JP2016221706A - Liquid discharge head, and recording device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head hardly causing anchoring of the inclusion components in a liquid in the vicinity of a discharge port, and to provide a recording device using the head.SOLUTION: A liquid discharge head includes: a flow channel member 4 having plural discharge ports 8, plural pressurization chambers 10 and plural partial flow paths 7; and plural pressurizing parts 30. Further, the flow channel member 4 has: a plurality of first oscillating flow channels 32a connecting to the plural partial flow paths 7, respectively; first liquid chambers 32b connecting to the first oscillating flow channels 32a; a first flow channel 33 connecting to the outside of the flow channel member 4; a first diaphragm 32c existing between the first liquid chamber 32b and the first flow channel 33; a plurality of second oscillating flow channels 34a connecting to the plural partial flow paths 7, respectively; second liquid chambers 34b connecting to the second oscillating flow channels 34a; a second flow channel 35 connecting to the outside of the flow channel member 4; and a second diaphragm 34c existing between the second liquid chamber 34b and the second flow channel 35.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a liquid discharge head and a recording apparatus using the same.

  Conventionally, as a print head, for example, a liquid discharge head that performs various types of printing by discharging a liquid onto a recording medium is known. A liquid discharge head is known that includes, for example, a discharge hole that discharges a liquid and a pressurizing chamber that pressurizes the liquid so that the liquid is discharged from the discharge hole. (For example, see Patent Document 1).

JP 2003-305852 A

  However, in the liquid discharge head described in Patent Document 1, for example, when ink that is quickly dried is discharged, the ink in the vicinity of the discharge hole is dried and the discharge hole is clogged or the discharge hole is narrow. As a result, the ink cannot be ejected, and the ejection characteristics such as the ejection amount and the ejection speed may fluctuate.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a liquid discharge head for which the liquid-containing component is hardly fixed in the vicinity of the discharge hole, and a recording apparatus using the same.

  The liquid discharge head of the present invention includes a plurality of discharge holes, a plurality of pressurization chambers, and a flow path member having a plurality of partial flow paths respectively connecting the plurality of discharge holes and the plurality of pressurization chambers, A liquid discharge head including a plurality of pressurizing units that pressurize the plurality of pressurizing chambers, wherein the flow path member is connected to the plurality of partial flow paths, respectively. The first liquid chamber connected to the first peristaltic flow path, the first flow path connected to the outside of the flow path member, one surface facing the first liquid chamber and the other surface A first diaphragm facing the first channel, a plurality of second peristaltic channels connected to the plurality of partial channels, a second liquid chamber connected to the second peristaltic channel, the flow The second flow path connected to the outside of the path member, and one surface faces the second liquid chamber Together second diaphragm and the other surface facing the second flow path, characterized in that it comprises further.

  The recording apparatus of the invention includes the liquid discharge head, a transport unit that transports a recording medium to the liquid discharge head, and a control unit that controls the liquid discharge head.

  According to the liquid ejection head of the present invention, it is possible to make it difficult for the liquid-containing components to stick around the ejection holes.

(A) is a side view of a recording apparatus including a liquid ejection head according to an embodiment of the present invention, and (b) is a plan view. FIG. 2 is a plan view of a head body that is a main part of the liquid ejection head of FIG. 1. FIG. 3 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. FIG. 3 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. FIG. 5 is an enlarged plan view of one plate constituting the flow path member shown in FIG. 4. FIG. 5 is an enlarged plan view of one plate constituting the flow path member shown in FIG. 4. (A) is a longitudinal cross-sectional view along the VV line of FIG. 3, (b) is a longitudinal cross-sectional view in the position along the XX line of FIG. 4 of FIG.

  FIG. 1A is a schematic side view of a color inkjet printer 1 (hereinafter sometimes simply referred to as a printer) which is a recording apparatus including a liquid discharge head 2 according to an embodiment of the present invention. (B) is a schematic plan view. The printer 1 moves the print paper P relative to the liquid ejection head 2 by transporting the print paper P as a recording medium from the guide roller 82 </ b> A to the transport roller 82 </ b> B. The control unit 88 controls the liquid ejection head 2 based on image and character data, ejects liquid toward the recording medium P, causes droplets to land on the printing paper P, and prints on the printing paper P. Record such as.

  In the present embodiment, the liquid discharge head 2 is fixed to the printer 1, and the printer 1 is a so-called line printer. As another embodiment of the recording apparatus of the present invention, the operation of moving the liquid ejection head 2 by reciprocating in the direction intersecting the transport direction of the printing paper P, for example, the direction substantially orthogonal, and the printing paper P There is a so-called serial printer that alternately conveys.

  A flat head mounting frame 70 (hereinafter sometimes simply referred to as a frame) is fixed to the printer 1 so as to be substantially parallel to the printing paper P. The frame 70 is provided with 20 holes (not shown), and the 20 liquid discharge heads 2 are mounted in the respective hole portions, and the portion of the liquid discharge head 2 that discharges the liquid is the printing paper P. It has come to face. The distance between the liquid ejection head 2 and the printing paper P is, for example, about 0.5 to 20 mm. The five liquid ejection heads 2 constitute one head group 72, and the printer 1 has four head groups 72.

  The liquid discharge head 2 has a long and narrow shape in the direction from the front to the back in FIG. 1A and in the vertical direction in FIG. This long direction is sometimes called the longitudinal direction. Within one head group 72, the three liquid ejection heads 2 are arranged along a direction that intersects the conveyance direction of the printing paper P, for example, a substantially orthogonal direction, and the other two liquid ejection heads 2 are conveyed. One of the three liquid ejection heads 2 is arranged at a position shifted along the direction. The liquid discharge heads 2 are arranged so that the printable range of each liquid discharge head 2 is connected in the width direction of the print paper P (in the direction intersecting the conveyance direction of the print paper P) or the ends overlap. Thus, printing without gaps in the width direction of the printing paper P is possible.

  The four head groups 72 are arranged along the conveyance direction of the recording paper P. A liquid, for example, ink is supplied to each liquid ejection head 2 from a liquid tank (not shown). The liquid discharge heads 2 belonging to one head group 72 are supplied with the same color ink, and the four head groups 72 can print four color inks. The colors of ink ejected from each head group 72 are, for example, magenta (M), yellow (Y), cyan (C), and black (K). A color image can be printed by printing such ink under the control of the control unit 88.

The number of the liquid discharge heads 2 mounted on the printer 1 may be one if it is a single color and the range that can be printed by one liquid discharge head 2 is printed. The number of liquid ejection heads 2 included in the head group 72 and the number of head groups 72 can be changed as appropriate according to the printing target and printing conditions. For example, the number of head groups 72 may be increased in order to perform multicolor printing. Also, if a plurality of head groups 72 that print in the same color are arranged and printed alternately in the transport direction, the transport speed can be increased even if the liquid ejection heads 2 having the same performance are used. Thereby, the printing area per time can be increased. Alternatively, a plurality of head groups 72 for printing in the same color may be prepared and arranged so as to be shifted in a direction crossing the transport direction, so that the resolution in the width direction of the print paper P may be increased.

