Liquid discharge head and liquid discharge device

Abstract

To provide a liquid discharge head and a liquid discharge device that can suppress the water hammer phenomenon.SOLUTION: A liquid discharge head according to an embodiment includes a nozzle plate having nozzles and a liquid flow path. The liquid flow path includes: multiple actuator grooves 1135 which form a pressure chamber communicating with each of the multiple nozzles; one or more common flow paths 1162 extending in a first direction and communicating with the multiple actuator grooves 1135; and a supply port 1111 through which liquid is supplied. When the thickness of the nozzle plate is T mm, the relationship between the maximum supply distance L mm being the distance in the first direction from a supply section 117 which supplies liquid to the common flow path 1162 to the farthest actuator groove 1135 in the common flow path 1162 and the flow path width W mm being the dimension of the common flow path 1162 in the second direction which intersects the first direction satisfies the formula 1. The nozzle plate is made of a flexible film and is formed so as to have a Young's modulus of 9.1 Gpa or greater.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] An embodiment of the present invention relates to a liquid ejection head and a liquid ejection apparatus. [Background technology]

[0002] Liquid ejection devices such as inkjet printers are required to be small and have a large ink ejection volume for high productivity. For this reason, some inkjet heads have a structure that supplies ink from both sides of the actuator groove of a side shooter type inkjet head, ensuring a sufficient ink flow rate and enabling high productivity. In order to make the liquid ejection heads smaller, the size of the ink flow path that supplies the ink is limited. On the other hand, depending on the size of the ink flow path, when switching from a state in which the ink flow rate inside the head is high to a state in which the ink flow rate is low, a water hammer phenomenon may occur, which may affect the stability of the meniscus, which is necessary for stable ejection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-077801 A [Patent Document 2] JP 2017-185817 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a liquid ejection head and a liquid ejection device capable of suppressing the water hammer phenomenon. [Means for solving the problem]

[0005] The liquid ejection head according to the embodiment includes a nozzle plate and a liquid flow path. The nozzle plate has nozzles. The liquid flow path has a plurality of actuator grooves that constitute pressure chambers that are respectively connected to the plurality of nozzles, and one or more common flow paths that extend in a first direction and are connected to the plurality of actuator grooves, and has a supply port through which liquid is supplied. When the thickness of the nozzle plate is T mm, the relationship between a maximum supply distance L mm, which is the distance in the first direction from a supply unit that supplies liquid to the common flow path to the farthest actuator groove in the common flow path, and a flow path width W mm, which is the dimension of the common flow path in a second direction intersecting with the first direction, is as follows:

number

[0006] [Figure 1] FIG. 1 is a perspective view showing a configuration of a liquid ejection head according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view showing the configuration of a head main body of the liquid ejection head. [Diagram 3] FIG. 2 is a bottom view showing the configuration of the liquid ejection head. [Figure 4] FIG. 2 is a cross-sectional view showing a configuration of a portion of the liquid ejection head. [Diagram 5] FIG. 2 is a cross-sectional view showing a configuration of a portion of the liquid ejection head. [Figure 6] FIG. 2 is an explanatory diagram showing the configuration of a flow path of the liquid ejection head. [Figure 7] FIG. 1 is an explanatory diagram illustrating a configuration of a liquid ejection device according to an embodiment. [Figure 8] FIG. 11 is an explanatory diagram showing the configuration of a flow path of a liquid ejection head according to another embodiment. [Figure 9] FIG. 11 is an explanatory diagram showing the configuration of a flow path of a liquid ejection head according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] A liquid ejection head 1 according to a first embodiment and a liquid ejection device 2 using the liquid ejection head 1 will be described below with reference to Figs. 1 to 7. Fig. 1 is a perspective view showing the configuration of the liquid ejection head according to this embodiment, and Fig. 2 is a perspective view showing the configuration of the head body. Fig. 3 is a bottom view showing the configuration of the liquid ejection head, and Fig. 4 is a cross-sectional view showing a part of the configuration of the liquid ejection head. Fig. 5 is a cross-sectional view showing a part of the configuration of the liquid ejection head, and Fig. 6 is an explanatory diagram showing the configuration of the flow path of the liquid ejection head. Fig. 7 is an explanatory diagram showing the configuration of the liquid ejection device according to this embodiment. In the figures, X, Y, and Z respectively indicate a first direction, a second direction, and a third direction that are orthogonal to each other. In each figure, the configuration is enlarged, reduced, or omitted as appropriate for the purpose of explanation.

