JP2021104665A - Liquid discharge head and recording device - Google Patents

Abstract

To prevent deterioration in rigidity of a plate when a release groove for releasing excessive adhesive is provided on the plate.SOLUTION: A liquid discharge head includes a flow passage member configured by adhering a plurality of plates including a first plate and a second plate laminated on the first plate with adhesive. The first plate has a groove for releasing the adhesive at positions which do not overlap each other in plan view on each of a first surface to be an abutting surface with the second plate and a second surface facing the first surface.SELECTED DRAWING: Figure 8

Description

The disclosed embodiments relate to a liquid discharge head and a recording device.

As a printing apparatus, an inkjet printer or an inkjet plotter using an inkjet recording method is known. Such an inkjet printing apparatus is equipped with a liquid ejection head for ejecting a liquid.

Further, in such a liquid discharge head, a plurality of pressure chambers, manifolds, nozzles, and flow path units forming an ink flow path connecting them have openings, holes, and the like for forming a pressure chamber and the like. It is composed by stacking the plates of.

By the way, a plurality of plates constituting such a flow path unit may be adhered with an adhesive and laminated with each other, and it is known that the plates are provided with relief grooves for allowing excess adhesive to escape. There is.

Japanese Unexamined Patent Publication No. 2005-559399

In the conventional liquid discharge head, when the plate is provided with a relief groove for allowing excess adhesive to escape, the plate is etched, so that the rigidity of the plate becomes a problem.

The liquid discharge head according to one aspect of the embodiment is a flow path member formed by bonding a plurality of plates including a first plate and a second plate laminated on the first plate with an adhesive. Be prepared. The first plate has an adhesive on each of the first surface, which is the contact surface with the second plate, and the second surface facing the first surface, at positions where they do not overlap each other in a plan view. It has a groove for escape.

FIG. 1 is a front view schematically showing a schematic front view of the printer according to the embodiment. FIG. 2 is a plan view schematically showing a schematic plane of the printer according to the embodiment. FIG. 3 is an exploded perspective view showing a schematic configuration of the liquid discharge head according to the embodiment. FIG. 4 is an enlarged plan view of the head body according to the embodiment. FIG. 5 is an enlarged view of the region surrounded by the alternate long and short dash line shown in FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI shown in FIG. FIG. 7 is an enlarged plan view of a part of the front and back surfaces of the aperture plate. FIG. 8 is an enlarged plan view comparing the back surface of the base plate and a part of the back surface of the aperture plate side by side. FIG. 9 is a schematic view showing an example of the relief groove pattern.

Hereinafter, embodiments of the liquid discharge head and the recording device disclosed in the present application will be described in detail with reference to the accompanying drawings. The embodiments described below do not limit the invention according to the present application.

As a printing apparatus, an inkjet printer or an inkjet plotter using an inkjet recording method is known. Such an inkjet printing apparatus is equipped with a liquid ejection head for ejecting a liquid.

Further, in such a liquid discharge head, the pressurizing chamber, the manifold, the nozzle, and the flow path member forming the ink flow path connecting them have openings, holes, and the like for forming the pressurizing chamber and the like. It is composed of a stack of multiple plates.

By the way, a plurality of plates constituting such a flow path member may be bonded to each other by an adhesive, and at this time, excess adhesive between the plates may flow into the ink flow path. Therefore, it is known that the plate is provided with a relief groove for allowing excess adhesive to escape.

If the plate is provided with relief grooves to allow excess adhesive to escape, the plate is etched. For example, when relief grooves are provided on both the front surface and the back surface of the plate, the rigidity of the portion where the relief grooves overlap may decrease, and the plate may be damaged.

Therefore, in view of such a problem, when the plate is provided with a relief groove for allowing excess adhesive to escape, it is required to prevent a decrease in the rigidity of the plate.

<Printer configuration>
An outline of the printer 1 which is an example of the recording device according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a front view schematically showing a schematic front view of the printer 1 according to the embodiment. FIG. 2 is a plan view schematically showing a schematic plane of the printer 1 according to the embodiment.

As shown in FIG. 1, the printer 1 includes a paper feed roller 2, a guide roller 3, a coating machine 4, a head case 5, a plurality of transfer rollers 6, a plurality of frames 7, and a plurality of liquid discharge heads. 8, the transfer roller 9, the dryer 10, the transfer roller 11, the sensor unit 12, and the collection roller 13.

Further, the printer 1 has a control unit 14 that controls each unit of the printer 1. The control unit 14 includes a paper feed roller 2, a guide roller 3, a coating machine 4, a head case 5, a plurality of transfer rollers 6, a plurality of frames 7, a plurality of liquid discharge heads 8, a transfer roller 9, a dryer 10, and a transfer roller. 11. Control the operation of the sensor unit 12 and the recovery roller 13.

The printer 1 records images and characters on the printing paper P by landing droplets on the printing paper P. The printing paper P is wound in a state where it can be pulled out to the paper feed roller 2 before use. The printer 1 conveys the printing paper P from the paper feed roller 2 to the inside of the head case 5 via the guide roller 3 and the coating machine 4.

