JP6571474B2 - Channel member, liquid discharge head using the same, and recording apparatus - Google Patents

Description

  The present invention relates to a flow path member, a liquid ejection head using the same, and a recording apparatus.

  Conventionally, as a liquid ejection head, for example, an inkjet head that performs various types of printing by ejecting a liquid onto a recording medium is known. As a flow path member having a discharge hole, a pressurizing chamber, and a common flow path used in a liquid discharge head, a member in which a plurality of metal plates each having a hole or groove to be a flow path are stacked is known. . These metal plates are joined with an adhesive. In the metal plate, an adhesive relief groove is formed in order to prevent the adhesive from flowing into the hole or groove during bonding (see, for example, Patent Document 1).

JP 2006-187967 A

  The plate in which the adhesive relief groove described in Patent Document 1 is formed has an adhesive relief groove, and the portion is thin, so that it can be bonded by handling during the manufacturing process. There was a case of bending along the escape groove of the agent. In particular, it was easy to bend due to the adhesive relief grooves being connected throughout the entire width of the plate.

  Even if extremely bent parts are removed during the manufacturing process, the use of a slightly deformed plate may slightly change the flow path structure and change the liquid ejection characteristics. .

  Accordingly, an object of the present invention is to provide a flow path member using a plate that is difficult to deform, a liquid discharge head using the plate member, and a recording apparatus.

  The flow path member of the present invention is a flow path having a plate in which holes or grooves are disposed, and another member bonded to one main surface of the plate via an adhesive layer. An adhesive relief groove and a rectangular adhesive allowance block around which the escape groove is arranged, and is disposed on the principal surface of the plate. The adhesive margin block and the release groove for the adhesive extending in the second direction that intersects the first direction are alternately arranged from one end of the first direction to the other end. Adhesive block blocks arranged side by side are disposed, and the adhesive is disposed corresponding to each of the bond block blocks belonging to the bond block block row and extends along the first direction. The side adhesive relief groove is the front relief groove. Wherein the not arranged linearly connected from one end of the first direction of the plate to the other end.

In addition, the flow path member of the present invention includes a plate in which holes or grooves are disposed and serves as a flow path, and another member bonded to one main surface of the plate via an adhesive layer. A plurality of flow path members extending in a first direction which is a direction intersecting the second direction and a relief groove for a second adhesive extending in the second direction on the main surface of the plate. A comb-like adhesive relief groove including the first adhesive relief groove, and the first adhesive relief groove of the one comb-like adhesive relief groove and the other. The comb-like adhesive relief grooves of the first adhesive are arranged opposite to each other and are arranged at different positions in the second direction.

  The liquid discharge head of the present invention is a liquid discharge head including the flow path member and a plurality of pressure units, and the flow path member has a plurality of discharge holes connected to the flow path. The plurality of pressurizing sections discharge the liquid from the plurality of discharge holes by pressurizing the liquid in the flow path.

  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 flow path member of the present invention, deformation does not easily occur in the manufacturing process, and when used in a liquid discharge head, variations in liquid discharge characteristics can be reduced.

(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 A surrounded by an alternate long and short dash line in FIG. FIG. 3 is an enlarged view of a region A surrounded by an alternate long and short dash line in FIG. It is a longitudinal cross-sectional view along the VV line of FIG. FIG. 3 is an enlarged view of one region B surrounded by a one-dot chain line in FIG. 2. (A)-(c) is arrangement | positioning of the escape groove | channel which concerns on other embodiment of this invention. It is arrangement | positioning of the escape groove | channel which concerns on other embodiment of this invention.

  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 directly transport the transport belt 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. In the case of giving, 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 a longitudinal sectional view taken along line VV in FIG. In FIGS. 3 and 4, for easy understanding of the drawings, the pressurizing chamber 10, the squeezing 6, the discharge holes 8, and the like that are to be drawn by broken lines below the piezoelectric actuator substrate 21 are drawn by solid lines.

  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.

  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.

