JP2020138433A - Liquid discharge head and recording apparatus - Google Patents

Abstract

To provide a liquid discharge head which realizes both adjustment of a pressure wave in a propagation direction, and increase in a discharge amount of a droplet.SOLUTION: A channel member includes: a discharge hole which is open to a discharge surface; a compression chamber 17 positioned on a compression surface side of the discharge hole; and a partial channel 19 extending from the compression chamber to the discharge hole. A compression element is superimposed on the compression surface, and applies pressure to a liquid in the compression chamber by deviating in a direction for approaching the pressure chamber and in an opposite direction thereof. The partial channel has one or more large-diameter sections in which a cross section area parallel to the compression surface is larger than an average area in the partial channel of the cross section area. In a plane perspective view of the compression surface, all the large-diameter sections respectively fall within a range R1. The range R1 includes an outer edge separated from an outer edge of the compression chamber to the outside by a length of 10% of the maximum diameter of the partial channel.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to a liquid discharge head and a recording device.

A liquid ejection head that ejects a liquid (for example, ink) toward a recording medium (for example, paper) is known (for example, Patent Document 1). Such a liquid discharge head has, for example, a discharge hole that opens to the outside of the head, a partial flow path that is connected to the discharge hole, and a pressurizing chamber that is connected to the partial flow path. Then, when pressure is applied to the liquid in the pressurizing chamber, the liquid is discharged from the discharge hole. The area of the cross section (cross section intersecting in the direction from the pressurizing chamber to the discharge hole) of the partial flow path may not be constant.

Japanese Unexamined Patent Publication No. 2006-96036

The liquid discharge head according to one aspect of the present disclosure is located on the discharge surface, the pressure surface on the back surface of the discharge surface, the discharge hole opened in the discharge surface, and the pressure surface side of the discharge hole. A flow path member having a pressurizing chamber and a partial flow path extending from the pressurizing chamber to the discharge hole and a flow path member overlapping the pressurizing surface in the direction toward the pressurizing chamber and in the opposite direction. It has a pressurizing element that is displaced to pressurize the liquid in the pressurizing chamber, and in the partial flow path, the area of the cross section parallel to the pressurizing surface is the partial flow of the area of the cross section. It has one or more large diameter portions that are larger than the average area in the road, and in the plan view of the pressurized surface, each of the large diameter portions has a length of 10% of the maximum diameter of the partial flow path. It is within the range having an outer edge separated from the outer edge of the pressurizing chamber to the outside.

The recording device according to one aspect of the present disclosure includes the liquid discharge head and a moving unit that relatively moves the liquid discharge head and the recording medium.

(A) is a side view of a recording device including a liquid discharge head according to an embodiment of the present disclosure, and (b) is a plan view. It is a vertical sectional view of a part of the liquid discharge head of FIG. It is a plan perspective view of the flow path member of the liquid discharge head of FIG. It is an enlarged view of the region IV of FIG. It is an enlarged view of the region V of FIG. It is a schematic diagram which shows by extracting a part of an individual flow path from FIG. It is a schematic plan perspective view which shows a part of a partial flow path and a pressurizing chamber.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The figures used in the following description are schematic, and the dimensional ratios and the like on the drawings do not always match the actual ones. Even in a plurality of drawings showing the same member, the dimensional ratios and the like may not match each other in order to exaggerate the shape and the like.

(Overall configuration of printer)
FIG. 1A shows a color inkjet printer 1 (an example of a recording device; hereinafter simply referred to as a printer) including a liquid ejection head 2 (hereinafter, may be simply referred to as a head) according to an embodiment of the present disclosure. ) Is a schematic side view. FIG. 1B is a schematic plan view of the printer 1.

The head 2 or the printer 1 can have an arbitrary direction as the vertical direction, but for convenience, the term "upper surface" or "lower surface" may be used with the vertical direction of the paper surface in FIG. 1 (a) as the vertical direction. is there. Further, the terms such as plan view are used to mean viewing in the vertical direction of the paper surface of FIG. 1 (a) unless otherwise specified.

The printer 1 moves the printing paper P relative to the head 2 by transporting the printing paper P (an example of a recording medium) from the paper feed roller 80A to the collection roller 80B. The paper feed roller 80A, the collection roller 80B, and various rollers described later form a moving unit 85 that relatively moves the printing paper P and the head 2. The control unit 88 controls the head 2 based on print data or the like which is data such as an image or characters to discharge liquid toward the printing paper P, land droplets on the printing paper P, and print. Recording such as printing is performed on paper P.

In the present embodiment, the head 2 is fixed to the printer 1, and the printer 1 is a so-called line printer. In another embodiment of the recording device, an operation of ejecting droplets while moving the head 2 in a direction intersecting the conveying direction of the printing paper P (for example, a direction substantially orthogonal to each other) and the conveying of the printing paper P are alternated. This is a so-called serial printer.

Four flat head mounting frames 70 (hereinafter, may be simply referred to as frames) are fixed to the printer 1 so as to be substantially parallel to the printing paper P. Each frame 70 is provided with five holes (not shown), and five heads 2 are mounted in the respective holes. The five heads 2 mounted on one frame 70 form one head group 72. The printer 1 has four head groups 72, and a total of 20 heads 2 are mounted.

In the head 2 mounted on the frame 70, the portion for discharging the liquid faces the printing paper P. The distance between the head 2 and the printing paper P is, for example, about 0.5 to 20 mm.

The 20 heads 2 may be directly connected to the control unit 88, or may be connected to the control unit 88 via a distribution unit that distributes print data. For example, the control unit 88 may transmit the print data to one distribution unit, and one distribution unit may distribute the print data to the 20 heads 2. Further, for example, the control unit 88 distributes the print data to the four distribution units corresponding to the four head groups 72, and each distribution unit distributes the print data to the five heads 2 in the corresponding head group 72. You may.

The head 2 has an elongated long shape in the direction from the front to the back in FIG. 1A and in the vertical direction in FIG. 1B. In one head group 72, the three heads 2 are arranged along a direction intersecting the conveying direction of the printing paper P (for example, a direction substantially orthogonal to each other), and the other two heads 2 are arranged in the conveying direction. One each is lined up between the three heads 2 at positions shifted along the line. In other words, in one head group 72, the heads 2 are arranged in a staggered pattern. The heads 2 are arranged so that the printable range of each head 2 is connected in the width direction of the printing paper P, that is, in the direction intersecting the conveying direction of the printing paper P, or the edges overlap. Printing without gaps in the width direction of the printing paper P is possible.

The four head groups 72 are arranged along the transport direction of the printing paper P. A liquid (for example, ink) is supplied to each head 2 from a liquid supply tank (not shown). Inks of the same color are supplied to the heads 2 belonging to one head group 72, and four colors of ink can be printed by the four head groups 72. The colors of the inks ejected from each head group 72 are, for example, magenta (M), yellow (Y), cyan (C), and black (K). By landing such ink on the printing paper P, a color image can be printed.

The number of heads 2 mounted on the printer 1 may be one as long as it is a single color and prints a printable range with one head 2. The number of heads 2 included in the head group 72 and the number of head groups 72 can be appropriately changed depending on the printing target and printing conditions. For example, the number of head groups 72 may be increased in order to print in more colors. Further, if a plurality of head groups 72 for printing in the same color are arranged and printed alternately in the transport direction, the transport speed can be increased even if the heads 2 having the same performance are used. As a result, the printing area per hour can be increased. Further, a plurality of head groups 72 for printing in the same color may be prepared and arranged so as to be offset in the direction intersecting the transport direction to increase the resolution in the width direction of the printing paper P.

Further, in addition to printing the colored ink, in order to perform the surface treatment of the printing paper P, a liquid such as a coating agent may be uniformly or patterned on the head 2 for printing. As the coating agent, for example, when a recording medium in which the liquid does not easily permeate is used, a coating agent that forms a liquid receiving layer can be used so that the liquid can be easily fixed. In addition, when a recording medium that is easily penetrated by a liquid is used as the coating agent, the liquid penetration is suppressed so that the liquid does not bleed too much or mix with another liquid that has landed next to it. Those that form a layer can be used. In addition to printing with the head 2, the coating agent may be uniformly applied by the coating machine 76 controlled by the control unit 88.

The printer 1 prints on the printing paper P which is a recording medium. The printing paper P is in a state of being wound around the paper feed roller 80A, and the printing paper P sent out from the paper feed roller 80A passes under the head 2 mounted on the frame 70, and then 2 It passes between the transfer rollers 82C and is finally collected by the collection roller 80B. When printing, the printing paper P is conveyed at a constant speed by rotating the conveying roller 82C, and is printed by the head 2.