The coating machine 4 uniformly applies the coating agent to the printing paper P. As a result, the printing paper P can be surface-treated, so that the print quality of the printer 1 can be improved.

The head case 5 accommodates a plurality of transfer rollers 6, a plurality of frames 7, and a plurality of liquid discharge heads 8. Inside the head case 5, a space isolated from the outside is formed except that a part such as a portion where the printing paper P enters and exits is connected to the outside.

The internal space of the head case 5 is controlled by the control unit 14 at least one of control factors such as temperature, humidity, and atmospheric pressure, if necessary. The transport roller 6 transports the printing paper P in the vicinity of the liquid discharge head 8 inside the head case 5.

The frame 7 is a rectangular flat plate, and is located close to the upper side of the printing paper P transported by the transport roller 6. Further, as shown in FIG. 2, a plurality (for example, four) frames 7 are provided inside the head case 5 so that the longitudinal direction is orthogonal to the transport direction of the printing paper P. Each of the plurality of frames 7 is arranged at predetermined intervals along the transport direction of the printing paper P.

In the following description, the transport direction of the printing paper P may be referred to as the “sub-scanning direction”, and the direction orthogonal to the sub-scanning direction and parallel to the printing paper P may be referred to as the “main scanning direction”.

A liquid, for example, ink is supplied to the liquid discharge head 8 from a liquid tank (not shown). The liquid discharge head 8 discharges the liquid supplied from the liquid tank.

The control unit 14 controls the liquid discharge head 8 based on data such as an image and characters, and discharges the liquid toward the printing paper P. The distance between the liquid ejection head 8 and the printing paper P is, for example, about 0.5 to 20 mm.

The liquid discharge head 8 is fixed to the frame 7. The liquid discharge head 8 is fixed to the frame 7 at both ends in the longitudinal direction, for example. The liquid discharge head 8 is fixed to the frame 7 so that the longitudinal direction is parallel to the main scanning direction.

That is, the printer 1 according to the embodiment is a so-called line printer in which the liquid discharge head 8 is fixed inside the printer 1. The printer 1 according to the embodiment is not limited to a line printer, and may be a so-called serial printer.

The serial printer alternately performs an operation of recording while moving the liquid discharge head 8 in a direction intersecting the conveying direction of the printing paper P, for example, reciprocating in a direction substantially orthogonal to each other, and conveying the printing paper P. It is a printer of the method to perform.

As shown in FIG. 2, a plurality of (for example, five) liquid discharge heads 8 are provided in one frame 7. FIG. 2 shows an example in which two liquid discharge heads 8 are arranged in the front and three liquid discharge heads in the rear in the sub-scanning direction, so that the centers of the respective liquid discharge heads 8 do not overlap in the sub-scanning direction. The liquid discharge head 8 is arranged in the.

The head group 8A is composed of a plurality of liquid discharge heads 8 provided in one frame 7. The four head groups 8A are located along the sub-scanning direction. Ink of the same color is supplied to the liquid ejection heads 8 belonging to the same head group 8A. As a result, the printer 1 can print with four colors of ink using the four head groups 8A.

The colors of the inks ejected from each head group 8A are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 14 can print a color image on the printing paper P by controlling each head group 8A and ejecting inks of a plurality of colors onto the printing paper P.

In addition, in order to perform the surface treatment of the printing paper P, the coating agent may be discharged from the liquid discharge head 8 onto the printing paper P.

Further, the number of liquid discharge heads 8 included in one head group 8A and the number of head groups 8A mounted on the printer 1 can be appropriately changed according to the printing target and printing conditions. For example, if the color to be printed on the printing paper P is a single color and the printable range is printed by one liquid ejection head 8, the number of liquid ejection heads 8 mounted on the printer 1 may be one. ..

The printing paper P printed inside the head case 5 is conveyed to the outside of the head case 5 by the conveying roller 9 and passes through the inside of the dryer 10. The dryer 10 dries the printed printing paper P. The printing paper P dried by the dryer 10 is conveyed by the conveying roller 11 and collected by the collecting roller 13.

In the printer 1, by drying the printing paper P with the dryer 10, it is possible to prevent the collection rollers 13 from adhering the printing papers P that are overlapped and wound up or rubbing the undried liquid. can.

The sensor unit 12 is composed of a position sensor, a speed sensor, a temperature sensor, and the like. The control unit 14 can determine the state of each unit of the printer 1 based on the information from the sensor unit 12 and control each unit of the printer 1.

In the printer 1 described so far, the case where the printing paper P is used as the printing target (that is, the recording medium) has been shown, but the printing target in the printer 1 is not limited to the printing paper P, and a roll-shaped cloth or the like is printed. May be.

Further, the printer 1 described above may be one that carries the printing paper P on a transport belt instead of directly transporting the printing paper P. By using the transport belt, the printer 1 can print a sheet of paper, a cut cloth, wood, a tile, or the like.

Further, the printer 1 described above may print a wiring pattern of an electronic device or the like by discharging a liquid containing conductive particles from the liquid discharge head 8.

