JP2018153968A - Inkjet recording head - Google Patents

Abstract

An ink jet recording head capable of ejecting ink droplets satisfactorily with a sufficient ejection pressure is provided. An ink jet recording head includes a plurality of ink pressure chambers extending in a first direction, a plurality of nozzles communicating with each ink pressure chamber, and a plurality of actuators capable of pressurizing ink in each ink pressure chamber. Are connected to one end of each ink pressure chamber along the first direction, and have a channel cross-sectional area larger than the channel cross-sectional area of the ink pressure chamber over the entire length, and supply ink to a plurality of ink pressure chambers. A common ink supply path that connects to the other end of each ink pressure chamber along the first direction, and has a flow path cross-sectional area that is larger than the flow path cross-sectional area of the ink pressure chamber over the entire length, and a plurality of inks A common ink discharge path for discharging ink from the pressure chamber. [Selection] Figure 1

Description

  Embodiments described herein relate generally to an ink jet recording head of a type that circulates ink in an ink pressure chamber communicating with a nozzle.

  The ink jet recording head includes a nozzle that ejects ink droplets, an ink pressure chamber that communicates with the nozzle, and an actuator that pressurizes ink in the ink pressure chamber. This head drives the actuator to pressurize ink in the ink pressure chamber and eject ink droplets from the nozzles.

  As an actuator, for example, a piezoelectric type that discharges ink droplets by deforming and displacing a wall surface (vibration plate) of an ink pressure chamber using a piezoelectric element is known. Piezoelectric actuators have the advantage that there is no restriction on the type of ink used because the piezoelectric element does not directly contact the ink and the heat generation of the piezoelectric element can be ignored. Therefore, a so-called piezoelectric MEMS type ink jet recording head in which semiconductor process technology is applied to the piezoelectric type has been attracting attention.

JP 2012-61631 A

  When pressure is applied to the ink in the ink pressure chamber and ink droplets are ejected from the nozzles, the ink pressure in the ink pressure chamber needs to be maintained in order to obtain a sufficient ejection pressure. For this reason, usually, a narrow portion (orifice) or a step portion is provided between the ink pressure chamber and the ink supply path so as to confine the ink in the ink pressure chamber.

  On the other hand, when bubbles are generated in the ink pressure chamber during the ink discharge operation, the pressure for discharging the ink droplets is absorbed by the bubbles, resulting in discharge failure. For this reason, there is known a head in which bubbles are removed by circulating ink in an ink pressure chamber.

  However, if an orifice or a stepped portion is provided in the ink supply path, the flow path resistance is increased, making it difficult for ink to flow and insufficiently removing bubbles.

  Therefore, development of an ink jet recording head that can discharge ink droplets satisfactorily with a sufficient discharge pressure is desired.

  An ink jet recording head according to an embodiment includes a plurality of ink pressure chambers extending in a first direction and arranged in a second direction orthogonal to the first direction, and one end of the plurality of ink pressure chambers in the first direction. A common ink supply path for supplying ink to a plurality of ink pressure chambers and a common ink discharge for discharging ink from the plurality of ink pressure chambers connected to the other end in the first direction of the plurality of ink pressure chambers A plurality of nozzles communicating with each ink pressure chamber on one side of each ink pressure chamber along a third direction orthogonal to the first direction and the second direction, and each along the third direction A plurality of actuators arranged on the other side of the ink pressure chamber and capable of pressurizing ink in each ink pressure chamber, and the flow path cross-sectional area of the common ink supply path and the flow path cross-sectional area of the common ink discharge path are Over the entire length of each ink pressure chamber Larger cross-sectional area.

  An ink jet recording head according to an embodiment is a first substrate having a first surface and a second surface parallel to the first surface, and extends in a first direction parallel to the first surface, and is in a first direction. A plurality of ink pressure chambers arranged in a second direction parallel to the first surface orthogonal to the first surface and penetrating the first substrate in communication with the first surface and the second surface. A common ink supply path that is connected to one end in the direction of 1 and connects the first surface and the second surface to penetrate the first substrate and supplies ink to a plurality of ink pressure chambers; and each ink pressure A common ink discharge path that is connected to the other end of the chamber in the first direction, is connected to the first surface and the second surface and penetrates the first substrate, and discharges ink from the plurality of ink pressure chambers. A first substrate having a plurality of ink pressure chambers, a common ink supply path, and a common ink discharge path A nozzle plate having a plurality of nozzles which are stacked on the first surface of the first substrate so as to block one surface side and communicates with each ink pressure chamber; a plurality of ink pressure chambers; a common ink supply path; and a common ink discharge path A diaphragm laminated on the second surface of the first substrate so as to block the second surface side of the first substrate, and opposed to each ink pressure chamber on the opposite side of the diaphragm from the first substrate, and the ink in each ink pressure chamber And a plurality of actuators that can pressurize each of them.

FIG. 1 is a partially enlarged view showing a main part of the ink jet recording head according to the first embodiment. FIG. 2 is a partially enlarged sectional view in which a section of the ink jet recording head of FIG. 1 is partially enlarged. FIG. 3 is a partially enlarged plan view of the drive substrate of the ink jet recording head of FIG. 1 viewed from the nozzle plate side. 4 is a rear view of the ink jet recording head of FIG. FIG. 5 is a schematic cross-sectional view showing a head model for simulating the relationship between the length of the ink pressure chamber and the volume of the ink droplet. FIG. 6 is a graph showing a simulation result using the model of FIG. FIG. 7 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 8 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 9 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 10 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 11 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 12 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 13 is a partially enlarged view showing a modification of the ink jet recording head of FIG. FIG. 14 is a partially enlarged view showing a main part of the ink jet recording head according to the second embodiment. FIG. 15 is a rear view of the ink jet recording head of FIG. 14 with the flow path substrate removed.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

  The ink jet recording head according to the embodiment includes a plurality of ink pressure chambers extending in a first direction and arranged in a second direction orthogonal to the first direction, and orthogonal to the first direction and the second direction. A plurality of nozzles that communicate with each ink pressure chamber at one side of each ink pressure chamber along the third direction and at the center along the first direction of each ink pressure chamber, and each along the third direction A plurality of actuators arranged on the other side of the ink pressure chamber and capable of pressurizing the ink in each ink pressure chamber, and a second direction connected in a liquid-tight manner to one end along the first direction of each ink pressure chamber A plurality of ink pressure chambers having a flow path cross-sectional area in a plane orthogonal to the second direction that is greater than a flow path cross-sectional area in a plane orthogonal to the first direction of the ink pressure chamber over the entire length. Common ink supply path for supplying ink to each ink pressure A liquid-tight connection to the other end along the first direction of the chamber extends in the second direction and extends over the entire length in a plane orthogonal to the second direction that is larger than the cross-sectional area of the flow path of the ink pressure chamber. And a common ink discharge path that discharges ink from the plurality of ink pressure chambers.

