chamber 103, and a valve element moving means 105 for moving the valve element 104. In the example shown in Fig. 1, the liquid ejection device 100 also includes a control unit 120 for controlling the movement of the valve element 104 by the valve element moving means 105, and a frame 106 to which an end of the valve element moving means 105 opposite to the side where the valve element 104 is located is connected. The liquid ejection device 100 also includes a supply port 107 through which the liquid P is supplied from the supply means 110 to the liquid chamber 103, and a discharge port 108 through which the liquid P in the liquid chamber 103 is discharged toward the supply means 110.

[0014] The liquid ejection device 100 ejects pressurized liquid P supplied to a liquid chamber 103 by a supply means 110 by moving a valve body 104 to open a nozzle hole 101 provided in the liquid chamber 103, and stops ejection by moving the valve body 104 to close the nozzle hole 101. The liquid ejection device 100 is a valve opening and closing type liquid ejection device. The liquid ejection device 100 ejects the liquid P through the nozzle hole 101 from the inside to the outside of the liquid chamber 103 in a direction parallel to the normal direction Y of the nozzle plate 102.

[0015] 1, a nozzle plate 102 has a plurality of nozzle holes 101 arranged side by side in the X direction. A plurality of liquid chambers 103 corresponding to the plurality of nozzle holes 101 are connected in the X direction to form a single common liquid chamber. Liquid P supplied from a supply means 110 flows through a common liquid chamber formed by the plurality of liquid chambers 103. The liquid ejection device 100 can eject the liquid P flowing through the common liquid chamber individually from the plurality of nozzle holes 101.

[0016] In a valve-opening and closing type liquid discharge device, when liquid P is not being discharged, if an end 101a of the nozzle hole 101 on the side where the valve element 104 is located is blocked and closed with the valve element 104 as shown in FIG. 2, liquid P may remain inside the nozzle hole 101. The liquid P inside the nozzle hole 101 shown in FIG. 2 is the liquid P that remains inside the nozzle hole 101. Because an end 101b of the nozzle hole 101 opposite to the end 101a is open to the atmosphere, if the device is left for a long period of time, the liquid P remaining inside the nozzle hole 101 is exposed to the atmosphere and dries. Due to the drying, the liquid P inside the nozzle hole 101 may thicken or adhere to the inner wall of the nozzle hole 101, etc. Due to such thickening of the liquid P or adhesion to the nozzle hole 101, the next time the liquid P is discharged from the nozzle hole 101, abnormal discharge may occur, such as the liquid P not being discharged or being discharged in a curved direction.

[0017] For example, Patent Document 1 discloses a method for reducing ejection abnormalities by vibrating the liquid surface in the nozzle hole when not ejecting, thereby stirring the thickened liquid in the liquid chamber. However, in a valve-opening and closing type liquid ejection device, the liquid in the liquid chamber is pressurized, so the liquid surface in the nozzle hole cannot be vibrated when not ejecting. Therefore, in a valve-opening and closing type liquid ejection device, the thickened liquid cannot be stirred in the liquid chamber by the method described in Patent Document 1, and ejection abnormalities cannot be reduced.

[0018] In the liquid ejection device 100 according to the embodiment of the present invention, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101 both when ejecting the liquid P and when not ejecting the liquid P. The amount of the liquid P supplied to the nozzle hole 101 when not ejecting the liquid P is less than the amount of the liquid P supplied to the nozzle hole 101 when ejecting the liquid P.

[0019] 3, in the liquid ejection device 100, even when the liquid P is not being ejected, the end 101a of the nozzle hole 101 is not completely closed by the end face 104a of the valve body 104 on the side where the nozzle plate 102 is located, so that a gap G0 is formed between the valve body 104 and the nozzle plate 102. By forming the gap G0, the liquid P can flow through the gap G0, and the liquid P can be supplied from the liquid chamber 103 to the nozzle hole 101. From another perspective, the liquid ejection device 100 provides the gap G0 to reduce the degree of sealing of the nozzle hole 101 by the valve body 104, so that the liquid P can be supplied to the nozzle hole 101 even when the liquid P is not being ejected.

[0020] Furthermore, the gap G0 when the liquid P is not being ejected is narrower than the gap that forms between the valve body 104 and the nozzle plate 102 when the liquid P is being ejected. As a result, the amount of liquid P supplied to the nozzle hole 101 when the liquid P is not being ejected is less than the amount of liquid P supplied to the nozzle hole 101 when the liquid P is being ejected, and the liquid P is not ejected from the nozzle hole 101.

[0021] In other words, when the liquid ejection device 100 is not ejecting the liquid P, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but the liquid P is not ejected from the nozzle hole 101. As a result, even if the liquid P remaining in the nozzle hole 101 is exposed to the outside air and dries, fresh liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, so it is possible to reduce the viscosity of the liquid P remaining in the nozzle hole 101 and its adhesion to the inner wall of the nozzle hole 101. As a result, when the liquid P is ejected again from the nozzle hole 101 after a non-ejection period, it is possible to reduce ejection abnormalities such as the liquid P not being ejected or being ejected in a curved manner. Note that the state in which the liquid P is not ejected from the nozzle hole 101 includes a state in which the liquid P does not leak or drip from the nozzle hole 101.

[0022] 3, when the liquid P is not being ejected, part of the liquid P disposed in the nozzle hole 101 protrudes from the nozzle plate 102. This makes it easier to achieve a state in which the liquid P is not ejected from the nozzle hole 101, although the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101.

[0023] Furthermore, in the liquid ejection device 100, the amount of liquid P supplied to the nozzle hole 101 when the liquid P is not being ejected varies depending on the physical properties of the liquid P and the environment near the nozzle hole. The physical properties of the liquid P include the viscosity or surface tension of the liquid P and the boiling point of the liquid P, and the environment near the nozzle hole is the vapor pressure near the nozzle hole. By varying the amount of liquid P supplied to the nozzle hole 101 when the liquid P is not being ejected depending on the physical properties of the liquid P, it is possible to stably achieve a state in which the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected, but the liquid P is not ejected from the nozzle hole 101, regardless of the physical properties of the liquid P. Similarly, by varying the amount of liquid P supplied to the nozzle hole 101 when liquid P is not being ejected depending on the vapor pressure near the nozzle hole, liquid P is supplied from the liquid chamber 103 to the nozzle hole 101 when liquid P is not being ejected, but a state in which liquid P is not ejected from the nozzle hole 101 can be stably achieved regardless of the environment near the nozzle hole.

[0024] Each component of the liquid ejection device 100 or related elements will be described in detail below.

[0025] (liquid P) Liquid P is, for example, a liquid with a viscosity greater than 10 mPa s, a liquid with a TI value (structural viscosity) greater than 1.3, a liquid with a solid content greater than 20 wt%, or a liquid containing particles with a particle diameter greater than 5 μm. The particles contained in Liquid P are ceramic particles, carbon particles, active material particles such as lithium transition metal oxides, etc.

[0026] (Nozzle hole 101 and nozzle plate 102) The nozzle plate 102 is a plate-like member made of a material such as a metal. The nozzle plate 102 forms part of the liquid chamber 103 and is disposed in a position facing the end of the valve body 104. The nozzle holes 101 are through-holes that are provided in the nozzle plate 102 and penetrate the nozzle plate 102 in the normal direction. The upper surface 102a of the nozzle plate 102 is the upper surface of the nozzle plate 102 on the side where the valve body 104 is located.

[0027] (Valve body 104) The valve bodies 104 are made up of a plurality of rod-shaped members each extending along the Y direction. A portion of the valve body 104 on the +Y side is arranged to be housed inside the liquid chamber 103. The valve body 104 is made up of a material including a metal material. The end of the valve body 104 on the side where the nozzle plate 102 is located may be prepared as a member separate from the main body member of the valve body 104, and the valve body 104 may be constructed by joining this member and the main body member.