  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 (rigidity) around the pressurizing chamber 10 one inner side from the end is close to the structure (rigidity) of the other pressurizing chambers 10, so that the difference in liquid ejection characteristics can be reduced. Less. 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. 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 with an adhesive layer 18 interposed therebetween. These plates are a cavity plate 4a, an aperture plate 4b, a supply plate 4c, manifold plates 4d to i, a cover plate 4j, and a nozzle plate 4l 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 hole and groove | channel arrange | positioned at each plate are demonstrated. These holes and grooves include a liquid flow path, and an adhesive escape groove 17 around the hole or groove or other disposed adhesive. The escape groove 17 will be described later.

  The following holes and grooves are used as the flow path. The first is the pressurizing chamber 10 formed in the cavity 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 aperture plate 4b (specifically, the inlet of the pressurizing chamber 10) to the supply plate 4c (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 base plate 4b (specifically, the outlet of the pressurizing chamber 10) to the nozzle plate 4l (specifically, the discharge hole 8).

Fourthly, there is a communication hole constituting the sub-manifold 5a. The communication holes are formed in the manifold plates 4c to i. Holes are formed in the manifold plates 4c to i 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 manifold plate 4c-i is connected to each manifold plate 4c-i by a half-etched support part (not shown 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 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.

  When the plates 4a to 1l are stacked via the adhesive layer 18, if the amount of the adhesive does not reach the entire surface between the plates 4a to 4l, an unbonded portion is generated. When pressure is applied for bonding in a state where the adhesive is spread over the entire surface between the plates 4a to 4l, a part of the adhesive flows into the flow path. In addition, if there is a variation in the amount of adhesive applied depending on the location, the variation in the amount applied will directly change in the thickness of the adhesive layer, resulting in fluctuations in ejection characteristics, or in areas where the amount of adhesive applied is small. It was difficult to apply pressure, and adhesion could not be achieved or adhesion could be weakened.

Therefore, an adhesive escape groove 17 is disposed around the hole and groove serving as the flow path and in other portions. The relief groove 17 is basically a groove formed in the plates 4a to 4k, and the plates 4a to 4
It is formed by half-etching k. However, the escape groove 17 may be formed through the plates 4a to 4k, and such a groove is also referred to as the escape groove 17.

  The escape groove 17 has the following two types. However, some are included in both. First, it is arranged around a hole or groove serving as a flow path. Their main role is to make it difficult for the overflowing adhesive to flow into the holes and grooves that form the flow paths.

  Secondly, it is arranged at a place where there are not so many holes and grooves to be flow paths. Such a place exists between the groups in which the holes and grooves that form the individual flow paths 12 from the discharge holes 8 to the squeeze 6 are solidly arranged, or outside some of these groups. The peripheral edge portions of the plates 4a to 4k, particularly both end portions in the longitudinal direction of the plates 4a to k, are places corresponding to such conditions.

  The escape groove 17 arranged in such a place has the following role. If the adhesive is applied locally thickly, even if the adhesive flows at the lamination pressure, the flow is not sufficient, and the adhesive layer becomes locally thicker, or it is difficult to apply pressure around it. ， Cannot be bonded or bond may be weak. In such a case, when the escape groove 17 is disposed, excess adhesive flows into the escape groove, and it is difficult for the adhesive layer to be locally thickened, and it is also difficult for adhesion to weaken around the adhesive layer. .

  In addition, bubbles may be caught in the adhesive layer when laminating. If holes and grooves that serve as flow paths are arranged around, bubbles may be discharged to the outside through them, or compressed and confined in holes and grooves that serve as flow paths. If there are no or few holes or grooves in the periphery, it may remain in the adhesive layer and the part may not be bonded. If the escape groove 17 is arranged in such a place, the air bubbles are compressed and confined in the escape groove 17 and hardly remain in the adhesive layer. In order to enhance such an effect, the escape groove 17 is directly connected to the outside of the flow path member 4 or the flow path member via holes or grooves disposed in the other plates 4a to 4l. 4 may be connected to the outside.