  Each ink pressure chamber has a sufficient length along the first direction in order to ensure a sufficient ink discharge pressure during ink droplet discharge without providing an orifice or a step portion at both ends in the first direction. Have. In other words, the length of each ink pressure chamber along the first direction sufficiently attenuates the pressure wave generated at the nozzle and propagating through the ink pressure chamber at the both ends of each ink pressure chamber. The length is set as possible. For example, it has been found that the desired length of each ink pressure chamber in a piezoelectric MEMS ink jet recording head is at least 500 μm or more, preferably 1 mm or more.

  As described above, according to the embodiment, each ink pressure chamber is made sufficiently long so that ink is confined in each ink pressure chamber using the inertial resistance of the ink. That is, in the embodiment, a structure in which an orifice or a step portion is not provided at both ends of each ink pressure chamber is realized after sufficient discharge pressure is secured by confining ink in each ink pressure chamber. By not providing an orifice or a step at both ends of each ink pressure chamber, the flow path resistance of the ink flowing through each ink pressure chamber can be reduced.

  In addition, according to the embodiment, the common ink supply path connected to one end of each ink pressure chamber has a flow passage cross-sectional area larger than that of each ink pressure chamber, and is connected to the other end of each ink pressure chamber. The cross-sectional area of the ink discharge path is made larger than the cross-sectional area of each ink pressure chamber. Therefore, at least the flow path resistance of the ink flowing through the common ink supply path and the common ink discharge path can be made smaller than the flow path resistance of the ink flowing through each ink pressure chamber.

  As described above, according to this embodiment, the flow resistance of the ink passing through the common ink supply path, the ink pressure chamber, and the common ink discharge path can be extremely reduced, and a sufficient amount of ink can be transferred at high speed to each ink. It can be circulated through the pressure chamber. Therefore, according to the embodiment, bubbles generated undesirably in each ink pressure chamber can be reliably and promptly discharged, pressure loss due to the presence of bubbles can be prevented, and ink droplets are excellent with sufficient discharge pressure. Can be discharged.

(First embodiment)
FIG. 1 is a partially enlarged view showing a main part of an ink jet recording head 100 (hereinafter simply referred to as the head 100) according to the first embodiment. FIG. 2 is a partially enlarged sectional view showing a part of the section of FIG. 1 in an enlarged manner. In FIG. 1, in order to make the piezoelectric element 40 and its wiring structure easy to see, the insulating film 60 is not shown, and the sealing substrate 50 is shown in a transparent state. The head described in each embodiment is a piezoelectric MEMS ink jet recording head.

  The head 100 includes a drive substrate 10 (first substrate) formed of, for example, Si, a nozzle plate 20 formed of, for example, an Si oxide film (thermal oxide film), a diaphragm 30 formed of, for example, Si, and a plurality of piezoelectric elements 40 (actuators). And a sealing substrate 50 (second substrate) formed of, for example, Si.

  The nozzle plate 20 is stacked on the lower first surface 10 a of the drive substrate 10, and the diaphragm 30 is stacked on the upper second surface 10 b of the drive substrate 10. The plurality of piezoelectric elements 40 are provided on the surface 30 a of the diaphragm 30 on the side away from the drive substrate 10. An insulating film 60 that covers the surfaces of the plurality of piezoelectric elements 40 is provided on the surface 30 a of the diaphragm 30. The sealing substrate 50 is laminated on the surface 30 a of the diaphragm 30 in a non-contact state with the plurality of piezoelectric elements 40. FIG. 3 is a partially enlarged plan view of the drive substrate 10 as viewed from the first surface 10a side with the nozzle plate 20 removed.

  The drive substrate 10 has a plurality of ink pressure chambers 11 that pass through the drive substrate 10 so as to connect the first surface 10a and the second surface 10b. The plurality of ink pressure chambers 11 are elongated holes respectively extending in a first direction (hereinafter sometimes referred to as a longitudinal direction) parallel to the first surface 10a and the second surface 10b of the drive substrate 10; The first surface 10a and the second surface 10b are arranged in parallel at a constant pitch in a second direction (hereinafter sometimes referred to as an arrangement direction) that is parallel to the first direction and orthogonal to the first direction. Each ink pressure chamber 11 has a substantially rectangular cross-sectional shape in a plane parallel to the first surface 10a and the second surface 10b.

  The ink pressure chambers 11 are provided so as to face the piezoelectric elements 40 provided on the surface 30a of the diaphragm 30 on a one-to-one basis. As shown in FIG. 1, the plurality of piezoelectric elements 40 have a substantially oval appearance extending in the first direction, and are arranged in a plurality of rows (only two rows are shown in FIG. 1). In order to draw out the wiring of each piezoelectric element 40 in the first direction, the two adjacent rows of piezoelectric elements 40 are laid out alternately shifted by ½ pitch in the arrangement direction. That is, the plurality of ink pressure chambers 11 provided on the drive substrate 10 are also arranged so as to be shifted from each other by ½ pitch in the alignment direction between two adjacent rows.

  The plurality of rows of ink pressure chambers 11 have both ends in the longitudinal direction aligned in the alignment direction. The length of each ink pressure chamber 11 along the longitudinal direction is about 600 μm to 2500 μm, and more preferably 1000 μm to 1500 μm. The width of each ink pressure chamber 11 along the arrangement direction is about 50 to 100 μm, and the pitch in the arrangement direction is about 60 to 150 μm. In the present embodiment, the cross-sectional shape of the ink pressure chamber 11 is a substantially rectangular shape that is slightly larger than the piezoelectric element 40.

  The drive substrate 10 includes a common ink supply path 12 that is liquid-tightly connected to one end along the longitudinal direction of the plurality of ink pressure chambers 11 in each row, and the other along the longitudinal direction of the plurality of ink pressure chambers 11 in the same row. A common ink discharge path 13 is liquid-tightly connected to the end. The common ink supply path 12 and the common ink discharge path 13 are provided according to the number of rows of the ink pressure chambers 11. The common ink supply path 12 supplies ink into each ink pressure chamber 11 from one end side of the plurality of ink pressure chambers 11 in each row. The common ink discharge path 13 discharges ink from the other end side of the plurality of ink pressure chambers 11 in each row.