[0008] The liquid ejection head 1 is, for example, a share mode inkjet head provided in a liquid ejection device 2 such as the inkjet recording device shown in Fig. 7. The liquid ejection head 1 has an independently driven structure that alternately includes, for example, pressure chambers 1131 and air chambers 1132. The liquid ejection head 1 is provided in a head unit 2130 that includes a supply tank 2132 as a liquid storage section provided in the liquid ejection device 2.

[0009] The liquid ejection head 1 is supplied with ink as liquid stored in a supply tank 2132. The liquid ejection head 1 may be a non-circulation type head that does not circulate ink, or may be a circulation type head that circulates ink. In this embodiment, the liquid ejection head 1 will be described using an example of a non-circulation type head.

[0010] 1 to 7, the liquid ejection head 1 includes a head body 11, a manifold unit 12, and a cover 15. For example, the liquid ejection head 1 is a side shooter type four-row integrated structure head that includes two head bodies 11 each having a pair of actuators 113.

[0011] The head body 11 ejects liquid. The head body 11 includes a substrate 111, a frame 112, an actuator 113 having a plurality of pressure chambers 1131 and a plurality of air chambers 1132, and a nozzle plate 114. A predetermined ink flow path 16 is formed inside the head body 11, the ink flow path 16 passing through the pressure chambers 1131 and communicating with the nozzles 1141. The ink flow path 16 is a liquid flow path.

[0012] The head main body 11 has a common flow path portion 116 that communicates with the multiple pressure chambers 1131 of the actuator 113 as a part of the ink flow path 16. The primary side of the multiple pressure chambers 1131 is the upstream side of the multiple pressure chambers 1131 in the direction in which the liquid flows. The secondary side of the multiple pressure chambers 1131 is the downstream side of the multiple pressure chambers 1131 in the direction in which the liquid flows.

[0013] Furthermore, the head body 11 has an electrode portion constituted by an electrode film formed on the substrate 111 and the actuator 113. Specifically, the head body 11 has, as the electrode portion, a plurality of individual electrodes that respectively drive a plurality of pressure chambers 1131 of the actuator 113, and one or a plurality of common electrodes that simultaneously drive the plurality of pressure chambers 1131.

[0014] In this embodiment, an example will be described in which the head main body 11 has two actuators 113, and the common flow path section 116 has one first common flow path 1161 and two second common flow paths 1162. The common flow path section 116 has, for example, the first common flow path 1161 communicating with one opening (the inlet of the pressure chamber 1131) of the multiple pressure chambers 1131 of the actuator 113, and the second common flow path 1162 communicating with the secondary side opening (the outlet of the pressure chamber 1131) of the multiple pressure chambers 1131 of the actuator 113. That is, a first common flow path 1161 is arranged at one end side in the second direction (Y direction) of a plurality of actuator grooves 1135 each extending in the second direction (Y direction), and a second common flow path 1162 is arranged at the other end side of the actuator grooves 1135 of a pair of actuators 113. The first common flow path 1161 and the second common flow path 1162 are connected to each other at both ends in the first direction.

[0015] The substrate 111 is formed in a rectangular plate shape from a ceramic material such as alumina. The substrate 111 is formed in a rectangular shape that is long in one direction (X direction), for example. An electrode film is formed on one main surface of the substrate 111, which surface constitutes the polishing surface. A pair of actuators 113 is provided on the surface of the substrate 111, aligned in the short direction (Y direction) of the substrate 111. The substrate 111 has a single supply port 1111 which is an opening through which a liquid passes. The supply port 1111 is a through hole that penetrates between both main surfaces of the substrate 111.

[0016] The back surface of substrate 111 faces manifold 121 and covers grooves that form cooling channels through which cooling water flows and are formed on the opposing surface of manifold 121. That is, substrate 111 and manifold 121 form the cooling channels.

