Liquid nozzle

Abstract

The present invention provides a liquid ejecting head that can suppress the reduction of printing quality even if a common electrode is provided. The liquid ejecting head of the embodiment includes an actuator, a substrate, a separate electrode, and a common electrode. The actuator has: a plurality of pressure chambers arranged in one direction and a plurality of air chambers adjacent to the pressure chambers and arranged in the one direction. The actuator is provided on one surface of the substrate, and a long hole that opens on the one surface and extends along the long side direction of the actuator is arranged on the actuator. Separate electrodes are formed on the one surface of the substrate to drive the pressure chambers respectively. A common electrode is formed on the one surface of the substrate and on the inner peripheral surface of the long hole to drive the plurality of pressure chambers.

Description

Technical Field

[0001] An embodiment of the present invention relates to a liquid ejecting head. Background Art

[0002] In the past, a liquid ejecting head was known in which a plurality of partitions were formed at predetermined intervals, a piezoelectric ceramic actuator was disposed on a ceramic substrate, with the spaces between the partitions serving as ink flow paths, and driving electrodes were formed on the sides of each partition. Furthermore, a liquid ejecting head was known in which the end faces of the partitions were formed as inclined surfaces that expanded outward from their top to bottom, and lead wires for the driving electrodes were formed on the inclined surfaces of the partitions and on the substrate. Such a liquid ejecting head is, for example, an inkjet head that ejects ink as a liquid.

[0003] Furthermore, to increase the speed of liquid ejection, a liquid ejection head is also known that utilizes an independently driven structure comprising a pressure chamber that ejects liquid from a nozzle and an air chamber that does not eject liquid. In one example, in the case of an independently driven liquid ejection head, the electrodes of the pressure chambers are clustered at the center of the substrate for common polarization, while the electrodes of the air chambers are led out toward the driver IC.

[0004] However, in such a liquid ejecting head, when all nozzles are driven simultaneously to eject liquid, a difference in driving waveform occurs between the end portion and the center portion within a row, deteriorating printing quality such as dot diameter and linearity. Summary of the Invention

[0005] Technical problem to be solved by the invention

[0006] An object of the present invention is to provide a liquid ejecting head capable of suppressing degradation of printing quality even when a common electrode is provided.

[0007] Technical solutions to technical problems

[0008] The liquid ejecting head of the embodiment includes an actuator, a substrate, individual electrodes, and a common electrode. The actuator has a plurality of pressure chambers arranged in one direction and a plurality of air chambers adjacent to the pressure chambers and arranged in the one direction. The substrate is provided with the actuator on one surface, and an elongated hole is formed on the actuator, which is open on the one surface and extends in the long side direction of the actuator. The individual electrodes are formed on the one surface of the substrate and drive the pressure chambers respectively. The common electrode is formed on the one surface of the substrate and on the inner peripheral surface of the elongated hole and drives the plurality of pressure chambers. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view showing the structure of the liquid ejecting head according to the first embodiment.

[0010] Figure 2It is a bottom view showing the structure of the liquid ejecting head according to the first embodiment.

[0011] Figure 3 It is a bottom view showing the liquid ejecting head according to the first embodiment with components omitted.

[0012] Figure 4 It is a perspective view showing the structure of a head body of the liquid ejecting head according to the first embodiment.

[0013] Figure 5 It is a cross-sectional view showing the structure of the head main body according to the first embodiment.

[0014] Figure 6 It is a plan view showing the structure of the head main body according to the first embodiment.

[0015] Figure 7 This is a cross-sectional view showing the head body according to the first embodiment with components omitted.

[0016] Figure 8 This is a cross-sectional view showing the head body according to the first embodiment with components omitted.

[0017] Figure 9 It is an explanatory diagram showing the structure of the liquid ejecting device according to the first embodiment.

[0018] Figure 10 It is a perspective view schematically showing the structure of a head body according to the second embodiment.

[0019] Figure 11 It is an explanatory diagram schematically showing the configuration of a head main body according to the second embodiment. DETAILED DESCRIPTION