[0028] The multiple valve elements 104 are paired with the multiple nozzle holes 101, with a portion of the +Y side inserted into the liquid chamber 103 and movable in the Y direction. The valve elements 104 open and close the nozzle holes 101 by moving the valve elements 104. The valve element moving means 105 moves the valve elements 104 in the Y direction in response to an applied voltage, thereby switching between a state in which the end face 104a of the valve element 104 does not block the end 101a of the nozzle hole 101, thereby opening the nozzle hole 101, and a state in which the end face 104a of the valve element 104 blocks the end 101a of the nozzle hole 101, thereby closing the nozzle hole 101.

[0029] (Valve body moving means 105) The valve element moving means 105 includes a piezoelectric element that expands and contracts in response to an applied voltage. For example, a piezoelectric element utilizing the d33 mode (longitudinal displacement type) can be used for this piezoelectric element. The piezoelectric element of the valve element moving means 105 expands and contracts along the Y-axis direction in response to an applied voltage. The material of the piezoelectric element is, for example, PZT (lead zirconate titanate). The piezoelectric element of the valve element moving means 105 is a layered piezoelectric element formed by stacking multiple piezoelectric elements along the Y-direction to increase the amount of displacement associated with expansion and contraction. The valve element moving means 105 shown in FIG. 1 moves the valve element 104 in the Y-direction by the piezoelectric element expanding and contracting in response to an applied voltage.

[0030] When the piezoelectric element of the valve element moving means 105 contracts along the Y direction in response to the applied voltage, the valve element 104 moves in the -Y direction, and the end face 104a of the valve element 104 moves away from the end 101a of the nozzle hole 101, opening the nozzle hole 101. When the piezoelectric element of the valve element moving means 105 expands along the Y direction in response to the applied voltage, the valve element 104 moves in the +Y direction, and the end face 104a of the valve element 104 blocks the end 101a of the nozzle hole 101, closing the nozzle hole 101.

[0031] (Supply means 110) 1 , the supply means 110 has a liquid storage section 111, an air compressor 112, an air tank 113, a regulator 114, and an air filter 115. The supply means 110 maintains the pressure by temporarily storing compressed air generated by the air compressor 112 in the air tank 113. Thereafter, the supply means 110 reduces the pressure of the compressed air using the regulator 114 to a pressure required for discharging the liquid P, removes foreign matter, moisture, oil, etc. using the air filter 115, and then pressurizes the inside of the liquid storage section 111. The liquid P pressurized by the supply means 110 is supplied to the liquid chamber 103 through the supply port 107.

[0032] Since the liquid P is pressurized by the supply means 110, when the nozzle hole 101 is opened by the valve body 104, the liquid P can be ejected through the nozzle hole 101 to the outside of the liquid chamber 103. When the nozzle hole 101 is closed by the valve body 104, the liquid P enters a non-ejection state.

[0033] 1, the valve element moving means 105 includes a piezoelectric element, but is not limited to this. For example, the valve element moving means 105 may include at least one of an electromagnet that generates a magnetic field in response to an applied voltage, an air cylinder that converts compressed air energy into linear motion in response to an applied voltage, a motor actuator that is driven in response to an applied voltage, or a hydraulic mechanism that generates hydraulic pressure in response to an applied voltage.

[0034] The liquid ejection device 100 can also be equipped with a valve element moving means 105 including a piezoelectric element that operates in the d31 mode. In this case, the relationship between the magnitude of the applied voltage and the expansion / contraction is the opposite of that when the d33 mode is used. For example, the valve element moving means 105 may be configured to include a hollow nozzle body having a nozzle hole 101 at its tip and an inlet for injecting liquid P near the nozzle hole 101, a piezoelectric element that is built into the nozzle body and expands and contracts in response to the application of an external voltage, a valve element that opens and closes the ejection hole, a reverse spring mechanism disposed between the valve element and the piezoelectric element, a sealing member that fits over the valve element to prevent ink from flowing into the piezoelectric element, and a pair of lead wires for applying voltage that are connected to electrodes of the piezoelectric element.

[0035] (control unit 120) The function of the control unit 120 will be described with reference to Fig. 4 to Fig. 6. Fig. 4 is a block diagram showing an example of the functional configuration of the control unit 120. Fig. 5 is a diagram showing an example of the drive voltage of the valve element moving means 105. Fig. 6 is a diagram showing an example of how the end face 104a of the valve element 104 moves in response to the drive voltage of Fig. 5.

[0036] The horizontal axis in Figures 5 and 6 represents time. The vertical axis in Figure 5 represents the voltage value of the drive voltage. The vertical axis in Figure 6 represents the position of the end face 104a of the valve body 104 in the Y direction. In Figures 5 and 6, the horizontal axis represents time. The position of the valve body 104 shown in Figure 6 changes depending on the voltage value of the drive voltage shown in Figure 5. In the example shown in Figures 5 and 6, there is an approximately linear relationship between the voltage value of the drive voltage and the position of the end face 104a. An approximately linear relationship means that there is an overall linear relationship, although there is a time delay in the change in the position of the end face 104a in response to the application of the drive voltage, linearity error, hysteresis, and other deviations from linearity.

[0037] The control unit 120 shown in FIG. 4 has an input unit 121, a drive voltage generation unit 122, an amplifier unit 123, and an output unit 124. These functions may be realized by electric circuits, or some of these functions may be realized by a CPU (Central Processing Unit). These functions may also be realized by multiple circuits or multiple CPUs. The control unit 120 generates a drive voltage by the drive voltage generation unit 122 to drive the valve element moving means 105 to open and close the nozzle hole 101 by the valve element 104, in accordance with data input via the input unit 121. The control unit 120 amplifies the drive voltage generated by the drive voltage generation unit 122 by the amplifier unit 123, and then outputs the amplified drive voltage to the valve element moving means 105 via the output unit 124.

[0038] The control unit 120 outputs the waveform of the driving voltage generated by the driving voltage generating unit 122 and amplified by the amplifying unit 123 to the liquid ejection device 100, thereby supplying the valve element moving means 105 with a driving voltage that changes over time.

[0039] In the liquid ejection device 100, the control unit 120 can switch between a first mode in which the liquid P is ejected and a second mode in which the liquid P is not ejected, by moving the valve element 104 using the valve element moving means 105. In the first mode, the end face 104a of the valve element 104 is positioned a first distance D1 away from the top surface 102a of the nozzle plate 102. Position Q2 in FIG. 6 corresponds to the position of the top surface 102a of the nozzle plate 102 in the Y direction. In the second mode, the end face 104a of the valve element 104 is positioned a second distance D2 away from the top surface 102a of the nozzle plate 102, which is shorter than the first distance D1. In the second mode, the liquid ejection device 100 supplies the liquid P from the liquid chamber 103 to the nozzle hole 101 through the gap between the end face 104a of the valve element 104 and the top surface 102a of the nozzle plate 102.

[0040] A more specific explanation will be given. When a first voltage E1 is applied to the valve element moving means 105, the piezoelectric element of the valve element moving means 105 contracts, and the end face 104a of the valve element 104 moves in the -Y direction, causing the end face 104a to move away from the end 101a of the nozzle hole 101, opening the nozzle hole 101. When the nozzle hole 101 opens, the liquid P is ejected from the nozzle hole 101. When a third voltage E3 greater than the first voltage E1 is applied to the valve element moving means 105, the piezoelectric element of the valve element moving means 105 expands, causing the end face 104a of the valve element 104 to move in the +Y direction, causing the end face 104a of the valve element 104 to almost completely block the end 101a of the nozzle hole 101, closing the nozzle hole 101. When the nozzle hole 101 closes, the liquid P is not ejected.

