Liquid discharge head, liquid discharge unit, and liquid discharge device

Abstract

The present invention provides a liquid discharge head using a nozzle opening / closing valve that can reduce liquid leakage when the nozzle is closed, even when the nozzle opening / closing valve is repeatedly brought into contact with and separated from the nozzle. [Solution] A liquid discharge head 100 comprising a nozzle plate 14 having a nozzle 14a for discharging liquid, a valve member 32 for opening and closing the nozzle 14a, and a moving means 2a for displacing the valve member 32 between an open position for opening the nozzle 14a and a closed position for closing the nozzle 14a, wherein the valve member 32 is rotatable relative to the nozzle 14a.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head, a liquid ejection unit, and a liquid ejection device.

Background Art

[0002] Conventionally, a liquid ejection head that ejects droplets of ink or the like from a nozzle, uses a nozzle opening / closing valve that is a needle valve disposed in the nozzle, nozzle opening / closing driving means including a solenoid, a piezoelectric element, an actuator, etc. that moves the nozzle opening / closing valve relative to the nozzle, and control means that controls the operation of the nozzle opening / closing driving means, and opens and closes the nozzle to eject liquid is known. Such a liquid ejection head pressurizes the liquid to be ejected to the nozzle, and by moving the nozzle opening / closing valve relative to the nozzle in a pressurized state, the liquid that is pressurized only while the nozzle opening / closing valve is separated from the nozzle is ejected from the nozzle. Since the liquid to be ejected is pressurized, the shape and operation of the nozzle opening / closing valve are most important for achieving good opening and closing of the nozzle.

[0003] As the above-described technology, there is known a configuration having an elastic member that seals the ejection of liquid when the nozzle opening / closing valve contacts the nozzle and a support portion (core material) that supports this elastic member, and the elastic moduli of the elastic member and the support portion are different from each other (see, for example, "Patent Document 1"). According to this technology, it is said that even if the nozzle opening / closing valve is not parallel to the nozzle plate having the nozzle, the pressurized liquid can be reliably sealed. Also, in the case of a liquid mixed with a filler or the like, since the nozzle opening / closing valve is composed of a number of members having different elastic moduli, it is said that indentations are suppressed from being formed on the outermost layer of the nozzle opening / closing valve by the filler when contacting the nozzle plate to seal the nozzle, and liquid leakage can be avoided. In addition, a technology has been proposed in which a sealing member that seals the tip of the nozzle opening / closing valve has a spherical shape, and the pressurized liquid can be applied not only to opening and closing the nozzle but also to controlling the bending of liquid ejection. Thus, many technologies have been proposed for controlling the sealing and ejection characteristics of pressurized liquid by using members of different materials and shapes in the nozzle opening / closing valve.

Summary of the Invention

[0004] In recent years, paint films applied to the exterior of automobiles and other parts have been required to have a high level of decorative quality, such as vividness, and metallic paints, which contain aluminum flakes mixed into the paint liquid, have been widely used. When dispensing metallic paint liquid using the technology disclosed in "Patent Document 1", there is a problem that the usable time is shortened. Because the aluminum flakes are soft, the metal flakes may easily adhere to the surface of the nozzle opening / closing valve when the valve moves in and out of contact with the nozzle to open and close the nozzle. In such cases, the volume of the adhered portion gradually increases with the usage time, and eventually the nozzle opening / closing valve may not be able to seal the nozzle, which could lead to liquid leakage.

[0005] On the other hand, in recent years there has been an increasing demand for liquids containing particles of inorganic materials different from soft metal fragments, such as mica and alumina. For example, in the manufacture of separators for secondary batteries, research and development of on-demand coating using the discharge head described in "Patent Document 1" is being actively pursued as a replacement for the conventional die coater coating process. In this case, the particles mixed into the liquid are inorganic particles with high Mohs hardness, and alumina particles, which are used industrially as abrasives, are one example, with particle sizes ranging from a few micrometers to several hundred micrometers.

[0006] In the configuration disclosed in "Patent Document 1," the nozzle opening and closing valve always opens and closes the nozzle hole at the same location, so instead of sticking like with metallic paint, scratches, dents, and indentations occur on the nozzle opening and closing valve due to friction. As usage time increases, small scratches, dents, and indentations grow, and eventually large scratches, dents, and indentations that become leak paths occur on the surface of the nozzle opening and closing valve, resulting in the problem that the nozzle cannot be opened and closed even when the nozzle is brought into contact with or away from it. The present invention aims to solve the above-mentioned problems and provide a liquid discharge head using a nozzle opening / closing valve that can reduce liquid leakage when the nozzle is closed, even when the nozzle opening / closing valve is repeatedly brought into contact with and separated from the nozzle. [Means for solving the problem]

[0007] The invention described in claim 1 comprises a nozzle plate having a nozzle for discharging liquid, a valve member for opening and closing the nozzle, and a means for displacing the valve member between an open position for opening the nozzle and a closed position for closing the nozzle, wherein the valve member is rotatable relative to the nozzle. [Effects of the Invention]

[0008] According to the present invention, when opening and closing the nozzle, the sealing portion rotates relative to the nozzle, thereby preventing the sealing portion from always contacting and separating from the nozzle plate at the same point. This provides a liquid discharge head using a nozzle opening / closing valve that can suppress sticking, scratches, dents, and other deformations that occur when the nozzle opening / closing valve repeatedly contacts and separates from the nozzle. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of a car body painting apparatus equipped with a liquid dispensing head to which one embodiment of the present invention can be applied. [Figure 2] Figure 1 is a schematic diagram showing an example of a vehicle body painting apparatus. [Figure 3] Figure 1 is a schematic diagram showing another example of the vehicle body painting apparatus. [Figure 4] Figure 1 is a schematic diagram showing an example of the configuration of a liquid discharge head related to a vehicle body painting apparatus. [Figure 5] Figure 1 is a schematic diagram showing an example of the internal configuration of a liquid discharge head related to a vehicle body painting apparatus. [Figure 6] Figure 1 is a schematic diagram showing an example of the configuration of a nozzle plate used in a liquid discharge head related to a vehicle body painting apparatus. [Figure 7] Figure 1 is a schematic diagram showing an example of a mounting method between the nozzle plate and the flow path member used in the liquid discharge head of the vehicle body painting apparatus shown in Figure 1. [Figure 8]Figure 1 is a schematic diagram showing an example of the arrangement of the liquid discharge unit within the liquid discharge head of the vehicle body painting apparatus. [Figure 9] Figure 1 is a schematic diagram showing an arm member used in the vehicle body painting apparatus. [Figure 10] Figure 1 is a schematic diagram showing an example of the configuration of a valve body used in the vehicle body painting device. [Figure 11] This is an enlarged view of section J in Figure 10. [Figure 12] Figure 8 is a schematic diagram showing a cross-section of CC. [Figure 13] Figure 8 is a schematic diagram showing the DD cross-section. [Figure 14] This is a schematic diagram showing an example of a conventional sealing method. [Figure 15] This is a schematic diagram showing an example of a liquid supply means applicable to one embodiment of the present invention. [Figure 16] This is a schematic diagram illustrating how a drive control device in a liquid discharge unit applicable to one embodiment of the present invention drives a needle valve by applying a voltage to a piezoelectric element. [Figure 17] This schematic diagram shows the operation of the needle valve, the change in displacement, and the change in applied voltage when the needle valve opening time is short. [Figure 18] This schematic diagram shows the operation of the needle valve, the change in displacement, and the change in applied voltage when the needle valve is open for a long time. [Figure 19] This is a schematic diagram of a needle valve according to the first embodiment of the present invention. [Figure 20] This is a schematic diagram of a needle valve according to another example of the first embodiment of the present invention. [Figure 21] This is a schematic diagram illustrating the behavior of the needle valve in the first embodiment of the present invention. [Figure 22] This is a schematic diagram showing a needle valve and nozzle in the first embodiment of the present invention. [Figure 23] This is a schematic diagram showing the wear portion of the needle valve in the first embodiment of the present invention. [Figure 24]Schematic diagram showing the worn part of the nozzle in the first embodiment of the present invention. [Figure 25] Schematic diagram of the needle valve according to the second embodiment of the present invention. [Figure 26] Schematic diagram of the needle valve according to a modified example of the second embodiment of the present invention. [Figure 27] Schematic diagrams respectively showing other examples of the operation of the needle valve, the change in the displacement amount, and the change in the applied voltage when the opening time of the needle valve is long. [Figure 28] Partial schematic diagram of the tip of the needle valve according to the third embodiment of the present invention. [Figure 29] Schematic diagram showing the sealing part according to the fourth embodiment of the present invention. [Figure 30] Schematic diagram showing modified examples of the third and fourth embodiments of the present invention. [Figure 31] Table comparing the liquid leakage situations when the nozzle is opened and closed between the needle valves according to the embodiments of the present invention and the needle valve of the comparative example. [Figure 32] Schematic front view of another liquid ejection device provided with a liquid ejection head according to the embodiments of the present invention. [Figure 33] Schematic plan view explaining the liquid ejection unit of another liquid ejection device provided with a liquid ejection head according to the embodiments of the present invention. [Figure 34] Schematic plan view of still another liquid ejection device provided with a liquid ejection head according to the embodiments of the present invention. [Figure 35] Schematic side view of still another liquid ejection device provided with a liquid ejection head according to the embodiments of the present invention. [Figure 36] Schematic plan view explaining the liquid ejection unit of still another liquid ejection device provided with a liquid ejection head according to the embodiments of the present invention. [Figure 37] Schematic front view explaining another liquid ejection unit of still another liquid ejection device provided with a liquid droplet ejection head according to the embodiments of the present invention. [Figure 38]A schematic front view of an electrode manufacturing apparatus, which is yet another liquid dispensing apparatus equipped with a liquid dispensing head according to each embodiment of the present invention. [Modes for carrying out the invention]

[0010] Figure 1 shows a vehicle body painting apparatus 40 to which one embodiment of the present invention can be applied. In the same figure, the vehicle body painting apparatus 40 as a liquid discharge device includes at least one liquid discharge head 100, a camera 82 positioned near the liquid discharge head 100, an XY table 81 for moving the liquid discharge head 100 and the camera 82 in the X and Y directions, image editing software S for editing images captured by the camera 82, a monitor 91 for displaying the images to be edited, and a control unit 90. The control unit 90 operates the XY table 81 based on a predetermined control program and includes a drive control device 50 that discharges a liquid L, such as paint or ink, from the liquid discharge head 100 (see Figure 5). As shown in Figure 2, the vehicle body painting apparatus 40 can apply the paint discharged from the liquid discharge head 100 to an object to be painted, such as a vehicle body.