Further, the printer 1 described above may produce a chemical by discharging a predetermined amount of a liquid chemical agent or a liquid containing the chemical agent from the liquid discharge head 8 toward a reaction vessel or the like.

Further, the printer 1 described above may include a cleaning unit for cleaning the liquid discharge head 8. The cleaning unit cleans the liquid discharge head 8 by, for example, a wiping process or a capping process.

The wiping process is performed by, for example, rubbing the surface of the portion where the liquid is discharged, for example, the second surface 21b (see FIG. 6) of the flow path member 21 (see FIG. 3) with a flexible wiper. This is a process for removing the liquid adhering to the two surfaces 21b.

The capping process is, for example, a process of covering a portion where the liquid is discharged with a cap and repeating the discharge of the liquid to clear the clogging in the discharge hole 63 (see FIG. 4), and is performed as follows. First, a cap is put on the portion where the liquid is discharged, for example, the second surface 21b of the flow path member 21 (this is called capping). As a result, a substantially sealed space is formed between the second surface 21b and the cap. Next, the liquid is repeatedly discharged in such a closed space. As a result, it is possible to remove liquids and foreign substances having a viscosity higher than that in the standard state, which are clogged in the discharge hole 63.

<Construction of liquid discharge head>
The configuration of the liquid discharge head 8 according to the embodiment will be described with reference to FIG. FIG. 3 is an exploded perspective view showing a schematic configuration of the liquid discharge head 8 according to the embodiment.

The liquid discharge head 8 includes a head main body 20, a wiring portion 30, a housing 40, and a pair of heat sinks 50. The head body 20 has a flow path member 21, a piezoelectric actuator board 22 (see FIG. 4), and a reservoir 23.

In the following description, for convenience, the direction in which the head body 20 is provided in the liquid discharge head 8 is referred to as "downward", and the direction in which the housing 40 is provided with respect to the head main body 20 is referred to as "upper". There is.

The flow path member 21 of the head body 20 has a substantially flat plate shape, and has a first surface 21a (see FIG. 6) which is one main surface and a second surface 21b (FIG. 6) located on the opposite side of the first surface 21a. 6) and. The first surface 21a has an opening 61a (see FIG. 4), and a liquid is supplied from the reservoir 23 to the inside of the flow path member 21 through the opening 61a.

The second surface 21b is provided with a plurality of ejection holes 63 (see FIG. 4) for ejecting liquid onto the printing paper P. Inside the flow path member 21, a flow path for flowing a liquid from the first surface 21a to the second surface 21b is formed.

The piezoelectric actuator substrate 22 is located on the first surface 21a of the flow path member 21. The piezoelectric actuator substrate 22 has a plurality of displacement elements 70 (see FIG. 6). Further, the flexible substrate 31 of the wiring portion 30 is electrically connected to the piezoelectric actuator substrate 22.

A reservoir 23 is arranged on the piezoelectric actuator substrate 22. The reservoir 23 is provided with openings 23a at both ends in the main scanning direction. The reservoir 23 has a flow path inside, and a liquid is supplied from the outside through the opening 23a. The reservoir 23 has a function of supplying a liquid to the flow path member 21 and a function of storing the supplied liquid.

The wiring unit 30 includes a flexible substrate 31, a wiring substrate 32, a plurality of driver ICs 33, a pressing member 34, and an elastic member 35. The flexible substrate 31 has a function of transmitting a predetermined signal sent from the outside to the head main body 20. As shown in FIG. 3, the liquid discharge head 8 according to the embodiment has two flexible substrates 31.

One end of the flexible substrate 31 is electrically connected to the piezoelectric actuator substrate 22 of the head body 20. The other end of the flexible substrate 31 is pulled out upward so as to insert the slit portion 23b of the reservoir 23, and is electrically connected to the wiring board 32. As a result, the piezoelectric actuator board 22 of the head body 20 and the outside can be electrically connected.

The wiring board 32 is located above the head body 20. The wiring board 32 has a function of distributing signals to a plurality of driver ICs 33.

A plurality of driver ICs 33 are provided on one main surface of the flexible substrate 31. As shown in FIG. 3, in the liquid discharge head 8 according to the embodiment, two driver ICs 33 are provided on one flexible substrate 31, but the driver ICs 33 provided on one flexible substrate 31. The number is not limited to two.

The driver IC 33 drives the piezoelectric actuator board 22 of the head body 20 based on the signal sent from the control unit 14 (see FIG. 1). As a result, the driver IC 33 drives the liquid discharge head 8.

The pressing member 34 has a substantially U-shape in cross-sectional view, and presses the driver IC 33 on the flexible substrate 31 from the inside toward the heat radiating plate 50. Thereby, in the embodiment, the heat generated when the driver IC 33 is driven can be efficiently dissipated to the outer heat radiating plate 50.

The elastic member 35 is provided so as to be in contact with the outer wall of a pressing portion (not shown) of the pressing member 34. By providing such an elastic member 35, it is possible to reduce the possibility that the pressing member 34 damages the flexible substrate 31 when the pressing member 34 presses the driver IC 33.

