JP2012254604A - Inkjet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet head high in printing quality by suppressing the difference of injection characteristics for each nozzle.SOLUTION: The inkjet head includes a plurality of common ink chambers 11 communicating with a plurality of pressure chambers and supplying ink to the plurality of pressure chambers. The plurality of common ink chambers 11 are arranged in a predetermined direction on one plane, and grooves 20 are formed adjoining the common ink chambers 11 located at the ends in the predetermined direction out of the plurality of common ink chambers 11 and on the outside of these common ink chambers 11.

Description

  The present invention relates to an inkjet head that performs printing by discharging ink onto a recording medium.

  Conventionally, after ink introduced into a common ink chamber is supplied to a plurality of pressure chambers via a plurality of ink supply paths, an actuator provided in the pressure chamber is selectively driven by a signal from a host device. Ink jet heads that perform recording by ejecting ink from a plurality of nozzles through a conduction path communicating with a pressure chamber are known. The plurality of nozzles are arranged at regular intervals, and the diameters of the nozzles are formed to be equal. Since the nozzles have the same diameter, when the pressure applied to the ink is the same for each nozzle, the ink ejection speed and the ink droplet size for each nozzle are equal, and stable ejection is possible.

  In such an ink jet head, a plurality of common ink chambers are provided corresponding to a plurality of ink colors, and a plurality of common ink chambers are arranged at equal intervals.

  In addition, a conduction path serving as a path for supplying ink from the pressure chamber to the nozzle corresponding to the pressure chamber is provided corresponding to the nozzle array, and the conduction path array including a plurality of conduction paths is adjacent to the common ink chamber. Is provided.

JP-A-2005-96171

  At this time, for the ink in the common ink chamber, heat is exchanged between the common ink chamber and the surrounding portion. However, the common ink chamber disposed at the end in the arrangement direction of the common ink chamber and the common ink chamber arranged at a position other than the end in the arrangement direction of the common ink chamber are arranged around the common ink chamber. Since the wall volumes are different, the heat exchange conditions are different, resulting in a difference in the temperature of the ink passing through the common ink chamber. When the temperature of the ink is different, the viscosity of the ink changes, so that the ejection of the ink becomes non-uniform, which adversely affects the print quality.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an ink jet head with good print quality by suppressing a difference in ejection characteristics for each nozzle.

  In order to achieve this object, an inkjet head according to claim 1 is an inkjet head having a plurality of common ink chambers that communicate with a plurality of pressure chambers and supply ink to the plurality of pressure chambers. The ink chambers are arranged in a predetermined direction on one plane, are adjacent to a common ink chamber located at an end in the predetermined direction among the plurality of common ink chambers, and the common ink chamber A groove is formed on the outer side.

  The ink jet head according to claim 2, wherein a heat capacity of a region sandwiched between the groove and a common ink chamber adjacent to the groove is that of a region sandwiched between two adjacent common ink chambers of the common ink chamber. The heat capacity is half the heat capacity.

  The ink jet head according to claim 3, wherein a distance between the groove and a common ink chamber adjacent to the groove is half of a distance between two adjacent common ink chambers of the common ink chambers. It is a distance.

  The ink jet head according to claim 4, wherein the groove communicates with one common ink chamber of the common ink chambers, and a common ink chamber adjacent to the groove and a region sandwiched between the grooves. The heat capacity is equal to the heat capacity of a region sandwiched between two adjacent common ink chambers of the common ink chambers.

  The inkjet head according to claim 5, wherein a distance between the common ink chamber adjacent to the groove and the groove is equal to a distance between two adjacent common ink chambers of the common ink chamber. It is a distance.

The inkjet head according to claim 6 includes a plurality of nozzles that eject ink;
And a plurality of communication passages connecting the plurality of pressure chambers and the plurality of nozzles, the communication passages being provided in a region sandwiched between the common ink chamber adjacent to the groove and the groove. It is characterized by that.