  The holes and grooves constituting the sub-manifold 5a and the individual flow path 12, which are liquid flow paths, are formed by etching the plates 4a to 4l. In FIG. 5, the details of the shape generated by the etching are omitted. In FIG. 5, the adhesive layer is also omitted. The holes penetrating the plates 4a to 1l are formed by etching the plates 4a to 1l from both sides. In those holes, the dimension near the center of the thickness of the plates 4a to l is narrower than the dimension of the opening. The grooves having a half depth of the plates 4a to 1l are formed by half-etching the plates 4a to 1l from one side. In these grooves, the dimension near the bottom of the groove is narrower than the dimension of the opening.

  A through hole formed in the plate 4k and having one opening serving as the discharge hole 8 is opened by punching.

  FIG. 6 is a plan view of one end portion in the second direction, which is the longitudinal direction of the plate 4c. On the left side of the figure, two holes to be the manifold 5 are opened. The holes and grooves to be the individual flow paths 12 are arranged at positions not drawn on the left side of the drawing, and the holes and grooves to be the individual flow paths 12 are arranged in FIG. There is no area. The other end of the plate 4c in the second direction has a structure in which FIG. 6 is reversed left and right.

  In the plate 4c, escape grooves 17 are arranged along a second direction and a first direction that is a direction intersecting the second direction. The angle formed by the first direction and the second direction is within 90 ± 30 degrees, and further within 90 ± 15 degrees, and is substantially perpendicular.

  Further, a through hole 19 is disposed in the plate 4c. The through holes 19 are arranged at the same position in the plates 4a to 4l and are connected to the escape grooves 17 respectively. A part of the air that has been sandwiched between the plates 4 a to 1 l when being stacked can be transmitted from the escape groove 17 to the through hole 19 and escape to the outside of the flow path member 4. The escape groove 17 may be arranged so as to be connected to the outer side of the plate 4 c, and may be configured to escape directly to the outside through the escape groove 17.

  From the viewpoint of air entrainment and averaging of the thickness of the adhesive layer, it is desirable to increase the number of escape grooves 17, but since the area of the bonding allowance actually bonded decreases as the number of escape grooves 17 increases, the bonding itself is become weak. If the adhesion at the peripheral edge of the plates 4a to 4l is weak, it tends to be a starting point where the adhesion starts to peel off. In addition, since a large number of holes and grooves serving as flow paths are arranged in the central region of the plates 4a to 4l and the bonding becomes relatively weak, it is necessary to firmly bond the peripheral edges of the plates 4a to 1l. In particular, at the end in the second direction, which is the longitudinal direction of the plates 4a to l, since external stress and impact are easily applied, it is necessary to bond more firmly.

  Therefore, a rectangular bonding allowance block 18 is provided as an adhering allowance, and a relief groove 17 is arranged around the block. An adhesive allowance block row 18A in which the adhesive allowance blocks 18 and the escape grooves 17 are alternately arranged is provided from one end in the first direction, which is the short direction of the plate 4c, to the other end. Thereby, a structure in which the bonding allowance block 18 is continuous from one end portion to the other end portion in the first direction can be formed, and the adhesion can be strengthened. In FIG. 6, the bonding allowance block row 18 </ b> A is a portion shaded by a wavy line. The bonding allowance block row 18A shaded by a wavy line is an example of a large number of bonding allowance block rows 18A.

  Of the relief grooves 17 surrounding the periphery of each bonding allowance block 18, the relief groove 17 extending in the first direction is referred to as a side relief groove 17a. A pair of side relief grooves 17a exist in each bonding margin block 18, and there are two side clearance grooves 17a. Further, the side relief groove 17a of the bonding margin block 18 belonging to the bonding margin block row 18A is not linearly connected from one end portion to the other end portion in the first direction. Thereby, the relief groove 17 extending in the first direction located in the second direction with respect to the bonding allowance block row 18A can be hardly bent.

  In the hatched adhesive margin block row 18A in FIG. 6, both the side relief groove 17a located on the right side of the adhesion margin block row 18A and the side relief groove 17a located on the left side are one end in the first direction. Although it is not connected in a straight line from the other end to the other end, it is possible to make it difficult to bend only one of the portions. It is more preferable that both are not connected linearly from one end in the first direction to the other end.