  Further, in addition to printing colored inks, a liquid such as a coating agent may be printed for surface treatment of the printing paper P.

  The printer 1 performs printing on a printing paper P that is a recording medium. The printing paper P is wound around the paper feed roller 80A, passes between the two guide rollers 82A, passes through the lower side of the liquid ejection head 2 mounted on the frame 70, and thereafter It passes between the two conveying rollers 82B and is finally collected by the collecting roller 80B. When printing, the printing paper P is transported at a constant speed by rotating the transport roller 82 </ b> B and printed by the liquid ejection head 2. The collection roller 80B winds up the printing paper P sent out from the conveyance roller 82B. The conveyance speed is, for example, 75 m / min. Each roller may be controlled by the controller 88 or may be manually operated by a person.

  In addition to the printing paper P, the recording medium may be a roll-like cloth. Further, instead of directly transporting the printing paper P, the printer 1 may transport the transport belt directly and transport the recording medium placed on the transport belt. By doing so, sheets, cut cloth, wood, tiles and the like can be used as the recording medium. Furthermore, a wiring pattern of an electronic device may be printed by discharging a liquid containing conductive particles from the liquid discharge head 2. Still further, the chemical may be produced by discharging a predetermined amount of liquid chemical agent or liquid containing the chemical agent from the liquid discharge head 2 toward the reaction container or the like and reacting.

  In addition, a position sensor, a speed sensor, a temperature sensor, and the like may be attached to the printer 1, and the control unit 88 may control each part of the printer 1 according to the state of each part of the printer 1 that can be understood from information from each sensor. . For example, the temperature of the liquid discharge head 2, the temperature of the liquid in the liquid tank, the pressure applied by the liquid in the liquid tank to the liquid discharge head 2, etc. affect the discharge characteristics such as the discharge amount and discharge speed of the discharged liquid. For example, the drive signal for ejecting the liquid may be changed according to the information.

  Next, the liquid ejection head 2 according to an embodiment of the present invention will be described. FIG. 2 is a plan view showing a head main body 2a which is a main part of the liquid ejection head 2 shown in FIG. FIG. 3 is an enlarged plan view of a region surrounded by a one-dot chain line in FIG. 2, and is a part of the head main body 2a. In FIG. 3, for the sake of explanation, some of the flow paths are omitted. FIG. 4 is an enlarged plan view at the same position as FIG. 3, and a part of the flow path different from FIG. 3 is omitted. FIG. 5 is an enlarged plan view of a plate 4n that is one of the plurality of plates constituting the flow path member 4 shown in FIG. FIG. 6 is an enlarged plan view of the other plate 4m constituting the flow path member 4 at the same location as FIG. FIG. 7A is a longitudinal sectional view taken along line VV in FIG. FIG. 7B is a longitudinal sectional view of FIG. 3, and is a longitudinal sectional view of a position along the line XX shown in FIG. 4. However, FIG. 7B is drawn to be reduced in the left-right direction of the figure as compared with FIG.

3 to 6, in order to make the drawings easy to understand, the pressurizing chamber 10, the squeezing 6, the discharge hole 8, and the like to be drawn with broken lines are drawn with solid lines because they are below the piezoelectric actuator substrate 21. Yes. Further, in FIG. 5, the arrangement of the sub-manifold 5a, the partition wall 15, the pressurizing chamber 10, and the like arranged on other plates other than the plate 4n are indicated by chain lines so that the arrangement of each flow path can be easily understood. Yes. Note that a large number of the pressurizing chambers 10 are actually arranged over the entire range shown in FIG. 5, but some of them are shown. Further, in FIG. 6, the sub-manifold 5a, the partition wall 15, the first liquid chamber 32b, the second liquid chamber 34b, etc., which are arranged on a plate other than the plate 4m, are shown so that the arrangement of each flow path can be easily understood. The arrangement is indicated by a chain line. Note that a large number of the first liquid chamber 32b and the second liquid chamber 34b are actually arranged over the entire range shown in FIG. 6, but some of them are shown.

  In addition to the head main body 2a, the liquid discharge head 2 may include a reservoir for supplying liquid to the head main body 2a and a housing. The head body 2a includes a flow path member 4 and a piezoelectric actuator substrate 21 in which a displacement element 30 that is a pressurizing unit is formed.

  The flow path member 4 constituting the head body 2a includes a manifold 5 which is a common flow path, a plurality of pressurizing chambers 10 connected to the manifold 5, and a plurality of discharge holes respectively connected to the plurality of pressurizing chambers 10. 8 and. The pressurizing chamber 10 opens to the upper surface of the flow path member 4, and the upper surface of the flow path member 4 is a pressurizing chamber surface 4-2. The upper surface of the flow path member 4 has an opening 5a connected to the manifold 5, and liquid is supplied from the opening 5a.

  A first peristaltic part 32 and a second peristaltic part 34 that peristate the liquid in the vicinity of the discharge hole 8 are arranged near the discharge hole 8. These will be described in detail later.

  In addition, a piezoelectric actuator substrate 21 including a displacement element 30 is joined to the upper surface of the flow path member 4, and each displacement element 30 is disposed on the pressurizing chamber 10. The piezoelectric actuator substrate 21 is connected to a signal transmission unit 60 that supplies a signal to each displacement element 30. In FIG. 2, the outline of the vicinity of the signal transmission unit 60 connected to the piezoelectric actuator substrate 21 is indicated by a dotted line so that the two signal transmission units 60 are connected to the piezoelectric actuator substrate 21. The electrodes formed on the signal transmission unit 60 that are electrically connected to the piezoelectric actuator substrate 21 are arranged in a rectangular shape at the end of the signal transmission unit 60. The two signal transmission parts 60 are connected so that each end comes to the center part in the short direction of the piezoelectric actuator substrate 21.

  The head main body 2 a has one piezoelectric actuator substrate 21 including a flat plate-like channel member 4 and a displacement element 30 joined on the channel member 4. The planar shape of the piezoelectric actuator substrate 21 is rectangular, and is arranged on the upper surface of the flow path member 4 so that the long side of the rectangle is along the longitudinal direction of the flow path member 4.

  Two manifolds 5 are formed inside the flow path member 4. The manifold 5 has an elongated shape extending from one end side in the longitudinal direction of the flow path member 4 to the other end side, and the opening of the manifold 5 that opens to the upper surface of the flow path member 4 at both ends thereof. 5a is formed.

  The manifold 5 is partitioned by a partition wall 15 provided at an interval in the short-side direction at least in the central portion in the longitudinal direction, which is a region connected to the pressurizing chamber 10. The partition wall 15 has the same height as the manifold 5 in the central portion in the longitudinal direction, which is a region connected to the pressurizing chamber 10, and completely separates the manifold 5 into a plurality of sub-manifolds 5b. By doing so, it is possible to provide the discharge hole 8 and the flow path connected from the discharge hole 8 to the pressurizing chamber 10 so as to overlap with the partition wall 15 in a plan view.