[0020] Below, refer to Figures 1 to 9 A liquid ejecting head 1 according to a first embodiment and a liquid ejecting device 2 using the liquid ejecting head 1 will be described. Figure 1 is a perspective view showing the structure of the liquid ejecting head 1 according to the first embodiment. Figure 2 It is a bottom view showing the structure of the liquid ejecting head 1. Figure 3 It is a bottom view showing the structure of the liquid ejecting head 1 with the nozzle plate 114 omitted. Figure 4 1 is a perspective view showing the structure of the head body 11 of the liquid ejecting head 1 with a portion of the nozzle plate 114 cut away. Figure 5 It is a cross-sectional view showing the structure of the head main body 11. Figure 6 It is a plan view showing the configuration of the substrate 111 , the actuator 113 , the plurality of individual electrodes 118 , and the common electrode 119 of the head main body 11 . Figure 7It is a cross-sectional view showing the configuration of the substrate 111 , the actuator 113 , the plurality of individual electrodes 118 , and the common electrode 119 of the head main body 11 . Figure 8 It is a cross-sectional view showing the configuration of the actuator 113 , the plurality of individual electrodes 118 , and the common electrode 119 of the head main body 11 . Figure 9 1 and 2 are explanatory diagrams showing the configuration of a liquid ejecting device 2 using the liquid ejecting head 1. In addition, in each figure, the configuration is appropriately enlarged, reduced, or omitted for the purpose of explanation.

[0021] The liquid ejecting head 1 is, for example, arranged at Figure 9 The inkjet head 1 is a shared mode inkjet head for a liquid ejecting device 2 such as an inkjet recording apparatus shown. The liquid ejecting head 1 is provided in a head unit 2130 including a supply tank 2132 as a liquid storage portion provided in the liquid ejecting device 2.

[0022] The liquid ejecting head 1 is supplied with ink as a liquid stored in the supply tank 2132. It should be noted that the liquid ejecting head 1 can be a non-circulating head that does not circulate the ink, or a circulating head that circulates the ink. In this embodiment, an example of a non-circulating head as the liquid ejecting head 1 is described. Furthermore, the liquid ejecting head 1 is connected to a temperature control device 2116 provided in the liquid ejecting device 2 and is supplied with a temperature control liquid (temperature-controlled water) for controlling the temperature of the ink.

[0023] like Figures 1 to 4 As shown, the liquid ejecting head 1 includes a head body 11, a manifold unit 12, a circuit board 13, and a cover 14. For example, the liquid ejecting head 1 is a side-shooting type four-column integrated head having two sets of head bodies 11 each having a pair of actuators 113.

[0024] The head body 11 ejects liquid. Figures 3 to 8 As shown, the head main 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 .

[0025] The head body 11 has a common liquid chamber 116 that communicates with multiple pressure chambers 1131 of the actuator 113. The primary side of the multiple pressure chambers 1131 is the upstream side of the multiple pressure chambers 1131 in the direction of liquid flow. The secondary side of the multiple pressure chambers 1131 is the downstream side of the multiple pressure chambers 1131 in the direction of liquid flow.

[0026] The head body 11 includes, on the substrate 111 and the actuator 113 , a plurality of individual electrodes 118 for driving the plurality of pressure chambers 1131 of the actuator 113 , and a single or multiple common electrodes 119 for driving the plurality of pressure chambers 1131 simultaneously.

[0027] In the example of this embodiment, the head body 11 includes two actuators 113, and the common liquid chamber 116 includes one first common liquid chamber 1161 and two second common liquid chambers 1162. The common liquid chamber 116 includes, for example, the first common liquid chamber 1161 that communicates with the primary-side openings (inlets of the pressure chambers 1131) of the multiple pressure chambers 1131 of the actuator 113, and the second common liquid chamber 1162 that communicates with the secondary-side openings (outlets of the pressure chambers 1131) of the multiple pressure chambers 1131 of the actuator 113.

[0028] The substrate 111 is formed in a rectangular plate shape using, for example, a ceramic material. The substrate 111 is formed in a rectangular shape that is elongated in one direction, for example. A wiring pattern that forms part of a plurality of individual electrodes 118 and a wiring pattern that forms part of a single common electrode 119 are formed on one surface of the substrate 111. On one surface of the substrate 111, a pair of actuators 113 are arranged along the short side direction of the substrate 111. One surface of the substrate 111 is a surface on one side of the substrate 111. The substrate 111 has a single supply port 1111 and a plurality of discharge ports 1112. The supply port 1111 and the discharge port 1112 are through-holes that pass through the two main surfaces of the substrate 111.

[0029] The supply port 1111 is the inlet for supplying ink to the first common liquid chamber 1161. The supply port 1111 is a through-hole formed in the center of the substrate 111 in the short-side direction. The supply port 1111 extends along the long-side direction of the substrate 111. In other words, the supply port 1111 is, for example, an elongated hole extending in one direction along the long-side direction of the actuator 113 and the long-side direction of the first common liquid chamber 1161. The supply port 1111 is located between the pair of actuators 113 and opens at a position opposite the first common liquid chamber 1161.