[0041] In the second mode of the liquid ejection device 100, the liquid ejection device 100 applies a second voltage E2, which is greater than the first voltage E1 and less than the third voltage E3, to the valve element moving means 105. In this case, the end face 104a of the valve element 104 does not completely block the end face 101a of the nozzle hole 101, creating a gap G0 as shown in FIG. 3. Closing the nozzle hole 101 prevents the liquid P from being ejected. In other words, in the second mode, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but the liquid P is not ejected from the nozzle hole 101. In the second mode, the liquid ejection device 100 can supply the liquid P from the liquid chamber 103 to the nozzle hole 101 through the gap G0 between the end face 104a of the valve element 104 and the upper surface 102a of the nozzle plate 102.

[0042] It is preferable that the second distance D2 be shorter as the pressure applied to the liquid P increases. When the length of the gap G0 in the Y direction is constant, the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 increases as the pressure applied to the liquid P increases. If the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 becomes too large, the liquid P may leak or drip from the nozzle hole 101. By shortening the second distance D2 as the pressure applied to the liquid P increases, it is possible to prevent the liquid P from leaking or dripping from the nozzle hole 101.

[0043] <Modification> Various modifications of the liquid discharge device 100 will be described below.

[0044] (First Modification) Fig. 7 is a schematic perspective view showing an example of a valve body 104 included in a liquid discharge device 100 according to a first modified example of the first embodiment of the present invention. Fig. 7 shows an end face 104a of the valve body 104, and the nozzle hole 101 and nozzle plate 102 facing the end face 104a.

[0045] In the liquid ejection device 100 according to the first modification, a first groove 41 is provided on the end surface 104a of the valve body 104. When the liquid P is not being ejected, the liquid ejection device 100 according to the first modification supplies the liquid P from the liquid chamber 103 to the nozzle hole 101 through the first groove 41. These are the main differences from the liquid ejection device 100 according to the first embodiment.

[0046] By providing the first groove 41 on the end face 104a of the valve body 104, the nozzle hole 101 is blocked by the end face 104a of the valve body 104, and even when the nozzle hole 101 is closed, i.e., when there is no gap G0 in FIG. 3 , or in other words, when the tip of the valve body 104 is located at position Q2, the liquid P in the liquid chamber 103 can pass through the first groove 41 and flow into the nozzle hole 101. As a result, in the liquid ejection device 100 according to the first modified example, when the liquid P is not being ejected, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but it is possible to achieve a state in which the liquid P is not ejected from the nozzle hole 101. Even if the liquid P remaining in the nozzle hole 101 is exposed to the outside air and dries, fresh liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, so it is possible to reduce the viscosity of the liquid P remaining in the nozzle hole 101 and the adhesion to the inner wall of the nozzle hole 101, etc. As a result, when the liquid P is ejected again from the nozzle hole 101 after a non-ejection period, ejection abnormalities such as the liquid P not being ejected or being ejected in a curved manner can be reduced.

[0047] In the liquid ejection device 100 according to the first modification, when the liquid P is not being ejected, the gap G0 in FIG. 3 does not necessarily have to be absent, and the gap G0 in FIG. 3 may be present. In other words, the tip of the valve element 104 does not necessarily have to be located at position Q2, and the tip of the valve element 104 may be located at a position shifted from position Q2. Furthermore, the first groove 41 is not limited to a groove extending in one direction as shown in FIG. 7. For example, the first groove 41 may include multiple grooves that intersect with each other or multiple grooves that extend radially from the center of the end face 104a. Since the ejection direction of the liquid P when ejected from the nozzle hole 101 may vary depending on the shape of the first groove 41, it is preferable that the first groove 41 be point-symmetric with respect to the center of the end face 104a in order to reduce the effect of the shape of the first groove 41 on the ejection direction.

[0048] (Second Modification) 8 is a schematic cross-sectional view showing an example of a valve body 104 included in a liquid discharge device 100 according to a second modified example of the first embodiment of the present invention. Fig. 8 is an enlarged view of a region corresponding to region II in Fig. 1.

[0049] In the liquid ejection device 100 according to the second modification, a first convex portion 42 is provided on the end surface 104a of the valve body 104. When the liquid ejection device 100 according to the second modification is not ejecting the liquid P, the liquid ejection device 100 supplies the liquid P from the liquid chamber 103 to the nozzle hole 101 through a first gap G1 formed by the first convex portion 42 abutting against the nozzle plate 102. These are the main differences from the liquid ejection device 100 according to the first embodiment.

[0050] By providing the first convex portion 42 on the end face 104a of the valve body 104, the nozzle hole 101 is blocked by the end face 104a of the valve body 104, and even when the nozzle hole 101 is closed, i.e., when there is no gap G0 in FIG. 3 , or in other words, when the tip of the valve body 104 is positioned at Q2, the liquid P in the liquid chamber 103 can pass through the first gap G1 and flow into the nozzle hole 101. As a result, in the liquid ejection device 100 according to the second modified example, when the liquid P is not being ejected, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but it is possible to achieve a state in which the liquid P is not ejected from the nozzle hole 101. Even if the liquid P remaining in the nozzle hole 101 is exposed to the outside air and dries, fresh liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, so that it is possible to reduce the viscosity of the liquid P remaining in the nozzle hole 101 and the adhesion to the inner wall of the nozzle hole 101, etc. As a result, when the liquid P is ejected again from the nozzle hole 101 after a non-ejection period, ejection abnormalities such as the liquid P not being ejected or being ejected in a curved manner can be reduced.

[0051] In the liquid ejection device 100 according to the second modified example, when the liquid P is not being ejected, the gap G0 in Fig. 3 does not necessarily have to be absent, and may be present. Furthermore, in the liquid ejection device according to the second modified example, the amount of liquid supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected can be changed by changing the shape or arrangement position of the first convex portion 42.

[0052] The first protrusions 42 may be formed by forming a mold with a shape corresponding to the first protrusions 42 and then molding the valve body 104 using the mold. Alternatively, the first protrusions 42 may be formed by forming recesses in the valve body 104 by sandblasting, etching, or stamping. Alternatively, the first protrusions 42 may be formed by adhesively fixing a member that constitutes the first protrusions 42 to the end face 104a of the valve body 104. The first protrusions 42 may also be formed by dispersing hard particles such as aluminum oxide on the end face 104a of the valve body 104 and then applying a coating over the hard particles. Furthermore, the first protrusions 42 may be formed by forming the valve body 104 from a flexible material and then pressing and fixing hard particles such as aluminum oxide against the flexible material with a strong force.

[0053] (Third Modification) 9 is a schematic cross-sectional view showing an example of a valve body 104 included in a liquid discharge device 100 according to a third modified example of the first embodiment of the present invention. Fig. 9 is an enlarged view of a region corresponding to region II in Fig. 1.

[0054] In the liquid discharge device 100 according to the third modification, the end surface 104a of the valve body 104 has a first porous structure 43. When the liquid discharge device 100 according to the third modification is not discharging the liquid P, the liquid discharge device 100 supplies the liquid P to the nozzle hole 101 through the holes of the first porous structure 43. These are the main differences from the liquid discharge device 100 according to the first embodiment.

[0055] Since the end surface 104a of the valve body 104 has the first porous structure 43, the nozzle hole 101 is blocked by the end surface 104a of the valve body 104, and even when the nozzle hole 101 is closed, i.e., when there is no gap G0 in FIG. 3 , or in other words, when the tip of the valve body 104 is positioned at Q2, the liquid P in the liquid chamber 103 can pass through the holes in the first porous structure 43 and flow into the nozzle hole 101. As a result, in the liquid ejection device 100 according to the third modified example, when the liquid P is not being ejected, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but it is possible to achieve a state in which the liquid P is not ejected from the nozzle hole 101. Even if the liquid P remaining in the nozzle hole 101 is exposed to the outside air and dries, fresh liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, thereby reducing the viscosity of the liquid P remaining in the nozzle hole 101 and preventing it from adhering to the inner wall of the nozzle hole 101, etc. As a result, when the liquid P is ejected again from the nozzle hole 101 after a non-ejection period, ejection abnormalities such as the liquid P not being ejected or being ejected in a curved manner can be reduced.