  Each of the common ink supply path 12 and the common ink discharge path 13 extends along the direction in which the plurality of ink pressure chambers 11 are arranged, and communicates with the first surface 10a and the second surface 10b of the drive substrate 10 to drive the drive substrate. 10 is provided. In other words, as shown in FIG. 3, the drive substrate 10 is generally constituted by a plurality of partition walls 14 provided between the ink pressure chambers 11 adjacent to each other in the arrangement direction.

  For example, in the structure illustrated in FIG. 1, the right end of the plurality of ink pressure chambers 11 in the left column of the drawing communicates with the common ink supply path 12, and the left end of the plurality of ink pressure chambers 11 in the same row is the common ink discharge. It communicates with the road 13. On the other hand, in FIG. 1, the left end of the plurality of ink pressure chambers 11 in the right column communicates with the same common ink supply path 12, and the right end of the plurality of ink pressure chambers 11 in the same column communicates with another common ink discharge path 13. Communicate.

  That is, in this example, the common ink supply path 12 between the two adjacent ink pressure chambers 11 is shared, and one end of the plurality of ink pressure chambers 11 in each line is connected to one common ink supply path 12. It is connected. In other words, by switching the direction of the ink flowing through the ink pressure chambers 11 in each adjacent row alternately, the common ink supply path 12 (or the common ink supply path 12 between the plurality of adjacent ink pressure chambers 11). One ink discharge path 13) is provided. In other words, in the present embodiment, the number of common ink flow paths, which is obtained by adding the number of common ink supply paths 12 and common ink discharge paths 13, is one more than the number of rows of ink pressure chambers 11.

  The drive substrate 10 has a thickness of 30 μm to 500 μm, for example, and preferably has a thickness of 50 μm to 200 μm. The thickness of the drive substrate 10 is a thickness that allows the partition 14 between the ink pressure chambers 11 adjacent to each other in the arrangement direction to have sufficient rigidity, and can increase the arrangement density of the ink pressure chambers 11 as much as possible. The thickness is set so that the volume of each ink pressure chamber 11 can be set to an appropriate value. The thickness of the drive substrate 10 corresponds to the depth of each ink pressure chamber 11 and also corresponds to the depth of the common ink supply path 12 and the common ink discharge path 13.

  The cross-sectional area of each of the common ink supply path 12 and the common ink discharge path 13 along the plane orthogonal to the flow direction (second direction) of the ink flowing through the common ink supply path 12 and the common ink discharge path 13 is It is larger than the flow path cross-sectional area of each ink pressure chamber 11 along the surface orthogonal to the flow direction (first direction) of the ink flowing through each ink pressure chamber 11 over the entire length.

  As described above, in the present embodiment, the depth of each ink pressure chamber 11, the depth of the common ink supply path 12, and the depth of the common ink discharge path 13 correspond to the thickness of the drive substrate 10. Therefore, the width of the common ink supply path 12 and the common ink discharge path 13 along the first direction is wider than the width of each ink pressure chamber 11 along the second direction. The cross-sectional area of the common ink supply path 12 and the cross-sectional area of the common ink discharge path 13 do not necessarily have the same cross-sectional area, and may be at least larger than the cross-sectional area of each ink pressure chamber 11.

  FIG. 3 is a partially enlarged plan view of the plurality of ink pressure chambers 11, the common ink supply path 12, and the common ink discharge path 13 of the drive substrate 10 as viewed from the nozzle plate 20 side (first surface 10a side). Each of the plurality of partition walls 14 between the arrangement directions of the plurality of ink pressure chambers 11 has a circumferential surface connecting smooth curved surfaces without corners. In particular, both ends in the longitudinal direction of each partition wall 14 have a shape in which the circumferential surface is curved in an arc shape, a connection portion between one end in the longitudinal direction of each ink pressure chamber 11 and the common ink supply path 12, and The connection portion between the other end in the longitudinal direction of each ink pressure chamber 11 and the common ink discharge path 13 is gently connected. In other words, the inner surface of the common ink supply path 12 and the inner surface of each ink pressure chamber 11 are smoothly connected, and the inner surface of the common ink discharge path 13 and the inner surface of each ink pressure chamber 11 are gently connected.

  The nozzle plate 20 is made of Si, for example. The nozzle plate 20 is fixed in contact with the first surface 10a of the drive substrate 10 through, for example, an adhesive 15. For this reason, the nozzle plate 20 closes the first surface 10 a side of each ink pressure chamber 11, and closes the first surface 10 a side of the common ink supply path 12 and the common ink discharge path 13. That is, the inner surfaces of the plurality of ink pressure chambers 11, the common ink supply path 12, and the common ink discharge path 13 on the first surface 10 a side are defined by the back surface 20 a of the nozzle plate 20. It becomes a flat surface.

  The nozzle plate 20 has a plurality of nozzles 21 communicating with each ink pressure chamber 11 at the center along the longitudinal direction of each ink pressure chamber 11. The plurality of nozzles 21 are provided through the nozzle plate 20. The nozzle 21 is provided near the center along the longitudinal direction of each ink pressure chamber 11, more preferably at the center. That is, each ink pressure chamber 11 communicates with the outside of the head 100 via the nozzle 21.

The diaphragm 30 is formed of, for example, a Si oxide film (SiO ₂ ) having a thickness of about 1 to 5 μm, which is formed by thermal oxidation or a CVD method. The Si oxide film is desirably amorphous from the viewpoint that uniform deformation can be realized. In addition, it is desirable that the diaphragm 30 is formed of a Si oxide film from the viewpoint of easy manufacture of a film having a stable composition and characteristics. Furthermore, it is desirable to form the diaphragm 30 with a Si oxide film from the viewpoint of good compatibility with the conventional semiconductor process.

  The diaphragm 30 is stacked in contact with the second surface 10 b of the drive substrate 10, closes the second surface 10 b side of each ink pressure chamber 11, and is on the second surface 10 b side of the common ink supply path 12 and the common ink discharge path 13. Is blocking. That is, the inner surfaces of the plurality of ink pressure chambers 11, the common ink supply path 12, and the common ink discharge path 13 on the second surface 10b side are defined by the back surface 30b of the diaphragm 30, and are flat without a continuous step. It becomes a serious aspect.