  The side relief grooves 17a in FIG. 6 are not connected in the first direction by being arranged at different positions in the second direction. There are twelve 12 side relief grooves 17a on the right side of the hatched adhesive margin block row 18A in FIG. These twelve side relief grooves 17a are arranged at three positions in the second direction, two at the right position, four at the center position, and five at the left position. The total length of the side relief grooves 17 arranged at the same position in the second direction is the leftmost position, which is less than 5/11 of the length of the plate 4c in the first direction. It has become. Therefore, the total length of the side relief grooves 17a arranged at the same position in the second direction is less than half of the first direction of the plate 4c, and it is difficult to bend at that position.

  Since the plate 4c is longer in the second direction than the first direction, the plate 4c is easily bent in the middle of the second direction. Therefore, it is preferable that the bonding margin block row 18A is arranged so that the bonding margin blocks 18 are continuous in the first direction, and the side relief grooves 17a are not linearly connected in the first direction.

  Further, in the bonding margin block 18 adjacent in the first direction, the side relief groove 17a is arranged at a different position with respect to the second direction, so that it is more difficult to bend.

  In order to shorten the distance to reach the escape groove 17 and to relatively increase the area of the bonding margin, the bonding margin block 18 has a ratio of the length in the longitudinal direction to the length in the short direction of 3 or less, and further 2 The smaller one is preferable, and a square shape is particularly preferable.

  Then, the arrangement | positioning of the escape groove | channel 17 of other embodiment of this invention is demonstrated using Fig.7 (a)-(c). Parts with little difference are given the same reference numerals and description thereof is omitted.

  In FIG. 7A, a separation portion 20 exists between one end of the side escape groove 17 a in the first direction and the other escape groove 17. Due to the presence of the separation portion 20, the side relief groove 17a is not linearly connected from one end portion in the first direction to the other end portion, and is difficult to bend. In addition, you may provide the separation part 20 in the middle of the side escape groove 17a. That is, the side relief groove 17a may be separated into a plurality of parts by the separation part 20 and may be in an interrupted state.

  In FIGS. 7B and 7C, the side relief groove 17a is not connected due to the presence of the separating portion 20, and the side relief groove 17a is arranged at a different position in the second direction. Yes. By combining these, it becomes more difficult to bend.

  Next, the arrangement of the escape grooves 17 according to another embodiment of the present invention will be described with reference to FIG. FIG. 8 is a plan view of the same portion as FIG. The plate 104c is provided with a first escape groove 17b extending in the first direction, which is the short direction of the plate 104c, and a second escape groove 17c extending in the second direction, which is the longitudinal direction. The one first escape groove 17b and the plurality of second escape grooves 17c constitute a comb-like escape groove. There are a plurality of comb-like escape grooves, and the first escape groove 17b of one comb-like escape groove and the first escape groove 17b of the other comb-like escape groove face each other, They are arranged at different positions in the second direction. Thereby, the plate 104c is difficult to bend along the first escape groove 17b. When there is the first escape groove 17b arranged at the same position in the second direction, the total length thereof is not more than half of the length from one end to the other end in the first direction. By doing so, the plate 104c can be made more difficult to bend along the first escape groove 17b.

  If there is a portion D where the first adhesive relief groove 17b of one comb-like escape groove and the first relief groove 17b of the other comb-like escape groove overlap in the first direction, adhesion It is possible to make it easier for bubbles in the core to escape and reach the grooves 17 and prevent the bubbles from being caught in the adhesive layer.

  In the present embodiment, the flow path member 4 is configured by laminating and laminating a large number of plates 4a to 4k via an adhesive layer, but is not limited to such a form. For example, it is within the scope of the present invention that a single plate in which holes and grooves to be flow paths are formed is bonded to another member having a flow path by grinding through an adhesive layer.