The inkjet head according to claim 7 is characterized in that a width of the groove in the predetermined direction is equal to a width of the common ink chamber in the predetermined direction.

  The ink jet head according to claim 8, wherein the groove has a length in a direction perpendicular to the predetermined direction on a surface on which the plurality of common ink chambers are formed, and the common ink in the perpendicular direction. It is characterized by being equal to the length of the chamber.

  The inkjet head according to claim 9, wherein the groove has a depth in a direction perpendicular to a surface on which the plurality of common ink chambers are formed, and a surface on which the plurality of common ink chambers are formed. The depth is equal to the depth of the common ink chamber in the vertical direction.

  The ink jet head according to claim 10 is configured such that a plurality of thin plate-like parts are laminated via an adhesive, and the adhesive enters the groove.

  The ink jet head according to claim 11 is characterized in that the groove communicates with the atmosphere.

  According to the ink jet head according to claim 1, since the groove is formed adjacent to the common ink chamber located at the end in the predetermined direction and outside the common ink chamber, the groove is located at the end. The region outside the common ink chamber is sandwiched between the common ink chamber located at the end and the groove, and the volume difference from the region sandwiched between the common ink chamber and the common ink chamber is reduced. It is possible to suppress the difference in heat capacity. Accordingly, since the difference between the heat exchange condition for the ink in the common ink chamber located at the end and the heat exchange condition for the ink in the other common ink chamber can be reduced, the difference in viscosity between the common ink chambers can be reduced. As a result, the difference in ejection characteristics between nozzles can be suppressed, and the print quality can be improved.

  According to the ink jet head of claim 2, since the region sandwiched between the common ink chamber and the common ink chamber exchanges heat with the two common ink chambers sandwiching the region, the heat capacity of the region is half. Is assigned to one common ink chamber of the two common ink chambers sandwiching the region.

  Since the heat capacity of the region sandwiched between the groove and the common ink chamber adjacent to the groove is half the heat capacity of the region sandwiched between two adjacent common ink chambers of the common ink chamber, the end The difference between the heat exchange condition for the ink in the common ink chamber located in the nozzle and the heat exchange condition for the ink in the other common ink chamber can be eliminated, and the difference in viscosity between the common ink chambers is eliminated. It is possible to suppress the difference in ejection characteristics every time and improve the printing quality.

  The region between the two common ink chambers of the common ink chamber exchanges heat with the ink in the two adjacent common ink chambers, and the region sandwiched between the common ink chamber and the groove is Then, heat is exchanged with ink in one adjacent common ink chamber. At this time, since the heat capacity of the area where heat is exchanged with the ink in one common ink chamber is half the heat capacity of the area sandwiched between the two common ink chambers, two adjacent common ink chambers among the common ink chambers The temperature change is the same between the region sandwiched between the two regions and the region sandwiched between the common ink chamber and the groove. Therefore, it is possible to suppress the difference in ejection characteristics for each nozzle and improve the printing quality.

   According to the ink jet head of claim 3, the distance between the groove and the common ink chamber adjacent to the groove is half the distance between two adjacent common ink chambers of the common ink chambers. Therefore, the heat capacity of the region sandwiched between the groove and the common ink chamber adjacent to the groove can be made half the heat capacity of the region sandwiched between two adjacent common ink chambers.

  Therefore, the difference between the heat exchange condition for the ink in the common ink chamber located at the end and the heat exchange condition for the ink in the other common ink chamber can be eliminated, so the viscosity between the common ink chambers can be eliminated. This eliminates the difference, suppresses the difference in ejection characteristics for each nozzle, and improves the printing quality. Further, since the region between two common ink chambers adjacent to each other among the common ink chambers and the region sandwiched between the common ink chamber and the groove have the same ease of temperature change, Thus, the difference in ejection characteristics can be suppressed and the printing quality can be improved.

   According to the ink jet head of the fourth aspect, the groove communicates with one common ink chamber among the common ink chambers, so that the common ink chamber can be enlarged.