The elastic member 35 is made of, for example, a foam double-sided tape. Further, by using, for example, a non-silicon-based heat conductive sheet as the elastic member 35, the heat dissipation of the driver IC 33 can be improved. The elastic member 35 does not necessarily have to be provided.

The housing 40 is arranged on the head body 20 so as to cover the wiring portion 30. As a result, the housing 40 can seal the wiring portion 30. The housing 40 is made of, for example, resin or metal.

The housing 40 has a box shape that extends long in the main scanning direction, and has a first opening 40a and a second opening 40b on a pair of side surfaces facing each other along the main scanning direction. Further, the housing 40 has a third opening 40c on the lower surface and a fourth opening 40d on the upper surface.

One of the heat radiating plates 50 is arranged in the first opening 40a so as to close the first opening 40a, and the other of the heat radiating plates 50 is arranged in the second opening 40b so as to close the second opening 40b. There is.

The heat radiating plate 50 is provided so as to extend in the main scanning direction, and is made of a metal or alloy having high heat radiating properties. The heat radiating plate 50 is provided so as to be in contact with the driver IC 33, and has a function of radiating heat generated by the driver IC 33.

Each pair of heat sinks 50 is fixed to the housing 40 by screws (not shown). Therefore, the housing 40 to which the heat radiating plate 50 is fixed has a box shape in which the first opening 40a and the second opening 40b are closed and the third opening 40c and the fourth opening 40d are opened.

The third opening 40c is provided so as to face the reservoir 23. A flexible substrate 31 and a pressing member 34 are inserted through the third opening 40c.

The fourth opening 40d is provided for inserting a connector (not shown) provided on the wiring board 32. It is preferable that the connector and the fourth opening 40d are sealed with a resin or the like. As a result, it is possible to prevent liquids, dust, and the like from entering the inside of the housing 40.

Further, the housing 40 has a heat insulating portion 40e. The heat insulating portion 40e is arranged so as to be adjacent to the first opening 40a and the second opening 40b, and is provided so as to project outward from the side surface of the housing 40 along the main scanning direction.

Further, the heat insulating portion 40e is formed so as to extend in the main scanning direction. That is, the heat insulating portion 40e is located between the heat radiating plate 50 and the head main body 20. By providing the heat insulating portion 40e in the housing 40 in this way, it is possible to suppress the heat generated by the driver IC 33 from being transmitted to the head body 20 via the heat radiating plate 50.

Note that FIG. 3 shows an example of the configuration of the liquid discharge head 8, and members other than the members shown in FIG. 3 may be further included.

<Structure of head body>
The configuration of the head main body 20 according to the embodiment will be described with reference to FIGS. 4 to 6. FIG. 4 is an enlarged plan view of the head body 20 according to the embodiment. FIG. 5 is an enlarged view of the region surrounded by the alternate long and short dash line shown in FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI shown in FIG.

As shown in FIG. 4, the head main body 20 has a flow path member 21 and a piezoelectric actuator substrate 22. The flow path member 21 has a supply manifold 61, a plurality of pressure chambers 62, and a plurality of discharge holes 63. In the following description, in the head body 20, the side that discharges the liquid may be referred to as a front end, and the side opposite to the side that discharges the liquid may be referred to as a back end.

The plurality of pressurizing chambers 62 are connected to the supply manifold 61. The plurality of discharge holes 63 are connected to the plurality of pressurizing chambers 62, respectively.

The pressurizing chamber 62 is open to the first surface 21a (see FIG. 6) of the flow path member 21. Further, the first surface 21a of the flow path member 21 has an opening 61a connected to the supply manifold 61. Then, the liquid is supplied from the reservoir 23 (see FIG. 3) to the inside of the flow path member 21 through the opening 61a.

In the example of FIG. 4, in the head main body 20, four supply manifolds 61 are located inside the flow path member 21. The supply manifold 61 has an elongated shape extending along the longitudinal direction (that is, the main scanning direction) of the flow path member 21, and at both ends thereof, openings of the supply manifold 61 in the first surface 21a of the flow path member 21. 61a is formed.

A plurality of pressurizing chambers 62 are formed in the flow path member 21 so as to expand two-dimensionally. As shown in FIG. 5, the pressurizing chamber 62 is a hollow region having a substantially rhombic planar shape with rounded corners. The pressurizing chamber 62 is open to the first surface 21a of the flow path member 21, and is closed by joining the piezoelectric actuator substrate 22 to the first surface 21a.

The pressurizing chamber 62 constitutes a pressurizing chamber row arranged in the longitudinal direction. The pressurizing chambers 62 in the pressurizing chamber row are arranged in a staggered manner between two adjacent pressurizing chamber rows. Then, one pressurizing chamber group is formed by four rows of pressurizing chambers connected to one supply manifold 61. In the example of FIG. 4, there are four pressure chamber groups to which the flow path member 21 is applied.

Further, the relative arrangement of the pressurizing chambers 62 in each pressurizing chamber group is the same, and each pressurizing chamber group is arranged slightly offset in the longitudinal direction.