  The plurality of piezoelectric elements 40 are stacked on the surface 30 a of the diaphragm 30 so as to face the plurality of ink pressure chambers 11 of the drive substrate 10. As shown in FIG. 2, each piezoelectric element 40 has a lower electrode 42 superimposed on the surface 30 a of the diaphragm 30, a piezoelectric film 44 superimposed on the lower electrode 42, and an upper electrode 46 superimposed on the piezoelectric film 44. The length of each piezoelectric element 40 along the first direction is shorter than the length of the ink pressure chamber 11 along the first direction. The width along the alignment direction of the piezoelectric elements 40 is shorter than the width along the alignment direction of the ink pressure chambers 11 described above.

  A part of the lower electrode 42 of each piezoelectric element 40 is extended in the first direction along the surface 30 a of the diaphragm 30 and functions as the individual drive wiring 43. An insulating film 60 is provided on the surface 30 a of the diaphragm 30 including the surface of the piezoelectric element 40. A via hole 62 is formed in a part of the insulating film 60 in contact with the upper electrode 46, and an extraction wiring 47 is extracted from the upper electrode 46 through the via hole 62 in the first direction.

A piezoelectric material having a large electrostriction constant such as lead zirconate titanate (Pb (Zr, Ti) O ₃ , PZT) is suitable for the piezoelectric film 44 of each piezoelectric element 40. When PZT is used for the piezoelectric film 44, a noble metal such as Pt, Au, or Ir or a conductive oxide such as SrRuO ₃ is suitable for the lower electrode 42 and the upper electrode 46. In addition, a piezoelectric material suitable for a silicon process such as AlN or ZrO ₂ can be used as the piezoelectric film 44. In this case, general electrode materials and wiring materials such as Al and Cu can be used as the lower electrode 42 and the upper electrode 46.

  The sealing substrate 50 is laminated on the surface 30 a side of the diaphragm 30 in a non-contact state with the plurality of piezoelectric elements 40. The sealing substrate 50 has a facing surface 50a that faces the surface 30a of the diaphragm 30, and a recess 51 that seals the plurality of piezoelectric elements 40 in a non-contact state on the facing surface 50a side. For example, a plurality of recesses 51 may be provided corresponding to each piezoelectric element 40, or may be a recess 51 that collectively covers a plurality of piezoelectric elements 40 in each row. You may make it cover in the place 51.

  4 is a rear view of the head 100 as viewed from the back surface 50b side of the sealing substrate 50. FIG. Here, the sealing substrate 50 is illustrated in a transparent state in order to make it easier to see a plurality of rows of piezoelectric elements 40 provided on the surface 30a of the diaphragm 30.

  The head 100 according to the present embodiment includes four rows of ink pressure chambers 11 and four rows of piezoelectric elements 40, and includes three common ink discharge paths 13 and two common ink discharge paths 13 disposed between the common ink discharge paths 13. An ink supply path 12 is provided. The sealing substrate 50 has a width that does not cover the connection terminal pads 48 connected to the end portions of the individual drive wirings 43 drawn from the piezoelectric elements 40.

  The diaphragm 30 has a plurality (two in this embodiment) of ink supply holes 32 communicating with the common ink supply path 12 and a plurality of (two in this embodiment) ink discharge holes 34 communicating with the common ink discharge path 13. Have The ink supply hole 32 and the ink discharge hole 34 are provided so as to penetrate the diaphragm 30 through communication with the front surface 30a and the back surface 30b of the diaphragm 30 at positions overlapping the common ink supply path 12 and the common ink discharge path 13, respectively. Yes.

  The sealing substrate 50 includes a plurality (two in this embodiment) of ink inflow holes 53 that overlap each ink supply hole 32 provided in the diaphragm 30 and a plurality of (this embodiment) that overlaps each ink discharge hole 34 provided in the diaphragm 30. The embodiment has two ink outflow holes 55. The ink inflow hole 53 and the ink outflow hole 55 are provided through the sealing substrate 50 so as to communicate with the opposing surface 50a and the back surface 50b of the sealing substrate 50, respectively.

Hereinafter, the operation of the head 100 described above will be described.
First, ink is supplied to the head 100 from an external ink supply pump (not shown). The ink flows from the back surface 50 b side of the sealing substrate 50 into the common ink supply path 12 of each column through the plurality of ink inflow holes 53 of the sealing substrate 50 and the plurality of ink supply holes 32 of the diaphragm 30. The ink that has flowed into the plurality of common ink supply paths 12 flows into the plurality of ink pressure chambers 11 connected to each common ink supply path 12.

  The ink flowing into each ink pressure chamber 11 is discharged by an external ink discharge pump (not shown) connected to the plurality of ink outflow holes 55 of the sealing substrate 50. At this time, the ink in the plurality of ink pressure chambers 11 is discharged to the common ink discharge path 13 connected to the other end, and the plurality of ink discharge holes 34 of the diaphragm 30 and the plurality of ink outflow holes of the sealing substrate 50. It is discharged out of the head 100 through 55. Thereby, the ink circulates in the plurality of ink pressure chambers 11.

  According to the head 100 of this embodiment, a relatively large amount of ink can be circulated at a relatively high speed through the plurality of common ink supply paths 12, the plurality of ink pressure chambers 11, and the plurality of common ink discharge paths 13. For this reason, unwanted objects such as bubbles that are generated undesirably in each ink pressure chamber 11 can be quickly discharged out of the ink pressure chamber 11, and a drop in ink droplet ejection performance can be prevented. .

  In the head 100 of this embodiment, the inner surface of each ink pressure chamber 11 and the inner surface of the common ink supply path 12 are gently connected, and the inner surface of each ink pressure chamber 11 and the inner surface of the common ink discharge path 13 are gently connected. . For this reason, there is no step in the connection portion between each ink pressure chamber 11 and the common ink supply path 12 and the connection portion between each ink pressure chamber 11 and the common ink discharge path 13. Further, in the head 100 of the present embodiment, the flow path cross-sectional area of each common ink supply path 12 is larger than the flow path cross-sectional area of each ink pressure chamber 11, and each flow cross-sectional area of each ink pressure chamber 11 is common. The flow path cross-sectional area of the ink discharge path 13 is larger. For this reason, the flow path resistance of the ink flowing through the head 100 is extremely small.

  As described above, in a state where ink is circulated in each ink pressure chamber 11, a drive voltage is selected between the lower electrode 42 and the upper electrode 46 of each piezoelectric element 40 in accordance with a recording signal from an external drive circuit (not shown). Apply the power. As a result, the piezoelectric film 44 of the piezoelectric element 40 to which the drive voltage is applied contracts and the piezoelectric element 40 bends and deforms in a concave shape, the volume of the corresponding ink pressure chamber 11 increases, and the common ink supply path to the ink pressure chamber 11 Ink flows in through 12. Next, when the drive voltage is removed, the bending deformation of the piezoelectric element 40 is restored, the volume of the ink pressure chamber 11 is reduced, the pressure in the ink pressure chamber 11 is increased, and ink droplets are ejected through the nozzles 21. To do.