  In addition, since the heat capacity of the area between the common ink chamber adjacent to the groove and the groove is equal to the heat capacity of the area between the two common ink chambers of the common ink chamber, The difference between the heat exchange condition for the ink in the common ink chamber located at the end and the heat exchange condition for the ink in the other common ink chamber can be eliminated, and the difference in viscosity between the common ink chambers is eliminated. The difference in ejection characteristics between nozzles can be suppressed, and the printing quality can be improved.

  The region between the two common ink chambers of the common ink chamber exchanges heat with the ink in the two adjacent common ink chambers, and the region sandwiched between the common ink chamber and the groove is Then, heat is exchanged with the ink in one adjacent common ink chamber and the ink in one adjacent groove. At this time, the heat capacity of one common ink chamber and the area where heat is exchanged with the ink in one adjacent groove is equal to the heat capacity of the area sandwiched between the two common ink chambers. The ease of temperature change is the same between the region sandwiched between two adjacent common ink chambers and the region sandwiched between the common ink chamber and the groove. Therefore, it is possible to suppress the difference in ejection characteristics for each nozzle and improve the printing quality.

  According to the ink jet head of claim 5, the distance between the groove and the common ink chamber adjacent to the groove is equal to the distance between two common ink chambers adjacent to each other among the common ink chambers. Therefore, the heat capacity of the region sandwiched between the groove and the common ink chamber adjacent to the groove can be made equal to the heat capacity of the region sandwiched between two adjacent common ink chambers.

  Therefore, the difference between the heat exchange condition for the ink in the common ink chamber located at the end and the heat exchange condition for the ink in the other common ink chamber can be eliminated, so the viscosity between the common ink chambers can be eliminated. This eliminates the difference, suppresses the difference in ejection characteristics for each nozzle, and improves the printing quality. Further, since the region between two common ink chambers adjacent to each other among the common ink chambers and the region sandwiched between the common ink chamber and the groove have the same ease of temperature change, Thus, the difference in ejection characteristics can be suppressed and the printing quality can be improved.

  According to the ink jet head of the sixth aspect, when the hole of the communication path is formed by wet etching, the etching liquid flows in the direction of the hole serving as the common ink chamber or the groove. Here, the processing conditions of the holes differ depending on the direction in which the etching solution flows. However, the communication path may be a region sandwiched between two common ink chambers among the common ink chambers or a common adjacent to the groove. Since it is provided in a region sandwiched between the ink chamber and the groove, the flow of the etching solution is the same for each communication path, and the processing of each communication path can be performed uniformly. Therefore, it is possible to suppress the difference in ejection characteristics for each nozzle and improve the printing quality.

  In the ink jet head according to claim 7, since the groove width in the predetermined direction is equal to the common ink chamber in the predetermined direction, the flow of the etching solution can be made uniform, The processing of the passage can be performed uniformly. Therefore, it is possible to suppress the difference in ejection characteristics for each nozzle and improve the printing quality.

  In the ink jet head according to claim 8, the groove has a length in a direction perpendicular to the predetermined direction on a surface on which the plurality of common ink chambers are formed. Therefore, all the communication paths are arranged in a region sandwiched between the common ink chamber and the groove or in a region sandwiched between the common ink chamber and the common ink chamber. The flow of the etching solution can be made uniform in the passages, and the processing of each communication passage can be performed uniformly. Therefore, it is possible to suppress the difference in ejection characteristics for each nozzle and improve the printing quality.

  Further, according to the ink jet head according to claim 10, the ink jet head has a configuration in which a plurality of thin plate-like parts are laminated via an adhesive, and the adhesive enters the groove, so that excessive adhesion is achieved. The agent can be stored in the groove, and excess adhesive can be prevented from entering the ink flow path. Accordingly, it is possible to prevent the excessive adhesive from entering the flow path and change the discharge conditions, thereby suppressing the difference in ejection characteristics for each nozzle and improving the print quality.