Subsequently, the details of the printer 1 will be described in the order in which the printing paper P is conveyed. The printing paper P sent out from the paper feed roller 80A passes between the two guide rollers 82A and then passes under the coating machine 76. The coating machine 76 applies the above-mentioned coating agent to the printing paper P.

The printing paper P subsequently enters the head chamber 74 in which the frame 70 on which the head 2 is mounted is housed. The head chamber 74 is a space that is generally isolated from the outside, although it is connected to the outside in a part such as a portion where the printing paper P enters and exits. In the head chamber 74, control factors such as temperature, humidity, and atmospheric pressure are controlled by the control unit 88 and the like, if necessary. In the head chamber 74, the influence of disturbance can be reduced as compared with the outside where the printer 1 is installed, so that the fluctuation range of the above-mentioned control factor can be narrowed as compared with the outside.

Five guide rollers 82B are arranged in the head chamber 74, and the printing paper P is conveyed on the guide rollers 82B. The five guide rollers 82B are arranged so that the center is convex toward the direction in which the frame 70 is arranged when viewed from the side surface. As a result, the printing paper P conveyed on the five guide rollers 82B has an arc shape when viewed from the side surface, and by applying tension to the printing paper P, the printing paper P between the guide rollers 82B is formed. Is stretched so that it becomes flat. One frame 70 is arranged between the two guide rollers 82B. The angle at which the frame 70 is installed is gradually changed so as to be parallel to the printing paper P conveyed under the frame 70.

The printing paper P that has come out of the head chamber 74 passes between the two transfer rollers 82C, passes through the dryer 78, passes between the two guide rollers 82D, and is collected by the collection roller 80B. The transport speed of the printing paper P is, for example, 100 m / min. Each roller may be controlled by the control unit 88 or may be manually operated by a person.

By drying in the dryer 78, it becomes difficult for the printing papers P that are overlapped and wound up to adhere to each other or the undried liquid to rub against each other in the recovery roller 80B. In order to print at high speed, it is necessary to dry quickly. In order to speed up the drying, the dryer 78 may be dried in order by a plurality of drying methods, or may be dried by using a plurality of drying methods in combination. Examples of the drying method used in such a case include blowing warm air, irradiating infrared rays, and contacting a heated roller. When irradiating infrared rays, infrared rays in a specific frequency range may be applied so that the printing paper P can be dried quickly while reducing damage to the printing paper P. When the printing paper P is brought into contact with the heated roller, the heat transfer time may be lengthened by transporting the printing paper P along the cylindrical surface of the roller. The range of transportation along the cylindrical surface of the roller is preferably 1/4 or more of the cylindrical surface of the roller, and more preferably 1/2 or more of the cylindrical surface of the roller. When printing UV curable ink or the like, a UV irradiation light source may be arranged in place of the dryer 78 or in addition to the dryer 78. The UV irradiation light source may be arranged between each frame 70.

The printer 1 may include a cleaning unit for cleaning the head 2. The cleaning unit is cleaned by, for example, wiping and / or capping. In the wiping, for example, a flexible wiper rubs the surface of the portion where the liquid is discharged, for example, the discharge surface 5a (described later) to remove the liquid adhering to the surface. Cleaning by capping is performed, for example, as follows. First, by covering a portion where the liquid is discharged, for example, a cap so as to cover the discharge surface 5a (this is called capping), the discharge surface 5a and the cap are substantially sealed to form a space. By repeating the discharge of the liquid in such a state, the liquid, the foreign matter, and the like that are clogged in the discharge hole 9 (described later) and have a viscosity higher than that in the standard state are removed. By capping, the liquid being washed is less likely to be scattered on the printer 1, and the liquid is less likely to adhere to the transport mechanism such as the printing paper P or the roller. The discharged surface 5a after cleaning may be further wiped. Cleaning by wiping and / or capping may be performed by manually operating the wiper and / or cap attached to the printer 1 or automatically by the control unit 88.

The recording medium may be a roll-shaped cloth or the like, in addition to the printing paper P. Further, instead of directly transporting the printing paper P, the printer 1 may transport the transport belt and place the recording medium on the transport belt for transport. In that way, sheet paper, cut cloth, wood or tiles can be used as recording media. Further, the wiring pattern of the electronic device or the like may be printed by discharging the liquid containing the conductive particles from the head 2. Further, a chemical agent may be produced by discharging a predetermined amount of liquid chemical agent or a liquid containing the chemical agent from the head 2 toward the reaction vessel or the like and causing the reaction.

Further, a position sensor, a speed sensor, and / or a temperature sensor and the like are attached to the printer 1, and the control unit 88 controls each part of the printer 1 according to the state of each part of the printer 1 which can be understood from the information from each sensor. May be good. For example, the temperature of the head 2, the temperature of the liquid in the liquid supply tank that supplies the liquid to the head 2, and / or the pressure that the liquid in the liquid supply tank applies to the head 2 are the discharge characteristics of the discharged liquid (for example, When the discharge amount and / or the discharge rate) is affected, the drive signal for discharging the liquid may be changed according to the information.

(Head body)
FIG. 2 is an enlarged cross-sectional view of a part of the head body 2a included in the head 2. This figure corresponds to line II-II of FIG. 5, which will be described later. The lower part of the paper surface in FIG. 2 is the printing paper P side.

The head body 2a is a substantially plate-shaped member that constitutes substantially the entire surface (discharge surface 5a) of the head 2 facing the printing paper P. Its thickness is, for example, 0.5 mm or more and 2 mm or less. A plurality of discharge holes 9 (only one is shown in FIG. 2) for discharging liquid drops are opened on the discharge surface 5a. The plurality of discharge holes 9 are two-dimensionally arranged along the discharge surface 5a.

The head body 2a is a piezo type head that applies pressure to a liquid by mechanical strain of a piezoelectric element to discharge droplets. The head main body 2a has a plurality of discharge elements 3 including discharge holes 9, respectively, and one discharge element 3 is shown in FIG. The plurality of discharge elements 3 are two-dimensionally arranged along the discharge surface 5a.

From another viewpoint, the head body 2a has a plate-shaped flow path member 5 in which a flow path through which a liquid (ink) flows is formed, and an actuator substrate for applying pressure to the liquid in the flow path member 5. Has 7 and. The plurality of discharge elements 3 are composed of a flow path member 5 and an actuator substrate 7. The discharge surface 5a is composed of a flow path member 5. The surface of the flow path member 5 opposite to the discharge surface 5a is referred to as a pressure surface 5b.

The flow path member 5 has a common flow path 11 and a plurality of individual flow paths 13 (one of which is shown in FIG. 2) connected to the common flow path 11. Each individual flow path 13 has the discharge hole 9 described above, and also has a connection flow path 15, a pressurizing chamber 17, and a partial flow path 19 in this order from the common flow path 11 to the discharge hole 9. ing.

The plurality of individual flow paths 13 and the common flow path 11 are filled with a liquid. By changing the volume of the plurality of pressurizing chambers 17 and applying pressure to the liquid, the liquid is sent from the plurality of pressurizing chambers 17 to the plurality of partial flow paths 19, and the plurality of liquids are sent from the plurality of discharge holes 9. Drops are ejected. Further, the plurality of pressurizing chambers 17 are replenished with liquid from the common flow path 11 via the plurality of connection flow paths 15.

The flow path member 5 is configured by, for example, laminating a plurality of plates 21A to 21N (hereinafter, A to N may be omitted). The plate 21 is formed with a plurality of holes (mainly through holes, which may be recessed) forming the plurality of individual flow paths 13 and the common flow path 11. The thickness and the number of layers of the plurality of plates 21 may be appropriately set according to the shapes of the plurality of individual flow paths 13 and the common flow paths 11. The plurality of plates 21 may be formed of an appropriate material. For example, the plurality of plates 21 are made of metal or resin. The thickness of the plate 21 is, for example, 10 μm or more and 300 μm or less.

The plates 21 are fixed to each other by, for example, an adhesive (not shown) interposed between the plates 21. In the description of this embodiment, the expression may ignore the presence of the adhesive.

(Common flow path)
FIG. 3 is a perspective perspective view of the flow path member 5. The paper surface penetration direction is the direction in which the head 2 and the printing paper P face each other. FIG. 3 shows only the common flow path 11 and the supply port 23 for supplying the liquid to the common flow path 11 among the flow paths in the flow path member 5.