[0011] The XY table 81 has an X-axis 83 formed with a linear movement mechanism, and a Y-axis 84 that moves the X-axis 83 in the Y direction while holding the X-axis 83 with two arms, and a shaft 85 is provided on the Y-axis 84. By holding the shaft 85 with a robot arm 86, the liquid discharge head 100 and the camera 82 can be freely positioned relative to the object U to be coated. The control unit 90 is a control means that controls the movement of the robot arm 86 based on a predetermined program, and at the same time, as described later, it also functions as a control means that controls the amount of liquid L discharged from the liquid discharge head 100 by controlling the opening and closing of the nozzle 14a of the liquid discharge head 100. Figure 2 shows a case where the object to be coated U is the body of an automobile, and the body coating device 40 is installed on top of the object to be coated U. However, as shown in Figure 3, the body coating device 40 may be positioned on the side of the object to be coated U. In the case shown in Figure 3, the liquid discharge head 100 will move freely in the YZ plane shown in Figure 1.

[0012] Figure 4 shows an external perspective view of the liquid discharge head 100, and Figure 5 shows an example of the AA cross-section of the liquid discharge head 100 shown in Figure 4. In the following explanation, the nozzle arrangement direction (longitudinal direction of the liquid discharge head 100) will be described as the X direction, the liquid discharge direction from the nozzle (height direction of the liquid discharge head 100) as the Z direction, and the direction perpendicular to both the X and Z directions (short direction of the liquid discharge head 100) as the Y direction, using the arrangement shown in Figure 2 as an example. However, the explanation is not limited to this configuration. The liquid discharge head 100 includes a nozzle plate 14 on the surface facing the object to be coated U, a flow path member 15 through which liquid L (paint) can flow, and a cover 11 which is a housing member. A supply port 12 for supplying liquid L is provided at one end of the flow path member 15 in the X direction, and a discharge port 13 for discharging liquid L is provided at the other end of the flow path member 15 in the X direction. In other words, the flow path member 15 is a member that defines the flow path of liquid L by connecting the supply port 12 and the discharge port 13. Furthermore, a harness pass-through hole 16 is provided at the top of the cover 11 for passing a harness including a communication cable for communicating with the actuator 2 housed inside the cover 11. In Figure 5, the liquid discharge unit 60 is composed of the control unit 90 and the liquid discharge head 100.

[0013] The cover 11 and the nozzle plate 14 are fixed to the flow path member 15 in a manner that allows for mechanical removal. The nozzle plate 14, the flow path member 15, and the cover 11 are all made of metal, resin, or ceramic material. Inside the cover 11, as shown in Figure 5, a plurality of liquid discharge modules 1 are housed and supported. Figure 6 illustrates an example of the nozzle arrangement of the nozzle plate 14. As shown in Figure 6, the nozzle plate 14 has multiple nozzles 14a formed thereon that discharge liquid L. As shown in Figure 6(a), one nozzle row can be provided in the center in the Y direction (short direction of the head), or as shown in Figure 6(b), the nozzles 14a can be arranged in a staggered pattern to provide multiple nozzle rows in the Y direction. Note that the nozzle arrangement shown in Figure 6 is just one example. For example, a configuration with two sets of two nozzle rows in the Y direction arranged in a staggered pattern to have a total of four nozzle rows, or a configuration with multiple nozzle rows where the nozzles are in the same position in the X direction (long direction of the head). The liquid discharge head 100 described below will be described as having two nozzle rows in the Y direction, arranged in a staggered pattern as shown in Figure 6(b).

[0014] Figure 7 illustrates the mechanical fixing of the nozzle plate 14 and the flow path member 15. Figure 7(a) is a schematic diagram of the nozzle plate 14, and Figure 7(b) is a schematic diagram of the connection portion of the flow path member 15 viewed from the bottom. At both ends of the nozzle plate 14 in the Y direction, five through holes 14b are provided at equal intervals in the X direction, through which a screw passes. In addition, at both ends of the nozzle plate 14 in the X direction, one positioning hole 14c is provided for positioning the nozzle plate 14 relative to the flow channel member 15. The positioning hole 14c at one end in the X direction is the primary reference for positioning, and is a round hole with a diameter approximately the same as the diameter of the positioning pin. The positioning hole 14c at the other end in the X direction is a secondary reference for positioning, and is formed as an elongated hole in the X direction. In this manner, the nozzle plate 14 and the flow path member 15 are positioned according to the positioning holes 14c and fixed together by screws.

[0015] As shown in Figure 5, the flow channel member 15 forms a flow channel (liquid chamber) 5 through which liquid L flows. As shown in Figure 7(b), a sealing member 15a made of an elastic material such as rubber is provided on the lower surface of the flow channel member 15 so as to surround the flow channel 5. In addition, five female screw portions 15b are provided at equal intervals in the X direction at both ends of the lower surface of the flow channel member 15 in the Y direction. Furthermore, one pin fitting hole 15c is provided at each end of the flow channel member 15 in the X direction into which a positioning pin is fitted. Note that the positioning pin may also be directly attached to the flow channel member 15.

[0016] When mechanically fixing the nozzle plate 14 and the flow path member 15, a positioning pin fitted into the pin fitting hole 15c of the flow path member 15 is inserted into the positioning hole 14c of the nozzle plate 14 to position the nozzle plate 14 relative to the flow path member 15. Then, screws are inserted into each through hole 14b of the nozzle plate 14 and screwed into the female threaded portion 15b of the flow path member 15, thereby mechanically and removably fixing the nozzle plate 14 to the flow path member 15. Furthermore, when the flow path member 15 is fixed in place, the sealing member 15a provided on the flow path member 15 is crushed by the nozzle plate 14, causing the sealing member 15a to adhere tightly to the nozzle plate 14 and sealing the space between the nozzle plate 14 and the flow path member 15. In this configuration, the nozzle plate 14 is fixed to the flow path member 15 by screw fastening, so the nozzle plate 14 can be easily removed from the flow path member 15 by unscrewing it, and the nozzle plate 14 can be easily replaced. This makes it possible to freely select and easily replace the nozzle plate 14 with a nozzle diameter that allows for optimal discharge characteristics for the object U to which the liquid L is discharged.

[0017] Inside the cover 11, multiple liquid discharge modules 1, each positioned to correspond to a nozzle 14a, are housed in two rows in a staggered pattern, as shown in Figure 8. Each liquid discharge module 1 includes a needle valve 8, which is a needle-type nozzle opening / closing valve that opens and closes the nozzle 14a; a compression spring 7, which is a biasing member that presses the needle valve 8 downwards; an arm member 3 that rotates to press the needle valve 8; and an actuator 2, which is a driving means that rotates the arm member 3 by pressing one end, thereby operating the needle valve 8.

[0018] Multiple liquid discharge modules 1 are arranged in two rows within the cover 11, with the needle valve 8 sides facing each other, and staggered in the X direction. Furthermore, as shown in Figure 8, the liquid discharge modules 1 are arranged so that parts of the arm members 3 overlap each other when viewed from the X direction. Here, we have described the case where the nozzles 14a are arranged in a staggered pattern in two rows on the nozzle plate 14, as shown in Figure 6(b). However, even when the nozzles 14a are arranged in a single row on the nozzle plate 14, as shown in Figure 6(a), the multiple liquid discharge modules 1 will be arranged so that parts of the arm members 3 overlap each other when viewed from the X direction. The arrangement of the liquid discharge modules 1 in an alternating pattern can also be described as arranging liquid discharge module 1a, in which actuator 2 is located on one side of the nozzle array, and liquid discharge module 1b, in which actuator 2 is located on the other side of the nozzle array, so that they face each other, and are arranged along the direction of the nozzle array such that a portion of the arm members 3 overlap each other when viewed from the direction of the nozzle array.

[0019] The actuator 2 consists of a piezoelectric element 2a and a holder 2b that has the role of applying preload to compress the piezoelectric element 2a and fixing it in place. The holder 2b is fixed to the inner wall surface of the cover 11 perpendicular to the Y direction. More specifically, the holder 2b fixes the end of the piezoelectric element 2a in the Z direction, which is the direction in which the piezoelectric element 2a expands and contracts, to the inner wall surface of the cover 11. Fixing is done by mechanical fixing using screws or the like, or by chemical fixing such as bonding with adhesive or thermal diffusion. As shown in Figure 8, the arm member 3 has a support shaft 4, which is rotatably supported by the cover 11 via a bearing. The arm member 3 has a connection portion at one end that connects to the actuator 2, and a contact portion 3a at the other end that contacts the arm receiving portion 8c fixed to the needle valve 8. The contact portion 3a that contacts the arm receiving portion 8c is hemispherical or crescent-shaped when viewed from the X direction, protruding towards the arm receiving portion 8c, and makes smooth contact with the arm receiving portion 8c when the arm member 3 rotates. As shown in Figure 9, a through-hole 3b is formed at the other end of the arm member 3, through which the needle valve 8 passes. The inner diameter of the through-hole 3b is larger than the outer diameter of the needle valve 8, so that the inner surface of the through-hole 3b does not come into contact with the outer surface of the needle valve 8 when the arm member 3 rotates.

[0020] As shown in Figure 8, the bottom surface of the cover 11 is provided with a plurality of valve through-holes 11a, which are provided as an example of the inner wall of the housing, through which needle valves 8, corresponding to each nozzle 14a, pass. As shown in Figure 10, a sealing member 25 is provided at the end of the valve through-hole 11a on the flow path member 15 side, and a valve receiving portion 20 is provided at the end of the valve through-hole 11a opposite to the flow path member 15 side, which functions as a regulating member that restricts movement in a direction perpendicular to the opening and closing direction of the needle valve 8 and allows the needle valve 8 to slide. In addition, the end of the needle valve 8 opposite to the nozzle plate 14 side passes through a spring receiving plate 18, which is located between the liquid discharge modules 1a and 1b facing each other. The needle valve 8 is held so as to be movable in a position parallel to the Z direction by the sealing member 25, the valve receiving portion 20, and the spring receiving plate 18.