The discharge hole 63 is arranged at a position of the flow path member 21 so as to avoid a region facing the supply manifold 61. That is, when the flow path member 21 is viewed through from the first surface 21a side, the discharge hole 63 does not overlap with the supply manifold 61.

Further, in a plan view, the discharge hole 63 is arranged so as to fit in the mounting area of the piezoelectric actuator board 22. Such discharge holes 63 occupy a region having substantially the same size and shape as the piezoelectric actuator substrate 22 as a group.

Then, by displacing the displacement element 70 (see FIG. 6) of the corresponding piezoelectric actuator substrate 22, the droplet is discharged from the discharge hole 63.

As shown in FIG. 6, the flow path member 21 has a laminated structure in which a plurality of plates are laminated. These plates are, in order from the upper surface of the flow path member 21, a cavity plate 21A, a base plate 21B, an aperture plate 21C, a supply plate 21D, a manifold plate 21E, 21F, 21G, a cover plate 21H, and a nozzle plate 21I.

Note that FIG. 6 shows an example of the laminated structure of each plate according to the embodiment, and the example shown in FIG. 6 does not need to be particularly limited. For example, the manifold plates 21E, 21F, and 21G may be configured by laminating three or more plates. Further, the cover plate 21H may be formed by laminating a plurality of plates.

A large number of holes are formed in the plate. The thickness of the plate is about 10 μm to 300 μm. Thereby, the accuracy of forming the hole can be improved. The plates are aligned and laminated so that these holes communicate with each other to form a predetermined flow path.

The plate has a relief groove for letting out excess adhesive among the adhesives for adhering the plates to each other. For example, the aperture plate 21C has a first surface SF _P _21C (contact surface with the base plate 21B) and a second surface SF _N _21C (contact surface with the supply plate 21D) on the front surface thereof. ) Has a relief groove. The relief groove is provided so as to avoid a large number of holes.

In the flow path member 21, the supply manifold 61 and the discharge hole 63 are connected by an individual flow path 64. The supply manifold 61 is located on the second surface 21b side inside the flow path member 21, and the discharge hole 63 is located on the second surface 21b of the flow path member 21.

The individual flow path 64 has a pressurizing chamber 62 and an individual supply flow path 65. The pressurizing chamber 62 is located on the first surface 21a of the flow path member 21, and the individual supply flow path 65 is a flow path connecting the supply manifold 61 and the pressurizing chamber 62.

Further, the individual supply flow path 65 includes a squeeze 66 having a width narrower than that of the other portion. Since the squeezing 66 is narrower than the other parts of the individual supply flow path 65, the flow path resistance is high. As described above, when the flow path resistance of the squeezing 66 is high, the pressure generated in the pressurizing chamber 62 does not easily escape to the supply manifold 61.

The piezoelectric actuator substrate 22 has piezoelectric ceramic layers 22A and 22B, a common electrode 71, an individual electrode 72, a connection electrode 73, a dummy connection electrode 74, and a surface electrode 75 (see FIG. 4).

Further, in the piezoelectric actuator substrate 22, the piezoelectric ceramic layer 22B, the common electrode 71, the piezoelectric ceramic layer 22A, and the individual electrodes 72 are laminated in this order.

Both the piezoelectric ceramic layers 22A and 22B extend on the first surface 21a of the flow path member 21 so as to straddle the plurality of pressure chambers 62. The piezoelectric ceramic layers 22A and 22B each have a thickness of about 20 μm. The piezoelectric ceramic layers 22A and 22B are made of, for example, a lead zirconate titanate (PZT) -based ceramic material having ferroelectricity.

The common electrode 71 is formed in the region between the piezoelectric ceramic layer 22A and the piezoelectric ceramic layer 22B over substantially the entire surface direction. That is, the common electrode 71 overlaps with all the pressurizing chambers 62 in the region facing the piezoelectric actuator substrate 22.

The thickness of the common electrode 71 is about 2 μm. The common electrode 71 is made of a metal material such as an Ag-Pd system.

The individual electrode 72 includes a main body electrode 72a and an extraction electrode 72b. The main body electrode 72a is located on the piezoelectric ceramic layer 22A in a region facing the pressurizing chamber 62. The main body electrode 72a is one size smaller than the pressurizing chamber 62, and has a shape substantially similar to that of the pressurizing chamber 62.

The extraction electrode 72b is drawn out from the main body electrode 72a to the outside of the region facing the pressurizing chamber 62. The individual electrode 72 is made of, for example, a metal material such as Au.

The connection electrode 73 is located on the extraction electrode 72b, has a thickness of about 15 μm, and is formed in a convex shape. Further, the connection electrode 73 is electrically connected to an electrode provided on the flexible substrate 31 (see FIG. 3). The connecting electrode 73 is made of silver-palladium containing, for example, a glass frit.

The dummy connection electrode 74 is located on the piezoelectric ceramic layer 22A so as not to overlap with various electrodes such as the individual electrodes 72. The dummy connection electrode 74 connects the piezoelectric actuator substrate 22 and the flexible substrate 31 to increase the connection strength.