The number of common flow paths 11 is arbitrary, and may be one or a plurality. In the example of FIG. 3, four common flow paths 11 are provided. The plurality of common flow paths 11 extend linearly in parallel with each other, for example. The configurations of the plurality of common flow paths 11 are basically the same as each other. The relative relationship between the extending direction of the common flow path 11 and the longitudinal direction of the flow path member 5 may be appropriately set, and in the illustrated example, both are parallel. That is, in the present embodiment, the common flow path 11 is in a direction substantially orthogonal to the transport direction of the printing paper P. The common flow path 11 may be inclined in the longitudinal direction of the flow path member 5 (direction substantially orthogonal to the transport direction).

Supply ports 23 are open at both ends of each common flow path 11. The supply port 23 leads to the outside of the flow path member 5 via a flow path (not shown). The liquid flows into the common flow path 11 from the supply ports 23 at both ends of the common flow path 11, and flows toward the center of the common flow path 11. The supply port 23 may be provided only at one end of each common flow path 11. Further, the plurality of common flow paths 11 may be merged at their ends to form a manifold or an annular flow path. From another viewpoint, one supply port 23 may be provided in the plurality of common flow paths 11. Further, a discharge port for flowing the liquid from the common flow path 11 to the outside of the flow path member 5 may be opened in the common flow path 11.

The shape of the cross section (FIG. 2) of the common flow path 11 and various dimensions of the common flow path 11 may be appropriately set. In the example of FIG. 2, the shape of the cross section of the common flow path 11 is rectangular. Below the common flow path 11, a damper 12 for attenuating the pressure fluctuation generated in the common flow path 11 is configured. The damper 12 may be provided above or in addition to below the common flow path 11.

(Outline of arrangement of individual flow paths)
FIG. 4 is an enlarged view (planar perspective view) of region IV of FIG. In FIG. 4, in addition to the flow path shown in FIG. 3, the pressurizing chamber 17 and the partial flow path 19 are also shown. FIG. 5 is an enlarged view (planar perspective view) of the region V of FIG. In FIG. 5, in addition to the flow path shown in FIG. 4, the discharge hole 9, the connection flow path 15, and the components of the actuator substrate 7 are also shown.

The plurality of individual flow paths 13 (discharge element 3 from another viewpoint) are arranged along each common flow path 11 (in the length direction of the common flow path 11). That is, the plurality of discharge holes 9 are arranged along the common flow path 11. The plurality of pressurizing chambers 17 are arranged along the common flow path 11. The plurality of partial flow paths 19 are arranged along the common flow path 11. The plurality of connecting flow paths 15 are arranged along the common flow path 11.

The configuration of one common flow path 11 and a plurality of individual flow paths 13 (a plurality of discharge elements 3 from another viewpoint) connected to the one common flow path 11 is basically composed of a plurality of common flow paths 11. It is the same. In the following, the description may be made focusing on only one common flow path 11.

The plurality of pressurizing chambers 17 connected to one common flow path 11 have two rows each on one side of the common flow path 11, and four rows in total on both sides of the first pressurizing chamber rows 25A to the fourth pressurization. It constitutes a room line 25D (hereinafter, A to D may be omitted). In the present embodiment, since there are four common flow paths 11, there are 16 pressurization chamber rows 25 in total.

In the following, the pressurizing chamber 17 belonging to the first pressurizing chamber row 25A may be referred to as a first pressurizing chamber 17A. Similarly, each of the pressurizing chambers 17 belonging to the second pressurizing chamber row 25B to the fourth pressurizing chamber row 25D may be referred to as a second pressurizing chamber 17B to a fourth pressurizing chamber 17D. The plurality of first pressurizing chambers 17A and the plurality of second pressurizing chambers 17B, and the plurality of third pressurizing chambers 17C and the plurality of fourth pressurizing chambers 17D are divided on both sides in the width direction of the common flow path 11. Therefore, the former can be regarded as the first pressurizing chamber group 39A, and the latter can be regarded as the second pressurizing chamber group 39B.

Similar to the plurality of pressurizing chambers 17, the plurality of discharge holes 9 connected to one common flow path 11 have two rows on one side of the common flow path, and four discharge hole rows 27 on both sides in total. Consists of. In the present embodiment, since there are four common flow paths 11, there are a total of 16 discharge hole rows 27.

Although not particularly designated, the partial flow paths 19 connected to one common flow path 11 are also 2 on one side of the common flow path, as in the case of the plurality of discharge holes 9 and the plurality of pressurizing chambers 17. Each row constitutes a total of four flow path rows on both sides.

A plurality of connecting flow paths 15 connected to one common flow path 11 also basically constitute four flow path lines. However, as shown in the illustrated example, the connection flow paths 15 connected to the adjacent pressurizing chamber rows 25 (25C and 25D) may have overlapping ranges of the common flow paths 11 in the width direction, and the four rows may overlap. The flow path lines of may look like three lines.

In the following, the row of the individual flow path 13 including the first pressurizing chamber row 25A may be referred to as the first individual flow path row 41A. Similarly, the line of the individual flow path 13 including the second pressure chamber line 25B to the fourth pressure chamber line 25D may be referred to as a second individual flow path line 41B to a fourth individual flow path line 41D. Further, the individual flow path line 41A to the fourth individual flow path line 41D may be referred to as the individual flow path line 41 without distinguishing them.

Further, the individual flow path 13 belonging to the first individual flow path line 41A may be referred to as the first individual flow path 13A. Similarly, each of the individual flow paths 13 belonging to the second individual flow path line 41B to the fourth individual flow path line 41D may be referred to as a second individual flow path 13B to a fourth individual flow path 13D. The connecting flow path 15 belonging to the first individual flow path line 41A may be referred to as the first connecting flow path 15A. Similarly, each of the connecting flow paths 15 belonging to the second individual flow path line 41B to the fourth individual flow path line 41D may be referred to as a second connection flow path 15B to a fourth connection flow path 15D.

When the plurality of discharge holes 9 are viewed in the direction intersecting the common flow path 11 (for example, the vertical direction of the paper surface in FIG. 5), the plurality of discharge holes 9 are arranged so as not to overlap each other. As a result, when the printing paper P is conveyed in the intersecting directions and the droplets are ejected toward the printing paper P, the pitch is narrower than the pitch of the ejection holes 9 in each pressurizing chamber row 25 and is orthogonal to the conveying direction. It is possible to form dots arranged in the direction of printing.

Dummy pressurizing chambers 18 are provided on both sides of the pressurizing chambers 17 in each pressurizing chamber row 25 in the arrangement direction. The dummy pressurizing chamber 18 does not communicate with the discharge hole 9, for example, and does not directly contribute to the discharge of the liquid drops. The dummy pressurizing chamber 18 also reproduces, for example, the structural influence of the pressurizing chamber 17 on both sides of the pressurizing chamber 17 for the pressurizing chamber 17 located at the end of the pressurizing chamber row 25. Contributes to. That is, it contributes to the uniform ejection characteristics of the liquid drops.

(Outline of the shape of individual flow paths)
Regarding the shape of the individual flow path 13, items common to the plurality of individual flow path rows 41 and the like will be described. The shape and dimensions of each part of the individual flow path 13 (connection flow path 15, pressurizing chamber 17, partial flow path 19 and discharge hole 9) may be appropriately set. In the examples shown in FIGS. 2, 4 and 5, it is as follows.

The pressurizing chamber 17 is formed in a thin shape that spreads with a constant thickness along the pressurizing surface 5b. The thin shape is, for example, a shape having a thickness smaller than any diameter in a plan view. The planar shape of the pressurizing chamber 17 is a rhombus with curved corners. However, the pressurizing chamber 17 may have a portion whose thickness changes, or may have another shape such as a circular shape or an elliptical shape in a plan view.

The pressurizing chamber 17 is opened to the pressurizing surface 5b, for example, and is closed by the actuator substrate 7. The pressurizing chamber 17 may be closed by the plate 21. However, this can also be considered as a problem of whether the plate 21 that closes the pressurizing chamber 17 is regarded as a part of the flow path member 5 or a part of the actuator substrate 7.

The pressurizing chamber 17 is located above the common flow path 11. Therefore, the pressurizing chamber 17 can be arranged so as to have an overlap with the common flow path 11 in a plan view.