[0056] In the liquid ejection device 100 according to the third modification, when the liquid P is not being ejected, the gap G0 in FIG. 3 does not necessarily have to be absent, and the gap G0 in FIG. 3 may be present. The first porous structure 43 can be made of a porous metal material, resin material, or the like. The valve body 104 can also be constructed by preparing a member having the first porous structure 43 separately from the main body member of the valve body 104, and joining the main body member and the member having the first porous structure. By changing the size of the holes in the first porous structure 43, the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected can be changed.

[0057] (Fourth Modification) Fig. 10 is a schematic cross-sectional view showing an example of a nozzle plate 102 included in a liquid discharge device 100 according to a fourth modified example of the first embodiment of the present invention. Fig. 10 shows an end face 104a of a valve body 104, and the nozzle hole 101 and nozzle plate 102 facing the end face 104a.

[0058] In the liquid ejection device 100 according to the fourth modification, a second groove 21 is provided on the upper surface 102a of the nozzle plate 102. When viewed in the normal direction of the nozzle plate, for example, the Y direction, at least a portion of the second groove 21 is located outside the valve body 104. When the liquid ejection device 100 according to the fourth modification is not ejecting the liquid P, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101 through the second groove 21. These are the main points that make it different from the liquid ejection device 100 according to the first embodiment.

[0059] By providing the second groove 21 on the upper surface 102a of the nozzle plate 102, the nozzle hole 101 is blocked by the end surface 104a of the valve body 104, and even when the nozzle hole 101 is closed, i.e., when there is no gap G0 in FIG. 3 , or in other words, when the tip of the valve body 104 is positioned at Q2, the liquid P in the liquid chamber 103 can pass through the second groove 21 and flow into the nozzle hole 101. As a result, in the liquid ejection device 100 according to the fourth modified example, when the liquid P is not being ejected, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but it is possible to achieve a state in which the liquid P is not ejected from the nozzle hole 101. Even if the liquid P remaining in the nozzle hole 101 is exposed to the outside air and dries, fresh liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, so that it is possible to reduce the viscosity of the liquid P remaining in the nozzle hole 101 and its adhesion to the inner wall of the nozzle hole 101, etc. As a result, when the liquid P is ejected again from the nozzle hole 101 after a non-ejection period, ejection abnormalities such as the liquid P not being ejected or being ejected in a curved manner can be reduced.

[0060] In the liquid ejection device 100 according to the fourth modified example, when the liquid P is not being ejected, the gap G0 in FIG. 3 does not necessarily have to be absent, and the gap G0 in FIG. 3 may be present. The second groove 21 shown in FIG. 10 includes two or more grooves that intersect with each other. However, the configuration is not limited to this, and the second groove 21 may include, for example, one groove extending in one direction, or multiple grooves extending radially from the nozzle hole 101. Since the ejection direction when the liquid P is ejected from the nozzle hole 101 may change depending on the shape of the second groove 21, it is preferable that the second groove 21 be point-symmetric with respect to the nozzle hole 101 in order to reduce the effect of the shape of the second groove 21 on the ejection direction.

[0061] (Fifth Modification) 11 is a schematic cross-sectional view showing an example of a nozzle plate 102 included in a liquid ejection device 100 according to a fifth modified example of the first embodiment of the present invention. Fig. 11 is an enlarged view of a region corresponding to region II in Fig. 1.

[0062] In the liquid ejection device 100 according to the fifth modification, a second convex portion 22 is provided on a part of the upper surface 102a of the nozzle plate 102. When the liquid ejection device 100 according to the fifth modification is not ejecting the liquid P, the liquid ejection device 100 supplies the liquid P from the liquid chamber 103 to the nozzle hole 101 through a second gap G2 formed by the second convex portion 22 abutting against the valve body 104. These are the main differences from the liquid ejection device 100 according to the first embodiment.

[0063] By providing the second protrusion 22 on the upper surface 102a of the nozzle plate 102, the nozzle hole 101 is blocked by the end surface 104a of the valve element 104, and even when the nozzle hole 101 is closed, i.e., when there is no gap G0 in FIG. 3 , or in other words, when the tip of the valve element 104 is positioned at Q2, the liquid P in the liquid chamber 103 can pass through the second gap G2 and flow into the nozzle hole 101. Note that in this embodiment, position Q2 is the position where the valve element 104 abuts against the second protrusion 22. As a result, in the liquid ejection device 100 according to the fifth modified example, when the liquid P is not being ejected, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but it is possible to achieve a state in which the liquid P is not ejected from the nozzle hole 101. Even if the liquid P remaining in the nozzle hole 101 is exposed to the outside air and dries, fresh liquid P is supplied to the nozzle hole 101 from the liquid chamber 103, which reduces the viscosity of the liquid P remaining in the nozzle hole 101 and reduces the adhesion of the liquid P to the inner wall of the nozzle hole 101. As described above, when the liquid P is ejected again from the nozzle hole 101 after a non-ejection period, ejection abnormalities such as the liquid P not being ejected or being ejected in a curved manner can be reduced.

[0064] In the liquid ejection device 100 according to the fifth modified example, when the liquid P is not being ejected, the gap G0 in Fig. 3 does not necessarily have to be absent, and may be present. Furthermore, in the liquid ejection device according to the fifth modified example, the amount of liquid supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected can be changed by changing the shape, size, or arrangement position of the second convex portion 22.

[0065] The second protrusions 22 can be formed on the nozzle plate 102 by cutting, sandblasting, etching, stamping, or the like. Alternatively, the second protrusions 22 can be provided by adhesively fixing a member that constitutes the second protrusions 22 to the upper surface 102a of the nozzle plate 102. The second protrusions 22 can also be provided by dispersing hard particles such as aluminum oxide on the upper surface 102a of the nozzle plate 102 and then applying a coating over the hard particles. Furthermore, the second protrusions 22 can be provided by forming the nozzle plate 102 from a flexible material and pressing and fixing hard particles such as aluminum oxide with a strong force.

[0066] When the second protrusions 22 are provided on a portion of the upper surface 102a of the nozzle plate 102, it is preferable that the second protrusions 22 are not provided near the nozzle holes. That is, it is preferable that an area where the second protrusions 22 are not provided is provided on the upper surface 102a of the nozzle plate 102 between the nozzle holes and the area where the second protrusions 22 are provided. By not providing a protrusion near the nozzle holes, the circularity of the nozzle hole edge on the liquid inlet side can be maintained, and good liquid ejection can be achieved.

[0067] (Sixth Modification) 12 is a schematic cross-sectional view showing an example of a nozzle plate 102 included in a liquid ejection device 100 according to a sixth modified example of the first embodiment of the present invention. Fig. 12 is an enlarged view of a region corresponding to region II in Fig. 1.

[0068] The liquid ejection device 100 according to the sixth modification has a second porous structure 23 on a part of the upper surface 102a of the nozzle plate 102. When the liquid ejection device 100 according to the sixth modification is not ejecting the liquid P, the liquid ejection device 100 supplies the liquid P to the nozzle hole 101 through the holes of the second porous structure 23. These are the main differences from the liquid ejection device 100 according to the first embodiment.