The portion of the manifold 5 divided into a plurality of parts may be referred to as a sub-manifold 5b. In the present embodiment, two manifolds 5 are provided independently, and openings 5a are provided at both ends. One manifold 5 is provided with seven partition walls 15 and divided into eight sub-manifolds 5b. The width of the sub-manifold 5b is larger than the width of the partition wall 15, so that a large amount of liquid can flow through the sub-manifold 5b.

  A wall surface on the discharge hole surface 4-1 side of the sub-manifold 5 b is a damper 18. One surface of the damper 18 faces the sub-manifold 5 b, and the other surface faces the damper chamber 19. Due to the presence of the damper chamber 19, the damper 18 can be deformed, and the volume of the sub-manifold 5b can be changed by the deformation. When the liquid in the pressurizing chamber 10 is pressurized to discharge the liquid, part of the pressure is transmitted to the sub manifold 5b through the liquid. As a result, the liquid in the sub-manifold 5b vibrates, and the vibration is transmitted to the original pressurizing chamber 10 or another pressurizing chamber 10 to cause fluid crosstalk that fluctuates the discharge characteristics of the liquid. . When the damper 18 exists, the vibration of the liquid transmitted to the sub manifold 5b vibrates and attenuates, so that the vibration of the liquid in the sub manifold 5b becomes difficult to be sustained. it can.

  The flow path member 4 is formed by two-dimensionally expanding a plurality of pressurizing chambers 10. The pressurizing chamber 10 is a hollow region having a substantially rhombic or elliptical planar shape with rounded corners.

  The pressurizing chamber 10 is connected to one sub-manifold 5 b through the throttle 6. Along with one sub-manifold 5b, two pressurizing chamber rows 11, which are rows of pressurizing chambers 10 connected to the sub-manifold 5b, are provided on each side of the sub-manifold 5b, for a total of two rows. Yes. Accordingly, 16 rows of pressurizing chambers 11 are provided for one manifold 5, and 32 heads of pressurizing chambers 11 are provided in the entire head body 2a. The intervals in the longitudinal direction of the pressurizing chambers 10 in the respective pressurizing chamber rows 11 are the same, for example, 37.5 dpi.

  One column of dummy pressurizing chambers 16 is provided at the end of each pressurizing chamber row 11. The dummy pressurizing chambers 16 in the dummy pressurizing chamber row are connected to the manifold 5 but are not connected to the discharge holes 8. Further, one dummy pressurizing chamber row in which dummy pressurizing chambers 16 are arranged in a straight line is provided outside the 32 pressurizing chamber rows 11. The dummy pressurizing chamber 16 in this dummy pressurizing chamber row is not connected to either the manifold 5 or the discharge hole 8. By these dummy pressurizing chambers 16, the structure around the pressurizing chamber 10 that is one inner side from the end is close to the structure of the other pressurizing chambers 10, thereby reducing the difference in rigidity caused by the structure. The difference in discharge characteristics can be reduced. In addition, since the influence of the surrounding structure difference has a large influence on the pressurizing chambers 10 adjacent to each other in the length direction, the dummy pressurizing chambers are provided at both ends in the length direction. Since the influence in the width direction is relatively small, it is provided only on the side closer to the end of the head main body 21a. Thereby, the width | variety of the head main body 21a can be made small.

The pressurizing chambers 10 connected to one manifold 5 are arranged in a lattice form having rows and columns along each outer side of the rectangular piezoelectric actuator substrate 21. As a result, the individual electrodes 25 formed on the pressurizing chamber 10 are arranged at equal distances from the outer side of the piezoelectric actuator substrate 21. Therefore, when forming the individual electrodes 25, the piezoelectric actuator substrate is formed. 21 can be hardly deformed. When the piezoelectric actuator substrate 21 and the flow path member 4 are joined, if this deformation is large, stress may be applied to the displacement element 30 near the outer side, resulting in variations in displacement characteristics. However, by reducing the deformation, The variation can be reduced. In addition, since the dummy pressurizing chamber row of the dummy pressurizing chamber 16 is provided outside the pressurizing chamber row 11 closest to the outer side, the influence of deformation can be made less susceptible. The pressurizing chambers 10 belonging to the pressurizing chamber row 11 are arranged at equal intervals, and the individual electrodes 25 corresponding to the pressurizing chamber rows 11 are also arranged at equal intervals. The pressurizing chamber rows 11 are arranged at equal intervals in the short direction, and the rows of the individual electrodes 25 corresponding to the pressurizing chamber rows 11 are also arranged at equal intervals in the short direction. Thereby, it is possible to eliminate a portion where the influence of the crosstalk becomes particularly large.

  In the present embodiment, the pressurizing chambers 10 are arranged in a lattice shape, but the pressurizing chambers 10 of adjacent pressurizing chamber rows 11 may be arranged in a staggered manner so as to be positioned between each other. In this way, since the distance between the pressurizing chambers 10 belonging to the adjacent pressurizing chamber row 11 becomes longer, crosstalk can be further suppressed.

  Regardless of how the pressurizing chamber rows 11 are arranged, when the flow path member 4 is viewed in plan, the pressurizing chamber 10 belonging to one pressurizing chamber row 11 is added to the adjacent pressurizing chamber row 11. By arranging the pressure chamber 10 and the liquid discharge head 2 so as not to overlap in the longitudinal direction, crosstalk can be suppressed. On the other hand, when the distance between the pressurizing chamber rows 11 is increased, the width of the liquid discharge head 2 is increased, so that the accuracy of the installation angle of the liquid discharge head 2 relative to the printer 1 and the use of a plurality of liquid discharge heads 2 are increased. The influence of the relative position accuracy of the liquid discharge head 2 on the printing result is increased. Therefore, by making the width of the partition wall 15 smaller than that of the sub-manifold 5b, the influence of the accuracy on the printing result can be reduced.

  The pressurizing chamber 10 connected to one sub-manifold 5 b forms two rows of pressurizing chamber rows 11, and the discharge holes 8 connected to the pressurizing chambers 10 belonging to one pressurizing chamber row 11 are One discharge hole row 9 is formed. The discharge holes 8 connected to the pressurizing chambers 10 belonging to the two pressurizing chamber rows 11 open to different sides of the sub-manifold 5b. In FIG. 4, two discharge hole rows 9 are provided in the partition wall 15, but the discharge holes 8 belonging to each discharge hole row 9 are connected to the sub-manifold 5 b on the side close to the discharge holes 8 in the pressurizing chamber 10. Are connected through. When the discharge hole 8 connected to the adjacent sub-manifold 5b via the pressurizing chamber row 11 and the liquid discharge head 2 are arranged so as not to overlap in the longitudinal direction, the pressurizing chamber 10 and the discharge hole 8 are connected. Since crosstalk between the flow paths can be suppressed, crosstalk can be further reduced. If the entire flow path connecting the pressurizing chamber 10 and the discharge hole 8 is arranged so as not to overlap in the longitudinal direction of the liquid discharge head 2, crosstalk can be further reduced.