  In order to eject ink droplets satisfactorily at a sufficient ejection pressure, it is necessary to maintain the pressure of the ink in the ink pressure chamber 11 at a certain level or higher when ejecting ink droplets. For this reason, in this embodiment, each ink pressure chamber 11 is made sufficiently long so that the distance from the nozzle 21 to the common ink supply path 12 and the distance from the nozzle 21 to the common ink discharge path 13 are sufficiently long. As a result, an inertial resistance due to the inertial mass of the ink filling each ink pressure chamber 11 is generated, and the pressure is prevented from escaping from the ink pressure chamber 11 to the common ink supply path 12 or the common ink discharge path 13.

  In other words, in the head 100 of this embodiment, the length of the ink pressure chamber 11 is set to such an extent that a sufficient discharge pressure can be obtained for bending and deforming each piezoelectric element 40 to discharge ink droplets. . Specifically, a vibration wave (hereinafter referred to as a pressure wave) based on a change in ink pressure during ink droplet ejection is sufficiently attenuated before the common ink supply path 12 and the common ink discharge path 13 to supply the common ink. The length of the ink pressure chamber 11 is set to such an extent that vibration is hardly transmitted to the path 12 and the common ink discharge path 13.

  As a result, ink droplets can be ejected at a sufficient ejection pressure, and a problem that a pressure wave is transmitted to another adjacent ink pressure chamber 11 via the common ink supply path 12 and the common ink discharge path 13 can be prevented. The ink droplet ejection operation in the adjacent ink pressure chambers 11 is not adversely affected.

  In order to determine the optimum length of the ink pressure chamber 11 that can sufficiently attenuate the pressure wave generated by the ejection of ink droplets, a head of the type shown in FIG. 5 (the common ink supply path 12 and the common ink discharge path) is used. The change in the volume of the ink droplets ejected from the nozzles 21 when the length of the ink pressure chamber 11 was variously changed using a head having no 13) was reproduced on a computer. The simulation result is shown in FIG.

  According to this, when the length of the ink pressure chamber 11 (both ends are open) centered on the nozzle 21 exceeds 1 mm, the volume of the ink droplet is ideal (the pressure in the ink pressure chamber 11 is completely confined). It was found that about 80% of the ink droplet volume in the state) was reached. In this case, it is also known that the width and depth of the ink pressure chamber 11, that is, the cross-sectional area of the ink pressure chamber 11, hardly affects the volume of the ink droplet. That is, in this case, by setting the length of the ink pressure chamber 11 to 500 μm or more on both sides of the nozzle 21, the pressure wave can be sufficiently attenuated at both ends of the ink pressure chamber 11, and a sufficiently sized ink droplet It can be seen that the liquid can be discharged stably.

  On the other hand, if the ink pressure chamber 11 is lengthened, the head 100 is increased in size. Considering this point, in the simulation result of FIG. 6, when the length of the ink pressure chamber 11 approaches 2500 μm, the size of the ink droplet is saturated and exceeds 95% of the ideal volume. For this reason, the length of the ink pressure chamber 11 is preferably 2500 μm or less.

Next, a method for manufacturing the head 100 described above will be described with reference to FIGS.
First, as shown in FIG. 7, the drive substrate 10 is oxidized by thermal oxidation to form a diaphragm 30 made of a Si oxide film. In this embodiment, the diaphragm 30 is formed by thermal oxidation of the Si substrate. However, a plasma CVD method other than the thermal oxidation method, a CVD method using TEOS as a raw material, or the like can also be used.

  Thereafter, a layer of a lower electrode 42 made of Ti / Pt is formed on the surface 30a of the diaphragm 30 by sputtering, a layer of the piezoelectric film 44 made of PZT is formed thereon, and an upper portion made of Au is further formed thereon. A layer of electrode 46 is formed. Next, the upper electrode 46, the piezoelectric film 44, and the lower electrode 42 are sequentially etched and patterned by photolithography and wet or dry etching to form a plurality of piezoelectric elements 40 and a plurality of individual drive wirings 43.

  Next, as shown in FIG. 8, an insulating film 60 that covers the surface 30a of the diaphragm 30 and the plurality of piezoelectric elements 40 is formed and patterned by photolithography and reactive ion etching, and the upper electrode 46 of each piezoelectric element 40 is formed. A plurality of via holes 62 (not shown here) are formed on the upper portion. Thereafter, patterning is performed by sputtering film formation, photolithography, and reactive ion etching to form a lead wiring 47 (not shown here) connected to the upper electrode 46 through each via hole 62.

  Next, as shown in FIG. 9, a sealing substrate 50 in which a plurality of recesses 51 are formed in the facing surface 50a is prepared in advance. Then, each recess 51 is aligned with the plurality of piezoelectric elements 40 in a non-contact state, and the sealing substrate 50 is overlaid on the surface 30 a of the diaphragm 30. At this time, the facing surface 50 a of the sealing substrate 50 is bonded and fixed to the surface 30 a of the diaphragm 30 through the layer of the adhesive 45.

  Next, as shown in FIG. 10, the drive substrate 10 is processed by grinding and CMP from the first surface 10a side to be thinned.

  Next, as shown in FIG. 11, from the first surface 10 a side of the drive substrate 10, a plurality of ink pressure chambers 11, a plurality of common ink supply paths 12, by back surface photolithography and deep etching (D-RIE). And a plurality of common ink discharge paths 13 are formed.

  Finally, as shown in FIG. 12, the nozzle plate 20 is bonded and fixed to the first surface 10 a of the drive substrate 10 through the adhesive 15. Then, a plurality of nozzles 21 are formed on the nozzle plate 20 by laser processing.

  In the series of film formation and etching described above, a large number of chips are simultaneously formed on a single wafer, and are divided into individual chips after the process is completed.

  As described above, according to the method of manufacturing the head 100 of the present embodiment, the head 100 can be manufactured by a simple process, has excellent ink circulation performance, and drops ink droplets with sufficient discharge pressure. It is possible to provide a piezoelectric MEMS type ink jet recording head 100 that can be ejected satisfactorily.