[0069] Since the upper surface 102a of the nozzle plate 102 has the second porous structure 23, the nozzle hole 101 is blocked by the end surface 104a of the valve body 104, and even when the nozzle hole 101 is closed, i.e., when there is no gap G0 in FIG. 3 , the liquid P in the liquid chamber 103 can pass through the holes in the second porous structure 23 and flow into the nozzle hole 101. Note that in this embodiment, position Q2 is the position where the valve body 104 abuts the second porous structure 23. As a result, in the liquid ejection device 100 according to the sixth modified example, when the liquid P is not being ejected, the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101, but it is possible to achieve a state in which the liquid P is not ejected from the nozzle hole 101. Even if the liquid P remaining in the nozzle hole 101 is exposed to the outside air and dries, fresh liquid P is supplied to the nozzle hole 101 from the liquid chamber 103, which reduces the viscosity of the liquid P remaining in the nozzle hole 101 and reduces the adhesion of the liquid P to the inner wall of the nozzle hole 101. As described above, when the liquid P is ejected again from the nozzle hole 101 after a non-ejection period, ejection abnormalities such as the liquid P not being ejected or being ejected in a curved manner can be reduced.

[0070] In the liquid ejection device 100 according to the sixth modification, when liquid P is not being ejected, the gap G0 in FIG. 3 does not necessarily have to be absent, in other words, the tip of the valve element 104 is positioned at position Q2, but may instead have the gap G0 in FIG. 3. The second porous structure 23 can be made of a porous metal material, resin material, or the like. The nozzle plate 102 can also be constructed by preparing a member having the second porous structure 23 separately from the main body member of the nozzle plate 102, and joining the main body member and the member having the porous structure. By changing the size of the holes in the second porous structure 23, the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 when liquid P is not being ejected can be changed.

[0071] (Seventh Modification) When the valve element moving means 105 includes a piezoelectric element, the amount of movement of the valve element 104 per unit of drive voltage may change depending on the temperature (see, for example, Japanese Patent Application Laid-Open No. 2023-029203). Also, if the total number of extensions and contractions of the valve element moving means 105 increases, the amount of movement of the valve element 104 per unit of drive voltage may decrease.

[0072] 5, which is applied to the valve element moving means 105 when the liquid P is not being ejected, according to the temperature of the valve element moving means 105 and the total number of extensions and contractions of the valve element moving means 105. This makes it possible to stabilize the amount of liquid P supplied to the nozzle hole 101 when the liquid P is not being ejected.

[0073] (Eighth Modification) In the liquid discharge device 100 according to the eighth modification, the control unit 120 can further switch to a third mode in which the liquid P is not supplied to the nozzle hole 101 by moving the valve element 104 using the valve element moving means 105. In the third mode, the end face 104a of the valve element 104 may be located a third distance away from the upper surface 102a of the nozzle plate 102 that is shorter than the second distance E2, or may be in contact with the upper surface 102a of the nozzle plate 102.

[0074] For example, when cleaning the nozzle hole 101 or the nozzle plate 102, cleaning may be difficult if the liquid P is supplied from the liquid chamber 103 to the nozzle hole 101. When cleaning the nozzle hole 101 or the nozzle plate 102, the liquid ejection device 100 according to the eighth modification can be set to the third mode to prevent the liquid P from being supplied from the liquid chamber 103 to the nozzle hole 101. This makes cleaning easier.

[0075] (Ninth Modification) In the liquid ejection device 100 according to the ninth modification, the control unit 120 switches between the second mode and the third mode at predetermined time intervals or for a predetermined length of time. By switching between the second mode and the third mode at predetermined time intervals, it is possible to adjust the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected.

[0076] For example, deterioration of the valve element 104 over time or the like may change the sealing ability of the nozzle hole 101 by the valve element 104, which may change the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101. In such cases, the liquid ejection device 100 according to the ninth modified example can adjust the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected by switching between the second mode and the third mode at predetermined time intervals, in accordance with changes in the sealing ability of the nozzle hole 101 by the valve element 104. This makes it possible to stabilize the amount of liquid P supplied to the nozzle hole 101 when the liquid P is not being ejected. Furthermore, since the amount of liquid supplied can be controlled by the length of time for which the second distance E2 is controlled and the time interval for control, it is possible to control the amount of liquid supplied with high precision (controlling the gap by the drive voltage has the problem of large changes and variations in the amount of liquid supplied). In the case of multiple nozzles, controlling the gap using drive voltage requires fine voltage adjustment for each nozzle, making the circuit configuration complex and expensive, but since adjustments to time and intervals can be made through programming, there is no need for fine voltage adjustment for each nozzle (voltage for each mode is required), allowing for a simple circuit configuration and low cost.

[0077] (Tenth Modification) For example, the higher the vapor pressure around the nozzle hole 101, the greater the amount of evaporation from the nozzle hole 101, and the lower the vapor pressure around the nozzle hole 101, the less the amount of evaporation from the nozzle hole 101.

[0078] In the liquid ejection device 100 according to the tenth modification, the control unit 120 may control the amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected so that the amount is increased as the vapor pressure around the nozzle hole 101 increases and decreased as the vapor pressure around the nozzle hole 101 decreases. This makes it possible to maintain an appropriate amount of liquid P supplied from the liquid chamber 103 to the nozzle hole 101 when the liquid P is not being ejected, even if the vapor pressure around the nozzle hole 101 changes.

[0079] (Other variations) To obtain the gap G0, the valve element moving means 105 is fixed to the frame 106 so that the distance between the end surface 104a of the valve element 104 and the upper surface 102a of the nozzle plate 102 is equal to the gap G0. This makes it easy to obtain the gap G0.

[0080] When particles are dispersed in the liquid P, the second distance D2 may be equal to or less than the maximum diameter of the particles, and is preferably equal to or less than the median diameter of the particles. For example, when the liquid P is not being ejected, if particles flow from the liquid chamber 103 into the nozzle hole 101, the particles may adhere to the nozzle hole 101, which may result in ejection abnormalities. By setting the second distance D2 to be equal to or less than the maximum diameter of the particles, it is possible to prevent particles from flowing from the liquid chamber 103 into the nozzle hole 101 when the liquid P is not being ejected. This makes it possible to reduce ejection abnormalities caused by particles adhering to the nozzle hole 101. Furthermore, if the second distance D2 is equal to or less than the median diameter of the particles, it is possible to further reduce ejection abnormalities.

[0081] 1 in which a plurality of liquid chambers are connected, it may be an individual liquid chamber in which a plurality of liquid chambers are provided separately. Furthermore, the liquid ejection device 100 is not limited to one having a plurality of nozzle holes 101, but may be a so-called single nozzle device having one nozzle hole 101, as described below.

[0082] [Second embodiment] Next, a liquid ejection device according to a second embodiment of the present invention will be described. Note that the same names and symbols as those in the previously described embodiments indicate the same or similar components or configurations, and detailed descriptions will be omitted as appropriate. This also applies to the following embodiments.

[0083] <Configuration of the liquid ejection device 100 according to the second embodiment of the present invention> The configuration of a liquid ejection device according to a second embodiment of the present invention will be described with reference to Figures 13 and 14. Figure 13 is a schematic cross-sectional view showing an example of a state in which a liquid ejection device 100a according to a second embodiment of the present invention is not ejecting liquid P. Figure 14 is a schematic cross-sectional view showing an example of a state in which a liquid ejection device 100a according to a second embodiment of the present invention is ejecting liquid P.

[0084] The liquid ejection device 100a is a device that ejects a liquid P through a single nozzle. The liquid ejection device 100a has a nozzle body 4, a nozzle hole 101, a valve body 104, a valve body moving means 105, a reverse spring mechanism 8, a sealing member 6, a pair of lead wires 9, and a lead wire 10.

[0085] The nozzle body 4 is provided with a nozzle hole 101 at its tip for discharging the liquid P, and an injection port 3 for injecting the liquid P is provided near the nozzle hole 101. The valve element moving means 105 is built into the nozzle body 4 and expands and contracts in response to the application of an external drive voltage. The valve element 104 opens and closes the nozzle hole 101. The inverse spring mechanism 8 is disposed between the valve element 104 and the valve element moving means 105. The sealing member 6 is fitted onto the valve element 104 and prevents the liquid P from flowing into the valve element moving means 105. A pair of lead wires 9 and 10 are connected to electrodes of the valve element moving means 105 and are used to apply a voltage.