[0030] The discharge port 1112 is an outlet for discharging ink from the second common liquid chamber 1162. A plurality of discharge ports 1112 are provided, for example, four. Each discharge port 1112 is located, for example, between the first common liquid chamber 1161 and each of the second common liquid chambers 1162 and adjacent to both longitudinal ends of the pair of actuators 113. It should be noted that multiple discharge ports 1112 may be provided in the second common liquid chamber 1162.

[0031] The frame 112 is fixed to one main surface of the substrate 111 by adhesive or the like. The frame 112 surrounds the supply port 1111 , the plurality of discharge ports 1112 , and the actuator 113 provided on the substrate 111 .

[0032] For example, the frame 112 is formed in a rectangular frame shape, and an opening long in one direction is formed along the longitudinal direction of the frame 112. A pair of actuators 113, a supply port 1111, and four discharge ports 1112 are arranged in the opening of the frame 112.

[0033] A pair of actuators 113 are bonded to the mounting surface of substrate 111. A pair of actuators 113 are arranged in two rows on substrate 111, sandwiching supply port 1111. Actuators 113 are formed into a plate shape that is elongated in one direction. Actuators 113 are positioned within the opening of frame 112 and bonded to the main surface of substrate 111.

[0034] like Figures 5 to 8 As shown, actuator 113 includes: a plurality of pressure chambers 1131 arranged at equal intervals along the longitudinal direction at the center thereof; and air chambers 1132 arranged at equal intervals along the longitudinal direction and between adjacent pressure chambers 1131. In other words, a plurality of pressure chambers 1131 and air chambers 1132 are alternately arranged along the longitudinal direction of actuator 113.

[0035] The surface of the actuator 113 opposite the substrate 111 is bonded to the nozzle plate 114. The actuator 113 is formed with multiple grooves arranged at equal intervals along the longitudinal direction and extending perpendicularly thereto. These grooves form multiple pressure chambers 1131 and multiple air chambers 1132. In other words, the actuator 113 includes multiple piezoelectric bodies 1133 as driving elements. These piezoelectric bodies 1133 form walls arranged at equal intervals along the longitudinal direction and forming grooves therebetween. The multiple piezoelectric bodies 1133 form multiple pressure chambers 1131 and multiple air chambers 1132 between adjacent piezoelectric bodies 1133. Application of a driving voltage causes the volume of the pressure chambers 1131 to change.

[0036] The width of actuator 113, for example, in the short-side direction, gradually increases from the top side toward substrate 111. The cross-sectional shape of actuator 113, taken along a direction perpendicular to its long-side direction (the short-side direction), is trapezoidal. Specifically, actuator 113 has inclined surfaces 1134 on its short-side side. These side surfaces (inclined surfaces 1134) are arranged opposite first common liquid chamber 1161 and second common liquid chamber 1162.

[0037] As a specific example, the actuator 113 is formed by bonding two piezoelectric materials in the shape of rectangular plates that are long in one direction to each other in a manner such that their polarization directions are opposite to each other. Here, the piezoelectric material is, for example, PZT (lead zirconate titanate). The actuator 113 is bonded to the mounting surface of the substrate 111, for example, by a thermosetting epoxy adhesive. Moreover, the actuator 113 is formed with an inclined surface 1134, for example, by cutting. In addition, the substrate 111 and the actuator 113 are ground together, for example, by grinding, to form a surface having a plurality of individual electrodes 118 and a common electrode 119 patterned thereon, thereby forming a ground surface. In addition, the actuator 113 is formed with a plurality of grooves that are formed by cutting, for example, to form a plurality of pressure chambers 1131 and a plurality of air chambers 1132, and is formed with side walls that divide adjacent grooves, namely, piezoelectric bodies (driving elements) 1133.

[0038] Furthermore, the actuator 113 includes wiring patterns that form part of the plurality of individual electrodes 118 and wiring patterns that form part of one or more common electrodes 119 .

[0039] During printing operations, such as those performed by the liquid ejecting head 1, the pressure chamber 1131 deforms, causing ink to be ejected from the nozzle 1141. The pressure chamber 1131 has an inlet opening into the first common liquid chamber 1161 and an outlet opening into the second common liquid chamber 1162. Ink flows into the pressure chamber 1131 through the inlet and flows out through the outlet. It should be noted that the pressure chamber 1131 may also be configured so that ink flows in through the two openings described as the inlet and outlet.