[0021] A compression spring 7 is provided as a biasing member between the arm receiving portion 8c fixed to the needle valve 8 and the spring receiving plate 18. The compression spring 7 biases the needle valve 8 toward the nozzle plate 14 via the arm receiving portion 8c. The compression spring 7 biases the needle valve 8 toward the nozzle plate 14, thereby stabilizing the movement of the needle valve 8 between the open position, which opens the nozzle 14a, and the closed position, which closes the nozzle 14a. The spring receiving plate 18 is attached to a fixing member 17 which is fixed to the cover 11.

[0022] As shown in Figure 8, the actuator 2 of each liquid discharge module 1 is connected via a harness to a drive control device 50 provided in the control unit 90. The drive control device 50 has a waveform generation circuit 51 and an amplification circuit 52, which are drive pulse generation units. The waveform generation circuit 51 generates a drive pulse waveform, the amplification circuit 52 amplifies the voltage value to the required value, and the amplified voltage signal is applied to the actuator 2. This voltage application allows the drive control device 50 to control the displacement of the piezoelectric element 2a, thereby moving the needle valve 8 up and down to control the opening and closing of the nozzle 14a. This up-and-down movement of the needle valve 8 controls the discharge of liquid L from the liquid discharge head 100. However, if the waveform generation circuit 51 can apply a sufficient voltage, the amplification circuit 52 may be omitted.

[0023] This configuration is a normally closed circuit, and when no signal is output from the drive control device 50 to the actuator 2, the needle valve 8 closes the nozzle 14a due to the biasing force of the compression spring 7. Here, when no signal is output to the actuator 2, it can be either a situation where the voltage is always 0 or a constant static voltage is applied. The waveform generation circuit 51 generates drive pulses, which are waveforms that change over time as the voltage applied to the actuator 2 evolves. The waveform generation circuit 51 receives input from an external PC or a microcontroller inside the device, for example, print data, and generates drive pulses based on the input print data. The waveform generation circuit 51 can change the voltage applied to the actuator 2 and generate multiple drive pulses. As the waveform generation circuit 51 generates drive pulses, the piezoelectric element 2a of the actuator 2 expands and contracts according to the drive pulses.

[0024] The operation of actuator 2 when such a drive pulse is input will now be described. When a predetermined voltage is applied to the piezoelectric element 2a, the piezoelectric element 2a extends. Since the arm member 3 is supported by the cover 11 on the support shaft 4, when the piezoelectric element 2a extends, the other end of the arm member 3 rotates around the support shaft 4 in a direction that lifts the arm receiving portion 8c. As a result, the arm receiving portion 8c rises against the biasing force of the compression spring 7 (moves toward the spring receiving plate 18), the needle valve 8 rises together with the arm receiving portion 8c, the nozzle 14a opens, and the liquid L is discharged from the nozzle 14a as droplets due to the pressure on the liquid L in the flow path 5. Next, the piezoelectric element 2a contracts as the voltage applied to it decreases. As the piezoelectric element 2a contracts, the arm member 3 rotates around the support shaft 4 so that its other end descends (moves towards the nozzle plate 14). Then, due to the biasing force of the compression spring 7, the arm receiving portion 8c descends to follow the movement of the other end of the arm member 3, and the nozzle 14a is closed by the needle valve 8, stopping the discharge of droplets from the nozzle 14a.

[0025] As described above, the actuator 2 is connected to the needle valve 8 via the arm member 3, and the needle valve 8 moves up and down as the arm member 3 rotates. Furthermore, the support shaft 4, which is the pivot point of the arm member 3, is positioned closer to the actuator 2, so that the displacement of the piezoelectric element 2a is amplified and transmitted to the needle valve 8. In this way, the actuator 2 functions as a driving means that drives the needle valve 8 using the piezoelectric element 2a, which is an internal drive source. In this configuration, the arm member 3 functions as a displacement amplification mechanism that amplifies the displacement of the actuator 2 using the principle of leverage and transmits it to the needle valve 8. In this configuration, a piezoelectric element 2a is used as actuator 2, but actuator 2 may be a different electrically driven configuration, such as a solenoid or a pneumatically driven piston equipped with an electromagnetic valve. Also, although a compression spring 7 is used in this embodiment, a tension spring that pulls the needle valve 8 toward the nozzle plate 14 may be used. In this case, for example, one end of the tension spring can be fixed to the bottom surface of the cover 11, and the other end can be fixed to the needle valve 8 or the arm receiving part 8c in an extended state.

[0026] Figure 11 is an enlarged view of the area indicated by the symbol J in Figure 10. As shown in Figure 11, a needle-shaped sealing member 8a is provided at the tip of the needle valve 8, and a mortar-shaped flow path opening / closing section 14d is formed on the flow path 5 side surface of the nozzle 14a. The sealing member 8a is made of elastomer, hard rubber, metal, or ceramics, and in the off state when the applied voltage is 0, the sealing member 8a contacts the flow path opening / closing section 14d to prevent the discharge of liquid L. Furthermore, the flow path opening / closing section 14d, which comes into contact with the sealing member 8a and the nozzle plate 14 when closed, may be coated with a sliding functional film such as ceramic or diamond-like carbon to improve sliding properties and durability. In addition, the needle valve 8 and the sealing member 8a may be formed as a single integrated part.

[0027] In this configuration, the tip of the sealing member 8a is needle-shaped and the flow path opening / closing part 14d is mortar-shaped, but the configuration is not limited to this. As another example, the tip of the sealing member 8a may be a smooth convex curved surface such as a sphere, and the flow path opening / closing part 14d may be a smooth concave curved surface that is in close contact with the tip of the sealing member 8a. Alternatively, the tip of the sealing member 8a may be a flat surface, and the tip of the sealing member 8a may be brought into contact with the area around the inlet of the nozzle 14a to seal the nozzle 14a. In any case, any combination of shapes in which the surface of the nozzle 14a on the flow path 5 side is sealed by the needle valve 8 is acceptable.

[0028] Furthermore, the nozzle plate 14 may have a multilayer structure consisting of a layer having a nozzle 14a and a layer having a flow path opening / closing section 14d. In that case, it is desirable that each layer of the nozzle plate 14 has a configuration that defines its position, is firmly fixed by chemical fixing such as bonding by adhesive or bonding by thermal diffusion, and that the liquid L does not leak from between the layers. According to the above configuration, by providing a sealing member 8a at the tip of the needle valve 8, when the sealing member 8a is pressed against the flow path opening / closing section 14d by the biasing force of the compression spring 7, the sealing member 8a adheres tightly to the flow path opening / closing section 14d, ensuring that the nozzle 14a is reliably closed.

[0029] Figure 12 is a schematic diagram showing a part of the CC cross-section shown in Figure 8. As shown in Figure 12, the fixing member 17, to which a spring receiving plate 18 is attached at its lower end, extends in the X direction (head longitudinal direction) of the cover 11 and is fixed so as to span across a pair of inner wall surfaces perpendicular to the X direction of the cover 11. The spring support plate 18 is provided between the actuator 2 located on one side of the nozzle 14a arrangement in the Y direction (upper side in the figure) and the actuator 2 located on the other side of the nozzle 14a arrangement (lower side in the figure), when viewed from the direction of arrangement of the nozzles 14a (X direction) in Figure 8. In this configuration, the actuators 2 and the needle valve 8 are connected by the arm member 3, so they are arranged so that they do not overlap when viewed from the direction of movement of the needle valve 8 (Z direction). Therefore, in this configuration, the spring support plate 18 can be placed in the space above and near the needle valve 8 (above in the Z-axis direction in Figure 8). With this configuration, the dimensions of the liquid discharge head 100 in both the Y and Z directions can be reduced.

[0030] In this configuration, the actuator 2, which is the largest component of the liquid discharge module 1, can be positioned closer to the Y-direction end of the cover 11 by having the arm member 3. As a result, as shown in Figures 8 and 12, the fixing member 17 can be positioned in the Y-center of the cover 11, and the spring receiving plate 18 can be fixed with a single fixing member 17. For example, if the actuator 2 is positioned in the Y-center without the arm member 3, it would be necessary to hold both ends of the spring receiving plate 18 in the Y-direction or both ends in the X-direction with fixing members 17. Thus, if the actuator 2 is positioned in the Y-center, two fixing members 17 would be required, which could lead to the liquid discharge head 100 becoming larger in the X-direction or Y-direction. Also, since the spring receiving plate 18 needs to be extended to a position that does not face the actuator 2, the spring receiving plate 18 will also become larger.

[0031] In contrast, this configuration allows the spring receiving plate 18 to be held by placing one fixing member 17 in the center of the Y direction inside the cover 11, thereby enabling miniaturization of the liquid discharge head 100. Furthermore, it is no longer necessary to extend the spring support plate 18 to a position where it does not face the actuator 2, allowing for a smaller spring support plate 18. In addition, by providing the arm member 3 and positioning the actuator 2 closer to the Y-direction end inside the cover 11, the distance between nozzle rows (distance in the Y-direction) can be shortened, as shown in Figure 13. This allows for an even shorter Y-direction length of the spring support plate 18, reducing material costs and thus lowering the cost of the liquid discharge head 100.

[0032] The liquid discharge head 100 in this configuration discharges liquid L using a so-called valve jet system, making it possible to spray high-viscosity liquids over longer distances. On the other hand, the droplet size is larger compared to systems that do not have a valve for each nozzle. Therefore, it is suitable for forming images on large objects U to be painted, such as the bodies of large vehicles, aircraft fuselages, building walls, and road surfaces. When forming images on such large objects to be painted, the formed image area is also large, and if the size of the droplets discharged from the nozzle is small, as in systems that do not have a valve for each nozzle, the image formation time will be significantly extended, so the valve jet system is preferable. Also, the liquid discharge head cannot be placed in close proximity to the bodies of vehicles, aircraft fuselages, building walls, road surfaces, etc. Furthermore, since the liquid is applied to inclined surfaces and surfaces perpendicular to the horizontal direction, high-viscosity liquids are often used to prevent the applied liquid from dripping. Therefore, a valve jet type liquid discharge head 100 that can discharge a high-viscosity liquid L and ejects droplets by applying relatively high pressure is suitable for printing on large objects to be painted, such as the bodies of large vehicles, aircraft fuselages, building walls, and road surfaces.