The partial flow path 19 extends from the pressurizing chamber 17 toward the discharge surface 5a. The shape of the partial flow path 19 is roughly a straight columnar shape. In a plan view, the partial flow path 19 is connected to, for example, an end portion of the pressurizing chamber 17 in the longitudinal direction (one corner portion having an acute angle of a rhombus in the illustrated example).

The discharge hole 9 is open to a part of the bottom surface (the surface opposite to the pressurizing chamber 17) of the partial flow path 19. The discharge hole 9 is located, for example, substantially in the center of the bottom surface of the partial flow path 19. More specifically, for example, in a plan view, the distance between the center of the discharge hole 9 and the center (center of gravity) of the bottom surface of the partial flow path 19 is equal to or less than the maximum diameter of the discharge hole 9. However, the discharge hole 9 may be provided eccentrically with respect to the center of the bottom surface of the partial flow path 19. The shape of the vertical cross section of the discharge hole 9 is tapered so that the diameter becomes smaller toward the discharge surface 5a side. However, the discharge hole 9 may be partially or wholly tapered.

The connection flow path 15 is connected to, for example, a first portion 15a connected to the upper surface of the common flow path 11 and a first portion 15a connected to the upper surface of the first portion 15a and extends in a plane direction (direction along the pressure surface 5b). It has two parts 15b and a third part 15c connected to the upper surface of the second part 15b and connected to the lower surface of the pressurizing chamber 17.

The first portion 15a is formed in a substantially columnar shape whose axial direction is, for example, the normal direction of the pressure surface 5b. The second portion 15b has a portion extending linearly with a constant width in a plan view and widening portions on both sides thereof. The widened portion is connected to the first portion 15a or the third portion 15c. The third portion 15c is formed in a substantially columnar shape whose axial direction is the normal direction of the pressure surface 5b. The second portion 15b has a smaller cross section perpendicular to the flow direction than the first portion 15a and the third portion 15c, and also as compared with the common flow path 11 and the pressurizing chamber 17. That is, the second portion 15b functions as a so-called squeeze.

In a plan view, the connection position of the connection flow path 15 (third portion 15c) with respect to the pressurizing chamber 17 is, for example, the side opposite to the partial flow path 19 with respect to the center of the lower surface of the lower surface of the pressurizing chamber 17. (In this embodiment, one end in the longitudinal direction of the pressurizing chamber 17). The connection position of the connection flow path 15 (first portion 15a) with respect to the common flow path 11 is set to an appropriate position in the width direction on the upper surface of the common flow path 11.

The individual flow path 13 having the above configuration is arranged so that at least a part of the pressurizing chamber 17, the partial flow path 19, and the discharge hole 9 do not overlap the common flow path 11. Further, the individual flow paths 13 are arranged so that the connection flow path 15 side is on the common flow path 11 side and the partial flow path 19 side is on the opposite side to the common flow path 11 with respect to the common flow path 11.

(Details of shape and arrangement of individual flow paths)
Regarding the shape and arrangement of the individual flow path 13, the differences between the plurality of individual flow path rows 41 will be described.

Within each individual flow path row 41, the shapes and orientations of the plurality of individual flow paths 13 (from another viewpoint, the connection flow path 15, the pressurizing chamber 17, the partial flow path 19 and / or the discharge hole 9) are basically different. It is said to be the same as each other. Then, in each individual flow path row 41, the plurality of individual flow paths 13 (15, 17, 19 and / or 9) are basically arranged at a constant pitch in the length direction of the common flow path 11. .. However, for various reasons, the pitch of the discharge holes 9 may fluctuate by an amount smaller than the pitch, or the pitch of the entire individual flow path 13 may fluctuate.

The shapes of the individual flow paths 13 in the first individual flow path lines 41A to the fourth individual flow path lines 41D are basically the same as each other except for the connection flow path 15. In other words, the shapes of the pressurizing chamber 17, the partial flow path 19, and the discharge hole 9 and the relative positional relationship of these portions are the same as each other. However, the shapes and positional relationships of these parts may differ between the individual flow path rows 41 in consideration of differences between the individual flow path rows 41 (for example, differences in relative positions with respect to the common flow path 11). ..

The angle of inclination of the connecting flow path 15 with respect to the pressurizing chamber 17 in a plan view is different between the first individual flow path lines 41A to the fourth individual flow path lines 41D. For example, in the example of FIG. 5, in the first individual flow path line 41A and the fourth individual flow path line 41D, the connection flow path 15 extends in the longitudinal direction of the pressurizing chamber 17, whereas the second individual flow path line 17 extends in the longitudinal direction. In the individual flow path line 41B and the third individual flow path line 41C, the connection flow path 15 extends inclined with respect to the longitudinal direction of the pressurizing chamber 17. The length of the former connection flow path 15 and the length of the latter connection flow path 15 may be the same or different from each other.

Except for the above differences, the shape of the connecting flow path 15 and the relative positional relationship with respect to other parts (17, 19 and 9) of the connecting flow path 15 are also the first individual flow path rows 41A to the fourth individual. It may be the same in the flow path rows 41D. Further, the shape of the individual flow path 13 may be the same in the first individual flow path line 41A and the fourth individual flow path line 41D. The shape of the individual flow path 13 may be the same for the second individual flow path line 41B and the fourth individual flow path line 41D.

The pitches of the plurality of individual flow paths 13 in each individual flow path line 41 are basically the same among the first individual flow path lines 41A to the fourth individual flow path lines 41D, for example. However, as described above, the pitches of the plurality of individual flow paths 13 may fluctuate within each individual flow path line 41, and the method of fluctuation is as follows: 1st individual flow path line 41A to 4th individual flow path. The rows 41D may be the same or symmetrical, or they may be completely different.

As shown in FIG. 5, in the following description, one side in the direction parallel to the width direction of the common flow path 11 is referred to as the D1 side, and the other side is referred to as the D2 side.

The first individual flow path line 41A (first pressurizing chamber line 25A) is the line located closest to the D1 side of the four individual flow path lines 41. In other words, the first individual flow path line 41A is a line of the two individual flow path lines 41 located on the D1 side with respect to the common flow path 11, which is relatively far from the common flow path 11. is there. The plurality of first individual flow paths 13A in the first individual flow path line 41A are provided, for example, at positions where the first pressurizing chamber 17A does not overlap the common flow path 11 in a plan view. Further, the plurality of first individual flow paths 13A are provided so that the partial flow paths 19 and the discharge holes 9 are located on the D1 side with respect to the first pressurizing chamber 17A. The first connection flow path 15A is connected to the first pressurizing chamber 17A outside the common flow path 11 in a plan view, extends from the connection position to the common flow path 11, and is connected to the common flow path 11. Has been done.

The second individual flow path line 41B (second pressurizing chamber line 25B) is the second line from the D1 side of the four individual flow path lines 41. In other words, the second individual flow path line 41B is a line that is relatively close to the common flow path 11 among the two individual flow path lines 41 located on the D1 side with respect to the common flow path 11. The plurality of second individual flow paths 13B in the second individual flow path line 41B are provided, for example, at positions where the second pressurizing chamber 17B overlaps the common flow path 11 in a plan view. Further, the plurality of second individual flow paths 13B are provided so that the partial flow paths 19 and the discharge holes 9 are located on the D1 side with respect to the second pressurizing chamber 17B. Then, the second connection flow path 15B is connected to the second pressurizing chamber 17B at a position overlapping the common flow path 11 in a plan view, extends in an appropriate direction from the connection position, and is connected to the common flow path 11. Has been done.

The plurality of first individual flow paths 13A of the first individual flow path line 41A and the plurality of second individual flow paths 13B of the second individual flow path line 41B alternate, for example, in the length direction of the common flow path 11. positioned. For example, focusing on the pressurizing chamber 17, the plurality of first pressurizing chambers 17A and the plurality of second pressurizing chambers 17B alternate in the length direction of the common flow path 11 so as not to overlap each other in a plan view. It is arranged in. However, the plurality of first pressurizing chambers 17A and the plurality of second pressurizing chambers 17B have a part of the arrangement range in the width direction of the common flow path 11 when viewed in the length direction of the common flow path 11. It is duplicated. Further, the plurality of first pressurizing chambers 17A and the plurality of second pressurizing chambers 17B have a part of the arrangement range in the length direction of the common flow path 11 when viewed in the width direction of the common flow path 11. It is duplicated. That is, the plurality of first pressurizing chambers 17A and the plurality of second pressurizing chambers 17B are relatively densely arranged.