[0040] like Figure 7 As shown, the air chamber 1132 is divided into a first common liquid chamber 1161 and a second common liquid chamber 1162 by blocking the inlet and outlet sides with liquid-proof walls 1135 formed of a photosensitive resin or the like. Specifically, after UV-curable resin is injected into the groove forming the air chamber 1132, UV light is irradiated using a mask or the like at the desired locations, such as the inlet and outlet ends of the groove, to form the liquid-proof walls 1135 of the air chamber 1132. These liquid-proof walls 1135 prevent ink from entering the air chamber 1132. Furthermore, the air chamber 1132 is blocked by the nozzle plate 114 and does not have any nozzles 1141. Therefore, ink does not flow into the air chamber 1132.

[0041] The nozzle plate 114 is formed in a plate shape. It is fixed to the main surface of the frame 112 opposite the substrate 111 using an adhesive or the like. The nozzle plate 114 includes a plurality of nozzles 1141 formed at positions opposing the plurality of pressure chambers 1131. In this embodiment, the nozzle plate 114 includes two nozzle arrays 1142, each of which includes a plurality of nozzles 1141 arranged in one direction.

[0042] The first common liquid chamber 1161 is formed between the center of the pair of actuators 113, excluding both ends, and forms a flow path for ink from the supply port 1111 to the primary-side openings (inlets) of the multiple pressure chambers 1131 of each actuator 113. The first common liquid chamber 1161 extends along the longitudinal direction of the actuator 113.

[0043] Second common liquid chambers 1162 are formed between each actuator 113 and housing 112. They form a flow path for ink from the secondary-side openings (outlets) of the plurality of pressure chambers 1131 to the discharge port 1112. They extend along the longitudinal direction of the actuator 113.

[0044] Individual electrodes 118 apply drive voltages individually to piezoelectric bodies 1133. Individual electrodes 118 individually deform pressure chambers 1131. Individual electrodes 118 are formed by wiring patterns formed on substrate 111 and wiring patterns formed on actuator 113.

[0045] As a specific example, Figure 7 as well as Figure 8 As shown, multiple individual electrodes 118 are formed on the inner surface of each pressure chamber 1131, the inclined surface 1134 of the actuator 113, and the substrate 111. Specifically, the individual electrodes 118 are formed on the surface of the piezoelectric body 1133 forming the pressure chamber 1131 and a portion of the piezoelectric component forming the bottom of the pressure chamber 1131. Alternatively, the individual electrodes 118 may be formed, for example, on the inclined surface 1134 and the polished surface of the substrate 111. The individual electrodes 118 extend from the interior of the pressure chamber 1131 toward the ends of the substrate 111 in the short-side direction, with their ends located at the connection portion 1116 of the substrate 111 to which the circuit board 13 is connected. The individual electrodes 118 are arranged to closely contact the bottom of the pressure chamber 1131 and the surface of the piezoelectric component forming the piezoelectric body 1133. The individual electrodes 118 are formed, for example, of a nickel thin film. It should be noted that the individual electrodes 118 are not limited to nickel thin films and may also be formed of thin films of gold or copper, for example. The thickness of the individual electrode 118 is, for example, 0.5 μm to 5 μm.

[0046] Common electrode 119 applies the same driving voltage to all of the multiple piezoelectric bodies 1133. Common electrode 119 simultaneously deforms the multiple pressure chambers 1131. Common electrode 119 is formed from a wiring pattern formed on substrate 111 and a wiring pattern formed on actuator 113. Common electrode 119 is a wiring pattern extending from the inner circumference of supply port 1111 of substrate 111 to the piezoelectric bodies 1133 that form the multiple air chambers 1132. Common electrode 119 is connected to circuit board 13.

[0047] As a specific example, Figure 7as well as Figure 8 As shown, the common electrode 119 is formed on the substrate 111, avoiding the inner surfaces of each air chamber 1132, the inclined surface 1134 of the actuator 113, and the area where the individual electrodes 118 are formed. Specifically, the common electrode 119 is formed on the surface of the piezoelectric body 1133 forming each air chamber 1132 and on a portion of the piezoelectric component forming the bottom of the air chamber 1132. Furthermore, the common electrode 119 is provided on the inclined surface 1134 extending from the inside of each air chamber 1132 toward the center of the substrate 111. It is also formed on the polished surface of the substrate 111 between the pair of actuators 113 and on the inner circumferential surface of the supply port 1111. Furthermore, the common electrode 119 extends toward the end of the substrate 111 in the short-side direction, with an end portion disposed at the connection portion 1116 of the substrate 111 to which the circuit board 13 is connected.