(Modification)
FIG. 13 is a partially enlarged view showing a main part of an ink jet recording head 110 (hereinafter simply referred to as the head 110) according to a modification of the first embodiment described above. The head 110 has substantially the same structure as the head 100 of the first embodiment described above, except that the structure of the nozzle plate 120 is different. Therefore, here, the same reference numerals are given to components that function in the same manner as the head 100 of the first embodiment described above, and detailed description thereof will be omitted.

  The nozzle plate 120 has a back surface 120a facing the drive substrate 10, and has a plurality of grooves 121 on the back surface 120a side. The plurality of grooves 121 extend in the direction in which the plurality of ink pressure chambers 11 are arranged, that is, in the second direction, so as to overlap the common ink supply path 12 and the common ink discharge path 13 of the opposing drive substrate 10. . That is, the nozzle plate 120 of the present modification is thicker than the nozzle plate 20 of the first embodiment in order to form the plurality of grooves 121 described above.

  Each groove 121 functions as the common ink supply path 112 in cooperation with the common ink supply path 12, and functions as the common ink discharge path 113 in cooperation with the common ink discharge path 13. That is, the common ink supply path 112 and the common ink discharge path 113 of the present modification can have a larger channel cross-sectional area than the common ink supply path 12 and the common ink discharge path 13 of the first embodiment.

  For this reason, according to this modification, the flow resistance of the ink flowing through the head 110 can be further reduced, and the ink circulation performance can be further improved. Therefore, also in the present modification, it is possible to provide the piezoelectric MEMS type ink jet recording head 110 that can eject ink droplets satisfactorily with a sufficient ejection pressure.

(Second Embodiment)
FIG. 14 is a partially enlarged view showing a main part of an ink jet recording head 200 (hereinafter simply referred to as the head 200) according to the second embodiment. The head 200 is provided with a large number of ink supply holes 32 and ink discharge holes 34 (not shown here) in the diaphragm 30, a large number of ink inflow holes 53 and ink outflow holes 55 in the sealing substrate 50, and the back surface of the sealing substrate 50. It has substantially the same structure as the head 100 of the first embodiment described above except that the flow path substrate 210 is bonded and fixed to the 50b via the adhesive 215. Therefore, here, the same reference numerals are given to components that function in the same manner as the head 100 of the first embodiment described above, and detailed description thereof will be omitted.

  The plurality of ink inflow holes 53 (and the ink supply holes 32) are provided so as to penetrate the sealing substrate 50 (and the diaphragm 30) side by side in the second direction at positions facing the respective common ink supply paths 12. . In addition, the plurality of ink outflow holes 55 (and ink discharge holes 34) are provided through the sealing substrate 50 (and the diaphragm 30) side by side in the second direction at positions facing the common ink discharge paths 13. ing. The number, size, shape, etc. of each ink inflow hole 53 (and ink supply hole 32) and each ink outflow hole 55 (and ink discharge hole 34) are determined so that the flow resistance of the ink passing through the hole can be made as small as possible. ing.

  The flow path substrate 210 has a facing surface 210 a that faces the back surface 50 b of the sealing substrate 50. A plurality of ink inflow grooves 212 facing the plurality of ink inflow holes 53 of the sealing substrate 50 and a plurality of inks facing the plurality of ink outflow holes 55 of the sealing substrate 50 are formed on the facing surface 210 a of the flow path substrate 210. An outflow groove 214 is provided. Each ink inflow groove 212 and each ink outflow groove 214 are extended in the second direction, and the width along the first direction is increased in order to reduce the flow path resistance. The width of each ink inflow groove 212 is at least larger than the width of the common ink supply path 12 of the drive substrate 10. The width of each ink outflow groove 214 is at least larger than the width of the common ink discharge path 13 of the drive substrate 10.

  Further, the flow path substrate 210 communicates the bottom surface of each ink inflow groove 212 and the back surface 210b of the flow path substrate 210 and passes through the flow path substrate 210, and the bottom surface of each ink outflow groove 214. And at least one ink outlet 218 penetrating the flow path substrate 210 in communication with the back surface 210b of the flow path substrate 210. The opening area of the ink supply port 216 is larger than the opening area of the ink inflow hole 53 of the sealing substrate 50, and the opening area of the ink discharge port 218 is larger than the opening area of the ink outflow hole 55 of the sealing substrate 50.

  FIG. 15 is a rear view of the state in which the flow path substrate 210 is removed from the head 200 of FIG. A plurality of piezoelectric elements 40 are provided on the surface 30 a of the diaphragm 30, and a plurality of individual drive wirings 43 and a plurality of lead wirings 47 corresponding to each piezoelectric element 40 are provided. For this reason, the ink supply hole 32 and the ink discharge hole 34 penetrating the diaphragm 30 and the ink inflow hole 53 and the ink outflow hole 55 penetrating the sealing substrate 50 are the piezoelectric element 40, the individual drive wiring 43, and the lead-out wiring 47. Must be laid out at a position that does not interfere with In the present embodiment, the individual drive wiring 43 and the ink supply hole 32 (ink inflow hole 53) and the ink discharge hole 34 (ink outflow hole 55) penetrating the diaphragm 30 (sealing substrate 50) are avoided as shown in the figure. The lead wiring 47 was laid out.

Hereinafter, how the ink flows in the head 200 of this embodiment will be described.
First, ink is supplied to the head 200 from an external ink supply pump (not shown). The ink flows into the ink inflow groove 212 through the ink supply port 216 of the flow path substrate 210. The ink that has flowed into the ink inflow groove 212 flows into the common ink supply path 12 of each column through the plurality of ink inflow holes 53 of the sealing substrate 50 and the plurality of ink supply holes 32 of the diaphragm 30. The ink that has flowed into the plurality of common ink supply paths 12 flows into the plurality of ink pressure chambers 11 connected to each common ink supply path 12.

  The ink flowing into each ink pressure chamber 11 is discharged by an external ink discharge pump (not shown) connected to the ink discharge port 218 of the flow path substrate 210. At this time, the ink in the plurality of ink pressure chambers 11 is discharged to the common ink discharge path 13 connected to the other end, and the plurality of ink discharge holes 34 of the diaphragm 30 and the plurality of ink outflow holes of the sealing substrate 50. 55 is discharged to the ink outflow groove 214 of the flow path substrate 210. The ink discharged to the ink outflow groove 214 is discharged out of the head 200 through the ink discharge port 218 of the flow path substrate 210. Thereby, the ink circulates in the plurality of ink pressure chambers 11.