The fourth individual flow path line 41D (fourth pressure chamber line 25D) and the third individual flow path line 41C (third pressure chamber line 25C) are, for example, roughly a symmetry point located at the center of the common flow path 11. The first individual flow path line 41A (first pressurizing chamber line 25A) and the second individual flow path line 41B (second pressurizing chamber line 25B) are 180 ° rotationally symmetric. Therefore, the description of the relative positions and directions of the individual flow paths 13 included in the first individual flow path line 41A and the second individual flow path line 41B with respect to the common flow path 11 is described in the fourth individual flow path line 41D. And may be applied to the third individual channel line 41C. At this time, A in the description may be replaced by D, B by C, the first by the fourth, the second by the third, and D1 by D2.

The plurality of second individual flow paths 13B and the plurality of third individual flow paths 13C are alternately located, for example, in the length direction of the common flow path 11. For example, both are arranged alternately in the length direction of the common flow path 11 so as not to overlap each other in a plan view. However, both of them partially overlap each other in the arrangement range in the width direction of the common flow path 11 when viewed in the length direction of the common flow path 11 (mainly the connection flow paths 15). Further, both of them partially overlap each other in the arrangement range in the length direction of the common flow path 11 when viewed in the width direction of the common flow path 11 (mainly the pressurizing chambers 17).

In the individual flow path rows 41 that are not adjacent to each other in the width direction of the common flow path 11 (41A and 41C, 41B and 41D, and 41A and 41D), the length direction of the common flow path 11 of the plurality of individual flow paths 13 The positional relationship in the above may be appropriately set. However, as already described, at least the positions of the discharge holes 9 are deviated from each other when viewed in the transport direction of the printing paper P (the direction intersecting the common flow path 11).

(Actuator board)
Returning to FIG. 2, the actuator substrate 7 has a substantially plate shape having an area extending over a plurality of pressurizing chambers 17. The actuator board 7 is composed of a so-called unimorph type piezoelectric actuator. The actuator substrate 7 may be made of a piezoelectric actuator of another type such as a bimorph type. The actuator substrate 7 has, for example, the piezoelectric layer 29A, the common electrode 31, the piezoelectric layer 29B, and the individual electrodes 33 in this order from the flow path member 5 side.

The piezoelectric layer 29A, the common electrode 31, and the piezoelectric layer 29B extend over a plurality of pressurizing chambers 17 in a plan view. That is, these are commonly provided in the plurality of pressurizing chambers 17. The individual electrodes 33 are provided at positions facing the pressurizing chamber 17 for each pressurizing chamber 17. The number of individual electrodes 33 is basically the same as the number of pressurizing chambers 17. The portion of the actuator substrate 7 corresponding to each pressurizing chamber 17 is referred to as a pressurizing element 38.

The portion of the piezoelectric layer 29B sandwiched between the individual electrode 33 and the common electrode 31 is polarized in the thickness direction. Therefore, for example, when an electric field (voltage) is applied in the polarization direction of the piezoelectric layer 29B by the individual electrodes 33 and the common electrode 31, the piezoelectric layer 29B contracts in the direction along the layer. This shrinkage is regulated by the piezoelectric layer 29A. As a result, the pressurizing element 38 bends and deforms so as to be convex toward the pressurizing chamber 17. As a result, the volume of the pressurizing chamber 17 is reduced, and pressure is applied to the liquid in the pressurizing chamber 17. When an electric field (voltage) is applied in the direction opposite to the above by the individual electrodes 33 and the common electrode 31, the pressurizing element 38 bends and deforms to the side opposite to the pressurizing chamber 17.

The thickness, material, and the like of each layer constituting the actuator substrate 7 may be appropriately set. As an example, the thicknesses of the piezoelectric layers 29A and 29B may be 10 μm or more and 40 μm or less, respectively. The thickness of the common electrode 31 may be 1 μm or more and 3 μm or less. The thickness of the individual electrode 33 may be 0.5 μm or more and 2 μm or less. The material of the piezoelectric layer 29A and 29B, for example, lead zirconate titanate (PZT), NaNbO ₃ system, BaTiO ₃ system, (BiNa) NbO ₃ based ceramic having ferroelectricity such as BiNaNb ₅ O ₁₅ system It may be used as a material. The material of the piezoelectric layer 29A (diaphragm) may be a material having no piezoelectricity. The material of the common electrode 31 may be a metal material such as an Ag-Pd system. The material of the individual electrode 33 may be a metal material such as Au.

The shape and dimensions of the individual electrodes 33 in a plan view are, for example, substantially the same as the shape and dimensions of the pressurizing chamber 17 in a plan view. In the present embodiment, as shown in FIG. 5, the individual electrode 33 has a rhombus shape that is one size smaller than the pressurizing chamber 17. However, the planar shape of the individual electrode 33 may be different from the planar shape of the pressurizing chamber 17.

As shown in FIGS. 2 and 5, the extraction electrode 35 extends from the individual electrode 33. The end portion (land 35a) of the extraction electrode 35 opposite to the individual electrode 33 reaches the outside of the pressurizing chamber 17, and the connection electrode 37 is formed on the land 35a. The connection electrode 37 is joined to a signal transmission member (for example, FPC: Flexible printed circuits) (not shown) included in the head 2. An electric potential (drive signal) is applied to the individual electrode 33 from the control unit 88 via a signal transmission member, a connection electrode 37, and an extraction electrode 35.

The extraction electrode 35 extends in the longitudinal direction of the pressurizing chamber 17, for example, from a portion of the outer edge of the individual electrode 33 that is on the end side in the longitudinal direction of the pressurizing chamber 17. As described above, the partial flow path 19 and the connection flow path 15 are connected to both ends of the pressurizing chamber 17 in the longitudinal direction. The extraction electrode 35 may be located on the partial flow path 19 side or on the connection flow path 15 side. In the example of FIG. 5, the extraction electrode 35 corresponding to the first pressurizing chamber row 25A and the second pressurizing chamber row 25B is located on the partial flow path 19 side, and the third pressurizing chamber row 25C and the fourth pressurizing chamber row 25C and the fourth. The extraction electrode 35 corresponding to the pressurizing chamber row 25D is located on the connection flow path 15 side. The extraction electrode 35 is integrally formed with, for example, the individual electrode 33, and its material and thickness are the same as those of the individual electrode 33.

The connection electrode 37 is made of a conductive resin containing conductive particles such as silver particles, and has a thickness of 5 μm or more and 200 μm or less.

Although not particularly shown, the common electrode 31 is connected to the above-mentioned signal transmission member via a through conductor penetrating the piezoelectric layer 29B at non-arranged positions of the plurality of individual electrodes 33 in a plan view, and thus is connected to the above-mentioned signal transmission member. , Is connected to the control unit 88. A reference potential is applied to the common electrode 31 via a signal transmission member.

(Other configurations in the head)
Although not particularly shown, the head 2 may include a housing, a driver IC, a wiring board, and the like in addition to the head main body 2a. Further, the head body 2a may include another flow path member that supplies the liquid to the flow path member 5. Such other flow path members may support the other members or contribute to the fixation of the head 2 to the frame 70.

(Details of partial flow path)
FIG. 6 is a schematic view showing a part of the individual flow path 13 extracted from the vertical cross-sectional view of FIG. Specifically, among the individual flow paths 13, a part of the pressurizing chamber 17 to the discharge hole 9 via the partial flow path 19 is extracted. FIG. 7 is a schematic plan perspective view showing a part of the partial flow path 19 and the pressurizing chamber 17.

In FIG. 6, the unevenness of the inner surface of the partial flow path 19 is exaggerated as compared with the actual one and / or a figure close to the actual one (for example, FIG. 2). Therefore, for example, the size of the step on the inner surface of the partial flow path 19 is drawn larger than the actual one as compared with the diameter of the partial flow path 19. FIG. 7 reflects the dimensions of FIG. Therefore, in FIG. 7, similarly to FIG. 6, the size of the step on the inner surface of the partial flow path 19 is drawn larger than the actual one as compared with the diameter of the partial flow path 19.

The area of the cross section of the partial flow path 19 (cross section parallel to the pressurizing surface 5b (corresponding to the upper side of the pressurizing chamber 17 in FIG. 6)) is in the vertical direction (direction orthogonal to the pressurizing surface 5b, vertical direction also in FIG. 6). ) Is changing. Further, the partial flow path 19 does not extend linearly from the pressurizing chamber 17 toward the discharge hole 9, and a part portion (43A) is parallel to the other portion in the plane direction (parallel to the pressurizing surface 5b). The direction is shifted in the left-right direction in FIG. Specifically, it is as follows.