  A plurality of pressurizing chambers are formed by a plurality of pressurizing chambers 10 connected to one manifold 5. Since there are two manifolds 5, there are two pressurizing chamber groups. The arrangement of the pressurizing chambers 10 related to ejection in each pressurizing chamber group is the same, and is arranged at a position translated in the short direction. These pressurizing chambers 10 are arranged over almost the entire surface although there are portions where the gaps between the pressurizing chamber groups are slightly wide in the region facing the piezoelectric actuator substrate 21 on the upper surface of the flow path member 4. . That is, the pressurizing chamber group formed by these pressurizing chambers 10 occupies a region having almost the same shape as the piezoelectric actuator substrate 21. Further, the opening of each pressurizing chamber 10 is closed by bonding the piezoelectric actuator substrate 21 to the upper surface of the flow path member 4.

  From the corner portion of the pressurizing chamber 10 facing the corner portion to which the squeezing 6 is connected, the flow channel connected to the discharge hole 8 opened on the discharge hole surface 4-1 on the lower surface of the flow channel member 4 extends. . This flow path extends in a direction away from the pressurizing chamber 10 in a plan view. More specifically, the pressurizing chamber 10 extends away from the direction along the long diagonal line while being shifted to the left and right with respect to that direction. As a result, the discharge chambers 8 can be arranged at intervals of 1200 dpi as a whole, while the pressurization chambers 10 are arranged in a lattice pattern in which the intervals within the pressurization chamber rows 11 are 37.5 dpi.

In other words, when the discharge holes 8 are projected so as to be orthogonal to the virtual straight line parallel to the longitudinal direction of the flow path member 4, each manifold 5 is within the range of R of the virtual straight line shown in FIG. That is, 16 discharge holes 8 connected to, and a total of 32 discharge holes 8 are equally spaced by 1200 dpi. Thus, by supplying the same color ink to all the manifolds 5, an image can be formed with a resolution of 1200 dpi in the longitudinal direction as a whole. Further, one discharge hole 8 connected to one manifold 5 is equally spaced at 600 dpi within the range of R of the imaginary straight line. As a result, by supplying different colors of ink to the respective manifolds 5, it is possible to form two-color images with a resolution of 600 dpi in the longitudinal direction as a whole. In this case, if two liquid ejection heads 2 are used, an image of four colors can be formed with a resolution of 600 dpi, and printing accuracy is higher than when four liquid ejection heads capable of printing at 600 dpi are used. Can also be done easily. In addition, the range of R of the imaginary straight line is covered with the discharge holes 8 connected to the pressurizing chambers 10 belonging to the one pressurizing chamber row arranged in the short direction of the head main body 2a.

  Individual electrodes 25 are formed at positions facing the pressurizing chambers 10 on the upper surface of the piezoelectric actuator substrate 21. The individual electrode 25 includes an individual electrode main body 25a that is slightly smaller than the pressurizing chamber 10 and has a shape substantially similar to the pressurizing chamber 10, and an extraction electrode 25b that is extracted from the individual electrode main body 25a. In the same manner as the pressurizing chamber 10, the individual electrode 25 constitutes an individual electrode row and an individual electrode group. A common electrode surface electrode 28 is disposed on the upper surface of the piezoelectric actuator substrate 21. The common electrode surface electrode 28 and the common electrode 24 are electrically connected through a through conductor (not shown) disposed in the piezoelectric ceramic layer 21b.

  The discharge hole 8 is disposed at a position avoiding a region facing the manifold 5 disposed on the lower surface side of the flow path member 4. Further, the discharge hole 8 is disposed in a region facing the piezoelectric actuator substrate 21 on the lower surface side of the flow path member 4. These discharge holes 8 occupy a region having almost the same shape as the piezoelectric actuator substrate 21 as one group, and a droplet is discharged from the discharge hole 8 by displacing the displacement element 30 of the corresponding piezoelectric actuator substrate 21. Can be discharged.

  The flow path member 4 included in the head main body 2a has a laminated structure in which a plurality of plates are laminated. In these plates, plates from the plate 4 a to the plate 4 o are laminated in order from the upper surface of the flow path member 4. A number of holes are formed in these plates. Since the thickness of each plate is about 10 to 300 μm, the hole formation accuracy can be increased. The thickness of the flow path member 4 is about 500 μm to 2 mm. Each plate is aligned and laminated so that these holes communicate with each other to form the individual flow path 12 and the manifold 5. In the head body 2a, the pressurizing chamber 10 is on the upper surface of the flow path member 4, the manifold 5 is on the inner lower surface side, and the discharge holes 8 are on the lower surface. The manifold 5 and the discharge hole 8 are connected via the pressurizing chamber 10.

  The following holes and grooves are used as the flow path. First, a pressurizing chamber 10 formed in the plate 4a. Secondly, there is a communication hole that forms a squeeze 6 that connects from one end of the pressurizing chamber 10 to the manifold 5. This communication hole is formed in each plate from the plate 4b (specifically, the inlet of the pressurizing chamber 10) to the plate 4d (specifically, the outlet of the manifold 5).

  Thirdly, the descender 7 is a partial flow path that constitutes a flow path that communicates with the discharge hole 8 from the other end opposite to the end to which the squeezing 6 of the pressurizing chamber 10 is connected. The descender 7 is formed on each plate from the plate 4b (specifically, the outlet of the pressurizing chamber 10) to the plate 4o (specifically, the discharge hole 8).

Fourthly, there is a communication hole constituting the sub-manifold 5a. This communication hole is formed in the plates 4e to 4j. Holes are formed in the plates 4e to 4j so that the partition portions to be the partition walls 15 remain so as to constitute the sub-manifold 5b. The partition part in each plate 4e-j is made into the state connected with each plate 4e-j by the support part which carried out the half etching. In addition, the support part is abbreviate | omitted in the figure.

  The first to fourth communication holes are connected to each other to form an individual flow path 12 from the liquid inflow port (outlet of the manifold 5) to the discharge hole 8 from the manifold 5. The liquid supplied to the manifold 5 is discharged from the discharge hole 8 through the following path. First, the manifold 5 reaches the one end of the aperture 6 upward. Next, it proceeds horizontally along the extending direction of the restriction 6 and reaches the other end of the restriction 6. From there, it reaches one end of the pressurizing chamber 10 upward. Furthermore, it progresses horizontally along the extending direction of the pressurizing chamber 10 and reaches the other end of the pressurizing chamber 10. The liquid that has entered the descender 7 from the pressurizing chamber 10 moves in the horizontal direction and is mainly directed downward and reaches the discharge hole 8 that is open on the lower surface, and is discharged to the outside.

  The hole or groove serving as the flow path further includes a flow path of the first peristaltic part 32 and a flow path of the second peristaltic part 34 connected to the descender 7.