[0048] In other words, the common electrode 119 is provided on the short-side center side of the substrate 111 between the pair of actuators 113 and the connecting portion 1116 formed at the end portion of the substrate 111 in the short-side direction. Figure 7 As shown, a portion of the common electrode 119 provided at the center side in the short-side direction of the substrate 111 is provided so as to extend along the thickness direction of the substrate 111 on the inner peripheral surface of the supply port 1111 at the center side in the short-side direction of the substrate 111. Furthermore, a portion of the common electrode 119 is provided from the center side in the short-side direction of the substrate 111 to the surface of the piezoelectric member forming each air chamber 1132.

[0049] Common electrode 119 is provided so as to be in close contact with the bottom of air chamber 1132 and the surface of the piezoelectric component forming piezoelectric body 1133. Common electrode 119 is formed, for example, from a nickel thin film. It should be noted that common electrode 119 is not limited to nickel thin films and can be formed from, for example, gold or copper thin films. The thickness of common electrode 119 is, for example, 0.5 μm to 5 μm.

[0050] For example, the common electrode 119 is covered on the lower surface of the frame body 112 with an adhesive for bonding the frame body 112 to the substrate 111 .

[0051] like Figure 1 、 Figure 2 、 Figure 4 as well as Figure 5 As shown, the manifold unit 12 includes a manifold 121, a top plate 122, an ink supply tube 123, an ink discharge tube 124, and a pair of temperature control tubes: a temperature control water supply tube 125 and a temperature control water discharge tube. The number of ink supply tubes 123, ink discharge tubes 124, temperature control water supply tubes 125, and temperature control water discharge tubes can be set as appropriate.

[0052] The manifold 121 is formed in a plate or block shape. Figure 5As shown, the manifold 121 includes: a supply flow path 1211, which is continuous with the supply port 1111 of the substrate 111 and forms a liquid supply flow path; a discharge flow path, which is continuous with the discharge port 1112 of the substrate 111 and forms a liquid discharge flow path; and a temperature control flow path 1213, which forms a flow path for the fluid used for temperature control.

[0053] One main surface of the manifold 121 is fixed to the main surface of the substrate 111. Furthermore, a top plate 122 is fixed to the main surface of the manifold 121 opposite to the main surface to which the substrate 111 is fixed. Furthermore, for example, the ink supply tube 123, the ink discharge tube 124, the temperature control water supply tube 125, and the temperature control water discharge tube are fixed to the manifold 121 via the top plate 122.

[0054] The supply flow path 1211 is a flow path formed by a hole or a groove in the manifold 121. The supply flow path 1211 fluidically connects the ink supply tube 123 and the supply port 1111 of the substrate 111.

[0055] The discharge flow path is a flow path formed by holes or grooves in the manifold 121. The discharge flow path fluidically connects the ink discharge tube 124 and the discharge port 1112 of the substrate 111.

[0056] The temperature control flow path 1213 is a flow path formed by holes or grooves in the manifold 121. The temperature control flow path 1213 fluidically connects the temperature control water supply pipe 125 and the temperature control water discharge pipe.

[0057] Both ends of the temperature control flow path 1213 are openings connected to the temperature control water supply pipe 125 and the temperature control water discharge pipe provided on one main surface of the manifold 121. The temperature control flow path 1213 is formed to be able to exchange heat with the substrate 111 fixed to the manifold 121.

[0058] The top plate 122 is provided on the surface of the manifold 121 opposite to the surface on which the substrate 111 is provided. The top plate 122 covers the manifold 121 to seal the supply flow path 1211 , the discharge flow path, and the temperature control flow path 1213 .

[0059] The top plate 122 has openings that connect the tubes 123 , 124 , and 125 and the flow paths 1211 and 1213 .

[0060] The ink supply tube 123 is connected to the supply flow path 1211. The ink discharge tube 124 is connected to the discharge flow path. The temperature control water supply tube 125 and the temperature control water discharge tube are connected to the primary side and the secondary side of the temperature control flow path 1213.

[0061] like Figure 4As shown, the circuit board 13 includes a wiring film 131 having one end connected to the connection portion 1116 of the substrate 111 , a driver IC 132 mounted on the wiring film 131 , and a printed wiring board 133 mounted on the other end of the wiring film 131 .

[0062] The circuit board 13 drives the actuator 113 by applying a driving voltage to the wiring pattern of the actuator 113 via the driver IC 132 , thereby increasing or decreasing the volume of the pressure chamber 1131 and ejecting liquid droplets from the nozzle 1141 .