(Type of diameter)
In the present embodiment, the shape of the cross section of the partial flow path 19 is circular at any position in the vertical direction. Therefore, in the description of the present embodiment, it may not be possible to distinguish between the description of the size of the area of the cross section and the description of the size of the diameter (diameter; the same applies hereinafter) with respect to the partial flow path 19. If it is not circular, the following diameter may be read as the equivalent diameter of a circle.

As described above, the flow path member 5 is formed by stacking a plurality of plates 21, and the flow path in the flow path member 5 is formed by holes formed in each of the plurality of plates 21. ing. Specifically, the pressurizing chamber 17 is composed of holes formed in the plate 21N. The partial flow path 19 is composed of holes 43A to 43L (hereinafter, A to L may be omitted) formed in the plates 21M to 21B. The discharge hole 9 is composed of holes formed in the plate 21A. Note that FIG. 7 shows the pressurizing chamber 17 and some of the holes 43A to 43L.

The plurality of holes 43 constituting the partial flow path 19 have different diameters at least partially. The size of the diameter may be appropriately set, and the relationship between the size of the diameter and the position of the hole 43 (vertical direction and plane direction) may be appropriately set.

In the illustrated example, the plurality of holes 43 can be divided into the following four groups according to the difference in diameter.
・ First group: Hole 43B
-Second group: Holes 43A, 43C, 43D and 43J-43L
-Third group: Holes 43E and 43I
・ Fourth group: Holes 43F to 43H

The diameters of the holes 43 belonging to each group are the same as each other. Further, the diameter of the hole 43 increases in order from the first group to the fourth group. The diameters of the holes 43 belonging to each group may be different from each other as long as the magnitude relationship of the diameters is not reversed with that of other groups.

The specific value of the diameter in each group and / or the specific difference in diameter between the groups may be set as appropriate. An example is given below. The diameter of the holes in the first to fourth groups is 100 μm or more and 300 μm or less. In the first to fourth groups, the difference in diameter between the front and rear groups (difference between the first and second, difference between the second and third, or difference between the third and fourth) is 5 μm or more and 50 μm or less. Is. Further, in the case of limiting to the second to fourth groups, the difference in diameter between the front and rear groups (difference between the second and third or the difference between the third and fourth) is 5 μm or more and 20 μm or less. In the first to fourth groups, the difference between the smallest diameter hole (43B) and the largest diameter hole (43F to 43H) is 20 μm or more and 100 μm or less. When limited to the second to fourth groups, the difference between the smallest diameter holes (holes 43A, 43C, 43D and 43J to 43L) and the largest diameter holes (43F to 43H) is 10 μm or more and 50 μm or less. ..

An example is given from the viewpoint of the diameter ratio. The average diameter, the minimum diameter (diameter of the hole 43B) or the maximum diameter (diameter of the holes 43F to 43H) of the partial flow path 19 is used as a reference diameter. For the average diameter, for example, it is assumed that the value obtained by integrating the diameter of the partial flow path 19 in the vertical direction is divided by the length of the partial flow path 19 in the vertical direction. At this time, in the first to fourth groups, the difference in diameter between the front and rear groups is 2% or more and 30% or less of the reference diameter. When limited to the second to fourth groups, the difference in diameter between the front and rear groups is 2% or more and 10% or less of the reference diameter. In the first to fourth groups, the difference between the smallest diameter hole and the largest diameter hole is 10% or more and 50% or less of the reference diameter. When limited to the second to fourth groups, the difference between the smallest diameter hole and the largest diameter hole is 5% or more and 20% or less of the reference diameter.

Although an example of the diameter is given above, the value of the above example may be converted into the value of the area, assuming that the shape of the cross section of the partial flow path 19 is circular. Then, the value of an example of the area may be applied to the case where the cross section is not circular. To be confirmed, the average area of the cross section of the partial flow path 19 is the length of the partial flow path 19 obtained by integrating the area of the cross section of the partial flow path 19 in the vertical direction (volume of the partial flow path 19). It is divided by.

(Large diameter part and small diameter part)
In addition to the above classifications, among the plurality of holes 43, those having a diameter equal to or larger than the predetermined large diameter side threshold value are defined as the large diameter portion, and those having a diameter equal to or less than the predetermined small diameter side threshold value are defined as the small diameter portion. It is also possible to classify as defined as. The large-diameter side threshold value and the small-diameter side threshold value may be the same value, or the large-diameter side threshold value may be larger than the small-diameter side threshold value. Alternatively, among the plurality of holes 43, the one having the largest diameter can be defined as the large diameter portion, and the one having the smallest diameter can be defined as the small diameter portion. It should be noted that the definition using the threshold value and the definition of the maximum or minimum viewpoint may be combined.

For example, the large diameter portion may be defined with the large diameter side threshold value (and / or the small diameter side threshold value) as the average diameter (average area). In this case, for example, in the illustrated example, each or all of the holes 43E to 43I of the third and fourth groups (one hole composed of the holes 43E to 43I) is a large diameter portion. Further, each or all of the holes 43F to 43G having the maximum diameter may be defined as a large diameter portion. In the following description, for convenience, each of the holes 43E to 43I or each of the holes 43F to 43G will be referred to as a large diameter portion. Further, for example, the hole 43B having the minimum diameter may be defined as the small diameter portion.

In the definition (classification) of the large diameter portion and the small diameter portion as described above, and / or in the case of grouping by the diameter as described above, the peculiar hole 43 may be excluded. For example, in the illustrated example, as will be described later, the hole 43A has a peculiarity regarding the position in the direction parallel to the pressure surface 5b, and the large-diameter portion and the small-diameter portion ignore such a hole 43A. May be defined.

(Relationship between diameter and vertical position)
The partial flow path 19 is basically configured to have a large diameter at a predetermined intermediate position in the vertical direction (except for the magnitude relationship between the holes 43A and the holes 43B). In other words, for example, all of the large diameter portions (holes 43E to 43I or 43F to 43H) defined as described above are pressurized chambers in the extending direction (flow path direction / flow direction) of the partial flow path 19. It is separated from both the 17 and the discharge hole 9. From another point of view, all the plates (21E-21I or 21F-21H) on which the large diameter portion is formed are the plate 21N on which the pressurizing chamber 17 is formed and the plate 21A on which the discharge hole 9 is formed. Not overlapping (not adjacent in the stacking direction).

The portion having a large diameter as described above may be located at the center of the height of the partial flow path 19 in the vertical direction (direction orthogonal to the pressure surface 5b). It may be located on the pressurizing chamber 17 side or the discharge hole 9 side from the center. In the illustrated example, the central position of the partial flow path 19 in the vertical direction is located in the hole 43F. Therefore, for example, the entire large-diameter portion (the entire holes 43E to 43I or the entire 43F to 43H) is biased toward the discharge hole 9 side while including the portion located at the center in the vertical direction of the partial flow path 19. It is located (the center of gravity is located closer to the discharge hole 9 than the center).

The diameter expansion of the partial flow path 19 at a predetermined intermediate position in the vertical direction is basically (except for the magnitude relationship between the holes 43A and 43B) to the intermediate position (the position of the maximum diameter from another viewpoint). The diameter is gradually changed toward it. Specifically, for example, the plurality of holes 43 are arranged in the following order from the pressurizing chamber 17 side to the discharge hole 9 side, except for the holes 43A. Holes 43B of the first group, holes 43C and 43D of the second group having a larger diameter, holes 43E of the third group having a larger diameter, holes 43F to 43H of the fourth group having a larger diameter, Holes 43I of the third group having a diameter smaller than this, holes 43J to L of the second group having a diameter smaller than this. Therefore, when considering excluding the hole 43A, the change from the minimum diameter (hole 43B) on the pressurizing chamber 17 side to the maximum diameter (hole 43F) is not one step but two or more steps (in the illustrated example). 3 steps). Similarly, the change from the maximum diameter (hole 43H) to the minimum diameter (hole 43J) on the discharge hole 9 side is not one step but two or more steps (two steps in the illustrated example).

Of the plurality of holes 43, the diameter of the hole 43A (the hole closest to the pressurizing chamber 17 and the hole of the plate 21M directly overlapping the plate 21N constituting the pressurizing chamber 17) that opens into the pressurizing chamber 17 is appropriately adjusted. May be set. For example, the diameter of the hole 43A may be the maximum diameter, the minimum diameter, the large diameter portion, the small diameter portion, or any of these. It may be a size that does not belong. In the illustrated example, the diameter of the hole 43A is smaller than the average diameter and larger than the minimum diameter.