[0033] In the liquid discharge head 100 described above, the liquid L is subjected to relatively high pressure within the flow path 5, and the liquid pressure inside the flow path 5 is set to approximately 4 to 5 atmospheres in this embodiment. In this configuration, the flow path 5 is sealed by a sealing member 25 to prevent backflow of the liquid L from the actuator 2 side. In such a high-pressure environment, it is preferable that the axial projection area of ​​the sealing member 25 be as small as possible, as this also serves the purpose of preventing backflow. Furthermore, as shown in Figure 13, if the nozzles 14a are arranged at a high density, the arrangement of the needle valves 8 corresponding to the nozzles 14a will inevitably also be at a high density. This presents the problem that the cross-sectional area of ​​the sealing member 25 per needle valve 8 must be kept small.

[0034] To address these challenges, conventional technology has used an O-ring 19 as a sealing member around the needle valve 8, as shown in the example in Figure 14. However, in a conventional method using an O-ring 19, maintaining sealing performance even in a high-pressure environment requires increasing the compressibility of the O-ring 19, that is, increasing the surface pressure that compresses the O-ring 19 to improve sealing performance. As described above, the needle valve 8 moves up and down in accordance with the operation of the actuator 2 to open and close the nozzle 14a. It has been found that increasing the surface pressure in this way causes the O-ring 19 itself to act as a sliding resistance to the up and down movement of the needle valve 8. Such an increase in sliding resistance is undesirable because it leads to a discrepancy in the responsiveness of the needle valve 8 during on / off switching. Furthermore, it has been found that if the sliding resistance of the O-ring 19 differs in each liquid discharge module 1, the discrepancy in responsiveness can cause unevenness in the amount of liquid L discharged from the nozzle 14a between channels.

[0035] Figure 15 shows an example of a liquid supply means applicable to the liquid ejection head 100 described above. The liquid supply means includes tanks 9a to 9d that contain the inks 6a to 6d ejected from a plurality of liquid ejection heads 100a, 100b, 100c, 100d, etc. In the following description, each ink, each tank, and each liquid ejection head will be referred to collectively as ink 6, tank 9, and liquid ejection head 100. The tank 9 and the supply port 12 of the liquid discharge head 100 are connected by tubes 10, and the tank 9 is connected to a compressor 23 that supplies pressurized air to the tank 9 by a pipe 22 including an air regulator 21. With this configuration, the ink 6 in the liquid discharge head 100 becomes pressurized, and when the needle valve 8 is opened, the ink 6 is discharged from the nozzle 14a. Of these components, the compressor 23, the pipe 22 including the air regulator 21, the tank 9, and the tubes 10 constitute a liquid supply means for pressurizing and supplying ink 6 to the liquid discharge head 100.

[0036] Next, the process by which the drive control device 50 applies voltage to the piezoelectric element 2a to drive the needle valve 8 will be explained using Figure 16. Figures 16(a) to (c) show the opening and closing of the needle valve 8, and Figure 16(d) shows the displacement of the needle valve 8 at that time. In Figure 16(d), the horizontal axis shows time t [s] and the vertical axis shows the displacement C [mm]. The displacement C of the needle valve 8 is defined as the amount by which the needle valve 8 moves upward in the opening direction in Figure 16(a), with the position where the needle valve 8 contacts the nozzle plate 14 and the needle valve 8 closes the nozzle 14a being taken as 0.

[0037] The drive control device 50 applies a drive pulse, which is a voltage pulse, to the piezoelectric element 2a, causing the piezoelectric element 2a to expand and contract, thereby displacing the arm member 3. This drive pulse is proportional to the amount of displacement of the needle valve 8. In other words, the drive pulse generated by the drive control device 50 with respect to time t has a waveform similar to the change in the amount of displacement of the needle valve 8 with respect to the change in time t shown in Figure 16(d). For this reason, in the following explanation, we will assume that the waveform of the displacement amount C shown in Figure 16(d) is the waveform of the drive pulse (or is equal to the waveform of the drive pulse).

[0038] When the voltage applied to the piezoelectric element 2a is set to 0V, as shown in Figure 16(a), the piezoelectric element 2a extends and the needle valve 8 contacts the nozzle plate 14, causing the needle valve 8 to close the nozzle 14a. In Figure 16(d), the state in which the needle valve 8 closes the nozzle 14a is represented as the state where the displacement of the needle valve 8 is 0, and the displacement of the needle valve 8 from this position is shown as displacement C. In this configuration, the voltage is set to 0V when closing the nozzle 14a, but any voltage smaller than the predetermined voltage described later may be used instead of 0V.

[0039] Furthermore, by applying a voltage to the piezoelectric element 2a, the piezoelectric element 2a contracts, and as shown in Figure 16(b), the needle valve 8 moves upward, forming a gap region 24 between the needle valve 8 and the nozzle plate 14. Then, by stopping the application of voltage to the piezoelectric element 2a, or by reducing the applied voltage, as shown in Figure 16(c), the needle valve 8 contacts the nozzle plate 14 again, and the nozzle 14a is closed. As shown in Figure 16(d), the opening and closing operation section by the needle valve 8 is divided into three sections: an upward section D1 in which the displacement of the needle valve 8 increases; a holding section D2 in which the displacement of the needle valve 8 is maintained in the range from 0.6 times the maximum displacement Cmax to the maximum displacement Cmax; and a downward section D3 in which the displacement of the needle valve 8 decreases.

[0040] Since the ink 6 in the flow path member 15 of the liquid discharge head 100 is pressurized by the compressor 23, as shown in Figure 16(b), when the needle valve 8 moves upward and the nozzle 14a opens, the ink 6 enters the gap region 24. Then, in the upward section D1 and the subsequent holding section D2, where the displacement of the needle valve 8 increases, the pressure applied to the ink 6 causes the ink 6 to start being discharged from the nozzle 14a. Subsequently, when the needle valve 8 starts to move downward, in the downward section D3, the ink 6 in the gap region 24 is further pushed out and discharged from the nozzle 14a due to the pressure from the moving needle valve 8 in addition to the pressure from the compressor 23. As described above, in a configuration in which the nozzle 14a is opened and closed by driving the needle valve 8, in addition to the pressure applied to the ink 6, the pressurizing force associated with the closing operation of the needle valve 8 also contributes to ink ejection.

[0041] Incidentally, as disclosed in Japanese Patent Publication No. 2023-168017, in conventional liquid ejection heads, changing the opening time or drive pulse width of the needle valve according to the size of the liquid droplet also changes the ink ejection speed. As a result, the position where the ink lands on the target object shifts depending on the size of the liquid droplet, and there is a problem that the ink cannot be attached to the desired position. Therefore, in this configuration, a needle valve control method described later is adopted to suppress fluctuations in the ink ejection speed. As mentioned above, the ink ejection speed is affected not only by the liquid pressure but also by the closing operation of the needle valve. Therefore, by changing the drive speed during the closing operation of the needle valve, the ink ejection speed can be changed, and fluctuations in the ejection speed can be suppressed. In this configuration, control is performed to change the drive speed of the needle valve according to the opening time of the needle valve. For this reason, in this configuration, the drive control device 50 that controls the drive of the needle valve 8 is equipped with a waveform generation circuit 51 that can generate multiple drive pulses. The waveform generation circuit 51 can generate multiple drive pulses that differ between the opening time of the needle valve 8 and the drive speed of the needle valve 8.

[0042] Figures 17 and 18 show the operation of the needle valve controlled by the drive control device 50 (waveform generation circuit 51) as (a) to (g), the change in the displacement of the needle valve as (h), and the change in the applied voltage applied to the piezoelectric element that drives the needle valve as (i). Figure 17 shows the control when the needle valve opening time is short, and Figure 18 shows the control when the needle valve opening time is long. In addition, the timings of (a) to (g) in (h) and (i) of each figure correspond to the respective operations of the needle valve (a) to (g).

[0043] The control shown in Figure 17 and the control shown in Figure 18 have different opening times for maintaining the needle valve in the open state, and therefore the holding time for the applied voltage that maintains the needle valve in the open state also differs (see the intervals shown as D2 or E2 in Figures 17 and 18). In this example, the open state and opening time of the needle valve refer to the state in which the displacement of the needle valve 8 is maintained in the range from 0.6 times the maximum displacement Cmax to the maximum displacement Cmax, and the holding interval D2 time during which this state is maintained (see Figures 17(h) and 18(h)), or the state in which the applied voltage applied to the piezoelectric element is maintained in the range from 0.6 times the maximum voltage Vmax to the maximum voltage Vmax, and the holding interval E2 time during which this state is maintained (see Figures 17(i) and 18(i)).

[0044] Furthermore, as shown in Figures 17 and 18, in this configuration, the drive speed of the needle valve and the slew rate of the applied voltage during closing operation are varied depending on the opening time (see the sections indicated by D3 or E3 in Figures 17 and 18). The drive speed of the needle valve during closing operation referred to here is the drive speed (amount of displacement of the needle valve per unit time) when the displacement of the needle valve 8 is less than 0.6 times the maximum displacement Cmax (section D3). The slew rate of the applied voltage to the needle valve during closing operation referred to here is the slew rate of the applied voltage (amount of change of applied voltage per unit time) when the applied voltage applied to the piezoelectric element is less than 0.6 times the maximum voltage Vmax (section E3).

[0045] The displacement of the needle valve during closing operation shown in Figures 17(h) and 18(h) is an example where the drive speed is constant (proportional to time) in section D3, but the drive speed may be varied in section D3. In that case, the value obtained by dividing the displacement of the needle valve in section D3 by the time in section D3 may be used as the drive speed during closing operation. Also, the applied voltage during closing operation shown in Figures 17(i) and 18(i) is an example where the amount of change in the applied voltage per unit time decreases with time in section E3. In such a case, the slew rate of the applied voltage during closing operation may be the value obtained by dividing the amount of change in the applied voltage in section E3 by the time in section E3 (or the average value of the slew rate in section E3).

[0046] Specifically, in this configuration, the slew rate of the applied voltage during closing operation is increased when the opening time is longer, as shown in Figure 18, compared to when the opening time is shorter, as shown in Figure 17, thereby increasing the drive speed during the closing operation of the needle valve. Therefore, in this configuration, the waveform generation circuit 51 of the drive control device 50 is configured to selectively generate a first drive pulse that drives the needle valve when the opening time of the needle valve is relatively short (as shown in Figure 17), and a second drive pulse (as shown in Figure 18) in which the opening time of the needle valve is longer than that of the first drive pulse and the drive speed during the closing operation of the needle valve is faster. In other words, the waveform generation circuit 51 is configured to selectively generate a first drive pulse (as shown in Figure 17) and a second drive pulse (as shown in Figure 18) in which the holding time of the applied voltage that maintains the needle valve in the open state is longer than that of the first drive pulse and the slew rate of the applied voltage during the closing operation of the needle valve is larger.