[0017] The supply port 1111 is an inlet for supplying ink to the first common flow channel 1161. The supply port 1111 is a through hole formed in the center of the short side direction of the substrate 111. The supply port 1111 extends along the longitudinal direction of the substrate 111. In other words, the supply port 1111 is, for example, a long hole that is long in one direction along the longitudinal direction of the actuators 113 and the longitudinal direction of the first common flow channel 1161. The supply port 1111 is provided between a pair of actuators 113, and opens at a position facing the first common flow channel 1161. A part of a common electrode may be formed on the inner wall surface of the supply port 1111.

[0018] An actuator 113 and a frame 112 are provided on a substrate 111. The inside of the frame 112 of the substrate 111 becomes a liquid contact area where ink is applied, and the outside of the frame 112 becomes a mounting area where various electronic components can be connected.

[0019] The frame 112 is fixed to one main surface of the substrate 111 with an adhesive or the like. The frame 112 surrounds a supply port 1111 and an actuator 113 provided in the substrate 111.

[0020] For example, the frame 112 is formed in a rectangular frame shape, thereby forming an opening that is long in one direction along the longitudinal direction of the frame 112. The frame 112 may have a stepped structure in which a part of the surface is recessed. A pair of actuators 113 and a supply port 1111 are arranged in the opening of the frame 112. The frame 112 surrounds the actuator 113 between the nozzle plate 114 and the substrate 111, and is configured to be able to hold liquid therein. That is, the frame 112, the nozzle plate 114, the substrate 111, and the actuator 113 form predetermined ink flow paths in the head main body 11, including a pressure chamber 1131 and common flow paths 1161 and 1162.

[0021] The pair of actuators 113 is adhered to the surface of the substrate 111. The pair of actuators 113 are arranged in two rows on the substrate 111 with a supply port 1111 between them. The actuators 113 are plate-like members that are long in one direction. The actuators 113 are disposed within the opening of the frame 112 and adhered to the surface of the substrate 111.

[0022] The actuator 113 has, at the center in the longitudinal direction, a plurality of pressure chambers 1131 arranged at equal intervals in the longitudinal direction, and air chambers 1132 arranged at equal intervals in the longitudinal direction and between adjacent pressure chambers 1131. In other words, the actuator 113 has a plurality of pressure chambers 1131 and air chambers 1132 arranged alternately along the longitudinal direction. The plurality of pressure chambers 1131 and the plurality of air chambers 1132 extend in a direction intersecting the arrangement direction, for example, in the short direction of the actuator 113.

[0023] A top surface portion of the actuator 113, which is the surface opposite to the substrate 111, is bonded to the nozzle plate 114. The actuators 113 are arranged at equal intervals in the longitudinal direction, and a plurality of actuator grooves 1135 are formed along a direction perpendicular to the longitudinal direction. The plurality of actuator grooves 1135 form a plurality of pressure chambers 1131 and a plurality of air chambers 1132. In other words, the actuator 113 has a plurality of piezoelectric bodies 1133 that are arranged at equal intervals in the longitudinal direction and are driving elements that constitute walls that form the actuator grooves 1135 therebetween. The plurality of piezoelectric bodies 1133 form a plurality of pressure chambers 1131 and a plurality of air chambers 1132 between adjacent piezoelectric bodies 1133, and the volume of the pressure chambers 1131 is changed by applying a driving voltage.

[0024] For example, the width of the actuator 113 in the short side direction gradually increases from the top side toward the substrate 111 side. The cross section of the actuator 113 along a direction perpendicular to the longitudinal direction (short side direction) is formed into a trapezoidal shape. That is, the actuator 113 has an inclined surface 1134 that is inclined on the side portion in the short side direction. The side portion (inclined surface 1134) is disposed opposite the first common flow path 1161 and the second common flow path 1162. An electrode film is formed on the inclined surface 1134 in a predetermined pattern.

[0025] As a specific example, the actuator 113 is formed of a laminated piezoelectric member in which two rectangular piezoelectric material plates long in one direction are bonded facing each other so that the polarization directions of the two are opposite to each other. Here, the piezoelectric material is, for example, PZT (lead zirconate titanate). The actuator 113 is bonded to the surface of the substrate 111 by, for example, an adhesive. The actuator 113 has an inclined surface 1134. The actuator 113 has a plurality of actuator grooves 1135 that form a plurality of pressure chambers 1131 and a plurality of air chambers 1132, and a piezoelectric body (driving element) 1133 that is a side wall that separates adjacent actuator grooves 1135 is formed.