DESCRIPTION OF SYMBOLS 1 ... Color inkjet printer 2 ... Liquid discharge head 2a ... Head main body 4 ... Flow path member 4a-1 ... (of flow path member) 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 17. ..Relief grooves (adhesive escape grooves)
17a: Side relief groove (side adhesive release groove)
17b... First relief groove (first adhesive relief groove)
17c ... second relief groove (second adhesive relief groove)
DESCRIPTION OF SYMBOLS 18 ... Adhesion allowance block 18A ... Adhesion allowance block row 19 ... Through-hole 20 ... Separation part 21 ... Piezoelectric actuator substrate 21a ... Piezoelectric ceramic layer (diaphragm)
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 60 ... Signal transmission unit 70 ... Head mounting frame 72 ... Head group 80A ... Paper feed roller 80B ... Collection roller 82A ... Guide roller 82B ... Conveying roller 88 ..Control unit P: Printing paper

Claims (13)

A flow path member having a plate in which holes or grooves are disposed, and another member bonded to one main surface of the plate via an adhesive layer, which serves as a flow path,
On the main surface of the plate, an adhesive relief groove and a rectangular adhesive allowance block around which the escape groove is arranged are arranged,
On the main surface of the plate, from one end to the other end in the first direction, the adhesive margin block and the adhesive extending in the second direction, which is a direction intersecting the first direction Adhesive allowance block rows are arranged with alternating escape grooves,
Side adhesive release grooves that are arranged corresponding to each of the adhesive allowance blocks belonging to the adhesive allowance block row and extend along the first direction are side adhesive release grooves. The plate is not arranged in a straight line from one end to the other end in the first direction ,
The side adhesive relief groove is not connected to another adhesive relief groove at least in one end of the first direction, or there is a portion that is interrupted in the first direction. A flow path member characterized by that.   Both of the pair of side adhesive relief grooves arranged corresponding to each of the adhesive allowance blocks belonging to the adhesive allowance block row are one end of the plate in the first direction. The flow path member according to claim 1, wherein the flow path member is not arranged in a straight line from the first end to the other end.   3. The flow path member according to claim 1, wherein escape grooves for the side adhesive are arranged at different positions in the second direction.   2. When the side adhesives arranged at the same position in the second direction are present, the side adhesives are not arranged connected to the first direction. The flow path member according to any one of?   The total length of the side adhesive relief grooves arranged at the same position in the second direction is not more than half of the length from one end portion to the other end portion in the first direction. The flow path member according to any one of claims 1 to 4. The plate, the size in the second direction, the flow path member according to any one of claims 1 to 5, wherein the greater than the magnitude of the first direction. The flow path member has a plurality of discharge holes and a plurality of individual flow paths respectively connected from the plurality of discharge holes.
In the plate, holes or grooves serving as the plurality of individual flow paths are arranged, and in the bonding margin block row, holes or grooves serving as the plurality of individual flow paths are not arranged. the flow path member according to any one of claims 1 to 6, characterized in that. The adhesion margins block column, flow path member according to claim 7, wherein the plurality of individual flow channels, characterized in that it is arranged in the second direction than all holes or grooves. A flow path member having a plate in which holes or grooves are disposed, and another member bonded to one main surface of the plate via an adhesive layer, which serves as a flow path,
A relief groove for a second adhesive extending in a second direction on the main surface of the plate, and a plurality of first adhesives extending in a first direction that intersects the second direction. Comb containing grooves and relief grooves for tooth-like adhesive are arranged,
The relief groove of the first adhesive in the relief groove of the one comb-tooth-shaped adhesive and the relief groove of the first adhesive in the relief groove of the other comb-tooth-like adhesive face each other. Are arranged at different positions in the second direction ,
The first adhesive relief groove of the one comb-like adhesive relief groove and the first adhesive relief groove of the other comb-like adhesive relief groove are the first A flow path member characterized by overlapping in a direction . The total length of the first adhesive relief grooves disposed at the same position in the second direction is less than half of the length from one end to the other end in the first direction. The flow path member according to claim 9 , wherein the flow path member is provided. The flow path member according to claim 9 or 10 , wherein the plate has a size in the second direction larger than a size in the first direction. A liquid discharge head and a flow path member and a plurality of the pressure according to any one of claims 1 to 11, wherein the flow path member, a plurality of discharge holes in communication with the flow path The liquid ejecting head according to claim 1, wherein the plurality of pressurizing units ejects the liquid from the plurality of ejection holes by pressurizing the liquid in the flow path. 13. A recording apparatus comprising: the liquid ejection head according to claim 12; a transport unit that transports a recording medium to the liquid ejection head; and a control unit that controls the liquid ejection head.

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