[0047] In this configuration, by increasing the drive speed (closing speed) of the needle valve when the opening time is long, the speed of the ink pushed out by the needle valve also increases, thus increasing the ink ejection speed from the nozzle 14a. This suppresses the decrease in ink ejection speed when the opening time is long and suppresses fluctuations in ink ejection speed due to changes in the opening time of the needle valve. Therefore, according to the control method of this configuration, it is possible to reduce variations in the ink landing position on the target object. In addition, by increasing the slew rate of the applied voltage during the closing operation of the needle valve, the control cycle (drive pulse width) of the applied voltage when the opening time is long can be shortened, making it possible to control the closing operation of the needle valve in a short cycle.

[0048] However, as described in the section on the problems the invention aims to solve, the nozzle opening and closing valve always opens and closes the nozzle hole at the same location, which causes scratches, dents, and dents on the nozzle opening and closing valve due to friction. As usage time increases, small scratches, dents, and dents grow, and eventually large scratches, dents, and dents that become leak paths appear on the surface of the nozzle opening and closing valve, resulting in the problem that the nozzle cannot be opened or closed even when the nozzle is brought into contact with or away from it. A configuration capable of solving the above-mentioned problems is described below as one embodiment of the present invention.

[0049] Figure 19 is a schematic diagram of a needle valve according to the first embodiment of the present invention, and Figure 20 is a schematic diagram of a needle valve used in another example of the first embodiment of the present invention. In Figure 19, the needle valve 30 has a cylindrical needle portion 31 which is a support member and a truncated cone-shaped sealing portion 32 which is a valve member that seals the nozzle 14a. In Figure 20, the needle valve 33 has a needle portion 31 and a spherical sealing portion 34 which is a valve member. The material of the needle portion 31 is preferably stainless steel, high-strength cemented carbide, alumina, or a ceramic material such as stabilized zirconia or semi-stabilized zirconia. Each needle valve 30 and 33 is used in place of the needle valve 8 in the above-described configuration and constitutes the liquid discharge head 100.

[0050] The sealing parts 32 and 34 may be made of the same material as the needle part 31, or a combination of different materials considering the application and compatibility with the liquid being discharged. For example, an inexpensive stainless steel material may be used for the needle part 31, while durable materials such as zirconia or alumina cemented carbide may be used for the sealing parts 32 and 34. The needle portion 31 and the sealing portion 32 are configured to rotate relative to each other. Specifically, a flange portion is formed at the upper end of the sealing portion 32 in Figure 19, facing outward in the circumferential direction, and an engaging portion is formed at the lower end of the needle portion 31 in Figure 19 to receive the flange portion. As a result, the sealing portion 32 is configured to rotate relative to the needle portion 31 about the central axis of the needle valve 30, shown by the dashed line in Figure 19, that is, the axis of rotation along the opening and closing direction of the nozzle 14a, which is the direction of movement of the needle valve 30.

[0051] In the needle valve 30, both the needle portion 31 and the sealing portion 32 are made of cemented carbide, and the diameter of the needle portion 31 is 1.2 mm. The needle valve 33 is similar, with the sealing portion 34 also made of cemented carbide. The vertical movement of the needle valves 30 and 33 is the opening and closing operation of the nozzle 14a, and the driving means for this operation can be an electromagnetic drive using a solenoid, a drive using a PZT, etc. In this embodiment, as described above, a piezoelectric element 2a is used as the moving means, and the actuator 2 that drives the piezoelectric element 2a functions as the driving means. Figure 21 shows a schematic diagram of the sealing of the nozzle 14a by the needle valve 30, where the diameter of the nozzle 14a's opening, i.e., the discharge port, is 0.15 mm. Reference numeral 35 indicates a bearing that rotatably holds the needle portion 31. The clearance of the bearing 35 affects how easily the needle portion 31 rotates; if it is too small, it becomes difficult to rotate, and if it is too large, it rotates easily, but there is a risk that the sealing force will be weak when sealing the nozzle 14a. Therefore, in this embodiment, the clearance is set to 0.1 mm or less.

[0052] In Figure 21, reference numeral 36 indicates the central axis of the nozzle 14a, and reference numeral 37 indicates the central axis of the needle portion 31. During the assembly process of the liquid discharge head 100, the concentricity of the respective central axes 36 and 37 is adjusted so that they do not shift relative to each other, but in reality, errors inevitably occur. In the configuration of this embodiment, the needle portion 31 is made rotatable by utilizing this virtually unavoidable error. As shown in Figure 21, due to the misalignment of the central axes 36 and 37, the conical portion of the sealing part 32 always makes contact with the nozzle 14a on one side. Therefore, as can be seen from Figure 21, when the sealing part 32 contacts the nozzle 14a and seals, a force F due to uneven contact is always generated on one side of the conical portion of the sealing part 32. This force F is the force that rotates the needle portion 31 around the central axis 37 when the needle valve 30 is separated from the nozzle 14a.

[0053] Figure 22 shows the sealing portion 32 separated from the nozzle 14a, Figure 23 shows a side view of the needle valve 30 after the sealing portion 32 has contacted the nozzle 14a 10,000 times, and Figure 24 shows a top view of the nozzle plate 14 and nozzle 14a after the sealing portion 32 has contacted the nozzle 14a 10,000 times. In Figure 23, reference numeral 38 indicates a wear portion formed on the sealing portion 32, and in Figure 24, reference numeral 39 indicates a wear portion formed on the nozzle plate 14. Note that the wear portions 38 and 39 are shown in a schematic manner.

[0054] Since the wear portion 38 is not formed at an angle perpendicular to the central axis of the cone-shaped sealing portion 32, and the wear portion 39 is also formed almost concentrically with the center of the nozzle 14a, it can be seen that the needle portion 31 rotates freely with its central axis 37 as the axis of rotation along the Z axis in the XY plane shown in Figure 19. On the other hand, in the case of a non-rotating configuration, as described above, uneven contact occurs, so the wear portion 38 of the sealing portion 32 becomes uneven, the wear is severe on the one-sided contact area, and the opposite side does not wear much, and the wear portions 38 and 39 often do not form a ring shape. Also, in the case of a non-rotating configuration where the uneven contact is minor and a ring-shaped wear portion is generated, the wear portion should be formed at an angle to the central axis of the cone of the sealing portion 32. In the above embodiment, the needle valve 30 was described, but the same applies to the needle valve 33. The sealing portion 34 is rotatably supported on the needle portion 31 with respect to the opening and closing direction of the nozzle 14a, that is, the axis of rotation along the central axis 37. This configuration can be realized, for example, by rotatably supporting an axis that passes through the vertical centerline of the sealing portion 34 on the needle portion 31, and attaching the sealing portion 34 to this axis.

[0055] With the above configuration, when the needle valves 30 and 33 open and close the nozzle 14a, the sealing portions 32 and 34 rotate relative to the nozzle 14a, thereby preventing the sealing portions 32 and 34 from always contacting and separating from the nozzle plate 14 at the same point. This not only suppresses the adhesion of soft metal foil, but also prevents scratches from growing in the same place when scratches occur, because the sealing portion 32 always contacts the nozzle plate 14 at different points, even with hard particles. Furthermore, since the sealing portions 32 and 34 have a needle portion 31 that rotatably supports them and connects to the piezoelectric element 2a, rotation ensures that different parts of the sealing portions 32 and 34 are brought into contact with and away from the nozzle plate 14, thereby reliably preventing damage to the sealing portions 32 and 34 due to sticking or scratches.

[0056] Furthermore, since the sealing portions 32 and 34 are configured to rotate relative to the needle portion 31 about the central axis of the needle valve 30, that is, the axis of rotation along the opening and closing direction of the nozzle 14a, which is the direction of movement of the needle valve 30, the same effects as described above can be obtained. Furthermore, since the needle portion 31 can rotate about a rotation axis along the direction of movement of the sealing portions 32 and 34, the sealing portions 32 and 34 can be brought into contact with and away from the nozzle plate 14 at different points by rotation, thereby more reliably avoiding damage to the sealing portions 32 and 34 due to sticking or scratches.

[0057] Figure 25 shows a second embodiment of the present invention. This second embodiment differs from the first embodiment only in that a needle valve 41 is used instead of the needle valve 30, and a needle holder 42 is used; all other configurations are the same. The needle valve 41 has a recess 41a at the top of the needle portion 31, and the holding portion 42a of the needle holder 42 is fitted into the recess 41a, resulting in improved rotational performance compared to the needle valve 30. This configuration makes it even more reliable to avoid damage caused by adhesion or scratches in the sealing portion 32.

[0058] Figure 26 shows a modified example of the second embodiment of the present invention. This modified example differs from the second embodiment only in that a needle valve 43 is used instead of a needle valve 41; all other configurations are the same. The needle valve 43 has a recess 43a on the upper part of the needle portion 31, and an asymmetrical center of gravity portion 43b is formed therein, with the holding portion 42a of the needle holder 42 fitted into the recess 43a. Due to the asymmetrical center of gravity portion 43b, the rotational center of the needle valve 41 has improved rotational performance compared to the needle valve 30. This configuration makes it even more reliable to avoid damage caused by adhesion or scratches in the sealing portion 32.

[0059] Furthermore, as described above, in the embodiment of the present invention, as shown in Figure 18(i), the slew rate from the applied voltage of 0V shown in (a), where the nozzle is closed, to the applied voltage Vmax shown in (c), where the nozzle is open, is made smaller than the slew rate from the open state to the closed state. Here, the slew rate in the operation of opening the nozzle from closed is the amount of voltage change per unit time in section E1, where the applied voltage changes from 0V to 0.6Vmax, and the slew rate in the operation of closing the nozzle from open is the amount of voltage change per unit time in section E3, where the applied voltage changes from 0.6Vmax to 0V. With this operation control, as shown in Figure 18(h), the movement speed of the needle valve in the operation of opening the nozzle from closed (amount of displacement per unit time in section D1) is smaller than the movement speed of the needle valve in the operation of closing the nozzle from open (amount of displacement per unit time in section D3).