  According to the ink jet head of the eleventh aspect, since the groove communicates with the atmosphere, excess adhesive easily enters the groove. Therefore, it is possible to prevent the excess adhesive from entering the flow path and changing the discharge conditions, thereby suppressing the difference in ejection characteristics for each nozzle and improving the printing quality.

1 is a schematic perspective view of an ink jet printer that employs an ink jet head of the present invention. It is a schematic perspective view of the principal part of the inkjet head of this invention. 3 is a plan view of a flow path unit 3. FIG. FIG. 4 is a partial cross-sectional view of the inkjet head 1 taken along the line II shown in FIG. 3. It is a fragmentary sectional view of inkjet head 1 of a 2nd embodiment. It is a top view of channel unit 3 of a 3rd embodiment. It is a fragmentary sectional view of the inkjet head 1 along the II-II line | wire shown in FIG.

  FIG. 1 is a schematic perspective view of an ink jet printer employing an ink jet head according to a first embodiment of the present invention. As shown in FIG. 1, an inkjet printer 100 includes a carriage 101 that can move in the left-right direction in FIG. 1, a serial inkjet head 1 that is provided on the carriage 101 and discharges ink onto a recording paper P, A conveyance roller 102 that conveys the recording paper P forward in FIG. 1 is provided. The inkjet head 1 moves in the left-right direction (scanning direction) integrally with the carriage 101, and ejects ink onto the recording paper P from the nozzles 8 formed on the lower ink ejection surface. Then, the recording paper P recorded by the inkjet head 1 is discharged forward (paper feeding direction) by the transport roller 102.

  Next, the inkjet head 1 will be described with reference to FIGS.

  FIG. 2 is a perspective view of the main part of the inkjet head 1. FIG. 3 is a plan view of the flow path unit 3. FIG. 4 is a partial cross-sectional view of the inkjet head 1 taken along the line I-I shown in FIG.

  As shown in FIG. 2, the inkjet head 1 has a plate-type actuator unit 4 joined to a flow path unit 3 composed of a plurality of plates, and a flexible printed wiring board (FPC) is formed on the upper surface of the actuator unit 4. 5 is lap-joined. The FPC 5 is provided with a drive IC 6 that outputs a signal for driving the actuator. The signal output from the drive IC 6 is transmitted to the actuator unit 4 via the FPC 5. A protective plate 7 made of an aluminum plate is bonded on the FPC 5. Further, a rectangular reinforcing plate 8 in plan view is assembled around the actuator unit 4, and four holes 9 having an oval shape in plan view are formed in the reinforcing plate 8.

  Four ink supply holes 10 having an oval shape in plan view are formed on the upper surface of the flow path unit 3 so as to correspond to the four holes 9. Then, four types of ink are supplied from the ink cartridge into the flow path unit 3 through the four holes 9 and the four ink supply holes 11 formed in the reinforcing plate 6. The flow path unit 3 is mounted so that the ink discharge surface is exposed.

  The flow path unit 3 includes four ink supply ports 10 to which ink is supplied, four common ink chambers 11 communicating with the four ink supply ports 10, one end connected to the common ink chamber 11, and the other end having pressure. A plurality of communication holes 12 connected to the chamber 13, a plurality of planarly arranged pressure chambers 21, a communication path 14 communicating with each of the plurality of pressure chambers, and a communication path 14 are connected to eject ink. A plurality of nozzles 15. An actuator unit 4 having a rectangular planar shape is bonded to the upper surface of the flow path unit 3 corresponding to each pressure chamber 21.

  The flow path unit 3 has a structure in which a plurality of metal plates are stacked, and is configured by joining the cavity plate 34, the spacer plate 33, the manifold plate 32, and the nozzle plate 31 with an adhesive. The actuator units 4 are stacked in correspondence with the pressure chambers 13 above the cavity plate 34 that is the uppermost plate of the flow path unit.