The piezoelectric actuator substrate 21 has a laminated structure composed of two piezoelectric ceramic layers 21a and 21b which are piezoelectric bodies. Each of these piezoelectric ceramic layers 21a and 21b has a thickness of about 20 μm. The thickness from the lower surface of the piezoelectric ceramic layer 21a of the piezoelectric actuator substrate 21 to the upper surface of the piezoelectric ceramic layer 21b is about 40 μm. Both of the piezoelectric ceramic layers 21 a and 21 b extend so as to straddle the plurality of pressure chambers 10. The piezoelectric ceramic layers 21a, 21b may, for example, strength with a dielectric, lead zirconate titanate (PZT), NaNbO ₃ system, BaTiO ₃ system, (BiNa) NbO ₃ system, such as BiNaNb ₅ O ₁₅ system Made of ceramic material. The piezoelectric ceramic layer 21a functions as a vibration plate and does not necessarily have to be a piezoelectric body. Instead, other ceramic layers or metal plates that are not piezoelectric bodies may be used.

  The piezoelectric actuator substrate 21 includes a common electrode 24 made of a metal material such as Ag—Pd and an individual electrode 25 made of a metal material such as Au. The common electrode 24 has a thickness of about 2 μm, and the individual electrode 25 has a thickness of about 1 μm.

  The individual electrodes 25 are respectively arranged at positions facing the pressurizing chambers 10 on the upper surface of the piezoelectric actuator substrate 21. The individual electrode 25 has a planar shape slightly smaller than that of the pressurizing chamber main body 10a and has a shape substantially similar to the pressurizing chamber main body 10a, and an extraction electrode drawn from the individual electrode main body 25a. 25b. A connection electrode 26 is disposed at a portion of one end of the extraction electrode 25 b that is extracted outside the region facing the pressurizing chamber 10. The connection electrode 26 is a conductive resin containing conductive particles such as silver particles, and is formed with a thickness of about 5 to 200 μm. Further, the connection electrode 26 is electrically joined to an electrode provided in the signal transmission unit 60.

  Although details will be described later, a drive signal is supplied from the control unit 88 to the individual electrode 25 through the signal transmission unit 60. The drive signal is supplied in a constant cycle in synchronization with the conveyance speed of the print medium P.

The common electrode 24 is formed over substantially the entire surface in the region between the piezoelectric ceramic layer 21b and the piezoelectric ceramic layer 21a. That is, the common electrode 24 extends so as to cover all the pressurizing chambers 10 in the region facing the piezoelectric actuator substrate 21. The common electrode 24 is connected to the common electrode surface electrode 28 formed on the piezoelectric ceramic layer 21b so as to avoid the electrode group composed of the individual electrodes 44 via a through conductor formed through the piezoelectric ceramic layer 21b. It is connected. Further, the common electrode 24 is grounded via the common electrode surface electricity 28 and is held at the ground potential. Similar to the individual electrode 25, the common electrode surface electrode 28 is directly or indirectly connected to the control unit 88.

  A portion sandwiched between the individual electrode 25 and the common electrode 24 of the piezoelectric ceramic layer 21b is polarized in the thickness direction, and becomes a displacement element 30 having a unimorph structure that is displaced when a voltage is applied to the individual electrode 25. Yes. More specifically, when an electric field is applied in the polarization direction to the piezoelectric ceramic layer 21b by setting the individual electrode 25 to a potential different from that of the common electrode 24, an active portion where the applied electric field is distorted by the piezoelectric effect. Work as. In this configuration, when the control unit 88 sets the individual electrode 25 to a predetermined positive or negative potential with respect to the common electrode 24 so that the electric field and the polarization are in the same direction, the portion sandwiched between the electrodes of the piezoelectric ceramic layer 21b. (Active part) contracts in the surface direction. On the other hand, the piezoelectric ceramic layer 21a, which is an inactive layer, is not affected by an electric field, so that it does not spontaneously shrink and tries to restrict deformation of the active portion. As a result, there is a difference in strain in the polarization direction between the piezoelectric ceramic layer 21a and the piezoelectric ceramic layer 21b, and the piezoelectric ceramic layer 21a is deformed so as to be convex toward the pressurizing chamber 10 (unimorph deformation).

  Next, the liquid discharge operation will be described. The displacement element 30 is driven (displaced) by a drive signal supplied to the individual electrode 25 through a driver IC or the like under the control of the control unit 88. In the present embodiment, liquid can be ejected by various driving signals. Here, a so-called strike driving method will be described.

  The individual electrode 25 is set to a potential higher than the common electrode 24 (hereinafter referred to as a high potential) in advance, and the individual electrode 25 is once set to the same potential as the common electrode 24 (hereinafter referred to as a low potential) each time there is a discharge request, and then a predetermined potential is set. At this timing, the potential is set again. Thereby, the piezoelectric ceramic layers 21a and 21b return to the original (flat) shape at the timing when the individual electrode 25 becomes low potential (beginning), and the volume of the pressurizing chamber 10 is in an initial state (the potentials of both electrodes are different). Increase compared to the state). As a result, a negative pressure is applied to the liquid in the pressurizing chamber 10. Then, the liquid in the pressurizing chamber 10 starts to vibrate with the natural vibration period. Specifically, first, the volume of the pressurizing chamber 10 begins to increase, and the negative pressure gradually decreases. Next, the volume of the pressurizing chamber 10 becomes maximum and the pressure becomes almost zero. Next, the volume of the pressurizing chamber 10 begins to decrease, and the pressure increases. Thereafter, the individual electrode 25 is set to a high potential at a timing at which the pressure becomes substantially maximum. Then, the first applied vibration overlaps with the next applied vibration, and a larger pressure is applied to the liquid. This pressure propagates through the descender 7 to discharge the liquid from the discharge hole 8.

In other words, a droplet can be ejected by supplying a pulse driving signal that is a low potential for a certain period with the high potential as a reference to the individual electrode 25. If this pulse width is AL (Acoustic Length), which is half the time of the natural vibration period of the liquid in the pressurizing chamber 10, in principle, the discharge speed and discharge amount of the liquid can be maximized. The natural vibration period of the liquid in the pressurizing chamber 10 is greatly affected by the physical properties of the liquid and the shape of the pressurizing chamber 10, but besides that, the physical properties of the piezoelectric actuator substrate 21 and the flow path connected to the pressurizing chamber 10 Also affected by the characteristics of.

  Note that the pulse width is actually set to a value of about 0.5 AL to 1.5 AL because there are other factors to consider, such as combining the ejected droplets into one. Further, since the discharge amount can be reduced by setting the pulse width to a value outside of AL, the pulse width is set to a value outside of AL in order to reduce the discharge amount.

In the head main body 2a of this embodiment, each descender 7 is connected to a first swing part 32 and a second swing part 34, respectively. The first peristaltic part 32 is connected to the first peristaltic flow path 32 a connected to the descender 7, the first liquid chamber 32 b connected to the first peristaltic flow path 32 a, and the first connected to the outside of the flow path member 4. The flow path 33 and the 1st diaphragm 32c which one side faces the 1st liquid chamber 32b and the other surface faces the 1st flow path 33 are included. Second peristaltic part 34
The second peristaltic flow path 34a connected to the descender 7, the second liquid chamber 34b connected to the second peristaltic flow path 34a, the second flow path 35 connected to the outside of the flow path member 4, One surface faces the second liquid chamber 34 b and the other surface includes the second diaphragm 34 c facing the second flow path 35.