[0060] By making the movement speed of the needle valve during the nozzle opening operation less than the movement speed during the nozzle closing operation, the force F shown in Figure 21 can be reduced during the nozzle opening operation compared to the nozzle closing operation. In other words, the amount of rotation of the needle valve during nozzle opening can be reduced to less than the amount of rotation of the needle valve during nozzle closing. Therefore, since the needle valve does not return to its original position in the rotational direction with a single nozzle opening and closing operation, if filler or other material adheres to the needle valve, it will not be repeatedly trapped in the same position on the nozzle. Consequently, damage to specific parts of the needle valve and nozzle due to repeated opening and closing operations can be reduced.

[0061] Figure 27 shows a modified example of one embodiment of the present invention, in which, compared to the case with a short opening time shown in Figure 17, the drive speed of the needle valve during closing operation is increased when the opening time is longer, and the drive speed of the needle valve during opening operation is also increased. In other words, in this configuration, the waveform generation circuit 51 can selectively generate a first drive pulse that drives the needle valve when the opening time of the needle valve is relatively short, as shown in Figure 17, and a second drive pulse that has a longer opening time for the needle valve than the first drive pulse and increases the drive speed for both the opening and closing operations of the needle valve. In other words, the waveform generation circuit 51 is configured to selectively generate a first drive pulse and a second drive pulse that has a higher slew rate for the applied voltage that maintains the needle valve in an open state compared to the first drive pulse. In this context, the drive speed and slew rate of the needle valve during opening operation refer to the drive speed (needle valve displacement per unit time) before the needle valve displacement reaches 0.6 times the maximum displacement Cmax (section D1), and the slew rate of the applied voltage (change in applied voltage per unit time) before the applied voltage applied to the piezoelectric element reaches 0.6 times the maximum voltage Vmax (section E1).

[0062] In Figure 27, the slew rate from the nozzle open state to the nozzle closed state is smaller than the slew rate from the nozzle closed state (a) with an applied voltage of 0V to the nozzle open state (c) with an applied voltage of Vmax. Here, the slew rate in the operation of opening the nozzle from closed is the amount of voltage change per unit time in section E1 where the applied voltage changes from 0V to 0.6Vmax, and the slew rate in the operation of closing the nozzle from open is the amount of voltage change per unit time in section E3 where the applied voltage changes from 0.6Vmax to 0V. With this operation control, as shown in Figure 27(h), the movement speed of the needle valve in the operation of opening the nozzle from closed (amount of displacement per unit time in section D1) is greater than the movement speed of the needle valve in the operation of closing the nozzle from open (amount of displacement per unit time in section D3). With this configuration, the same effect as described above can be obtained.

[0063] Figure 28 shows a third embodiment of the present invention. The needle valve 44 shown in Figure 28 differs from the needle valve 30 only in that it uses a needle portion 45 as a support member instead of a needle portion 31, and uses a sealing portion 46 as a valve member instead of a sealing portion 32; all other configurations are the same. The sealing portion 46 is spherical, and in this embodiment, zirconia beads of grade TZ-B250 manufactured by Tosoh Corporation are used. Although these zirconia beads have a particle size distribution, those with a diameter of 0.25 mm are selected during sorting and used for the sealing portion 46. The needle portion 45 is cylindrical in shape and made of SUS303, with a diameter of 1.2 mm. The tip of the needle portion 45 forms a spherical recess 45a, the diameter of which is slightly larger than that of the sealing portion 46, and in this embodiment, the diameter of the recess 45a is 0.27 mm.

[0064] The sealing portion 46 described above is housed in the recess 45a and crimped, integrating the needle portion 45 and the sealing portion 46 in a state where the sealing portion 46 is rotatable. In this configuration, more than half of the volume of the spherical sealing portion 46 is housed inside the recess 45a, and since there is a gap 47 as shown in Figure 28 inside the recess 45a, the sealing portion 46 can rotate freely. That is, the sealing portion 46 is configured to rotate around multiple rotation axes that are not parallel to each other. In this configuration, the recess 45a functions as a housing portion that houses a part of the sealing portion 46.

[0065] Figure 28(a) shows the state in which the sealing portion 46 is in contact with the nozzle 14a. As described above, the central axis of the needle valve 44 is always offset from the central axis of the nozzle 14a, so uneven contact occurs. The location of the uneven contact is indicated by point A, and a force F is generated in the direction normal to it. Simultaneously with this contact, the needle valve 44 closes the nozzle 14a, generating a downward force in the negative Z direction, i.e., the droplet discharge direction. This causes the needle valve 44 to rotate the sealing portion 46 and descend from the position Z1 shown in Figure 28(a) to the position Z2 shown in Figure 28(b), completely closing the nozzle 14a. Along with this movement, the sealing portion 46 also rotates, and point A is displaced to the position of point A'.

[0066] As described above, in the third embodiment, the sealing portion 46 could be rotated by utilizing the axial misalignment that could not be completely suppressed during the assembly process. As can be seen from the displacement at point A, the sealing portion 46 was able to close the nozzle 14a at a different location each time the nozzle 14a was opened and closed. Furthermore, as can be seen from Figure 28, the crimping portion of the recess 45a also has the function of cutting off particles or metal foil strips attached to the surface of the sealing portion 46, thus solving the problem of adhesion. According to the above configuration, the sealing portion 46 can rotate around multiple rotation axes that are not parallel to each other, thus increasing the degree of freedom of rotation. This allows the sealing portion 46 to more reliably move in and out of contact with the nozzle plate 14 at different points, further reducing the occurrence of damage to the sealing portion 46 due to sticking or scratches.

[0067] Figure 29 shows a fourth embodiment of the present invention. The fourth embodiment differs from the third embodiment only in that a sealing portion 48 is used as a valve member instead of the sealing portion 46; all other configurations are the same. The sealing portion 48 has multiple recesses 48a formed on its surface, as shown by the symbol B in Figure 29(a) and in the enlarged cross-sectional view in Figure 29(b). The recesses 48a can be formed by laser processing, co-ground polishing with high-hardness block-shaped alumina particles, or compression bonding. While it is difficult to form a regular arrangement of recesses 48a like the dimples on a golf ball, the above method can reliably form a fine shape with alternating bumps and depressions.

[0068] As shown in the third embodiment, the force F acts on the sealing portion 48 in the XZ plane with a high probability. However, in this embodiment, by forming multiple irregular recesses 48a on the surface of the sealing portion 48, the direction of the contact occurring at point A shown in Figure 28(a) varies irregularly due to the edges of the irregularly formed recesses 48a. Therefore, according to this embodiment, the sealing portion 48 can rotate more freely and irregularly, and the part of the sealing portion 48 that contacts the nozzle plate 14 near the nozzle 14a constantly changes with the repeated opening and closing operation of the needle valve. With this configuration, since the sealing portion 48 has multiple recesses 48a on the surface of the part that contacts the nozzle plate 14, the vector direction of the force F when it contacts the nozzle 14a constantly changes due to the recesses 48a, and the sealing portion 48 can reliably rotate freely. As a result, the degree of freedom of rotation is further increased, and the sealing portion 48 can more reliably make different parts contact and separate from the nozzle plate 14, and the occurrence of damage due to sticking or scratching of the sealing portion 48 can be more reliably avoided.

[0069] In the third and fourth embodiments, examples were shown using sealing parts 46 and 48 made of zirconia beads, but ruby ​​balls with even higher hardness may also be used. If the sphericity is poor when using ruby ​​balls, for example, when the sealing part 49 is an ellipsoidal body of revolution as shown in Figure 30, it is also possible to configure the sealing part 49 so that the end of the long axis is rotatably held by the holding part 45a of the needle part 45 (by crimping). In this way, by holding the end of the long axis by the holding part 45a of the needle part 45, the sealing part 49 can rotate around its long axis as its central axis. Furthermore, when the discharge liquid contains impurities such as fine particles or foil fragments, inexpensive and corrosion-resistant organic materials, such as resin balls made of tetrafluoroethylene, can also be used.

[0070] To confirm the effects of the present invention, a needle valve with the same configuration as the needle valve 30 shown in Figure 21 was prepared as Comparative Example 1, in which the needle portion 31 and the sealing portion 32 are immobile. In this configuration, the clearance of the bearing 35 is reduced to restrict the rotation of the needle portion 31, and the sealing portion 32 is fixed to or integrally formed with the needle portion 31. Figure 31 shows the life test results for each embodiment of the present invention and Comparative Example 1. A liquid mixed with alumina particles with an average particle size of 20 μm was used as the discharge liquid, and the pressure of the discharge liquid in the head was set to 0.3 MPa. The life of the needle valve was determined by whether or not liquid leakage occurred when the nozzle was closed. As is clear from Figure 31, in Comparative Example 1, where the sealing part does not rotate, the sealing part wore out and liquid leakage occurred in less than 8,000 closing cycles, but in the configurations of each embodiment 1 to 4, no liquid leakage occurred even after more than 30,000 closing cycles. From these results, it can be seen that the ability of the sealing part to rotate relative to the nozzle ensures that different parts of the sealing part are in contact with the nozzle plate at all times when the nozzle is closed, thereby significantly increasing the life of the sealing part.

[0071] In each of the above embodiments, the sealing portion is configured to have a shape that includes a part of a sphere or a part of a cone. This configuration ensures that the nozzle is closed more reliably even if different parts of the sealing portion come into contact with and separate from the nozzle plate each time the nozzle is closed, and that the pressurized liquid is discharged stably. In the third and fourth embodiments, the needle portion 45 has a recess 45a that serves as a housing for a portion of the sealing portions 46, 48, and 49, and at least half of the volume of the sealing portions 46, 48, and 49 is housed in the recess 45a. With this configuration, the sealing portions 46, 48, and 49 are securely enclosed within the needle portion 45 and do not detach from the needle portion 45, allowing for reliable free rotation. This makes it possible to more reliably avoid damage to the sealing portions 46, 48, and 49 due to sticking or scratches.

[0072] In each of the above embodiments, by constructing the sealing portion from a material including metal, ceramics, and alloys, the occurrence of scratches on inorganic particles such as alumina can be suppressed, extending the lifespan and improving durability. Furthermore, by constructing the sealing portion from a material containing resin, such as organic materials like polyethylene or tetrafluoroethylene, the materials become inexpensive and readily available, thus significantly reducing costs.