  The cavity plate 34 has a number of holes that serve as the pressure chambers 13. One end portion of the pressure chamber 13 communicates with the nozzle 15 in the nozzle plate 31 through a communication hole which is a through hole having a small diameter formed in the spacer plate 33 and the manifold plate 32. The other end portion of the pressure chamber 13 different from the one end portion communicates with the common ink chamber 11 in the manifold plate 32 through a communication hole having a small diameter formed in the spacer plate 33.

  The spacer plate 33 has, for one pressure chamber 13 of the cavity plate 34, a hole serving as a communication hole 12 for communicating the pressure chamber 13 and the common ink chamber 11 and a communication path 14 serving as a flow path from the pressure chamber 13 to the nozzle 15. It is a metal plate provided with each hole.

  The manifold plate 32 is a metal plate provided with holes constituting the common ink chamber 11 and provided with communication holes from the pressure chamber 21 to the nozzle 20 corresponding to one pressure chamber 13 of the cavity plate 34. is there.

  The common ink chamber 11 is a rectangular opening extending along the longitudinal direction of the plate, and four common ink chambers 11 are arranged in a direction perpendicular to the longitudinal direction. The four common ink chambers 11 have the same shape, and the intervals between the adjacent common ink chambers 11 and the common ink chambers 11 have the same width. The common ink chamber 11 communicates with the plurality of pressure chambers 13 formed in the cavity plate 34 through the plurality of communication holes 12 formed in the spacer plate 33.

  A groove 20 is formed adjacent to the common ink chamber 11 in the direction in which the common ink chambers 11 are arranged. The groove 20 is formed outside the outermost one of the plurality of common ink chambers 11 along the common ink chamber 11. In this embodiment, the distance between the groove 20 and the common ink chamber 11 is half the distance between the common ink chamber 11 and the common ink chamber 11. Further, the shape of the groove 20 is substantially the same as the shape of the common ink chamber 11.

  A plurality of holes serving as the communication passages 14 are formed corresponding to the pressure chambers 13 and the nozzles 15, and the holes serving as the communication passages 14 are arranged in a direction parallel to the longitudinal direction of the common ink chamber 11. The row is provided at a position adjacent to the common ink chamber 11. At this time, four rows of holes serving as the communication passages 14 are provided, and the rows b, c, and d are arranged in a region sandwiched between the two common ink chambers 11. The row a is arranged in a region sandwiched between one common ink chamber 11 and the groove 20 adjacent thereto.

  The nozzle plate 31 is a metal plate in which a plurality of nozzles 15 are provided at minute intervals corresponding to the pressure chambers 13 of the cavity plate 34. These nozzles 15 are arranged in four rows along the longitudinal direction of the nozzle plate 34. The intervals between the nozzle rows are substantially equal. Further, the interval between the adjacent nozzles 15 is formed to be substantially the same width for each nozzle.

  The actuator unit 4 includes a diaphragm 35 disposed so as to cover all the pressure chambers, a piezoelectric layer continuously formed across the plurality of pressure chambers 21 on the upper surface of the diaphragm 35, and an upper surface of the piezoelectric layer. And a plurality of individual electrodes respectively formed corresponding to the plurality of pressure chambers.

  Here, the operation of the actuator unit 4 will be described. When printing on the recording paper P, a drive signal is output from the drive IC 6. The output drive signal is output to each individual electrode via the FPC 5. At this time, since the diaphragm 35 is held at the ground potential, a potential difference is generated between the diaphragm 35 and the individual electrodes. Then, an electric field in the thickness direction is generated in a region (active layer) sandwiched between the individual electrodes of the piezoelectric layer and the diaphragm 35, and contracts in a horizontal direction perpendicular to the thickness direction that is a polarization direction. Along with this contraction, distortion in the stacking direction (deformation that increases the volume of the pressure chamber 13 and then returns to the original volume) occurs in the region of the piezoelectric layer facing the pressure chamber 13 and the region of the vibration plate 35. A pressure is applied to the ink in the pressure chamber. The ink to which pressure is applied passes through the communication path 14, and the ink to which pressure is applied is ejected from the nozzle corresponding to the individual electrode. Thus, predetermined printing on the recording paper P is performed.