[0063] The wiring film 131 is connected to the plurality of individual electrodes 118 and the common electrode 119. For example, the wiring film 131 is an ACF (anisotropic conductive film) fixed to the connection portion of the substrate 111 by heat pressing or the like. For example, multiple wiring films 131 are provided for each head body 11. In this embodiment, two wiring films 131 are connected to one actuator 113. For example, the wiring film 131 is a COF (chip on film) on which a driver IC 132 is mounted.

[0064] The driver IC 132 is connected to the plurality of individual electrodes 118 and the common electrode 119 via the wiring film 131. It should be noted that the driver IC 132 may be connected to the plurality of individual electrodes 118 and the common electrode 119 not via the wiring film 131 but via other means such as ACP (anisotropic conductive paste), NCF (non-conductive film), or NCP (non-conductive paste).

[0065] The printed wiring board 133 is a PWA (Printing Wiring Assembly) on which various electronic components and connectors are mounted.

[0066] The cover 14 includes, for example, an outer shell 141 that covers the side surfaces of the pair of head main bodies 11 , the manifold unit 12 , and the circuit board 13 , and a mask plate 142 that covers a portion of the nozzle plate 114 side of the pair of head main bodies 11 .

[0067] The outer shell 141 exposes, for example, the ink supply tube 123 , the ink discharge tube 124 , the temperature control water supply tube 125 , the temperature control water discharge tube 125 , and the end portions of the circuit board 13 in the manifold unit 12 to the outside.

[0068] The mask plate 142 covers the plurality of nozzles 1141 in the pair of head main bodies 11 and the nozzle plate 114 except for the areas around the plurality of nozzles 1141 .

[0069] The liquid ejecting head 1 configured in this manner includes, in the head main body 11 , a plurality of individual electrodes 118 capable of applying a driving voltage to each piezoelectric body 1133 , and a common electrode 119 capable of applying a driving voltage to all the piezoelectric bodies 1133 .

[0070] Therefore, the liquid ejecting head 1 can selectively drive the plurality of pressure chambers 1131 individually or in common. Furthermore, when the pressure chambers 1131 are driven, they deform into a shared mode, pressurizing the ink supplied into the pressure chambers 1131. Consequently, the liquid ejecting head 1 can selectively eject the pressurized ink from the nozzles 1141 facing the pressure chambers 1131.

[0071] In addition, in addition to the actuator 113 mounting surface of the substrate 111 , the inclined surface 1134 of the actuator 113 , and the inner surface of the air chamber 1132 , the common electrode 119 is also formed on the inner peripheral surface of the supply port 1111 formed in the substrate 111 .

[0072] By also providing the common electrode 119 on the inner circumferential surface of the supply port 1111, the liquid ejecting head 1 can ensure the electrode surface area of ​​the common electrode 119, thereby reducing the resistance of the common electrode 119. Therefore, even when the distance between the rows of the piezoelectric bodies 1133 of the actuator 113 is narrowed, it is possible to suppress the difference in ejection performance between the center side and the end sides in the arrangement direction of the nozzles 1141 of the head body 11.

[0073] Below, refer to Figure 9 The following describes an inkjet recording device 2 having a liquid ejecting head 1. The inkjet recording device 2 includes a housing 2111, a medium supply unit 2112, an image forming unit 2113, a medium discharge unit 2114, a transport device 2115 as a support device, a maintenance device 2117, and a control unit 2118. The inkjet recording device 2 also includes a temperature control device for adjusting the temperature of ink supplied to the liquid ejecting head 1.

[0074] The inkjet recording device 2 is an inkjet printer that ejects ink or other liquid while transporting a recording medium such as paper P as a ejection object along a predetermined transport path 2001 from a medium supply section 2112 through an image forming section 2113 to a medium discharge section 2114, thereby performing image forming processing on the paper P.

[0075] The medium supply unit 2112 includes a plurality of paper cassettes 21121. The image forming unit 2113 includes a support unit 2120 for supporting paper and a plurality of head units 2130 disposed above and facing the support unit 2120. The medium discharge unit 2114 includes a paper discharge tray 21141.

[0076] The support portion 2120 includes a conveyor belt 21201 having a predetermined area for image formation in an endless shape, 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 .

[0077] The head unit 2130 includes: liquid ejecting heads 1 as a plurality of inkjet heads; a plurality of supply tanks 2132 as liquid tanks respectively mounted on the liquid ejecting heads 1; a pump 2134 for supplying ink; and a connection flow path 2135 connecting the liquid ejecting heads 1 and the supply tanks 2132.

[0078] This embodiment includes four color inkjet heads 1 (cyan, magenta, yellow, and black) and four color supply tanks 2132 for storing inks of these colors. The supply tanks 2132 are connected to the liquid jet heads 1 via connection channels 2135 .