The hole 43B is a hole having the smallest diameter among all the plurality of holes 43 constituting the partial flow path 19. From another viewpoint, the hole 43B is the smallest hole 43 among the holes 43 located closer to the pressurizing chamber 17 than the central position in the vertical direction of the partial flow path 19. As will be understood from the above description, such a hole 43B is next to the hole 43A (a hole having a peculiarity in a planar position as described later) opened in the pressurizing chamber 17 in the illustrated example. It is a hole close to the pressurizing chamber 17 (a hole in the plate 21L that directly overlaps the plate 21M).

(Position of the hole in the plane direction)
The plurality of holes 43 are basically arranged coaxially in the vertical direction (except for the holes 43A), for example. In other words, when the pressure surface 5b is viewed through the plane, the centroids (centers in the circle) of the plurality of holes 43 coincide with each other. To be confirmed, the center of gravity is a point in a flat figure where the first moment of cross section with respect to an arbitrary axis passing through the point becomes zero. Even if the centers of gravity match, it goes without saying that there may be deviations due to manufacturing errors. Examples of the manufacturing error include an error when the hole 43 is formed in the plate 21 and an error when the plates 21 are laminated and fixed.

The fact that the plurality of holes 43 are arranged coaxially means that, in terms of planar perspective, the amount of deviation between the centers of gravity of the plurality of holes 43 (excluding the holes 43A) is less than or equal to a predetermined size. It can be said that there is. For example, in a plurality of holes 43B to 43L, the maximum value of the amount of deviation between the centroids (not limited to the centroids of adjacent holes 43) is the deviation between the centroids of the holes 43A and the centroids of the holes 43B. Less than 1 times, 1/2 or less or 1/4 or less of the amount. From another viewpoint, the maximum value of the deviation amount is, for example, 10 μm or less or 5 μm or less. From yet another viewpoint, the maximum value of the deviation amount is, for example, 5% or less or 2% or less of the maximum diameter of the partial flow path 19.

Since the plurality of holes 43 (excluding 43A) are arranged coaxially, each hole 43 is housed in a hole 43 having a diameter larger than that of itself in plan perspective. For example, the small diameter portion (43B) is contained in the large diameter portion (43E to 43I or 43F to 43H).

When the pressurizing surface 5b is viewed through a plane, the centers of gravity of the plurality of holes 43 (including 43A) are contained in the pressurizing chamber 17. In FIG. 7, the center of gravity G1 of the holes 43B to 43L and the center of gravity G2 of the holes 43A are shown.

As can be seen from FIGS. 2 and 5 in which the unevenness of the inner surface of the partial flow path 19 is not exaggerated, when the pressurized surface 5b is viewed through a plane, the plurality of holes 43 are basically (excluding the holes 43A), for example. ), Almost the whole fits in the pressurizing chamber 17. In addition, in FIGS. 6 and 7, since the unevenness of the partial flow path 19 is exaggerated as described above, the holes 43E to 43I having a relatively large diameter are different from the actual ones and are added. It is drawn as if it protrudes greatly from the pressure chamber 17.

More specifically, for example, in the plan view of the pressurizing surface 5b, each of the plurality of holes 43 (excluding 43A) is contained in the pressurizing chamber 17, or the amount of protrusion from the pressurizing chamber 17 is predetermined. It is not less than the upper limit value (distance d1 in FIG. 7). When it is said that the hole 43 is housed in the pressurizing chamber 17, the edge portion of the hole 43 may overlap the edge portion of the pressurizing chamber 17, and the hole 43 protrudes from the pressurizing chamber 17 within the range of manufacturing error. You may have.

In the illustrated example, the holes 43B to 43D and 43J to 43L of the first and second groups are housed in the pressurizing chamber 17. The holes 43E to 43I (large diameter portion from another viewpoint) of the third and fourth groups protrude from the pressurizing chamber 17, but the amount of protrusion is not more than the upper limit value (distance d1).

The upper limit value (distance d1) may be appropriately set, may be set in common for a plurality of holes 43, or may be set for each hole 43. For example, the upper limit value may be set in common to the plurality of holes 43, and may be a length obtained by multiplying the reference diameter (minimum diameter, average diameter, or maximum diameter of the partial flow path 19) by a predetermined upper limit specified ratio. Further, for example, the upper limit value may be set for each hole 43 and may be a length obtained by multiplying the diameter of the hole 43 by the upper limit specified ratio. The upper limit specified ratio may be, for example, 10% or 5%.

In FIG. 7, a dotted line is shown at a position separated outward at a distance d1 from the outer edge of the pressurizing chamber 17. The distance d1 here is, for example, the length of the upper limit specified ratio (for example, 10% or 5%) of the diameter of the maximum diameter (holes 43F to 43H) of the partial flow path 19. However, in FIG. 7, the distance d1 is drawn longer than 10% or 5% of the diameter of the hole 43F, unlike the actual one, because the unevenness of the inner surface of the partial flow path 19 is exaggerated. As can be seen from FIG. 7, it is said that the plurality of holes 43 (including the large diameter portion) are within the range R1 having the outer edge separated from the outer edge of the pressurizing chamber 17 outward at a distance d1. You can catch it.

(Position of the hole that opens in the pressurizing chamber in the plane direction)
The hole 43A, which is a portion of the partial flow path 19 connected to the pressurizing chamber 17, is deviated from the center of gravity of at least a part (all in the illustrated example) of the partial flow path 19 in plan perspective. In other words, the hole 43A closest to the pressurizing chamber 17 among the plurality of holes 43 is deviated from the center of gravity of at least one of the other holes 43. Further, the hole 43A has a portion located outside the pressurizing chamber 17 in plan perspective. Specifically, it is as follows.

In plan perspective, the hole 43A protrudes from the pressurizing chamber 17 in a predetermined direction. The predetermined direction is a direction from the center of the pressurizing chamber 17 to the partial flow path 19. Further, in the present embodiment, the predetermined direction is one side in the longitudinal direction of the pressurizing chamber 17, and more specifically, one side of the relatively long diagonal line of the rhombus. Such a configuration contributes to, for example, reducing the probability that an air pool will occur at the end of the pressurizing chamber 17 on the partial flow path 19 side.

The amount of protrusion of the hole 43A from the pressurizing chamber 17 may be appropriately set. For example, the distance from the outer edge of the pressurizing chamber 17 to the portion of the outer edge of the hole 43A located outside the pressurizing chamber 17 (the shortest distance from each point on the outer edge of the pressurizing chamber 17 to the outer edge of the hole 43A). Consider the longest distance as the maximum value of the amount of protrusion. This maximum value is larger than, for example, the amount of misalignment between the hole 43A and the pressurizing chamber 17 caused by a manufacturing error.

Further, the maximum value of the amount of protrusion may be larger, equal to, or smaller than the upper limit value when the above-mentioned hole 43 is generally contained in the pressurizing chamber 17. Further, for example, the maximum value of the protrusion amount of the hole 43A is the diameter or the reference diameter of the hole 43A (minimum diameter, average diameter or maximum diameter of the partial flow path 19) regardless of or related to the above upper limit value. It may be larger than a predetermined ratio (for example, 10% or 5%), equal to or smaller than a predetermined ratio.

In the illustrated example, the maximum value of the protrusion amount of the hole 43A is set to be equal to or larger than the upper limit specified ratio (10% or 5%) of the maximum diameter. In other words, the maximum value of the protrusion amount of the holes 43A is larger than the maximum value of the protrusion amount of the holes 43F to 43H having the maximum diameter. From another point of view, in plan perspective, the hole 43A protrudes from all the large diameter portions (holes 43E to 43I or 43F to 43H) in a predetermined direction (opposite to the pressurizing chamber 17).

The amount of deviation between the center of gravity G2 of the hole 43A and the center of gravity G1 of the other hole 43 may be appropriately set. For example, the specific example of the maximum value of the amount of protrusion of the hole 43A from the pressurizing chamber 17 may be applied to the amount of deviation between the center of gravity G2 and G1. For example, the amount of deviation between the center of gravity G2 and G1 may be larger, equal, or smaller than the upper limit value when the hole 43 is generally contained in the pressurizing chamber 17. Further, the amount of deviation between the center of gravity G2 and G1 is determined by the diameter of the hole 43A or the reference diameter (minimum diameter, average diameter or maximum diameter of the partial flow path 19) in relation to or regardless of the above upper limit value. It may be greater than, equal to, or less than the proportion (eg, 10% or 5%). In the illustrated example, the maximum value of the protrusion amount of the hole 43A and the deviation amount between the centers of gravity G2 and G1 are the same.