[0026] Further, on the actuator 113, an electrode film constituting an individual electrode and a common electrode is formed in a predetermined pattern.

[0027] The pressure chamber 1131 deforms when the liquid ejection head 1 performs an operation such as printing, thereby ejecting ink from the nozzle 1141. The pressure chamber 1131 has an inlet that opens to a first common flow path 1161 and an outlet that opens to a second common flow path 1162. Ink flows into the pressure chamber 1131 from the inlet and flows out from the outlet. Note that the pressure chamber 1131 may be configured so that ink flows in from both the openings described as the inlet and outlet. Individual electrodes are formed in the actuator grooves 1135 that form the pressure chamber 1131.

[0028] The air chamber 1132 is separated from the first common flow path 1161 and the second common flow path 1162 by being closed at the inlet side and the outlet side by a liquid-proof wall formed of a photosensitive resin or the like. The liquid-proof wall of the air chamber 1132 is formed by injecting an ultraviolet-curable resin onto the electrodes in the actuator groove 1135 forming the air chamber 1132, and then irradiating an area to be exposed, for example, both ends that are the inlet side and the outlet side of the actuator groove 1135, with ultraviolet light using an exposure mask or the like. Such a liquid-proof wall prevents ink from entering the air chamber 1132. In addition, the air chamber 1132 is closed by the nozzle plate 114, and the nozzle 1141 is not arranged. Therefore, ink does not flow into the air chamber 1132.

[0029] The nozzle plate 114 is formed in a plate shape. The nozzle plate 114 is made of a flexible film such as a polyimide film. The nozzle plate 114 has a Young's modulus of 9.1 GPa or more. The nozzle plate 114 is disposed opposite one side of the actuator 113 in the third direction (Z direction). For example, the nozzle plate 114 functions as a pressure buffer damper when the pressure of the opposing pressure chamber 1131 fluctuates. The nozzle plate 114 is fixed to the main surface of the frame 112 opposite the substrate 111 with an adhesive or the like. The nozzle plate 114 has a plurality of nozzles 1141 formed at positions opposite the plurality of pressure chambers 1131. In this embodiment, the nozzle plate 114 has two nozzle rows 1142 in which the plurality of nozzles 1141 are aligned in one direction.

[0030] The first common flow path 1161 is formed between the central sides of the pair of actuators 113 excluding both ends, and constitutes an ink flow path from the supply port 1111 to the primary side openings (inlets) of the multiple pressure chambers 1131 of each actuator 113. The first common flow path 1161 extends along the longitudinal direction of the actuator 113. The first common flow path 1161 constitutes a part of the ink flow path 16.

[0031] The second common flow paths 1162 are formed between each actuator 113 and the frame 112. The second common flow paths 1162 form flow paths for ink from secondary openings (outlets) of the multiple pressure chambers 1131. The second common flow paths 1162 extend along the longitudinal direction of the actuator 113. The second common flow paths 1162 form a part of the ink flow path 16.

[0032] 6, liquid flows into the supply port 1111, passes through the central first common flow path 1161, passes through the outside of both ends of the actuator 113 in the first direction, and flows into the second common flow path 1162. That is, ink supplied from the supply port 1111 passes through the first common flow path 1161, which is the central flow path closer to the supply port 1111, and the second common flow path 1162, which is a side flow path farther from the supply port 1111, and is supplied to the actuator groove 1135 forming the pressure chamber 1131 from both sides in the Y direction, which is the extension direction of the actuator groove 1135.

[0033] That is, the inlet of the actuator groove 1135 located in the center of the arrangement direction of the side flow channels on the opposite side of the supply port 1111 and the actuator 113 is the inlet of the actuator groove 1135 located farthest from the supply port 1111 .