  The 1st flow path 33 is connected with the opening 33a opened to the pressurization surface 4-2 of the flow path member 4, and a pressure is applied from the outside. The 2nd flow path 35 is connected with the opening 35a opened to the pressurization surface 4-2 of the flow path member 4, and a pressure is applied from the outside. The first flow path 33 and the second flow path 35 are not connected, and different values of pressure are applied. The first flow path 33 and the second flow path 35 are basically filled with a gas such as air, and pressure is applied via the gas. Although liquid may be used without using gas, the flow resistance of the first flow path 33 becomes smaller when gas is used, so that the difference in pressure applied to each first liquid chamber 32b can be reduced. In addition, since the flow path resistance of the second flow path 35 is reduced, the difference in pressure applied to each second liquid chamber 34b can be reduced. In addition, when liquid is used, bubbles may remain in a part of the first flow path 33 and the second flow path 35, or bubbles may be generated from the liquid used. When such bubbles are present, pressure may be difficult to be transmitted to a part of the bubbles, but such a thing can be made difficult to occur by using gas.

  If a pressure larger than the liquid near the descender 7 is applied to the first flow path 33, the first diaphragm 32c is bent toward the first liquid chamber 32b, and the liquid is sent to the descender 7 through the first peristaltic flow path 32a. . When a pressure smaller than the liquid near the descender 7 is applied to the first flow path 33, the first diaphragm 32c bends toward the first flow path 33, and the liquid in the descender 7 is drawn into the first peristaltic flow path 32a. Similarly, applying a pressure to the second flow path 35 causes a liquid flow between the descender 7 and the second peristaltic flow path 34a. In addition, the case where a negative pressure is applied is also included in applying the pressure said here. Regarding the pressure applied to the first flow path 33 and the second flow path 35, a pressure higher than the pressure of the liquid in the descender 7 is referred to as a positive pressure, and a smaller pressure is referred to as a negative pressure.

  By peristating the liquid in the vicinity of the discharge hole 8, the constituent components contained in the liquid are fixed, or the liquid having a high viscosity stays in a state where it is difficult to be discharged (hereinafter, these states are generically named). May be fixed). Compared with the case where it is stationary, peristalsis is applied, and the moving liquid is less likely to stick. Although it is conceivable to increase peristalsis in order to make sticking or the like less likely to occur, if the absolute value of the pressure applied to the descender 7 is increased, if the pressure is positive, the liquid may overflow from the discharge hole 8 and negative If the pressure is applied, the liquid may be drawn from the discharge hole 8 and external air may enter the flow path member 4.

  Therefore, two or more peristaltic parts that cause peristalsis are connected to the descender 7, and positive pressure is applied to one peristaltic part and negative pressure is applied to the other peristaltic part. By doing in this way, the flow amount of the liquid in the descender 7 can be increased while keeping the fluctuation of the pressure applied to the descender 7 small. When the amount of flow is increased, it is preferable that the ratio of the liquid component that has been lowered by drying approaches the original ratio because it is mixed with the surrounding liquid as compared with the case of simply adding peristalsis. Further, it is more preferable that the liquid flow in the descender 7 occurs in the vicinity of the discharge hole 8 because the liquid facing the discharge hole 8 can be easily replaced.

Three or more peristaltic portions may be connected, but if there are two, it is possible to apply a positive pressure and a negative pressure to each of them, and the space required for arrangement can be reduced, so it is preferable to connect two. . In the present embodiment, the two swinging portions of the first swinging portion 32 and the second swinging portion 34 are connected to the descender 7. The first peristaltic flow path 32a and the second peristaltic flow path 34a connected to the descender 7 have a flow path resistance larger than that of the nozzle portion where the cross-sectional area of the descender 7 on the discharge hole 8 side is small. ing. Thereby, the pressure at the time of discharge becomes difficult to escape to the 1st peristaltic flow path 32a and the 2nd peristaltic flow path 34a, and it becomes difficult to reduce the discharge amount and the discharge speed. The combined resistance of the first peristaltic flow path 32a and the second peristaltic flow path 34a combined is preferably larger than the flow resistance of the nozzle portion. Thereby, the pressure at the time of discharge becomes difficult to escape to the 1st peristaltic flow path 32a and the 2nd peristaltic flow path 34a, and it becomes difficult to reduce the discharge amount and the discharge speed. Even when three or more peristaltic parts are connected, the combined resistance of the peristaltic flow path connected to the descender 7 is preferably larger than the flow path resistance of the nozzle part. The channel resistance of each first peristaltic channel 32a is preferably the same within the range of manufacturing accuracy. The channel resistance of each second peristaltic channel 34a is preferably the same within the range of manufacturing accuracy. Further, if the flow resistance of the first peristaltic flow path 32a and the flow resistance of the second peristaltic flow path 34a are set to be substantially the same, the pressure applied to the first flow path 33 and the second flow path 35 is an absolute value. Are substantially the same, the pressure can be reversed between positive and negative, and the pressure applied to the descender 7 can be reduced, so that the control can be simplified.

  At least one of the first peristaltic channel 32 a and the second peristaltic channel 34 a is preferably connected to a position closer to the discharge hole 8 than the pressurizing chamber 10 in the descender 7. If so, it is possible to perturb the liquid at a position close to the discharge hole 8. At least one of the first peristaltic flow path 32a and the second peristaltic flow path 34a is preferably connected from the discharge hole 8 to a position that is 1/4 or less of the length of the descender 7, and is at a position that is 1/8 or less. It is more preferable that they are connected. Moreover, it is preferable that both the first peristaltic channel 32 a and the second peristaltic channel 34 a are connected at a position close to the discharge hole 8. It is particularly preferable that the openings of both the first peristaltic flow path 32a and the second peristaltic flow path 34a are arranged facing the plate 4o where the discharge holes 8 are open.

  When the flow path member 4 is viewed in plan, the first connection part where the descender 7 and the first peristaltic flow path 32a are connected is the second connection part where the descender 7 and the second peristaltic flow path 34a are connected. On the other hand, it is preferably arranged on the opposite side of the descender 7. Specifically, the angle formed by the line connecting the discharge hole 8 and the first connection part and the line connecting the discharge hole 8 and the second connection part is preferably 120 degrees or more, and 150 degrees The above is more preferable. With such an arrangement, the liquid located on the discharge hole 8 can be easily perturbed, and the liquid located on the discharge hole 8 can be easily replaced.

  Since the first liquid chamber 32b is wider than the first peristaltic flow path 32a, the first diaphragm 32c is easily bent. Each descender 7 is connected to a first peristaltic channel 32a, but a plurality of first peristaltic channels 32a may be connected to the first liquid chamber 32b. If the first liquid chamber 32b is connected to the plurality of first peristaltic channels 32a, the deformation amount of the first diaphragm 32c can be increased even if the pressure applied to the first channel 33 is the same. The amount of liquid flowing in each first peristaltic flow channel 32a is an amount divided into the connected first peristaltic flow channels 32a, but can be larger than providing the first liquid chamber 32b individually.