  As described above, according to the head 200 of the present embodiment, compared to the head 100 of the first embodiment, the ink flow resistance can be made smaller, and more ink can be circulated at a higher speed. be able to. For this reason, unwanted objects such as bubbles that are generated undesirably in each ink pressure chamber 11 can be quickly discharged out of the ink pressure chamber 11, and a drop in ink droplet ejection performance can be prevented. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Drive board, 10a ... 1st surface, 10b ... 2nd surface, 11 ... Ink pressure chamber, 12 ... Common ink supply path, 13 ... Common ink discharge path, 14 ... Partition, 20 ... Nozzle plate, 21 ... Nozzle, DESCRIPTION OF SYMBOLS 30 ... Diaphragm, 40 ... Piezoelectric element, 50 ... Sealing substrate, 51 ... Recess, 100, 110, 200 ... Inkjet recording head, 210 ... Channel substrate.

An ink jet recording head according to an embodiment includes a plurality of ink pressure chambers extending in a first direction and arranged in a second direction orthogonal to the first direction, and a plurality of ink pressure chambers in a first direction. A common ink supply path extending in the second direction , connected to one end and supplying ink to the plurality of ink pressure chambers, and connected to the other end in the first direction of the plurality of ink pressure chambers; A first substrate having a common ink discharge path extending in a second direction for discharging ink from the ink pressure chamber, and a third direction orthogonal to the first direction and the second direction; A nozzle plate having a plurality of nozzles communicated with each ink pressure chamber on one side of each ink pressure chamber, and disposed on the other side of each ink pressure chamber along the third direction to apply ink in each ink pressure chamber. It includes a plurality of actuators capable of pressure, a plurality of in- Pressure chambers, the common ink supply path, and the inner surface of the nozzle plate side of the common ink discharge passage is a flat surface with no step difference of a stretch, the flow path of the flow path cross-sectional area and the common ink discharge path of the common ink supply path The cross-sectional area is larger than the flow path cross-sectional area of each ink pressure chamber over its entire length.

An ink jet recording head according to an embodiment is a first substrate having a first surface and a second surface parallel to the first surface, and extends in a first direction parallel to the first surface, and is in a first direction. A plurality of ink pressure chambers arranged in a second direction parallel to the first surface orthogonal to the first surface and penetrating the first substrate in communication with the first surface and the second surface. 1 is connected to one end of the first direction and extends in the second direction . The first surface is connected to the second surface and penetrates the first substrate to supply ink to a plurality of ink pressure chambers. A common ink supply path and the other end in the first direction of each ink pressure chamber are connected to extend in the second direction, communicate with the first surface and the second surface, and pass through the first substrate. A first substrate having a common ink discharge path provided to discharge ink from the plurality of ink pressure chambers; and a plurality of ink pressure chambers A nozzle plate having a plurality of nozzles stacked on the first surface of the first substrate so as to block the first surface side of the common ink supply path and the common ink discharge path, and a plurality of nozzles communicating with each ink pressure chamber; A diaphragm laminated on the second surface of the first substrate so as to close the second surface side of the chamber, the common ink supply path, and the common ink discharge path, and each ink pressure chamber on the opposite side of the diaphragm from the first substrate. provided oppositely, each of the ink pressure chamber of the ink possess a plurality of actuators that can be pressurized respectively, a plurality of ink pressure chambers, the common ink supply path, and the inner face of the first face side of the common ink discharge path Is a flat surface without a step, and the cross-sectional area of the common ink supply path and the cross-sectional area of the common ink discharge path are more than the cross-sectional areas of the plurality of ink pressure chambers over the entire length. Big There.

Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.
Hereinafter, the invention described in the scope of claims at the beginning of the application of the present application will be added.
[1]
A plurality of ink pressure chambers extending in a first direction and arranged in a second direction orthogonal to the first direction;
A common ink supply path connected to one end of the plurality of ink pressure chambers in the first direction and supplying ink to the plurality of ink pressure chambers;
A common ink discharge path connected to the other end of the plurality of ink pressure chambers in the first direction and discharging ink from the plurality of ink pressure chambers;
A plurality of nozzles communicated with each ink pressure chamber on one side of each ink pressure chamber along a third direction orthogonal to the first direction and the second direction;
A plurality of actuators arranged on the other side of each ink pressure chamber along the third direction and capable of pressurizing the ink in each ink pressure chamber;
The ink jet recording head has a flow path cross-sectional area of the common ink supply path and a flow path cross-sectional area of the common ink discharge path that are larger than the flow path cross-sectional areas of the ink pressure chambers over the entire length.
[2]
The common ink supply path and the common ink discharge path each have an inner surface gently connected to the inner surface of each ink pressure chamber.
[1] Inkjet recording head.
[3]
The inner surfaces of the common ink supply path and the common ink discharge path include a flat surface that is continuous with the inner surface of the one side where each ink pressure chamber has the nozzle.
The ink jet recording head according to [1] or [2].
[4]
Inner surfaces of the common ink supply path and the common ink discharge path include a flat surface that is flush with the inner surface of the other side of each ink pressure chamber.
[3] Inkjet recording head.
[5]
The flow path length from each end in the first direction of each ink pressure chamber to the nozzle is 300 μm to 1250 μm.
[1] Inkjet recording head.
[6]
A first substrate having a first surface and a second surface parallel to the first surface, the first surface extending in a first direction parallel to the first surface and orthogonal to the first direction; A plurality of ink pressure chambers arranged in a parallel second direction and provided through the first substrate in communication with the first surface and the second surface, and the first direction of each ink pressure chamber A common ink supply path that is connected to one end of the first and connecting the first surface and the second surface and that penetrates the first substrate and supplies ink to the plurality of ink pressure chambers; Connected to the other end of the pressure chamber in the first direction, is connected to the first surface and the second surface and penetrates the first substrate, and discharges ink from the plurality of ink pressure chambers. A first substrate having a common ink discharge path;
The plurality of ink pressure chambers, the common ink supply path, and the common ink discharge path are stacked on the first surface of the first substrate so as to close the first surface side, and communicate with the ink pressure chambers. A nozzle plate having a plurality of nozzles;
A diaphragm laminated on the second surface of the first substrate so as to close the second surface side of the plurality of ink pressure chambers, the common ink supply path, and the common ink discharge path;
A plurality of actuators provided opposite to the first substrate of the diaphragm to face the ink pressure chambers and capable of pressurizing ink in the ink pressure chambers, respectively.
An ink jet recording head.
[7]
The flow path cross-sectional area of the common ink supply path and the flow path cross-sectional area of the common ink discharge path are larger than the flow path cross-sectional areas of the plurality of ink pressure chambers over the entire length thereof.
[6] An ink jet recording head.
[8]
The inner surface of the common ink supply path and the inner surface of the common ink discharge path respectively have inner surfaces that gently connect to the inner surfaces of the ink pressure chambers.
The ink jet recording head according to [6] or [7].
[9]
The flow path length from each end in the first direction of each ink pressure chamber to the nozzle is 300 μm to 1250 μm.
[6] An ink jet recording head.
[10]
An ink supply hole communicating with the common ink supply path and penetrating the diaphragm;
An ink discharge hole provided in communication with the common ink discharge path and penetrating the diaphragm;
[6] An ink jet recording head.
[11]
An ink inflow hole that is laminated on the opposite side of the diaphragm to the first substrate, and that has a recess for sealing the plurality of actuators in a non-contact state on an opposing surface facing the diaphragm; A second substrate having an ink outflow hole communicating with the ink discharge hole;
[10] The ink jet recording head.
[12]
The ink inflow hole and the ink outflow hole are provided through the second substrate in communication with the back surface opposite to the facing surface of the second substrate and the facing surface,
A third substrate that is laminated on the back side of the second substrate and has an ink inflow groove that communicates with the ink inflow hole and an ink outflow groove that communicates with the ink outflow hole on an opposing surface facing the second substrate; Have
[11] An ink jet recording head.
[13]
The third substrate has an ink supply port that communicates the ink inflow groove with a back surface opposite to the opposing surface facing the second substrate, and an ink discharge port that communicates the back surface of the third substrate with the ink outflow groove. In addition,
[12] Inkjet recording head.
[14]
The nozzle plate has a back surface facing the first surface of the first substrate, and has a groove facing the common ink supply path and a groove facing the common ink discharge path on the back surface.
[6] An ink jet recording head.