[0086] The nozzle body 4 is formed into a cylindrical or rectangular tubular shape overall, and is closed except for the nozzle hole 101 and the injection port 3. The nozzle hole 101 is an opening formed at the tip of the nozzle body 4, and is designed to eject the liquid P. The injection port 3 is provided on the side surface of the nozzle body 4 near the nozzle hole 101, and is connected to a liquid storage section, and the liquid P is continuously supplied to the liquid ejection device 100a by a pressurizing means.

[0087] The valve element moving means 105 is made of zirconia ceramics or the like, and is formed with an appropriate outer shape and thickness depending on the amount of the discharged liquid P. The valve element moving means 105 is controlled by a drive voltage from the control unit 120.

[0088] The sealing member 6 is, for example, a packing or an O-ring, and by fitting the sealing member 6 onto the outside of the valve body 104, ink is prevented from flowing from the injection port 3 side to the valve body moving means 105 side.

[0089] The reverse spring mechanism 8 is an elastic member formed by molding a suitably deformable material such as rubber or soft resin, or a thin metal plate. The reverse spring mechanism 8 includes a deformation portion 8a having a generally trapezoidal cross section formed to abut against the base end surface of the valve body 104, a fixed portion 8b fixed to the inner wall surface of the nozzle body 4, and a guide portion 8c connected to the end surface of the valve body moving means 105. The long side of the trapezoidal deformation portion 8a (corresponding to the lower base of the trapezoid) is a bent side 8d connected to the fixed portion 8b.

[0090] When a drive voltage is applied to the valve element moving means 105, the reverse spring mechanism 8 expands, causing the guide portion 8c to move toward the nozzle hole 101 and press against the vicinity of the center of the bent side 8d of the deformation portion 8a. As a result, the apex of the deformation portion 8a (corresponding to the upper base of the trapezoid) connected to the valve element 104 moves toward the valve element moving means 105. The valve element 104 is pulled toward the valve element moving means 105 by a distance d shown in Figure 13, thereby opening the nozzle hole 101.

[0091] By appropriately adjusting the distance between the apex of the deforming portion 8a of the inverse spring mechanism 8, which is the connecting portion with the valve element 104, and the curved side 8d, as well as the length of the curved side 8d, the length of movement of the valve element 104 can be made longer than the length of extension of the valve element moving means 105. In other words, the inverse spring mechanism 8 can amplify the slight extension of the valve element moving means 105. This allows the length of the expensive valve element moving means 105 to be shorter than before, thereby significantly reducing the production cost of the liquid discharge device 100. For example, the length of the valve element 104 can be shortened by setting the movement distance of the valve element 104 to twice the movement distance of the end face of the valve element moving means 105.

[0092] When no drive voltage is applied to the valve disc moving means 105, the valve disc moving means 105 returns to its original shape, so no external force is applied to the reverse spring mechanism 8 and no deformation occurs. On the other hand, when a drive voltage is applied to the valve disc moving means 105, the valve disc moving means 105 expands, and in response, the guide portion 8c of the reverse spring mechanism 8 moves toward the nozzle hole 101, so that the deforming portion 8a is deformed as if it were being crushed.

[0093] The liquid ejection device and liquid ejection method according to the embodiment of the present invention can also be applied to the single-nozzle liquid ejection device 100a shown in Figures 13 and 14, and can achieve the same effects as the liquid ejection device and liquid ejection method according to the first embodiment of the present invention.

[0094] [Third embodiment] Next, a coating apparatus according to a third embodiment of the present invention will be described with reference to Figs. 15 to 17. Fig. 15 is a diagram showing an example of the configuration of a coating apparatus 1001 according to the third embodiment of the present invention. Fig. 16 is a diagram showing a first example of the arrangement of the coating apparatus 1001 according to the third embodiment of the present invention on the target U. Fig. 17 is a diagram showing a second example of the arrangement of the coating apparatus 1001 according to the third embodiment of the present invention on the target U.

[0095] The coating device 1001 includes a liquid discharge device 100, a camera 1004 as a photographing means disposed near the liquid discharge device 100, an AB table 1003 that moves the liquid discharge device 100 and the camera 1004 in directions A and B, image editing software S that edits images taken by the camera 1004, and a control unit 120g. The control unit 120g also operates the AB table 1003 and causes the liquid discharge device 100 to discharge a liquid P based on a predetermined control program. The coating device 1001 can apply the liquid P discharged by the liquid discharge device 100 to a target object U.

[0096] The liquid ejection device 100 ejects liquid P from multiple nozzle holes 101 toward the surface of the object U to be coated. The liquid P ejected from the nozzle holes 101 is ejected in a direction perpendicular to the plane AB. The ejection directions of the liquid P ejected from each of the multiple nozzle holes 101 are parallel. The distance between the nozzle holes 101 and the surface of the object U to be coated is, for example, about 20 cm.

[0097] The AB table 1003 has an A-axis 1005 formed with a linear movement mechanism, and a B-axis 1006 that moves the A-axis 1005 in the Y direction while holding the A-axis 1005 with two arms. The liquid discharge device 100 and a camera 1004 are attached to a slider. A shaft 1007 is provided on the B-axis 1006. By holding this shaft 1007 with a robot arm 1008, the liquid discharge device 100 can be freely positioned with respect to the target object U.

[0098] For example, if the object U is an automobile, the robot arm 1008 can be placed above the object U as shown in Fig. 16, or can be placed to the side of the object U as shown in Fig. 17. The control unit 120g controls the operation of the robot arm 1008 based on a predetermined program.

[0099] The camera 1004 is mounted on a slider on an A-axis 1005 near the liquid discharge device 100, and while moving in the AB direction, photographs a predetermined range of the surface of the object U to be coated at constant, minute intervals. The camera 1004 is, for example, a digital camera. The specifications of the lens or resolution, etc., that enable the camera 1004 to photograph a plurality of subdivided images obtained by dividing the predetermined range of the surface to be coated are appropriately selected. The camera 1004 photographs the plurality of subdivided images of the surface to be coated continuously and automatically according to a program pre-installed in the control unit 120g.

[0100] As described above, the coating apparatus 1001 includes the liquid ejection device 100, and thus can apply the liquid P to a desired position on the target object U with high precision, even when the distance between the target object U and the nozzle hole 101 is long. Furthermore, since the liquid ejection device 100 can stably eject the liquid P, the coating apparatus 1001 can apply the liquid P to the target object U with high precision. The coating apparatus 1001 may include the liquid ejection device 100a instead of or in addition to the liquid ejection device 100.

[0101] The particles contained in the liquid P discharged by the coating device 1001 are, for example, aluminum flakes, mica, titanium oxide, etc. The dispersion medium used in the liquid P discharged by the coating device 1001 is, for example, a liquid that evaporates easily, such as acetone, and if the particle concentration of the liquid remaining in the discharge holes increases due to evaporation when not discharging, there is a concern that this may reduce discharge stability when re-discharging. However, by applying this embodiment, it is possible to suppress an increase in the concentration of the liquid remaining in the discharge holes.

[0102] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0103] Here, Fig. 18 is a first schematic cross-sectional view showing a nozzle plate included in a liquid ejection device according to a seventh modified example of the present invention, and Fig. 19 is a second schematic cross-sectional view showing a nozzle plate included in a liquid ejection device according to the seventh modified example of the present invention.

[0104] On the upper surface of the nozzle plate 102 on the side where the valve body 104 is located, an area where the second protrusion 22 is not formed may be provided between the nozzle hole 101 and the area where the second protrusion 22 is formed.

[0105] For example, a liquid passage can be provided by making the tip surface of the valve element 104 uneven by sandblasting, etching, stamping, etc. Also, a liquid passage can be provided by making at least the surface of the nozzle plate 102 that comes into contact with the valve element 104 uneven by sandblasting, etching, stamping, etc.