[0034] When the thickness, which is the dimension in the Z direction of the nozzle plate, is T mm, the distance in the first direction from the supply unit 117 through which the liquid is supplied to the second common flow channel 1162 to the farthest actuator groove 1135 is the maximum supply distance L mm, and the width dimension in the second direction of the second common flow channel 1162 is the flow channel width W mm, the relationship between L, T, and W is

number

[0035] As shown in FIG. 5, the width dimension W of the cross section of the second common flow path 1162 in the second direction is the width dimension of the portion of the second common flow path 1162 facing the nozzle plate 114, for example, in the case where the width changes depending on the depth direction.

[0036] For example, when the supply port 1111 is disposed at a position different from the second common flow path 1162, the supply unit 117 is set to be the end of the primary side of the second common flow path 1162. In other words, the maximum supply distance L is the distance from the supply unit 117, which is the end of the actuator 113 in the first direction (X direction) and is a communication unit that serves as an inlet for liquid to flow into the second common flow path 1162, to the actuator groove 1135 at the farthest position.

[0037] The individual electrodes apply driving voltages individually to the piezoelectric bodies 1133 which are driving elements. The individual electrodes individually deform each pressure chamber 1131. The individual electrodes are formed by a wiring pattern formed on the substrate 111 and a wiring pattern formed on the actuator 113.

[0038] The common electrode applies the same driving voltage to all of the plurality of piezoelectric bodies 1133. The common electrode simultaneously deforms the plurality of pressure chambers 1131. The common electrode is formed by a wiring pattern formed on the substrate 111 and a wiring pattern formed on the actuator 113.

[0039] The individual electrodes or common electrodes of the actuator 113 are disposed inside the cover 15 and are connected to a circuit board on which a driver IC is mounted. For example, the circuit board drives the actuator 113 by applying a drive voltage to the wiring pattern of the actuator 113 by the driver IC, thereby increasing or decreasing the volume of the pressure chamber 1131 and discharging a droplet from the nozzle 1141.

[0040] The manifold unit 12 includes a manifold 121 and an ink supply pipe 123. The manifold unit 12 may further include a cooling water supply pipe and a cooling water discharge pipe.

[0041] The manifold 121 is formed in a plate or block shape and is formed, for example, by integrally assembling a plurality of members, and forms a supply passage 1211 and a cooling passage.

[0042] For example, the manifold 121 includes a supply path 1211 that is continuous with the supply port 1111 of the substrate 111 and forms a liquid supply path, and a cooling path that forms a path for a cooling fluid. Since the manifold 121 is connected to a pair of head bodies 11, it has a pair of supply paths 1211.

[0043] One of the main surfaces of the manifold 121 is fixed to the main surface of the substrate 111. A top plate is provided on the main surface of the manifold 121 opposite to the main surface to which the substrate 111 is fixed. Ink supply pipes 123 are fixed to the manifold 121 via the top plate.

[0044] The supply path 1211 fluidly connects the ink supply tube 123 and the supply port 1111 of the substrate 111. The supply path 1211 is a flow path for liquid between the ink supply tube 123 and the supply port 1111.

[0045] The ink supply pipes 123 are connected to the supply paths 1211. In this embodiment, the liquid ejection head 1 includes a pair of head bodies 11, and therefore a pair of ink supply pipes 123 are provided.

[0046] The cover 15 includes, for example, an outer shell that covers the side surfaces of the pair of head bodies 11 and the manifold unit 12, and a mask plate that covers a portion of the pair of head bodies 11 on the nozzle plate 114 side.

[0047] Further, the outer shell exposes, for example, the ink supply pipe 123 of the manifold unit 12 to the outside.

[0048] The mask plate covers the pair of head bodies 11 except for the plurality of nozzles 1141 and the areas around the plurality of nozzles 1141 of the nozzle plate 114 .

[0049] The liquid ejection head 1 configured in this manner has, on the head body 11 , a plurality of individual electrodes capable of applying a drive voltage to each piezoelectric body 1133 individually, and a common electrode capable of applying a drive voltage to all piezoelectric bodies 1133 .

[0050] Therefore, the liquid ejection head 1 can selectively drive the multiple pressure chambers 1131 individually or in common. When the pressure chamber 1131 is driven, the pressure chamber 1131 undergoes shear mode deformation, and the ink supplied to the pressure chamber 1131 is pressurized. Therefore, the liquid ejection head 1 can selectively eject the pressurized ink from the nozzle 1141 facing the pressure chamber 1131.