[0079] The pump 2134 is a liquid delivery pump composed of, for example, a piezoelectric pump, and is connected to the control unit 2118 and driven and controlled by the control unit 2118 .

[0080] The connecting flow path 2135 includes a supply flow path connected to the ink supply tube 123 of the liquid ejecting head 1. Furthermore, the connecting flow path 2135 includes a recovery flow path connected to the ink discharge tube 124 of the liquid ejecting head 1. For example, if the liquid ejecting head 1 is a non-circulating type, the recovery circuit is connected to the maintenance device 2117, and if the liquid ejecting head 1 is a circulating type, the recovery flow path is connected to the supply tank 2132.

[0081] The transport device 2115 transports paper P along a transport path 2001, which leads from the paper feed cassette 21121 of the medium supply unit 2112 through the image forming unit 2113 to the paper discharge tray 21141 of the medium discharge unit 2114. The transport device 2115 includes a plurality of guide plate pairs 21211 to 21218 arranged along the transport path 2001 and a plurality of transport rollers 21221 to 21228. The transport device 2115 supports the paper P so that it can move relative to the liquid ejecting head 1.

[0082] The maintenance device 2117, for example, suctions and recovers ink remaining on the outer surface of the nozzle plate 114 during maintenance. Furthermore, if the liquid ejecting head 1 is a non-circulating type, the maintenance device 2117 recovers ink within the head body 11 during maintenance. The maintenance device 2117 includes a tray, tank, or the like for storing the recovered ink.

[0083] The control unit 2118 includes: a CPU (Central Processing Unit) 21181 as an example of a processor; memories such as 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.

[0084] According to the liquid ejecting head 1 and the liquid ejecting device 2 configured in this manner, since the common electrode 119 is also provided on the inner peripheral surface of the supply port 1111 serving as the elongated hole, degradation of printing quality can be suppressed even if the common electrode 119 is provided.

[0085] It should be noted that the embodiments of the present invention are not limited to the above-mentioned configurations. Hereinafter, several embodiments will be described. In the embodiments described below, the same configurations as those in the first embodiment will be denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0086] For example, in the above example, the liquid ejecting head 1 is described as having a pair of head bodies 11, but the present invention is not limited thereto. The liquid ejecting head 1 may also be configured as having a single head body 11. Furthermore, in the above example, the head body 11 is described as having a pair of actuators 113, but the present invention is not limited thereto. For example, the head body 11 may also be configured as having a single actuator 113.

[0087] In the above example, the head body 11 is described as providing the common electrode 119 also on the inner peripheral surface of the supply port 1111 to ensure the electrode surface area of ​​the common electrode 119 in order to reduce the resistance of the common electrode 119 , but the present invention is not limited to this.

[0088] For example, Figure 10 as well as Figure 11 As shown in the second embodiment, the head body 11 of the liquid jet head 1 may also be configured to provide a groove portion 1113 on the surface between the actuator 113 and the supply port 1111 of the substrate 111 in the area where the common electrode 119 is formed, that is, a region. For example, the groove portion 1113 is formed by a plurality of grooves 1114. The grooves 1114 extend along the long side direction of the actuator 113, in other words, along the long side direction of the supply port 1111. The plurality of grooves 1114 are arranged, for example, in the short side direction of the actuator 113. For example, three grooves 1114 are provided. The cross-sectional shape of the groove 1114 in the short side direction is formed in a V shape. That is, the width of the groove 1114 in the short side direction gradually decreases from the upper end side toward the bottom. Moreover, the common electrode 119 is also formed on the upper surface of the plurality of grooves 1114 formed on the substrate 111, that is, the inclined surface.

[0089] The head body 11 of the liquid ejecting head 1 according to the second embodiment has a common electrode 119 formed on the upper surface of a plurality of grooves 1114, in addition to the inner circumferential surface of the supply port 1111. Therefore, the head body 11 can further reduce the resistance of the common electrode 119 while ensuring the electrode surface area of ​​the common electrode 119. Furthermore, the head body 11 is configured such that the surface area of ​​the substrate 111 is increased by forming the grooves 1113 in the region where the common electrode 119 is formed.

[0090] Moreover, the groove 1114 can be formed in the substrate 111 by processing a part of the mounting surface of the substrate 111, so that the head body 11 can easily increase the surface area of ​​the region where the common electrode 119 is provided. It should be noted that the groove portion 1113 is not limited to being formed by a plurality of grooves 1114 extending in one direction in a V-shape, and for example, it can also be formed by a plurality of rectangular or conical grooves or depressions. In order to form the common electrode 119, it is preferred that the surface of the groove portion 1113 is a surface inclined relative to the mounting surface of the substrate 111. In addition, the number of grooves 1114 is not limited to three and can be set appropriately.