Further, the dummy connection electrode 74 makes the distribution of contact positions between the piezoelectric actuator substrate 22 and the piezoelectric actuator substrate 22 uniform, and stabilizes the electrical connection. The dummy connection electrode 74 may be made of the same material as the connection electrode 73, and may be formed in the same process as the connection electrode 73.

The surface electrode 75 shown in FIG. 4 is formed on the piezoelectric ceramic layer 22A at a position avoiding the individual electrodes 72. The surface electrode 75 is connected to the common electrode 71 via a via hole formed in the piezoelectric ceramic layer 22B.

As a result, the surface electrode 75 is grounded and held at the ground potential. The surface electrode 75 may be made of the same material as the individual electrode 72, and may be formed in the same process as the individual electrode 72.

The plurality of individual electrodes 72 are individually electrically connected to the control unit 14 (see FIG. 1) via a flexible substrate 31 and wiring in order to individually control the potential. Then, when an electric field is applied in the polarization direction of the piezoelectric ceramic layer 22A with the individual electrodes 72 and the common electrode 71 having different potentials, the portion of the piezoelectric ceramic layer 22A to which the electric field is applied is distorted by the piezoelectric effect. Works as.

That is, in the piezoelectric actuator substrate 22, the portions of the individual electrode 72, the piezoelectric ceramic layer 22A, and the common electrode 71 facing the pressurizing chamber 62 function as the displacement element 70.

Then, the displacement element 70 is unimorphically deformed, so that the pressurizing chamber 62 is pressed and the liquid is discharged from the discharge hole 63.

Subsequently, the driving procedure of the liquid discharge head 8 according to the embodiment will be described. The individual electrode 72 is set to a higher potential (hereinafter referred to as a high potential) than the common electrode 71 in advance. Then, each time there is a discharge request, the individual electrode 72 is once set to the same potential as the common electrode 71 (hereinafter, referred to as a low potential), and then is set to a high potential again at a predetermined timing.

As a result, the piezoelectric ceramic layers 22A and 22B return to their original shapes at the timing when the individual electrodes 72 have a low potential, and the volume of the pressurizing chamber 62 increases from the initial state, that is, the high potential state.

At this time, since a negative pressure is applied to the pressure chamber 62, the liquid in the supply manifold 61 is sucked into the pressure chamber 62.

After that, the piezoelectric ceramic layers 22A and 22B are deformed so as to be convex toward the pressurizing chamber 62 at the timing when the individual electrodes 72 are raised to a high potential again.

That is, as the volume of the pressurizing chamber 62 decreases, the pressure in the pressurizing chamber 62 becomes a positive pressure. As a result, the pressure of the liquid inside the pressurizing chamber 62 rises, and the droplets are discharged from the discharge hole 63.

That is, in order to eject the droplet from the ejection hole 63, the control unit 14 supplies the drive signal including the pulse with reference to the high potential to the individual electrode 72 by using the driver IC 33. The width of this pulse may be AL (Acoustic Length), which is the length of time for the pressure wave to propagate from the squeeze 66 to the discharge hole 63.

As a result, when the inside of the pressurizing chamber 62 reverses from the negative pressure state to the positive pressure state, the pressures of both are combined, and the droplets can be ejected with a stronger pressure.

Further, in gradation printing, gradation expression is performed by the number of droplets continuously ejected from the ejection hole 63, that is, the amount of droplets (volume) adjusted by the number of droplet ejections. Therefore, the droplets are continuously ejected a number of times corresponding to the designated gradation expression from the ejection holes 63 corresponding to the designated dot region.

Generally, when the liquid is continuously discharged, the interval between the pulses supplied to discharge the droplets may be AL. As a result, the period of the residual pressure wave of the pressure generated when the droplet discharged earlier is discharged and the pressure wave of the pressure generated when the droplet discharged later is discharged coincide with each other.

Therefore, the residual pressure wave and the pressure wave are superimposed, and the pressure for ejecting the droplet can be amplified. In this case, the velocity of the droplets ejected later becomes faster, and the landing points of the plurality of droplets become closer.

<Plate details>
The details of the plate according to the embodiment will be described with reference to FIGS. 7 to 9. FIG. 7 is an enlarged plan view of a part of the front surface and the back surface of the aperture plate 21C. FIG. 8 is an enlarged plan view comparing the back surface of the base plate 21B and a part of the back surface of the aperture plate 21C side by side. FIG. 9 is a schematic view showing an example of the relief groove pattern.

As shown in FIG. 7, (an example of the first plate) aperture plate 21C includes a first surface _SF P _21C a contact surface of the base plate 21B (an example of the second plate) (surface, P surface) , And the second surface SF _N _21C (back surface, N surface) facing the first surface SF _P _21C, each of which has a groove (relief groove) for allowing the adhesive to escape at a position where they do not overlap each other in a plan view. Have.