[0106] Alternatively, a recess may be provided at the tip of the valve element 104, and the inlet-side periphery of the nozzle hole 101 may not contact the tip of the valve element 104 (see, for example, the valved print head disclosed in Patent Document No. 7310404). Region B of the nozzle plate 102, which is larger than region A that contacts the valve element 104, may be provided with irregularities by sandblasting, etching, stamping, or the like. Region C around the inlet side of the nozzle hole 101 that does not contact the tip of the valve element 104 does not need to be provided with irregularities. These configurations maintain the roundness of the inlet-side edge of the nozzle hole 101, making it possible to obtain a valved inkjet print head with irregularities that serve as a liquid passageway, without impairing the straightness of the liquid ejection.

[0107] In the liquid ejection device according to the embodiment of the present invention, the open state when the end face 104a of the valve body 104 moves the first distance D1 is not limited to a state in which the nozzle hole 101 is completely open, but also includes a state in which the nozzle hole 101 is partially open. Even in a state in which the nozzle hole 101 is partially open, the effect of reducing ejection abnormalities can be obtained. Furthermore, the ejection amount of the ejected liquid P can also be changed depending on the open state of the nozzle hole 101.

[0108] The ordinal numbers, quantities, and other figures used in the description of the embodiments are all provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the illustrated figures. Furthermore, the connection relationships between components are provided as examples to specifically explain the technology of the present invention, and the connection relationships for realizing the functions of the present invention are not limited to these.

[0109] The division of blocks in the functional block diagram is an example, and multiple blocks may be realized as a single block, one block may be divided into multiple blocks, or some functions may be moved to another block.Furthermore, the functions of multiple blocks having similar functions may be processed in parallel or time-shared by a single piece of hardware or software.

[0110] Each function of the above-described embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to perform each function by software, such as a processor implemented by an electronic circuit, as well as devices designed to perform each of the above-described functions, such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), a CPLD (Complex Programmable Logic Device), or a conventional circuit module.

[0111] The liquid ejection device and liquid ejection method according to the embodiments of the present invention can reduce ejection abnormalities in a valve opening / closing type liquid ejection device and liquid ejection method, and can therefore be suitably used in manufacturing devices for electrochemical elements, electrode printing devices, painting devices that apply ejected paint to an object, image forming devices such as inkjet printers, etc.

[0112] While electrochemical elements generally include secondary batteries and capacitors, the liquid ejection device and liquid ejection method according to the present invention are particularly suitable for use in the manufacture of lithium-ion secondary batteries. For example, the liquid ejection device and liquid ejection method according to the present invention can dramatically lengthen the non-ejection period compared to cases where the liquid ejection device and liquid ejection method according to the present invention are not used. Here, the non-ejection period refers to the period from when the liquid P is not ejected until when it is ejected again, during which no ejection abnormalities occur when the liquid P is ejected again. For example, with respect to a roll-shaped substrate used in the manufacture of lithium-ion secondary batteries using a liquid ejection device, even if a 2000 m substrate is run at 60 mpm (meter per minute) for 30 minutes, no ejection abnormalities occur during the re-ejection.

[0113] For example, aspects of the present invention are as follows. <1> The liquid ejection device comprises a liquid chamber including a nozzle plate having a nozzle hole, a supply means for supplying liquid to the liquid chamber, a valve body provided in the liquid chamber, and a valve body moving means for moving the valve body, and the liquid is supplied from the liquid chamber to the nozzle hole both when the liquid is being ejected and when the liquid is not being ejected, and the amount of liquid supplied to the nozzle hole when the liquid is not being ejected is less than the amount of liquid supplied to the nozzle hole when the liquid is being ejected. <2> a first groove is provided on an end surface of the valve body on the side where the nozzle plate is located, and when the liquid is not being ejected, the liquid is supplied from the liquid chamber to the nozzle hole through the first groove; <1> 1 is a liquid ejection device according to the first embodiment. <3> a first convex portion is provided on an end face of the valve body on the side where the nozzle plate is located, and when the liquid is not being ejected, the first convex portion abuts against the nozzle plate to form a first gap through which the liquid is supplied from the liquid chamber to the nozzle hole; <1> or the above <2> 1 is a liquid ejection device according to the first embodiment. <4> an end surface of the valve body on the side where the nozzle plate is located has a first porous structure, and when the liquid is not being ejected, the liquid is supplied to the nozzle hole through holes in the first porous structure; <1> From the above <3> The liquid ejection device according to any one of the above items. <5> a second groove is provided on an upper surface of the nozzle plate on the side where the valve body is located, and when the liquid is not being ejected, the liquid is supplied from the liquid chamber to the nozzle hole through the second groove; <1> From the above <4> The liquid ejection device according to any one of the above items. <6> a second convex portion is provided on an upper surface of the nozzle plate on the side where the valve body is located, and when the liquid is not being ejected, the second convex portion abuts against the valve body to form a second gap, through which the liquid is supplied from the liquid chamber to the nozzle hole; <1> From the above <5> The liquid ejection device according to any one of the above items. <7> an area where the second convex portion is not formed is provided between the nozzle hole and the area where the second convex portion is formed on the upper surface of the nozzle plate on the side where the valve body is located; <6> 1 is a liquid ejection device according to the first embodiment. <8> an upper surface of the nozzle plate on which the valve body is located has a second porous structure, and when the liquid is not being ejected, the liquid is supplied from the liquid chamber to the nozzle hole through holes in the second porous structure; <1> From the above <7> The liquid ejection device according to any one of the above items. <9> the control unit is further provided with a control unit that controls movement of the valve element by the valve element moving means, and the control unit is capable of switching between a first mode in which the liquid is discharged and a second mode in which the liquid is not discharged by movement of the valve element by the valve element moving means, and in the first mode, an end face of the valve element on the side where the nozzle plate is located is located a first distance from an upper surface of the nozzle plate on the side where the valve element is located, and in the second mode, the end face of the valve element is located a second distance shorter than the first distance from the upper surface of the nozzle plate, and in the second mode, the liquid is supplied from the liquid chamber to the nozzle hole through a gap between the end face of the valve element and the upper surface of the nozzle plate; <1> From the above <8> The liquid ejection device according to any one of the above items. <10> the control unit can further switch to a third mode in which the liquid is not supplied to the nozzle hole by moving the valve element by the valve element moving means, and in the third mode, the end face of the valve element is located a third distance shorter than the second distance from the upper surface of the nozzle plate, or is in contact with the upper surface of the nozzle plate; <9> 1 is a liquid ejection device according to the first embodiment. <11> the control unit switches between the second mode and the third mode at predetermined time intervals; <10> 1 is a liquid ejection device according to the first embodiment. <12> A liquid ejection method using a liquid ejection device comprising: a liquid chamber including a nozzle plate having a nozzle hole for ejecting liquid; a supply means for supplying the pressurized liquid to the liquid chamber; a valve body provided in the liquid chamber; and a valve body moving means for moving the valve body, wherein the liquid ejection device supplies the liquid from the liquid chamber to the nozzle hole both when ejecting the liquid and when not ejecting the liquid, and the amount of liquid supplied to the nozzle hole when not ejecting the liquid is less than the amount of liquid supplied to the nozzle hole when ejecting the liquid. <13> the amount of the liquid supplied to the nozzle hole when the liquid is not being ejected varies depending on the type of the liquid; <12> 2. A liquid ejection method according to claim 1. <14> a control unit controls movement of the valve element by the valve element moving means, and the control unit is capable of switching between a first mode in which the liquid is discharged and a second mode in which the liquid is not discharged by moving the valve element by the valve element moving means, wherein in the first mode, an end face of the valve element on the side where the nozzle plate is located is located a first distance away from an upper surface of the nozzle plate on the side where the valve element is located, and in the second mode, the end face of the valve element is located a second distance away from the upper surface of the nozzle plate that is shorter than the first distance, and in the second mode, the liquid is supplied from the liquid chamber to the nozzle hole through a gap between the end face of the valve element and the upper surface of the nozzle plate; <12> or the above <13> 2. A liquid ejection method according to claim 1. <15> Particles are dispersed in the liquid, and the second distance is equal to or less than the maximum diameter of the particles. <14> 2. A liquid ejection method according to claim 1. <16> the control unit can further switch to a third mode in which the liquid is not supplied to the nozzle hole by moving the valve element by the valve element moving means, and in the third mode, the end face of the valve element is located a third distance shorter than the second distance from the upper surface of the nozzle plate or abuts against the upper surface of the nozzle plate; <14> or the above <15> 2. A liquid ejection method according to claim 1. <17> the control unit is capable of switching between the second mode and the third mode at predetermined time intervals; <16> 2. A liquid ejection method according to claim 1. <18> When the liquid is not being ejected, a part of the liquid disposed in the nozzle hole protrudes from the nozzle plate. <12> From the above <17> The liquid ejection method is described in any one of the above. [Explanation of symbols]