[0051] The liquid ejection head 1 has a manifold unit 12 for cooling a head main body 11 which is a liquid ejection section.

[0052] A liquid ejection device 2 having a liquid ejection head 1 will be described below with reference to Fig. 7. The liquid ejection device 2 includes a housing 2111, a medium supply unit 2112, an image forming unit 2113, a medium ejection unit 2114, a transport device 2115 which is a support device, a maintenance device 2117, and a control unit 2118. The liquid ejection device 2 also includes a cooling device which adjusts the temperature of the ink supplied to the liquid ejection head 1.

[0053] The liquid ejection device 2 is an inkjet printer that performs an image formation process on paper P by ejecting liquid such as ink while transporting the paper P as a recording medium, which is the object of ejection, along a predetermined transport path 2001 from a medium supply section 2112 through an image forming section 2113 to a medium ejection section 2114.

[0054] The medium supply unit 2112 includes a plurality of paper feed cassettes 21121. The image forming unit 2113 includes a support unit 2120 that supports paper, and a plurality of head units 2130 that are disposed above and facing the support unit 2120. The medium discharge unit 2114 includes a paper discharge tray 21141.

[0055] The support section 2120 includes a conveyor belt 21201 provided in a loop shape in a predetermined area where image formation is performed, a support plate 21202 supporting the conveyor belt 21201 from the rear side, and a plurality of belt rollers 21203 provided on the rear side of the conveyor belt 21201.

[0056] The head unit 2130 includes liquid ejection heads 1 which are multiple inkjet heads, multiple supply tanks 2132 as liquid tanks mounted on each liquid ejection head 1, a pump 2134 which supplies ink, and a connection flow path 2135 which connects the liquid ejection heads 1 and the supply tanks 2132.

[0057] In this embodiment, the liquid ejection heads 1 are provided with four colors, cyan, magenta, yellow, and black, and four supply tanks 2132 for storing ink of each color. The supply tanks 2132 are connected to the liquid ejection heads 1 by connection flow paths 2135.

[0058] The pump 2134 is a liquid-sending pump constituted by, for example, a piezoelectric pump. The pump 2134 is connected to the control unit 2118, and is drive-controlled by the control unit 2118.

[0059] The connection flow path 2135 includes a supply flow path that is connected to the ink supply pipe 123 of the liquid ejection head 1 .

[0060] The transport device 2115 transports the paper P along a transport path 2001 that runs from a paper feed cassette 21121 of the medium supply unit 2112 through the image forming unit 2113 to a paper discharge tray 21141 of the medium discharge unit 2114. The transport device 2115 includes a plurality of guide plate pairs 21211-21218 and a plurality of transport rollers 21221-21228 that are arranged along the transport path 2001. The transport device 2115 supports the paper P so that it can move relative to the liquid ejection head 1.

[0061] The cooling device 2116 includes a cooling water tank, a cooling circuit such as piping and tubes for supplying cooling water, a pump for supplying cooling water, and a cooler for adjusting the temperature of the cooling water. The cooling device 2116 supplies cooling water from the cooling water tank adjusted to a predetermined temperature by the cooler to a cooling flow path in the manifold via the cooling circuit by pumping water, or recovers water discharged through the cooling flow path in the manifold. The cooler is, for example, a cooler.

[0062] The maintenance device 2117, for example, during maintenance, sucks and recovers ink remaining on the outer surface of the nozzle plate 114. Furthermore, if the liquid ejection head 1 is of a non-circulation type, the maintenance device 2117 recovers ink inside the head body 11 during maintenance. Such a maintenance device 2117 has a tray, tank, etc. for storing the recovered ink.

[0063] The control unit 2118 includes a CPU 21181 as an example of a processor having a processing circuit, a ROM (Read Only Memory) for storing various programs, a RAM (Random Access Memory) for temporarily storing various variable data, image data, etc., and an interface unit for inputting data from the outside and outputting data to the outside.