[0073] In the embodiments described above, as shown in Figure 21, the needle portion 31 is shown to be rotatable by a bearing 35. However, since the sealing portions 32 and 34 are each rotatably supported relative to the needle portion 31 and the sealing portions 32 and 34 are rotatable relative to the nozzle 14a, the needle portion 31 does not necessarily need to be rotatable. Furthermore, if the needle portion 31 is configured to be rotatable, even if the sealing portions 32 and 34 are fixed relative to the needle portion 31, the sealing portions 32 and 34 will still be rotatable relative to the nozzle 14a. Furthermore, while the above-described configuration shows an example in which a piezoelectric element 2a is used as a means of moving the needle valve 8, the means of moving is not limited to a piezoelectric element, and other electrically driven configurations such as a solenoid or a pneumatically driven piston equipped with an electromagnetic valve may also be used.

[0074] Next, we will describe another liquid dispensing device equipped with the liquid dispensing head 100 described above. As shown in Figures 32 and 33, the printing apparatus 500, which is a liquid ejection device, includes an incoming means 501 for loading the continuous body 510, which is the recording medium, and a guiding and transporting means 503 for guiding and transporting the continuous body 510 loaded by the incoming means 501 toward the printing means 505. The printing apparatus 500 also includes a printing means 505 that performs a printing operation to form an image by ejecting droplets onto the continuous body 510, a drying means 507 for drying the continuous body 510 to which the droplets have adhered, and an outgoing means 509 for outgoing the continuous body 510. The continuous material 510 is fed out from the main winding roller 511 of the loading means 501, guided and transported by rollers of the loading means 501, the guiding and transporting means 503, the drying means 507, and the unloading means 509, and then wound onto the winding roller 591 of the unloading means 509. In the printing means 505, the continuous material 510 is transported on the transport guide member 559, facing the head unit 550, which is a liquid discharge unit, and an image is printed by droplets discharged from the head unit 550.

[0075] The printing apparatus 500 is equipped with a head unit 550 and liquid ejection units 100A and 100B, each of which is mounted on a common base member 552. Each liquid dispensing unit 100A and 100B, when the direction in which the liquid dispensing heads 100 are arranged in a direction perpendicular to the continuous material transport direction is defined as the head arrangement direction, will dispense droplets of the same color from the head row 100A1 and 100A2 of liquid dispensing unit 100A. Similarly, the head row 100B1 and 100B2 of liquid dispensing unit 100A, the head row 100C1 and 100C2 of liquid dispensing unit 100B, and the head row 100D1 and 100D2 of liquid dispensing unit 100B will dispense liquids of the desired color, respectively.

[0076] Next, yet another example of a printing apparatus which is a liquid dispensing device according to the present invention will be described with reference to Figures 34 and 35. The printing apparatus 400, as a liquid ejection device, is a serial type printing apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is stretched across the left and right side plates 491A and 491B, and holds the carriage 403 in a movable position. The carriage 403 reciprocates in the main scanning direction by receiving the driving force of the main scanning motor 405 via the timing belt 408 stretched between the drive pulley 406 and the driven pulley 407.

[0077] The carriage 403 is equipped with a liquid dispensing unit 440 which integrally includes a liquid dispensing head 100 and a head tank 441. Here, the liquid dispensing head 100 dispenses liquids of various colors, such as yellow (Y), cyan (C), magenta (M), and black (K). The liquid dispensing head 100 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and with the liquid dispensing direction facing downwards. The liquid dispensing head 100 is connected to a liquid circulation device (not shown), and the liquid of the desired color is circulated and supplied to the liquid dispensing head 100.

[0078] The printing apparatus 400 is equipped with a transport mechanism 495 for transporting the paper 410, which is the recording medium. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 that drives the transport belt 412. The transport belt 412, which is an endless belt, is stretched between a transport roller 413 and a tension roller 414, and is used to pick up the paper 410 and transport it to a position facing the liquid discharge head 100. Pickup is performed by electrostatic attraction or air suction, etc. The transport belt 412 is moved circumferentially in the sub-scanning direction by the driving force of the sub-scanning motor 416 being transmitted via a timing belt 417 and a timing pulley 418.

[0079] A maintenance and recovery mechanism 420 for maintaining and restoring the liquid discharge head 100 is positioned on one side of the carriage 403 in the main scanning direction and to the side of the conveyor belt 412. The maintenance and recovery mechanism 420 consists of, for example, a cap member 421 that caps the nozzle surface of the liquid discharge head 100, a wiper member 422 that wipes the nozzle surface, and so on. The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the conveyor mechanism 495 are mounted on a housing that includes side plates 491A, 491B, and a back plate 491C. In the printing apparatus 400 with the above configuration, the paper 410 is held in place by the transport belt 412, and the paper 410 is transported in the sub-scanning direction by the circular movement of the transport belt 412. At this time, the carriage 403 is moved in the main scanning direction, and the liquid ejection head 100 is driven according to the image signal, thereby ejecting liquid onto the stationary paper 410 to form an image.

[0080] Next, the liquid dispensing unit 440 described above will be explained with reference to Figure 36. The liquid ejection unit 440 is composed of a housing portion consisting of side plates 491A, 491B and a back plate 491C, which are components of the printing device 400, which is a liquid ejection device, as well as a main scanning movement mechanism 493, a carriage 403, a liquid ejection head 100, and the like. Furthermore, it is also possible to configure a liquid dispensing unit in which the maintenance and recovery mechanism 420 described above is further attached to, for example, the side plate 491B of the liquid dispensing unit 440.

[0081] Next, another example of a liquid dispensing unit according to one embodiment of the present invention will be described with reference to Figure 37. The liquid discharge unit 450 shown in Figure 37 includes a liquid discharge head 100 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444. The flow path component 444 is located inside a cover 442, and a connector 443 for electrical connection to the liquid discharge head 100 is provided on the upper part of the flow path component 444. A configuration including a head tank 441 instead of the flow path component 444 is also possible. In the liquid ejection units 100A, 100B, 440, 450, 550, and the printing devices 400, 500, which are liquid ejection devices, the same effects and benefits as those of the liquid ejection head 100 described above can be obtained.

[0082] In the present invention, the liquid used can be any liquid having viscosity and surface tension that allows it to be discharged from a liquid discharge head, and its properties are not particularly limited, however, it is preferable that its viscosity becomes 30 mPa·s or less at room temperature and atmospheric pressure, or upon heating and cooling. More specifically, this includes solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functional materials such as surfactants, biocompatible materials such as DNA, amino acids and proteins, and calcium, edible materials such as natural pigments, and solutions, suspensions, and emulsions containing these. These can be used, for example, in inkjet inks, surface treatment liquids, and three-dimensional molding material liquids. The energy source for discharging liquid includes piezoelectric actuators (multilayer piezoelectric elements and thin-film piezoelectric elements), thermal actuators using electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a diaphragm and a counter electrode.

[0083] The "liquid discharge head" is not limited to any particular pressure generating means. For example, in addition to the piezoelectric actuator described above (which may use a multilayer piezoelectric element), it may also use a thermal actuator that uses an electrothermal conversion element such as a heating resistor, or an electrostatic actuator consisting of a diaphragm and a counter electrode. A "liquid discharge unit" is a liquid discharge head with integrated functional components and mechanisms, and includes an assembly of parts related to liquid discharge. For example, a "liquid discharge unit" may include a combination of a liquid discharge head with at least one of the following components: a head tank, carriage, supply mechanism, maintenance and recovery mechanism, main scanning movement mechanism, and liquid circulation device. Here, integration includes, for example, cases where a liquid dispensing head and functional components or mechanisms are fixed to each other by fastening, bonding, engaging, etc., or where one is held movably relative to the other. Furthermore, the liquid dispensing head and functional components or mechanisms may be detachable from each other.

[0084] Liquid dispensing units can be configured with an integrated liquid dispensing head and head tank, or with the two integrated by being connected to each other via tubing or similar means. It is also possible to add a unit containing a filter between the liquid dispensing head and head tank of these liquid dispensing units. Furthermore, liquid dispensing units include those in which the liquid dispensing head and carriage are integrated, and those in which the liquid dispensing head, carriage, and main scanning movement mechanism are integrated. Additionally, some liquid dispensing units have the liquid dispensing head movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid dispensing head and scanning movement mechanism are integrated.

[0085] Some liquid discharge units integrate the liquid discharge head, carriage, and maintenance / recovery mechanism by fixing a cap component, which is part of the maintenance / recovery mechanism, to a carriage to which the liquid discharge head is attached. Other liquid discharge units integrate the liquid discharge head and supply mechanism by connecting a tube to a liquid discharge head to which a head tank or flow path component is attached. Liquid from a liquid storage source is supplied to the liquid discharge head via this tube. The main scanning movement mechanism shall include the guide member alone. The supply mechanism shall include the tube alone and the loading section alone.

[0086] In this invention, the liquid discharge unit is described in combination with a liquid discharge head, but the liquid discharge unit also includes a head module that includes the liquid discharge head described above, and a head unit in which the functional components and mechanisms described above are integrated. Liquid dispensing devices include those that drive the liquid dispensing head to dispense liquid, and are equipped with a liquid dispensing head, liquid dispensing unit, head module, head unit, etc. Liquid dispensing devices include not only those that can dispense liquid onto surfaces to which liquid can adhere, but also those that dispense liquid into gases or liquids.

[0087] The liquid dispensing device may also include means for feeding, conveying, and dispensing paper onto materials to which liquid can adhere, as well as other pre-treatment and post-treatment devices. Examples of liquid ejection devices include image forming devices that eject ink to form an image on a recording medium, and three-dimensional molding devices that eject molding liquid onto a powder layer formed in layers to create three-dimensional objects. Furthermore, liquid dispensing devices are not limited to those that visualize meaningful images such as letters or figures through the dispensed liquid. For example, they also include devices that form patterns that do not have meaning in themselves, or devices that create three-dimensional images.

[0088] The above-mentioned objects to which liquids can adhere refer to objects to which liquids can adhere, at least temporarily, including those that adhere and solidify or adhere and penetrate. Specific examples include recording media such as paper, film, and cloth; electronic components such as electronic circuit boards and piezoelectric elements; powder layers; organ models; and inspection cells. Unless otherwise specified, it includes all objects to which liquids can adhere. The material to which the liquid can adhere may be any material, such as paper, thread, fibers, fabric, leather, metal, plastic, glass, wood, or ceramics, as long as the liquid can adhere to it, even temporarily.