[0091] In addition, in the above example, the liquid ejector 1 is described as a non-circulating type, but it can also be a circulating type. In addition, it can also be constructed so that the actuator 113 has a primary side opening continuous to the second pressure chamber for cleaning the second common liquid chamber 1162, and has a third common liquid chamber on the secondary side of the second pressure chamber.

[0092] According to at least one embodiment described above, by providing the common electrode also on the inner peripheral surface of the supply port as the long hole, it is possible to suppress degradation of printing quality even if the common electrode is provided.

[0093] Although several embodiments have been described, these embodiments are provided for illustrative purposes only and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways and can be omitted, replaced, or modified without departing from the spirit of the invention. These embodiments and their variations are intended to be included within the scope and spirit of the invention and are also intended to be included within the scope of the invention set forth in the claims and their equivalents.

[0094] Description of Reference Numerals

[0095] 1: Liquid ejecting head (inkjet head); 2: Liquid ejecting device (inkjet recording device); 11: Head body; 12: Manifold unit; 13: Circuit board; 14: Cover; 111: Substrate; 112: Frame; 113: Actuator; 114: Nozzle plate; 116: Common liquid chamber; 118: Individual electrode; 119: Common electrode; 121: Manifold; 122: Top plate; 123: Ink supply pipe; 124: Ink discharge Tube; 125: Temperature control water supply pipe; 131: Wiring film; 133: Printed wiring board; 141: Outer shell; 142: Mask plate; 1111: Supply port; 1112: Discharge port; 1113: Groove; 1114: Groove; 1116: Connecting portion; 1131: Pressure chamber; 1132: Air chamber; 1133: Piezoelectric element (driving element); 1134: Inclined surface; 1135: Liquid-proof wall; 1141 : Nozzle; 1142: Nozzle array; 1161: First common liquid chamber; 1162: Second common liquid chamber; 1211: Supply flow path; 1213: Temperature control flow path; 2001: Conveyance path; 2111: Housing; 2112: Medium supply unit; 2113: Image forming unit; 2114: Medium discharge unit; 2115: Conveyor device; 2116: Temperature control device; 2117: Maintenance device; 2118 : Control unit; 2120: Support unit; 2130: Head unit; 2132: Supply tank; 2134: Pump; 2135: Connecting flow path; 21121: Paper supply box; 21141: Paper discharge tray; 21201: Conveyor belt; 21202: Support plate; 21203: Belt roller; 21211~21218: Guide plate pair; 21221~21228: Conveying roller; 132: Driver IC; P: Paper.

Claims

1. A liquid spray head comprising: An actuator comprising: a plurality of pressure chambers arranged in one direction; and a plurality of air chambers adjacent to the pressure chambers and arranged in the one direction; a substrate having the actuator provided on one surface thereof, and a long hole opened on the one surface and extending in the longitudinal direction of the actuator so as to be aligned with the actuator; Individual electrodes are formed on the one surface of the substrate and drive the pressure chambers respectively; as well as a common electrode formed on the one surface of the substrate and the inner peripheral surface of the long hole, and driving the plurality of pressure chambers; The actuator is arranged in a pair along a direction perpendicular to the longitudinal direction of the actuator. The long hole is provided between the pair of actuators.

2. The liquid ejecting head according to claim 1, wherein The liquid ejecting head further includes a head body, a manifold unit, a circuit substrate, and a cover.

3. The liquid ejecting head according to claim 1, wherein The substrate has a single supply port and a plurality of discharge ports.

4. The liquid ejecting head according to claim 1, wherein The individual electrodes and the common electrode are formed of a thin film of nickel, gold, or copper.

5. The liquid ejecting head according to claim 1, wherein The thickness of the individual electrodes and the common electrode is 0.5 μm to 5 μm. The liquid ejecting head according to claim 1 , wherein: The long hole is a supply hole for supplying liquid between the pair of actuators.

7. The liquid ejecting head according to claim 3, wherein The substrate is formed of a ceramic material in a rectangular plate shape.

8. The liquid ejecting head according to any one of claims 1 to 7, wherein The substrate has a groove portion formed on the one surface between the long hole and the actuator and provided with a portion of the common electrode.

9. The liquid ejecting head according to claim 8, wherein The groove portion is a V-shaped groove that is formed in plurality along the short side direction of the actuator and extends along the long side direction of the actuator.

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