[0064] According to the liquid ejection head 1 and liquid ejection device 2 thus configured, the nozzle plate forming the nozzles is used as a pressure buffer damper, thereby suppressing the effect of water hammer. Also, for example, in a highly productive inkjet head with a large ink ejection volume, it is desirable to supply ink from both sides of the actuator groove 1135 that ejects ink, so the ink ejection volume can be secured by detouring from both ends of the actuator substrate forming the actuator groove 1135 and passing through the second common flow path 1162 on the side to supply ink from both sides of the groove. At this time, in the case of a highly productive inkjet head with a large ink supply volume for high-speed printing and high-speed drive, if the duty is suddenly reduced from a high duty, the ink flow rate will suddenly decrease, causing a water hammer phenomenon, which may affect the stability of the meniscus required for stable printing. However, when the thickness of the nozzle plate 114 is T mm, the relationship between the distance L mm between the supply port and the furthest actuator 113 and the ink flow path width W mm is as follows:

number

[0065] The embodiment of the present invention is not limited to the above-mentioned configuration.

[0066] For example, in the above example, a configuration in which the supply port 1111, which is a long hole, is arranged between a pair of actuators 113 and no supply port is arranged in the second common flow paths 1162 on both sides, has been exemplified, but the present invention is not limited to this. The shape, number, and arrangement of the supply ports 1111 can be set as appropriate. For example, the common flow path 1162 may also have a supply port 1111 formed as a through hole through which liquid flows in. For example, when the supply port 1111 is provided at the center of the second common flow paths 1162 on both sides in the first direction, the length of the maximum supply distance L is halved, and the length L of the ink flow path is also reduced by reducing the interval between the supply ports 1111.

[0067] For example, the position of the supply unit 117 that is the reference position of the maximum supply distance L changes depending on whether or not the supply port 1111 is formed in the common flow channel 1162 that has the actuator groove 1135 farthest from the supply port. That is, the supply unit 117 that supplies liquid to the common flow channel 1162 is the supply port 1111 formed in the common flow channel 1162, or the end of the common flow channel 1162 in the first direction. Therefore, the maximum supply distance L may be 1 / 2 the distance in the first direction between the multiple supply ports 1111 arranged in the same common flow channel 1162, or 1 / 2 the distance from the end of the common flow channel 1162 in the first direction to the supply port 1111 arranged in the same common flow channel 1162. The maximum supply distance L may also be 1 / 2 the length of the common flow channel 1162 in the first direction.

[0068] For example, as another embodiment, as shown in Fig. 8, in addition to the supply port 1111 formed in the first common flow channel 1161 in the center, the supply port 1111 may be provided in the second common flow channel 1162 on both sides. That is, for example, as shown in Fig. 8 and Fig. 9, when the supply port 1111 and the inlet of the farthest actuator groove 1135 are arranged in the same common flow channel 1162, the supply port 1111 becomes the supply unit 117. For example, as shown in Fig. 8, in the case of a flow channel configuration in which the supply port 1111 is provided in the center of the common flow channel 1162, L is 1 / 2 the distance between the two supply units 117 lined up along the common flow channel 1162, for example, 1 / 2 the distance between the supply unit 117 at the end of the common flow channel 1162 and the supply unit 117 in the center. For example, when the supply port 1111 is located in the center of the second common flow path 1162, L is half the length when the common flow path 1162, which has the actuator groove 1135 furthest from the supply port 1111, does not have the supply port 1111 and the end of the actuator 113 in the first direction is used as the reference. When the flow path length from the supply port 1111 to the furthest actuator groove 1135 varies depending on the location, the longest distance is taken as L, and when the thickness of the nozzle plate 114 is T mm, the relationship between the distance L mm between the supply port 1111 or supply section 117 and the furthest actuator groove 1135 and the ink flow path width W mm is

number

number

[0069] In addition, in the above embodiment, a side shooter type inkjet head is exemplified, but the present invention is not limited to this and an end shooter type inkjet head may also be used. For example, the common flow paths on both sides of the pressure chamber 1131 are the supply side, and ink flows in from both sides, but the present invention is not limited to this. As an example, an inkjet head may be used in which one side of the pressure chamber 1131 is the supply side and the other side is the discharge side, and ink flows in from one side of the pressure chamber 1131 and flows out from the other side. Alternatively, the supply side and discharge side may be reversed, or may be configured to be switchable.