Claims (14)

A plurality of ink pressure chambers extending in a first direction and arranged in a second direction orthogonal to the first direction;
A common ink supply path connected to one end of the plurality of ink pressure chambers in the first direction and supplying ink to the plurality of ink pressure chambers;
A common ink discharge path connected to the other end of the plurality of ink pressure chambers in the first direction and discharging ink from the plurality of ink pressure chambers;
A plurality of nozzles communicated with each ink pressure chamber on one side of each ink pressure chamber along a third direction orthogonal to the first direction and the second direction;
A plurality of actuators arranged on the other side of each ink pressure chamber along the third direction and capable of pressurizing the ink in each ink pressure chamber;
The ink jet recording head has a flow path cross-sectional area of the common ink supply path and a flow path cross-sectional area of the common ink discharge path that are larger than the flow path cross-sectional areas of the ink pressure chambers over the entire length. The common ink supply path and the common ink discharge path each have an inner surface gently connected to the inner surface of each ink pressure chamber.
The ink jet recording head according to claim 1. The inner surfaces of the common ink supply path and the common ink discharge path include a flat surface that is continuous with the inner surface of the one side where each ink pressure chamber has the nozzle.
An ink jet recording head according to claim 1 or 2. Inner surfaces of the common ink supply path and the common ink discharge path include a flat surface that is flush with the inner surface of the other side of each ink pressure chamber.
The ink jet recording head according to claim 3. The flow path length from each end in the first direction of each ink pressure chamber to the nozzle is 300 μm to 1250 μm.
The ink jet recording head according to claim 1. A first substrate having a first surface and a second surface parallel to the first surface, the first surface extending in a first direction parallel to the first surface and orthogonal to the first direction; A plurality of ink pressure chambers arranged in a parallel second direction and provided through the first substrate in communication with the first surface and the second surface, and the first direction of each ink pressure chamber A common ink supply path that is connected to one end of the first and connecting the first surface and the second surface and that penetrates the first substrate and supplies ink to the plurality of ink pressure chambers; Connected to the other end of the pressure chamber in the first direction, is connected to the first surface and the second surface and penetrates the first substrate, and discharges ink from the plurality of ink pressure chambers. A first substrate having a common ink discharge path;
The plurality of ink pressure chambers, the common ink supply path, and the common ink discharge path are stacked on the first surface of the first substrate so as to close the first surface side, and communicate with the ink pressure chambers. A nozzle plate having a plurality of nozzles;
A diaphragm laminated on the second surface of the first substrate so as to close the second surface side of the plurality of ink pressure chambers, the common ink supply path, and the common ink discharge path;
A plurality of actuators provided opposite to the first substrate of the diaphragm to face the ink pressure chambers and capable of pressurizing ink in the ink pressure chambers, respectively.
An ink jet recording head. The flow path cross-sectional area of the common ink supply path and the flow path cross-sectional area of the common ink discharge path are larger than the flow path cross-sectional areas of the plurality of ink pressure chambers over the entire length thereof.
The ink jet recording head according to claim 6. The inner surface of the common ink supply path and the inner surface of the common ink discharge path respectively have inner surfaces that gently connect to the inner surfaces of the ink pressure chambers.
An ink jet recording head according to claim 6 or 7. The flow path length from each end in the first direction of each ink pressure chamber to the nozzle is 300 μm to 1250 μm.
The ink jet recording head according to claim 6. An ink supply hole communicating with the common ink supply path and penetrating the diaphragm;
An ink discharge hole provided in communication with the common ink discharge path and penetrating the diaphragm;
The ink jet recording head according to claim 6. An ink inflow hole that is laminated on the opposite side of the diaphragm to the first substrate, and that has a recess for sealing the plurality of actuators in a non-contact state on an opposing surface facing the diaphragm; A second substrate having an ink outflow hole communicating with the ink discharge hole;
The ink jet recording head according to claim 10. The ink inflow hole and the ink outflow hole are provided through the second substrate in communication with the back surface opposite to the facing surface of the second substrate and the facing surface,
A third substrate that is laminated on the back side of the second substrate and has an ink inflow groove that communicates with the ink inflow hole and an ink outflow groove that communicates with the ink outflow hole on an opposing surface facing the second substrate; Have
The ink jet recording head according to claim 11. The third substrate has an ink supply port that communicates the ink inflow groove with a back surface opposite to the opposing surface facing the second substrate, and an ink discharge port that communicates the back surface of the third substrate with the ink outflow groove. In addition,
The ink jet recording head according to claim 12. The nozzle plate has a back surface facing the first surface of the first substrate, and has a groove facing the common ink supply path and a groove facing the common ink discharge path on the back surface.
The ink jet recording head according to claim 6.