  Here, the heat exchange of the ink in the common ink chamber 11 will be described. When the temperature of the ink is higher than the temperature of the plate, the heat of the ink in the common ink chamber 11 is absorbed by the portion of the plate located around the common ink chamber 11. The heat capacity absorbed by the plate increases in proportion to the volume of the plate. In this embodiment, since the groove is arranged so that the distance between the common ink chamber 11 and the groove 20 is half the distance between the common ink chamber 11 and the common ink chamber 11, The volume of the region sandwiched between the ink chamber 11 and the groove 20 is half of the volume of the region sandwiched between the common ink chamber 11 and the common ink chamber 11. Therefore, the heat capacity of the region sandwiched between the common ink chamber 11 and the groove 20 is half the heat capacity of the region sandwiched between the common ink chamber 11 and the common ink chamber 11.

  Since the area between the common ink chamber 11 and the common ink chamber 11 exchanges heat with the two common ink chambers 11 that sandwich the area, the heat capacity that is half the heat capacity of the area 2 sandwiches the area. One common ink chamber 11 is assigned to one common ink chamber 11.

  On the other hand, since the ink does not flow into the groove 20, the region sandwiched between the groove 20 and the common ink chamber 11 does not exchange heat with the groove 20 adjacent to the region, and one region adjacent to the region does not exchange heat. Since heat is exchanged only with the common ink chamber 11, all the heat capacities out of the heat capacities in the region are assigned to one common ink chamber 11 adjacent to the region.

  In this embodiment, the heat capacity of the region sandwiched between the groove 20 and the common ink chamber 11 adjacent to the groove 20 is equal to the heat capacity of the region sandwiched between two adjacent common ink chambers 11 in the common ink chamber 11. Since the groove 20 is formed at a position where the heat capacity is half, the heat exchange condition relating to the ink in the common ink chamber 11 located at the end and the heat exchange condition relating to the ink in the other common ink chamber 11 are established. Become equivalent. Therefore, the difference in viscosity between the common ink chambers 11 is eliminated, the difference in ejection characteristics between nozzles can be suppressed, and the print quality can be improved.

  Moreover, in this embodiment, each plate 31,32,33,34 is adhere | attached and laminated | stacked via an adhesive agent. At this time, the groove 20 may be configured such that excess adhesive enters the groove 20. In this way, since the excessive adhesive enters the groove 20, the excessive adhesive can be stored in the groove 20, and the excessive adhesive can be prevented from entering the ink flow path. Accordingly, it is possible to prevent the excessive adhesive from entering the flow path and change the discharge conditions, thereby suppressing the difference in ejection characteristics for each nozzle and improving the print quality.

  Next, a method for making holes in each plate will be described.

  First, a hole constituting the common ink chamber 11 is formed through the manifold plate 32 by a method such as etching.

  Next, an etching solution is sprayed from the spray nozzle to the entire manifold plate 32 in which the holes constituting the common ink chamber 11 are formed. At this time, the photoresist is not provided in the portion where the through hole is formed. When the etching solution is sprayed, the portion of the metal without the photoresist is corroded, so that the through-hole portion where the photoresist is not provided is fully etched and the manifold plate 32 is penetrated.

  At this time, the sprayed etching solution flows on the surface of the manifold plate 32, and flows to the back surface side of the manifold plate 32 through the holes constituting the common ink chamber 11 provided in the manifold plate 32. In the present embodiment, holes or grooves 20 constituting the common ink chamber 11 are formed through both sides of the through hole portion. Therefore, the etching solution sprayed on the manifold plate 32 flows toward the holes or grooves 20 constituting the common ink chamber 11 on both sides sandwiching the through hole portion. That is, the etching solution flows from the through hole forming portion to both sides of the through hole forming portion.