[0070] In the above example, the liquid ejection head 1 is of a non-circulating type, but may be of a circulating type. For example, as a configuration in which a flow path is formed on the discharge side as well, a configuration in which discharge ports are formed at both ends, for example, in the first direction, of the substrate 111, a liquid discharge path continuing to the discharge port of the substrate 111 is formed in the manifold, and further, a recovery flow path connected to the liquid discharge path is provided as a connection flow path 2135.

[0071] For example, in this embodiment, the cross section of the actuator 113 is trapezoidal, and the cross section of the second common flow path 1162 is also trapezoidal with one side inclined, but this is not limited to this. For example, the cross section may be rectangular or have another shape.

[0072] Furthermore, for example, the liquid to be ejected is not limited to ink for printing, but may be, for example, a device that ejects liquid containing conductive particles for forming a wiring pattern on a printed wiring board.

[0073] In addition, in the above embodiment, the inkjet head is used in a liquid ejection device such as an inkjet printer, but the present invention is not limited to this and can also be used in, for example, 3D printers, industrial manufacturing machines, and medical applications, enabling reduction in size, weight, and cost.

[0074] According to at least one of the embodiments described above, water hammer can be suppressed.

[0075] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0076] 1...liquid ejection head, 2...liquid ejection device, 11...head body, 12...manifold unit, 15...cover, 16...ink flow path (liquid flow path), 111...substrate, 112...frame, 113...actuator, 114...nozzle plate, 116...common flow path section, 117...supply section, 121...manifold, 123...ink supply tube, 1111...supply port, 1131...pressure chamber, 1132...air chamber, 1133...piezoelectric body, 1134...inclined surface, 1135...actuator groove, 1141...nozzle, 1142...nozzle row, 1161...first common flow path, 1162...second common flow path (common flow path), 1211...supply path, 2001...transport path, 2111...housing, 2112...medium supply section, 2113...image forming section, 2114...medium discharge section, 2115...transport device, 2116...cooling device, 2117...maintenance device, 2118...control section, 2120...support section, 2130...head unit, 2132...supply tank, 2134...pump, 2135...connecting flow path, 21121...paper feed cassette, 21141...paper discharge tray, 21181...CPU, 21201...transport belt, 21202...support plate, 21203...belt roller, 21211-21218...guide plate pair, 21221-21228...transport rollers.

Claims

1. a nozzle plate having a nozzle; a liquid flow path having a plurality of actuator grooves forming pressure chambers each communicating with a plurality of the nozzles, and one or more common flow paths extending in a first direction and communicating with the plurality of actuator grooves, and having a supply port through which liquid is supplied; Equipped with When the thickness of the nozzle plate is T mm, the relationship between a maximum supply distance L mm, which is the distance in a first direction from a supply unit that supplies liquid to the common flow channel to the farthest actuator groove in the common flow channel, and a flow channel width W mm, which is the dimension of the common flow channel in a second direction intersecting the first direction, is [0010] Fulfilling The nozzle plate is made of a flexible film and has a Young's modulus of 9.1 Gpa or more. Liquid ejection head.

2. one or more of the common flow paths, and the supply port is formed in at least one of the common flow paths; The liquid ejection head according to claim 1 , wherein the supply portion through which the liquid is supplied to the common flow path is the supply port or an end portion of the common flow path in the first direction.

3. 3. A liquid ejection head as described in claim 2, wherein the maximum supply distance L is 1 / 2 the distance in the first direction between multiple supply ports arranged in the same common flow path, or 1 / 2 the distance from an end of the common flow path in the first direction to a supply port arranged in the same common flow path, or 1 / 2 the length of the common flow path in the first direction.

4. The nozzles are provided in a plurality in at least the first direction, an actuator having a plurality of actuator grooves formed therein and arranged to face the nozzle plate in a third direction intersecting the first direction and the second direction; the actuator has a plurality of actuator grooves in the first direction, each of the actuator grooves extending in the second direction intersecting the first direction, The liquid ejection head according to claim 1 , wherein the common flow path is formed along the first direction at one end side and the other end side in the second direction of each of a plurality of actuator grooves.

5. A liquid ejection apparatus comprising the liquid ejection head according to claim 1 .

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