[0114] 3 Inlet 4 Nozzle body 6 Sealing member 8 Reverse spring mechanism 8a Deformed part 8b Fixed part 8c Guide part 8d Bent edge 9 pairs of leads 10 Lead Wire 21 Second Groove 22 Second protrusion 23 Second porous structure 41 First Groove 42 First protrusion 43 First porous structure 100 Liquid discharge device 101 nozzle hole 101a, 101b end 102 nozzle plate 102a Top side 103 Liquid chamber 104 Valve body 104a End face 105 Valve body moving means 106 frames 107 Supply port 108 Outlet 110 Supply means 111 Liquid storage section 112 Air Compressor 113 Air Tank 114 Regulator 115 Air Filter 120, 120g control section 121 Input section 122 Drive voltage generation unit 123 Amplification section 124 Output section 1001 Coating equipment 1003 AB Table 1004 Camera 1005 A-axis 1006 B-axis 1007 Shaft 1008 Robot Arm 1010 monitor D1 First distance D2 Second distance E1 First drive voltage E2 Second drive voltage E3 Third drive voltage G0 gap G1 First gap G2 Second gap P liquid Q1 open position Q2 Closed position S Software U Object [Prior art documents] [Patent documents]

[0115] [Patent Document 1] Patent No. 6035226

Claims

1. a liquid chamber including a nozzle plate having nozzle holes; a supply means for supplying liquid to the liquid chamber; a valve body provided in the liquid chamber; a valve element moving means for moving the valve element, The liquid is supplied from the liquid chamber to the nozzle hole both when the liquid is being ejected and when the liquid is not being ejected; The liquid ejection device, wherein the amount of the liquid supplied to the nozzle hole when the liquid is not ejected is less than the amount of the liquid supplied to the nozzle hole when the liquid is ejected.

2. a first groove is provided in an end surface of the valve body on a side where the nozzle plate is located, The liquid ejection device according to claim 1 , wherein the liquid is supplied from the liquid chamber to the nozzle hole through the first groove when the liquid is not being ejected.

3. a first protrusion is provided on an end surface of the valve body on a side where the nozzle plate is located, 3. The liquid ejection device according to claim 1, wherein when the liquid is not being ejected, the liquid is supplied from the liquid chamber to the nozzle hole through a first gap formed by the first convex portion abutting against the nozzle plate.

4. an end surface of the valve body on a side where the nozzle plate is located has a first porous structure; 3. The liquid ejection device according to claim 1, wherein when the liquid is not being ejected, the liquid is supplied to the nozzle hole through holes of the first porous structure.

5. a second groove is provided on an upper surface of the nozzle plate on a side where the valve body is located, 3. The liquid ejection device according to claim 1, wherein the liquid is supplied from the liquid chamber to the nozzle hole through the second groove when the liquid is not being ejected.

6. a second protrusion is provided on an upper surface of the nozzle plate on a side where the valve body is located, 3. The liquid ejection device according to claim 1, wherein when the liquid is not being ejected, the liquid is supplied from the liquid chamber to the nozzle hole through a second gap formed by the second convex portion abutting the valve body.

7. 7. The liquid ejection device according to claim 6, wherein an area in which the second convex portion is not formed is provided between the nozzle hole and the area in which the second convex portion is formed on the upper surface of the nozzle plate on the side where the valve body is located.

8. an upper surface of the nozzle plate on which the valve body is located has a second porous structure; 3. The liquid ejection device according to claim 1, wherein when the liquid is not being ejected, the liquid is supplied from the liquid chamber to the nozzle hole through holes of the second porous structure.

9. a control unit for controlling the movement of the valve element by the valve element moving means the control unit is capable of switching between a first mode in which the liquid is discharged and a second mode in which the liquid is not discharged by moving the valve body by the valve body moving means, In the first mode, an end face of the valve body on a side where the nozzle plate is located is located a first distance away from an upper surface of the nozzle plate on a side where the valve body is located, In the second mode, the end surface of the valve body is located a second distance from the top surface of the nozzle plate that is shorter than the first distance, 3. The liquid ejection device according to claim 1, wherein in the second mode, the liquid is supplied from the liquid chamber to the nozzle hole through a gap between the end face of the valve body and the upper surface of the nozzle plate.

10. the control unit is further capable of switching to a third mode in which the liquid is not supplied to the nozzle hole by moving the valve body by the valve body moving means, 10. The liquid ejection device according to claim 9, wherein in the third mode, the end face of the valve body is located a third distance away from the upper surface of the nozzle plate that is shorter than the second distance, or abuts against the upper surface of the nozzle plate.

11. The liquid ejection device according to claim 10 , wherein the control unit switches between the second mode and the third mode at predetermined time intervals.

12. a liquid chamber including a nozzle plate provided with nozzle holes for ejecting liquid; a supply means for supplying the pressurized liquid to the liquid chamber; a valve body provided in the liquid chamber; a valve element moving means for moving the valve element, The liquid is supplied from the liquid chamber to the nozzle hole both when the liquid is being ejected and when the liquid is not being ejected; A liquid ejection method, wherein the amount of the liquid supplied to the nozzle hole when the liquid is not ejected is less than the amount of the liquid supplied to the nozzle hole when the liquid is ejected.

13. The liquid ejection method according to claim 12 , wherein the amount of the liquid supplied to the nozzle hole when the liquid is not ejected varies depending on the type of the liquid.

14. a control unit controls the movement of the valve element by the valve element moving means; the control unit is capable of switching between a first mode in which the liquid is discharged and a second mode in which the liquid is not discharged by moving the valve body by the valve body moving means, In the first mode, an end face of the valve body on a side where the nozzle plate is located is located a first distance away from an upper surface of the nozzle plate on a side where the valve body is located, In the second mode, the end face of the valve disc is positioned a second distance from the top surface of the nozzle plate that is shorter than the first distance; The liquid ejection method according to claim 12 , wherein in the second mode, the liquid is supplied from the liquid chamber to the nozzle hole through a gap between the end face of the valve body and the upper surface of the nozzle plate.

15. The liquid has particles dispersed therein, The liquid ejection method according to claim 14 , wherein the second distance is equal to or less than a maximum diameter of the particle.

16. the control unit is further capable of switching to a third mode in which the liquid is not supplied to the nozzle hole by moving the valve body by the valve body moving means, The liquid ejection method according to claim 14, wherein in the third mode, the end face of the valve body is positioned a third distance shorter than the second distance from the upper surface of the nozzle plate or abuts against the upper surface of the nozzle plate.

17. The liquid ejection method according to claim 16 , wherein the control unit is capable of switching between the second mode and the third mode at predetermined time intervals.

18. The liquid ejection method according to claim 12 , wherein when the liquid is not ejected, a portion of the liquid disposed in the nozzle hole protrudes from the nozzle plate.

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