  If the groove 20 is not formed, the hole forming the common ink chamber 11 is formed only on one side of the through-hole forming portion at the outermost through-hole forming portion. In this case, the flow of the etching liquid in the outermost through hole forming portion is a flow toward the holes constituting the common ink chamber 11, and there are holes constituting the common ink chamber 11 on both sides of the through hole portion. The flow of the etching solution is different from the flow of the etching solution in the through hole portion.

However, in the present embodiment, the through hole forming portion is sandwiched between the common ink chamber 11 and the groove 20 between the two common ink chambers 11 adjacent to each other, or the common ink chamber 11 adjacent to the groove 20. Since it is provided in the region, the flow of the etching solution is the same for each communication path, and the processing of each communication path can be performed uniformly. Therefore, it is possible to suppress the difference in ejection characteristics for each nozzle and improve the printing quality.
(Second Embodiment)
Here, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, in addition to the above-described configuration, a lead-in hole 41 and an air release hole 42 are provided in the spacer plate 33 and the cavity plate 34. The drawing hole 41 has one end communicating with the groove 20 and the other end opened to the outside. One end of the air opening hole 42 communicates with the groove 20 and the other end opens to the outside. The lead-in hole 41 and the air opening hole 42 are disposed outside the region where the actuator unit 4 and the flow path unit 3 are bonded. The drawing hole 41 is disposed in the vicinity of the region to be bonded, and the through hole 42 is disposed at a position farther from the bonding region than the drawing hole 41.

  The surplus adhesive when the actuator unit 4 and the flow path unit 3 are joined with the adhesive moves to the groove 20 through the drawing hole 41. At this time, the air opening hole 42 becomes an air escape path. The adhesive reaching the groove 20 is cured and held in the groove 20. That is, excess adhesive used for joining the actuator unit 4 and the flow path unit 3 is held in the groove 20. Accordingly, excessive adhesive does not reach the ink supply port 10, and it is possible to suppress instability of discharge due to the adhesive entering the ink supply port 10.

In addition to the above configuration, an intake mechanism K may be further provided. The intake mechanism K is connected to the atmosphere opening hole 42 and applies a negative pressure to the groove 20 from the atmosphere opening hole 42. Excess adhesive is easily drawn into the groove 20 by negative pressure. By providing the intake mechanism K, surplus adhesive can be more reliably pulled into the groove 20.
(Third embodiment)
Here, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a plan view of the flow path unit 3 of the third embodiment.

  In the third embodiment, the heat capacity of the region sandwiched between the groove 20 and the common ink chamber 11 adjacent to the groove 20 is equal to the heat capacity of the region sandwiched between the two common ink chambers 11 adjacent to the common ink chamber 11. A groove 20 is formed at a position where the heat capacity is equivalent. That is, the groove 20 is formed at a position where the distance between the groove 20 and the common ink chamber 11 adjacent to the groove 20 is equal to the distance between the two adjacent common ink chambers 11. Further, the groove 20 communicates with the adjacent common ink chamber 11, and ink in the adjacent common ink chamber 11 can enter the groove 20.

  Since the area between the common ink chamber 11 and the common ink chamber 11 exchanges heat with the two common ink chambers 11 that sandwich the area, the heat capacity that is half the heat capacity of the area 2 sandwiches the area. One common ink chamber 11 is assigned to one common ink chamber 11.

  A position where the heat capacity of the region sandwiched between the groove 20 and the common ink chamber 11 adjacent to the groove 20 is equal to the heat capacity of the region sandwiched between the two common ink chambers 11 adjacent to the common ink chamber 11. In addition, since the groove 20 is formed, it is possible to eliminate the difference between the heat exchange condition relating to the ink in the common ink chamber 11 located at the end and the heat exchange condition relating to the ink in the other common ink chamber 11. it can. Therefore, the difference in viscosity between the common ink chambers 11 is eliminated, the difference in ejection characteristics between nozzles can be suppressed, and the print quality can be improved.