That is, as shown in FIG. 7, aperture plate 21C is the first surface _SF P _21C (surface), the first surface _SF P a plurality of _21C provided in the hole _HL 1 _{_21C, HL} 2 _21C (individual has a groove escape grooves _CH 1 _SF _P positioned so as to surround the flow path, etc.). In FIG. 7 shows a part of the grooves CH ₁ _SF _P of the plurality of holes annular provided so as to surround the (individual channels, etc.).

Further, as shown in FIG. 7, the aperture plate 21C has a _{groove CH 1} _SF _N , a groove CH ₂ _SF _N , a groove CH ₃ _SF _N , a groove CH ₄ _SF _N , on _{the second surface SF N} _21C (back surface). And the groove CH ₅ _SF _N is provided as a relief groove. The groove CH ₁ _SF _N , the groove CH ₂ _SF _N , the groove CH ₃ _SF _N , the groove CH ₄ _SF _N , and the groove CH ₅ _SF _N are each provided with a plurality of holes HL provided in the second surface SF _{N _21C. It is located so as to surround 1} _21C and HL ₂ _21C (individual flow paths, etc.). Note that FIG. 7 shows a part of _{the grooves CH 1} _SF _{N to CH 5} _SF _N provided so as to surround the plurality of holes (individual flow paths and the like).

The grooves CH ₁ _SF _{P located on the first surface SF P} _21C of the aperture plate 21C and the grooves CH ₁ _SF _{N to CH 5} _SF _N located on the second surface SF _N _21C are as shown in FIG. By half-etching the aperture plates 21C, the aperture plates 21C are provided at positions that do not overlap each other in a plan view. Therefore, it is possible to avoid the formation of overlapping grooves along the cross-sectional direction of the aperture plate 21C, and it is possible to prevent a decrease in the rigidity of the aperture plate 21C.

_{Relief groove (groove CH 1} _SF _P ) on the first surface SF _P _21C (front surface) of the aperture plate 21C and relief groove (groove CH ₁ _SF _N ~ _{) on the second surface SF N} _21C (back surface) of the aperture plate 21C. The distance from the groove CH ₅ _SF _N ) may be wider than the width of the relief groove. With such a configuration, even if relief grooves are provided on both sides of the aperture plate 21C, the rigidity of the aperture plate 21C is unlikely to decrease.

Further, _CH 1 _SF _P located on the first surface _SF P _21C the aperture plate 21C (surface) is positioned so as to surround the outer periphery of a plurality of holes located on a first surface _SF P _21C (surface) There is. As a result, the adhesive is less likely to be clogged in the plurality of holes, and excess adhesive can be prevented from leaking from the outside of the aperture plate. _{Further, CH 1} _SF _{N and} CH ₄ _SF _{N located on the second surface SF N} _21C (back surface) of the aperture plate 21C are located so as to surround a plurality of linearly arranged holes, respectively. _{Further, the groove CH 3} _SF _{N located on the second surface SF N} _21C (back surface) of the aperture plate 21C is located relatively close to a plurality of holes (individual flow paths, etc.) so as to surround the plurality of holes. Is located in. As a result, the adhesive is less likely to be clogged in the plurality of holes. _{Further, the groove CH 2} _SF _{N located on the second surface SF N} _21C (back surface) of the aperture plate 21C is located so as to surround the plurality of grooves CH ₃ _SF _N , and has a plurality of holes (individual flow paths, etc.). ) Can be retained and the adhesive strength can be secured. _{Further, the groove CH 5} _SF _{N located on the second surface SF N} _21C (back surface) of the aperture plate 21C is located so as to surround a plurality of holes and the outer circumference of the groove. This makes it possible to prevent excess adhesive from leaking from the outside of the aperture plate. Note that the first surface _SF P escape grooves of _21C (surface) of the aperture plate 21C (grooves _CH 1 _SF _P), the second surface _SF N escape grooves of _21C (back surface) of the aperture plate 21C (groove _CH 1 _SF _N to groove CH ₅ _SF _P ) may be replaced with each other. That is, the first surface _SF P _21C the aperture plate 21C (surface), providing the second surface _SF N escape grooves of _21C (back surface) illustrated in FIG. 7, the second surface _SF N _21C the aperture plate 21C (the back surface) may be provided with a first surface _SF P escape grooves of _21C (surface) illustrated in FIG.

Further, in FIG. 8, among a plurality of plates constituting the flow path member 21, the back surface SF _{N _21B of the base plate 21B which is adjacent to each other and the second surface SF N} _21C which is the back surface of the aperture plate 21C are shown. Shown side by side. _{The back surface SF N} _21B of the base plate 21B _{and the first surface SF P} _21C (see the right figure of FIG. 7), which is the front surface of the aperture plate 21C, are brought into contact with each other by being bonded with an adhesive.