  Since the flow resistance of the first peristaltic flow path 32a is high, the discharge pressure is hardly transmitted to the first liquid chamber 32b, but a part of the pressure is transmitted. If the first liquid chamber 32b is provided in each first peristaltic flow path 32a, the discharge pressure is transmitted and fluid crosstalk in which the discharge characteristics fluctuate can be suppressed. However, if the first liquid chamber 32b is a substantially closed space connected to only one first peristaltic channel 32a, it is difficult to introduce liquid into the first peristaltic channel 32a.

Therefore, adjacent first liquid chambers 32b are connected by a first connection flow path 32d having a flow path resistance higher than that of the first liquid chamber 32b. Since the flow resistance of the first connection flow path 32d is high, fluid crosstalk can be suppressed, and the liquid can be easily introduced by being connected by the first connection flow path 32d. The first liquid chamber 32b connected via the first connection channel 32d is further connected to the sub-manifold 5b and the like to introduce liquid. In the present embodiment, the flow path connected to the first liquid chamber 32b is connected to the manifold 5 through the opening 36 (see FIG. 3). Since the opening 36 is disposed outside the range in the manifold 5 where the pressurizing chamber 10 is connected, fluid crosstalk due to the pressure transmitted from the opening 36 to the manifold 5 can hardly occur.

  The same applies to the second liquid chamber 34b connected to the second peristaltic channel 34a. The opening 36 is also connected to the second liquid chamber 32b, and introduces liquid into the second liquid chamber 32b.

  The first liquid chamber 32b has a hexagonal planar shape (see FIG. 5), and the first diaphragm 32c has a similar hexagonal shape. The plurality of first diaphragms 32 c face the first flow path 33. The first flow paths 33 in the flow path member 4 are all connected, and are connected to the outside of the flow path member 4 through the openings 33a. Similarly, the second liquid chamber 34b has a hexagonal shape in plan view (see FIG. 5), and the second diaphragm 34c has a similar hexagonal shape. The plurality of second diaphragms 34 c face the second flow path 35. The second flow paths 35 in the flow path member 4 are all connected, and are connected to the outside of the flow path member 4 through the opening 35a.

  It is possible to extend the first peristaltic flow path 32a and the second peristaltic flow path 34a connected to the descender 7 and apply peristalsis through the liquid from the outside of the flow path member 4, but such a flow path is Since the cross section is narrow, it is necessary to increase the applied pressure, and the liquid discharge head 2 may be damaged by the internal pressure. Moreover, since the pressure applied from the outside has a pressure loss, it is difficult to apply the same pressure to each descender 7. The first peristaltic part 32 and the second peristaltic part 34 are arranged in the vicinity of each descender 7 and the pressure is supplied to each peristaltic part by gas, so that the difference between the positive pressure and the negative pressure applied to each descender 7 is reduced. The pressure applied to the first flow path 33 and the second flow path 35 can be reduced.

  The planar shape of the first flow path 33 is a shape in which one side of the first liquid chamber 32b having a hexagonal shape is connected, and extends in the longitudinal direction of the head body 2a. Each first flow path 33 extends to a region where the pressurizing chamber 10 is not disposed, and is connected to the right side of the illustrated portion of FIG. 7 and the upper side of FIG. The flow path to which each first flow path 33 is connected is directed to the inside of the flow path member 4 toward the pressurizing chamber surface 4-2 and is connected to the outside through an opening 33a. Each first flow path 33 may be connected or may not be connected on the left side of the illustrated portion of FIG. 7 and on the lower side of FIG.

  The planar shape of the second flow path 35 is a shape in which one side of the second liquid chamber 34b having a hexagonal shape is connected to each other, and extends in the longitudinal direction of the head body 2a. Each of the second flow paths 35 extends to a region where the pressurizing chamber 10 is not disposed, and is all connected on the left side and the lower side of FIG. The flow path connected to each second flow path 35 is directed to the inside of the flow path member 4 toward the pressurizing chamber surface 4-2 and is connected to the outside through the opening 35a. Each second flow path 35 may or may not be connected on the right side of the illustrated portion of FIG. 7 and on the upper side of FIG.

Since the first swinging portion 32 and the second swinging portion 34 are preferably connected to the descender 7 in the vicinity of the discharge hole 8, the first swinging portion 32 and the second swinging portion 34 overlap with the manifold 5 in order to arrange the flow member 4 with high space efficiency. It is preferable to arrange in the. Moreover, since it is preferable to arrange | position the 1st swing part 32 and the 2nd swing part 34 near the discharge hole 8 of the descender 7, the 1st swing part 32 and the 2nd swing part 34 are the discharge hole surfaces of the manifold 5. It is preferable to arrange on the 4-1 side. With such an arrangement, a part of the first flow path 33 and the second flow path 35 overlaps the manifold 5. When pressure is applied to the first flow path 33 and the second flow path 35, a part of the pressure may be transmitted to the manifold 5, but one manifold 5 (one sub-manifold 5b in this embodiment) If both the first flow path 33 and the second flow path 35 are arranged so as to overlap each other, a positive and negative pressure is basically applied to them to cancel each other, so that the pressure transmitted to the manifold 5 can be reduced.

  Further, by arranging the damper chamber 19 that is a gap between the manifold 5 and the first flow path 33 and the second flow path 35, the pressure transmitted to the manifold 5 can be reduced. Further, the total thickness of the solid portions of the plates disposed between the first flow path 33 and the second flow path 35 and the manifold 5 is made thicker than the thicknesses of the first diaphragm 32c and the second diaphragm 34c. As a result, pressure can be easily applied to the first liquid chamber 32b and the second liquid chamber 34b, and the pressure transmitted to the manifold 5 can be reduced.

  The sub-manifold 5b depicted on the upper side of FIG. 5 is the sub-manifold 5b located at the end. Therefore, only one discharge hole row 9 is arranged on the sub-manifold 5b in FIG. 5, and the descender 7 is also arranged for only one row. In each partition wall 15, two discharge hole rows 9 are arranged, and the corresponding descenders 7 are also arranged in two rows. That is, the design of the periphery of the sub manifold 5b located at the end is different from that of the other sub manifold 5b.

  Therefore, the dummy first liquid chamber 32b1, the dummy second liquid chamber 32b1, and the dummy first liquid chamber 32b1 and the dummy second liquid chamber 32b1 are connected to the periphery of the sub manifold 5b located at the end. A dummy peristaltic part including the dummy peristaltic flow path 32a1 is disposed. The dummy peristaltic flow path 32 a 1 is not connected to the descender 7. The dummy first liquid chamber 32b1 is connected to the adjacent first liquid chamber 32b, and the dummy second liquid chamber 34b1 is connected to the adjacent second liquid chamber 34b. Thereby, the liquid can be smoothly introduced into the first liquid chamber 32b and the second liquid chamber 34b. The dummy first liquid chamber 32b1 and the dummy second liquid chamber 34b1 are arranged to have the same arrangement as the surrounding first liquid chamber 32b and second liquid chamber 32b. As a result, the structure around the sub-manifold 5b located at the end is close to the structure around the other sub-manifold 5b, and it is difficult to cause fluctuations in discharge characteristics due to differences in rigidity.