  An area between the two adjacent common ink chambers 11 in the common ink chamber 11 exchanges heat with the ink in the two adjacent common ink chambers 11, and the common ink chamber 11 and the groove 20 are exchanged. In the region between the two, heat exchange is performed with the ink in one adjacent common ink chamber 11 and the ink in one adjacent groove 20. At this time, since the heat capacity of the region where heat is exchanged with the ink in one common ink chamber 11 and one adjacent groove 20 is equal to the heat capacity of the region sandwiched between the two common ink chambers 11, the common ink The state of temperature change is the same between a region sandwiched between two adjacent common ink chambers 11 in the chamber 11 and a region sandwiched between the common ink chamber 11 and the groove 20. Therefore, it is possible to suppress the difference in ejection characteristics for each nozzle and improve the printing quality.

DESCRIPTION OF SYMBOLS 100 Inkjet printer 101 Carriage 102 Conveyance roller P Recording paper 1 Inkjet head 3 Flow path unit 4 Actuator unit 5 Flexible substrate 6 Drive IC
7 Protection plate 8 Reinforcement plate 9 Hole 10 Ink supply port 11 Common ink chamber 12 Communication hole 13 Pressure chamber 14 Communication passage 15 Nozzle 20 Groove 21 Groove 22 Groove 31 Nozzle plate 32 Manifold plate 33 Spacer plate 34 Cavity plate 35 Vibration plate 41 Pull-in口 42 Open to the atmosphere

Claims (12)

In an inkjet head having a plurality of common ink chambers that communicate with a plurality of pressure chambers and supply ink to the plurality of pressure chambers,
The plurality of common ink chambers are arranged in a predetermined direction on one plane,
An ink jet head, wherein a groove is formed adjacent to a common ink chamber located at an end in the predetermined direction among the plurality of common ink chambers and outside the common ink chamber. The heat capacity of the region sandwiched between the groove and the common ink chamber adjacent to the groove is half the heat capacity of the region sandwiched between two common ink chambers of the common ink chamber. The inkjet head according to claim 1. 3. The distance between the groove and a common ink chamber adjacent to the groove is half the distance between two adjacent common ink chambers of the common ink chamber. The inkjet head described in 1. The groove communicates with one of the common ink chambers;
A heat capacity of a region sandwiched between the common ink chamber adjacent to the groove and the groove is equal to a heat capacity of a region sandwiched between two adjacent common ink chambers of the common ink chamber. The inkjet head according to claim 1. 5. The distance between the common ink chamber adjacent to the groove and the groove is equal to the distance between two adjacent common ink chambers of the common ink chamber. The inkjet head described in 1. A plurality of nozzles that eject ink;
A plurality of communication passages connecting the plurality of pressure chambers and the plurality of nozzles;
The inkjet head according to claim 1, wherein the communication path is provided in a region sandwiched between the common ink chamber adjacent to the groove and the groove.   The inkjet head according to claim 6, wherein a width of the groove in the predetermined direction is equal to a width of the common ink chamber in the predetermined direction. The groove has a length in a direction perpendicular to the predetermined direction on a surface where the plurality of common ink chambers are formed, which is equal to a length of the common ink chamber in the perpendicular direction. Item 8. The ink jet head according to Item 6 or 7.   The groove has a depth in a direction perpendicular to a surface on which the plurality of common ink chambers are formed, and a depth of the common ink chamber in a direction perpendicular to a surface on which the plurality of common ink chambers are formed. The inkjet head according to claim 6, wherein the inkjet head is equal. The ink jet head according to claim 1, wherein the ink jet head has a configuration in which a plurality of thin plate-like components are laminated via an adhesive, and the adhesive enters the groove.   The inkjet head according to claim 10, wherein the groove communicates with the atmosphere. The inkjet head has a configuration in which a plurality of thin plate components are laminated,
The plurality of plate-like components have at least one manifold plate constituting the plurality of common ink chambers,
The inkjet head according to claim 1, wherein the manifold plate has the groove.

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