[0089] A liquid dispensing device includes a configuration in which a liquid dispensing head and an object to which the liquid can adhere move relative to each other, but the object that moves is not limited to either one or the other. Specific examples include serial type devices in which the liquid dispensing head moves, and line type devices in which the liquid dispensing head does not move. Other examples of liquid dispensing devices include processing liquid coating devices that dispense processing liquid onto the surface of paper for purposes such as modifying the surface of the paper, and injection granulation devices that granulate fine particles of raw materials by spraying a composition liquid, in which raw materials are dispersed in a solution, through a nozzle.

[0090] The liquid dispensing apparatus of the present invention also includes apparatus for manufacturing electrodes and electrochemical elements. The electrode manufacturing apparatus will be described below. Figure 38 is a schematic diagram showing an example of an electrode manufacturing apparatus according to one embodiment of the present invention. The electrode manufacturing apparatus 700 is an apparatus for manufacturing an electrode including a layer having an electrode material by discharging a liquid composition using a liquid discharging unit including a liquid discharging head. First, the means and process for forming the layer containing the electrode material will be described. The liquid discharge means provided in the electrode manufacturing apparatus 700 shown in Figure 38 is the liquid discharge unit of the present invention described above. A liquid composition is discharged from the liquid discharge head of the liquid discharge unit, thereby applying the liquid composition to the target object and forming a liquid composition layer. The target object (hereinafter sometimes referred to as the "discharge target object") is not particularly limited as long as it is an object on which a layer containing electrode material is formed, and can be appropriately selected according to the purpose. For example, the target object may be an electrode substrate (current collector), an active material layer, a layer containing solid electrode material, etc. The target object may also be an electrode composite layer containing active material on an electrode substrate. Furthermore, the discharge means and discharge process may be means and processes for forming a layer containing electrode material by directly discharging the liquid composition, as long as it is possible to form a layer containing electrode material on the discharge target object. Moreover, the discharge means and discharge process may be means and processes for forming a layer containing electrode material by indirectly discharging the liquid composition.

[0091] Next, we will describe the other components and processes. Other components included in the electrode composite layer manufacturing apparatus are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected according to the purpose. Similarly, other steps included in the electrode composite layer manufacturing method are not particularly limited as long as they do not impair the effects of the present invention and can be appropriately selected according to the purpose. For example, components and steps included in the electrode composite layer manufacturing apparatus and manufacturing method include heating means and heating steps.

[0092] Next, the heating means and heating process will be described. The heating means included in the electrode composite layer manufacturing apparatus is a means for heating the liquid composition discharged by the discharge means. Furthermore, the heating step included in the electrode composite layer manufacturing method is a step for heating the liquid composition discharged in the discharge step. By heating the liquid composition, it can be dried.

[0093] Next, a configuration for forming a layer containing electrode material by direct discharge of a liquid composition will be described. Here, as an example of an electrode manufacturing apparatus that forms a layer containing electrode material, an electrode manufacturing apparatus that forms an electrode composite layer containing active material on an electrode substrate (current collector) will be described. As shown in Figure 38, the electrode manufacturing apparatus 700 includes a discharge process section 110 which includes a step of applying a liquid composition onto a printing substrate 704 having an object to be discharged to form a liquid composition layer, and a heating process section 130 which includes a heating step of heating the liquid composition to obtain an electrode composite layer.

[0094] The electrode manufacturing apparatus 700 is equipped with a transport means 705 for transporting the printing substrate 704, and the transport means 705 transports the printing substrate 704 at a preset speed in the order of the discharge process section 110 and the heating process section 130. There are no particular restrictions on the method for manufacturing the printing substrate 704 having an object to be discharged, such as an active material layer, and well-known methods can be appropriately selected. The discharge process section 110 is equipped with a liquid discharge head 281a for realizing a liquid composition application process for applying a liquid composition onto the printing substrate 704, a storage container 281b for containing the liquid composition 707, a supply tube 281c for supplying the liquid composition 707 in the storage container 281b to the liquid discharge head 281a, and the like.

[0095] In the discharge process section 110, the liquid composition 707 is discharged from the liquid discharge head 281a, and the liquid composition 707 is applied to the printing substrate 704 to form a thin film layer of the liquid composition. The containment container 281b may be integrated with the electrode composite layer manufacturing apparatus, or it may be detachable from the electrode composite layer manufacturing apparatus. Alternatively, the containment container 281b may be a container used for adding to a containment container integrated with the electrode composite layer manufacturing apparatus, or a containment container detachable from the electrode composite layer manufacturing apparatus. The containment container 281b and the supply tube 281c can be arbitrarily selected as long as they are capable of stably containing and supplying the liquid composition 707.

[0096] In the heating section 130, a solvent removal step is performed to remove any solvent remaining in the liquid composition layer by heating. Specifically, the solvent remaining in the liquid composition layer is removed from the liquid composition layer by drying it with heating by the heating device 703 provided in the heating section 130, thereby forming the electrode composite layer. Furthermore, the solvent removal step in the heating section 130 may be performed under reduced pressure. There are no particular restrictions on the heating device 703, and it can be appropriately selected according to the purpose. For example, the heating device 703 can be a substrate heater, an IR heater, a hot air heater, etc. The heating device 703 may also be a combination of at least two of the substrate heater, IR heater, and hot air heater. The heating temperature and heating time can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the film thickness to be formed.

[0097] In the electrode manufacturing apparatus 700, the same type of liquid discharge head 281a as the liquid discharge head 100 described above is used. By using the electrode manufacturing apparatus 700 according to an embodiment of the present invention, a liquid composition can be discharged to a target position on the object to be discharged. The electrode mixture layer can be suitably used, for example, as part of the configuration of an electrochemical element. There are no particular restrictions on the components of the electrochemical element other than the electrode mixture layer, and well-known components can be appropriately selected. Examples of components other than the electrode mixture layer include a positive electrode, a negative electrode, a separator, etc.

[0098] Examples of the present invention are as follows: [1] A liquid dispensing head comprising a nozzle plate having a nozzle for dispensing liquid, a valve member for opening and closing the nozzle, and a means for displacing the valve member between an open position for opening the nozzle and a closed position for closing the nozzle, wherein the valve member is a liquid dispensing head that is rotatable relative to the nozzle. [2] The liquid discharge head according to [1], characterized in that it has a support member that rotatably supports the valve member and connects to the moving means. [3] The liquid discharge head according to [1] or [2], characterized in that the valve member is rotatable about a rotation axis along the direction of movement of the valve member. [4] The liquid discharge head according to [1] or [2] is characterized in that the valve member is rotatable about a plurality of rotation axes that are not parallel to each other. [5] The liquid discharge head according to [2] is characterized in that the support member is rotatable about a rotation axis along the direction of movement of the valve member. [6] The liquid discharge head according to any one of [1] to [5], characterized in that the valve member includes the shape of a part of a sphere or a part of a cone. [7] The liquid discharge head according to [2] or [5], wherein the support member has a housing portion that houses a part of the sealing portion, and at least half of the volume of the sealing portion is housed in the housing portion. [8] The liquid discharge head according to any one of [1] to [7], characterized in that the valve member has a plurality of recesses on the surface of the portion that contacts the nozzle plate. [9] The liquid discharge head according to any one of [1] to [8], characterized in that the valve member is made of a material including metal, ceramics, or alloy.

[10] The liquid discharge head according to any one of [1] to [8], characterized in that the valve member is made of a material including a resin material. A liquid discharge unit comprising a liquid discharge head as described in

[11] [1] and a drive means for driving the moving means, wherein the drive means drives the drive means such that the speed at which the valve member moves from the closed position to the open position is different from the speed at which the valve member moves from the open position to the closed position. A liquid dispensing device comprising a liquid dispensing head as described in

[12] [1] to

[10] and a driving means for driving the moving means.

[0099] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the spirit of the invention as described in the claims, unless otherwise specifically limited in the above description. The effects described in the embodiments of the present invention are merely illustrative of the most preferred effects that may arise from the present invention, and the effects of the present invention are not limited to those described in the embodiments. [Explanation of symbols]

[0100] 2. Driving means (actuator) 2a Means of movement (piezoelectric element) 14 Nozzle Plate 14a Nozzle 31,45 Support member (needle part) 32,34,46,48,49 Valve member (sealing part) 40. Liquid dispensing device (vehicle body coating device) 45a Storage section (recess) 48a Recess 60 Liquid Dispensing Units 100 liquid dispensing heads [Prior art documents] [Patent Documents]

[0101] [Patent Document 1] Japanese Patent Publication No. 2024-93126

Claims

1. A nozzle plate having a nozzle for dispensing liquid, A valve member for opening and closing the nozzle, The system includes a moving means for displacing the valve member between an open position in which the nozzle is opened and a closed position in which the nozzle is closed, The valve member is a liquid discharge head that is rotatable relative to the nozzle.

2. In the liquid dispensing head according to claim 1, A liquid dispensing head characterized by having a support member that rotatably supports the valve member and connects to the moving means.

3. In the liquid dispensing head according to claim 1, The liquid dispensing head is characterized in that the valve member is rotatable about a rotation axis along the direction of movement of the valve member.

4. In the liquid dispensing head according to claim 1, The liquid discharge head is characterized in that the valve member is rotatable about a plurality of rotation axes that are not parallel to each other.

5. In the liquid dispensing head according to claim 2, The liquid dispensing head is characterized in that the support member is rotatable about a rotation axis along the direction of movement of the valve member.

6. In the liquid dispensing head according to claim 1, The liquid discharge head is characterized in that the valve member includes the shape of a part of a sphere or a part of a cone.

7. In the liquid dispensing head according to claim 2, The liquid discharge head is characterized in that the support member has a housing portion for housing a part of the valve member, and at least half of the volume of the valve member is housed in the housing portion.

8. In the liquid dispensing head according to claim 1, The liquid discharge head is characterized in that the valve member has a plurality of recesses on the surface of the portion that contacts the nozzle plate.

9. In the liquid dispensing head according to claim 1, The liquid dispensing head is characterized in that the valve member is made of a material including metal, ceramics, and alloy.

10. In the liquid dispensing head according to claim 1, The liquid dispensing head is characterized in that the valve member is made of a material including a resin material.

11. The liquid dispensing head according to claim 1, The system comprises a drive means for driving the aforementioned moving means, The liquid discharge unit is characterized in that the driving means drives the moving means such that the speed at which the valve member moves from the closed position to the open position is different from the speed at which the valve member moves from the open position to the closed position.

12. A liquid dispensing head according to claims 1 to 10, A driving means for driving the aforementioned moving means, A liquid dispensing device equipped with the following features.

Images