  The dummy first liquid chamber 32b1 is adapted to receive pressure from the first flow path 33 via the first diaphragm 32c, and the dummy second liquid chamber 34b1 is configured to receive the second flow path 35 via the second diaphragm 34c. It comes to receive pressure from. Thus, the pressure applied to the first liquid chamber 32b and the second liquid chamber 34b located around the dummy first liquid chamber 32b1 and the dummy second liquid chamber 34b1, and the first liquid chamber 32b and the second liquid chamber at the other positions. The difference from the pressure applied to the liquid chamber 34b can be reduced. If the dummy first liquid chamber 32b1 and the dummy second liquid chamber 32b1 are connected by the dummy peristaltic flow path 32a1, since the peristalsis actually occurs in the dummy peristaltic flow path 32a1, the above-described pressure difference can be further reduced. .

  In addition, the dummy first liquid chamber 32b1 and the dummy second liquid chamber 32b1 are disposed, and the first flow path 33 and the second flow path 35 are disposed so as to face them, so that the sub-liquid disposed at the end is disposed. Also in the manifold 5b, the balance between the pressure of the first flow path 33 and the pressure of the second flow path 35 is improved, and the pressure applied to the sub-manifold 5b can be further reduced.

  If the pressure applied to the first peristaltic part 32 and the pressure applied to the second peristaltic part 34 are the same in absolute value and opposite in positive and negative with respect to the pressure of the liquid in the descender 7, the descender 7 Substantial pressure applied can be reduced. However, a flow is generated in the descender 7 by the peristaltic movement, so that the pressure in the descender 7 is slightly reduced. In order to suppress this, the absolute value of the positive pressure may be made larger than the absolute value of the negative pressure.

Next, introduction of liquid and peristalsis during printing will be described. The liquid is introduced from the opening 5a of the head body 2a. The liquid that has entered from the opening 5 a enters the manifold 5. A portion of the liquid that has entered the manifold 5 passes through the opening 36 and enters the first liquid chamber 32b and the second liquid chamber 34b. The liquid that has entered the first liquid chamber 32b and the second liquid chamber 34b enters the descender 7 through the first peristaltic flow path 32a and the second peristaltic flow path 34a, is discharged from the discharge hole 8, and is discharged to the first peristaltic part. The liquid can be introduced into the 32 and the second peristaltic part 34.

  The peristaltic movement may be performed when printing itself is stopped. Further, the peristaltic movement may be performed between discharges during printing. Since the positive and negative pressures are applied to the first peristaltic part 32 and the second peristaltic part 34, the pressure fluctuation in the descender 7 can be reduced, so that it is difficult to affect the next discharge.

  The peristaltic movement is performed by the controller 88 controlling the air pump provided in the printer 1 and applying pressure to the first flow path 33 and the second flow path 35. The control unit 88 applies a positive pressure to one of the first peristaltic unit 32 and the second peristaltic unit 34 and applies a negative pressure to the other one time to apply peristalsis. The controller 88 may apply the peristalsis a plurality of times by repeatedly reversing the positive and negative pressures applied to the first peristaltic part 32 and the second peristaltic part 34.

DESCRIPTION OF SYMBOLS 1 ... Color inkjet printer 2 ... Liquid discharge head 2a ... Head main body 4 ... Flow path member 4a-o ... (flow path member) plate 4-1 ... Discharge hole surface 4 -2 ... Pressurizing chamber surface 5 ... Manifold 5a ... (manifold) opening 5b ... Sub-manifold (common flow path)
6 ... Shibori 7 ... Descender (partial flow path)
8 ... Discharge hole 9 ... Discharge hole row 10 ... Pressure chamber 11 ... Pressure chamber row 12 ... Individual flow path 15 ... Partition wall 16 ... Dummy pressurization chamber 18. ..Damper 19 ... Damper chamber 21 ... Piezoelectric actuator substrate 21a ... Piezoelectric ceramic layer (vibrating plate)
21b ... Piezoelectric ceramic layer 24 ... Common electrode 25 ... Individual electrode 25a ... Individual electrode body 25b ... Extraction electrode 26 ... Connection electrode 28 ... Surface electrode for common electrode 30 ... Displacement element 32: first peristaltic part 32a: first peristaltic flow path 32a1: dummy peristaltic flow path 32b: first liquid chamber 32b1: dummy first liquid chamber 32c: first 1 diaphragm 32d ... 1st connection channel 33 ... 1st channel 33a ... (connected to the 1st channel) opening 34 ... 2nd peristaltic part 34a ... 2nd peristaltic flow Path 34b ... second liquid chamber 34b1 ... dummy second liquid chamber 34c ... second diaphragm 34d ... second connection channel 35 ... second channel 35a ... (second flow) Opening 36 (connected to the road) (connected to the first and second liquid chambers) Opening 60 ... Signal transmission unit 70 ... Head mounting frame 72 ... Head group 80A ... Feeding roller 80B ... Recovery roller 82A ... Guide roller 82B ... Conveying roller 88 ... Control part P ... Printing paper

Claims (6)

A plurality of discharge holes, a plurality of pressurizing chambers, a flow path member having a plurality of partial flow channels respectively connecting the plurality of discharge holes and the plurality of pressurizing chambers, and the plurality of pressurizing chambers are respectively added. A liquid discharge head including a plurality of pressurizing units for pressing,
The channel member is connected to a plurality of first peristaltic channels connected to the plurality of partial channels, a first liquid chamber connected to the first peristaltic channel, and the outside of the channel member. A first flow path, a first diaphragm with one surface facing the first liquid chamber and a second surface facing the first flow path, and a plurality connected to the plurality of partial flow paths, respectively. The second peristaltic channel, the second fluid chamber connected to the second peristaltic channel, the second fluid channel connected to the outside of the channel member, and one surface facing the second fluid chamber. And a second diaphragm whose other surface faces the second flow path. When the flow path member is viewed in plan view,
The connecting portion between the first peristaltic channel and the partial channel is disposed on the opposite side of the partial channel with respect to the connecting portion between the second peristaltic channel and the partial channel. The liquid discharge head according to claim 1, wherein:   At least one of the connection portion between the first peristaltic flow channel and the partial flow channel and the connection portion between the second peristaltic flow channel and the partial flow channel is more than the pressurizing chamber in the partial flow channel. The liquid discharge head according to claim 1, wherein the liquid discharge head is disposed near the discharge hole. The flow path member further includes a common flow path connected to the plurality of pressure chambers,
The liquid discharge head according to claim 1, wherein a gap is disposed in the flow path member between the common flow path and the first flow path.   5. A liquid discharge head according to claim 1, a transport unit that transports a recording medium to the liquid discharge head, and a control unit that controls the liquid discharge head. Recording device.   The control unit applies a pressure larger than the pressure of the partial flow channel to one of the first flow channel and the second flow channel, and applies a pressure smaller than the pressure of the partial flow channel to the other. The recording apparatus according to claim 5.

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