As shown in FIG. 8, the back surface SF _N _21B of the base plate 21B is provided with _{grooves CH 1} _21B to grooving CH _{5 _21B as relief grooves. The groove CH 1} _21B to the groove CH ₅ _21B that the base plate 21B has as a relief groove _{are the groove CH 1} _SF _N to the groove CH ₅ _SF provided as a relief groove on _{the second surface SF N} _21C which is the back surface of the aperture plate 21C. It is composed of the same pattern as _N. That is, among the relief grooves provided in the base plate 21B, the grooves CH ₁ _21B and the lined grooves CH ₄ _21B are located so as to surround the plurality of linearly arranged holes. The groove CH ₃ _21B provided on the base plate 21B is located relatively close to a plurality of holes (individual channels, etc.), are located a plurality of holes a to surround respectively. _{Further, the groove CH 2} _21B provided on the base plate 21B is located so as to surround the plurality of grooves CH _{3 _21B.} The groove CH ₅ _21B provided on the base plate 21B are located so as to surround the outer periphery of the plurality of holes or grooves. Therefore, when the base plate 21B and the aperture plate 21C is bonded, by relief grooves located on the back surface of the base plate 21B, the first surface _SF P _21C a surface of the aperture plate 21C (see the right view of FIG. 7) A plurality of located holes (individual flow paths, etc.) will be surrounded. This can suppress the flow of a plurality of holes adhesive to (individual channels, etc.) located on the first surface SF _P _21C a surface of the aperture plate 21C (see the right view of FIG. 7).

Further, (right see FIG. 7) grooves _CH 1 _SF _P a relief groove in the first surface _SF P _21C a surface of the aperture plate 21C is escape groove which is provided on the back surface _SF N _21B of the base plate 21B It is located in a different place in a plan view. _{In other words, the relief groove of the first surface SF P} _21C, which is the surface of the aperture plate 21C, is not located at a position facing the relief groove located on the back surface SF _{N _21B of the base plate 21B.} As a result, the contact area between the base plate 21B and the aperture plate 21C is difficult to reduce, and it is easy to secure the joint strength between the base plate 21B and the aperture plate 21C.

The groove of the base plate 21B (an example of the second plate) has the same pattern as the groove of the back surface (an example of the second surface) of the aperture plate 21C (an example of the first plate). Means that the overlapping region in a plan view is 70% or more, preferably 80% or more, and more preferably 90% or more.

FIG. 9 schematically shows an example of a relief groove pattern provided on the plate constituting the flow path member 21. In FIG. 9, the circular hole is a through hole connected to the discharge hole 63 (see FIG. 6). As shown in the right figure of FIG. 9, the groove CH _R provided as a relief groove on the plate may be provided in a broken line pattern. As shown in the left figure of FIG. 9, when a linear groove CH _L is provided on the plate as the relief groove, it is conceivable that the relief groove continuously reduces the thickness of the plate. On the other hand, as shown in the right figure of FIG. 9, by forming the groove provided in the plate as a relief groove in a broken line pattern, the portion where the thickness of the plate becomes thin can be continuously formed, and the rigidity of the plate can be increased. Can be expected to have the effect of preventing the decrease in.

The broken line-shaped pattern, the interval between the escaping groove CH _R may be larger than the spacing of the through holes to each other. In that case, the adhesive is sufficiently supplied between the through holes, excess adhesive is less likely to be generated, and the through holes are less likely to be clogged.

The above-described embodiment can be applied to each of the contact surfaces of the plates that come into contact with each other when the plates constituting the flow path member 21 are bonded with an adhesive.

1 Printer 4 Coating machine 6 Conveying roller 7 Frame 8 Liquid discharge head 10 Dryer 14 Control unit 20 Head body 21 Flow path member 22 Piezoelectric actuator board 23 Reservoir 23a Opening 23b Slit part 31 Flexible board 32 Wiring board 33 Driver IC
63 Discharge hole P Printing paper CH ₁ _SF _P groove CH ₁ _SF _{N to CH 5} _SF _N groove CH ₁ _21B to _{CH 5} _21B groove CH _L , CH _R groove

Claims (8)

A flow path member formed by bonding a plurality of plates including a first plate and a second plate laminated on the first plate with an adhesive is provided.
The first plate is
Grooves for allowing the adhesive to escape to positions that do not overlap each other in a plan view are provided on each of the first surface, which is the contact surface with the second plate, and the second surface facing the first surface. Liquid discharge head to have. The second plate
The liquid discharge head according to claim 1, which has a groove on the contact surface with the first plate to allow the adhesive to escape. The liquid discharge head according to claim 2, wherein the groove of the second plate has the same pattern as the groove of the second surface of the first plate. The first plate and the second plate are
The first or second aspect of the present invention, wherein the groove provided on the first surface of the first plate is bonded so as to overlap the adhesive region where the groove of the second plate is not provided on the contact surface. Liquid discharge head. The liquid discharge head according to any one of claims 1 to 4, wherein the groove has a broken line pattern. The first plate has a through hole connected to the discharge hole, and has a through hole.
The liquid discharge head according to claim 5, wherein the broken line pattern has a distance between the grooves larger than a distance between the through holes. The first plate is an aperture plate and
The liquid discharge head according to any one of claims 1 to 6, wherein the second plate is a base plate. A recording device including the liquid discharge head according to any one of claims 1 to 7.

Images