The hole 43B is a portion of the partial flow path 19 that is connected to the discharge hole 9 side of the hole 43A (a hole of the plurality of holes 43 that is closest to the pressurizing chamber 17 next to the hole 43A). In the plan perspective, the center of gravity G2 of the hole 43A is shifted to the outside of the pressurizing chamber 17 with respect to the center of gravity G1 of the hole 43B, so that a part of the hole 43B is inside the pressurizing chamber 17 with respect to the hole 43A. (It protrudes from the hole 43A to the inside of the pressurizing chamber 17). From another viewpoint, the plate 21M having the hole 43A is a portion sandwiched between a part of the pressurizing chamber 17 and a part of the hole 43B in the vertical direction (the edge of the hole 43A on the pressurizing chamber 17 side). It has a part that constitutes a part). From yet another viewpoint, the hole 43B has a portion protruding from the hole 43A in a direction opposite to the direction in which the hole 43A protrudes from the large diameter portion (holes 43E to 43I or 43F to 43H).

(Plate thickness)
The thickness of the plates 21A to 21N may be appropriately set. In the illustrated example, the plates 21A to 21N can be divided into the following four plate groups according to the difference in thickness.
First plate group: Plates 21C, 21D and 21L
Second plate group: Plates 21A, 21B and 21N
・ Third plate group: Plate 21M
-Fourth plate group: Plates 21E-21K

The thickness of the plates 21 belonging to each plate group is the same as each other. Further, the thickness of the plate 21 increases in order from the first plate group to the fourth plate group. The thickness of the plates 21 belonging to each plate group may be different from each other as long as the magnitude relationship of the thickness is not reversed with that of other groups.

Specific values for the thickness in each plate group may be set as appropriate. An example is given below. The thickness of the first plate group is 10 μm or more and 50 μm or less. The thickness of the second plate group is 30 μm or more and 100 μm or less (however, it is thicker than the thickness of the first plate group). The thickness of the third plate group is 50 μm or more and 200 μm or less (however, it is thicker than the thickness of the second plate group). The thickness of the fourth plate group is 80 μm or more and 300 μm or less (however, it is thicker than the thickness of the third plate group).

Similarly, specific differences in thickness between groups may be set as appropriate. An example is shown below. The thickness of the fourth plate group is used as the reference thickness. At this time, the thickness of the first plate group is 10% or more and 40% or less of the reference thickness. The thickness of the second plate group is 20% or more and 70% or less of the standard thickness. The thickness of the third plate group is 30% or more and 90% or less of the standard thickness. The thickness of the third plate group is 1.5 times or more and 5 times or less the thickness of the first plate group.

In the plates 21B to 21M constituting the partial flow path 19, the thickness of the plate 21 may be classified into two types based on the average thickness of the plate 21. To be confirmed, the average thickness is a value obtained by dividing the total thickness of the plates 21B to 21M by the number of plates 21B to 21M. An example of the average thickness is 50 μm or more and 200 μm or less. In the illustrated example, the thickness of the plates 21E-21K is larger than the average thickness, and the thickness of the other plates 21 is smaller than the average thickness.

(Relationship between plate thickness and hole specifications)
From the above description of the thickness of the plate 21, for example, the following items shall be described regarding the relationship between the diameters of the plurality of holes 43 and the thickness of the plate 21 (the length of the holes 43 in the vertical direction). Can be done.

In the plates 21B to 21M constituting the partial flow path 19, each of the plates 21I to 21E constituting the large diameter portion (holes 43E to 43I or 43F to 43H) is larger than the thickness of at least one other plate 21. It has a thickness and is thicker than the thickness of each of the other plates 21. And / or each of the plates 21I-21E has a thickness greater than the average thickness of the plurality of plates 21B-21M. More specifically, each of the plates 21I-21E has a maximum thickness of a plurality of plates 21B-21M.

In the plates 21B to 21M forming the partial flow path 19, the plate 21L forming the small diameter portion (hole 43B) has a thickness smaller than the thickness of at least one other plate 21, and all the others. It has a thickness equal to or less than the thickness of each of the plates 21. And / or, the plate 21L has a thickness smaller than the average thickness of the plurality of plates 21B to 21M. More specifically, the plate 21L has a minimum thickness of a plurality of plates 21B-21M.

The plate 21M is a plate forming a hole 43A that opens into the pressurizing chamber 17, and the plate 21L is a plate (directly in the hole 43A) adjacent to the plate 21M on the opposite side of the pressurizing chamber 17. It is a plate constituting the connecting hole 43B). The plate 21L is thinner than the plate 21M.

(Positional relationship between land and flow path)
Return to FIG. The positional relationship between the land 35a and the flow path of the flow path member 5 may be appropriately set. In the illustrated example, the land 35a corresponding to the first pressurizing chamber group 39A located on one side (above the paper surface) of the common flow path 11 in the width direction is positioned so as not to overlap with any of the flow paths of the flow path member 5. Have been placed. As a result, the land 35a corresponding to the first pressurizing chamber group 39A does not overlap the pressurizing chamber 17, and any flow path (hole 43A) of the plate 21M overlapping the plate 21N constituting the pressurizing chamber 17. And it does not overlap with the third portion 15c) of the connection flow path 15. Further, the land 35a corresponding to the first pressurizing chamber group 39A is located on the partial flow path 19 side with respect to the pressurizing chamber 17, but any of the plurality of holes 43 constituting the partial flow path 19. Does not overlap.

The land 35a corresponding to the second pressurizing chamber group 39B on the side opposite to the first pressurizing chamber group 39A (below the paper surface) with respect to the common flow path 11 is connected to the pressurizing chamber 17 in plan perspective. It is located on the road 15 side and overlaps the connecting flow path 15. However, the land 35a corresponding to the second pressurizing chamber group 39B is also located on the partial flow path 19 side with respect to the pressurizing chamber 17, and flows, similarly to the land 35a corresponding to the first pressurizing chamber group 39A. It may be arranged at a position that does not overlap with any of the flow paths of the road member 5. More specifically, the land 35a corresponding to the second pressurizing chamber group 39B overlaps the second portion 15b of the connection flow path 15. Therefore, the land 35a corresponding to the second pressurizing chamber group 39B does not overlap with the pressurizing chamber 17, and constitutes the pressurizing chamber 17, like the land 35a corresponding to the first pressurizing chamber group 39A. It does not overlap any of the flow paths (hole 43A and the third portion 15c of the connection flow path 15) of the plate 21M that overlaps the plate 21N.

As described above, in the present embodiment, the liquid discharge head 2 (head body 2a) has the flow path member 5 and the pressurizing element 38. The flow path member 5 has a discharge surface 5a and a pressure surface 5b which is the back surface of the discharge surface 5a. Further, the flow path member 5 extends from the discharge hole 9 opened in the discharge surface 5a, the pressure chamber 17 located on the pressure surface 5b side of the discharge hole 9, and the pressure chamber 17 to the discharge hole 9. It has a partial flow path 19. The pressurizing element 38 overlaps the pressurizing surface 5b and is displaced in the direction toward the pressurizing chamber 17 and in the opposite direction to pressurize the liquid in the pressurizing chamber 17. The partial flow path 19 has one or more large diameter portions (holes 43E to 43I or 43F to 43G) whose cross-sectional area parallel to the pressure surface 5b is larger than the average area of the partial flow path 19 in the cross-sectional area. have. In the planar perspective of the pressurized surface 5b, each of the large diameter portions is within the range R1. The range R1 is a range having a length of 10% of the maximum diameter of the partial flow path 19 and having an outer edge separated from the outer edge of the pressurizing chamber 17 to the outside.

Therefore, for example, having a large diameter portion increases the volume of the partial flow path 19. As a result, it becomes easy to increase the discharge amount of the droplets. On the other hand, since the large-diameter portion is generally contained in the pressurizing chamber 17 in plan perspective, the pressure applied to the pressurizing chamber 17 in the vertical direction (direction intersecting the pressurizing surface 5b) is in the planar direction (in the plane direction). The probability of escaping in the direction along the pressure surface 5b) is reduced. In other words, the loss of pressure waves is reduced. As a result, pressure can be efficiently applied to the liquid in the partial flow path 19 having a large volume, and the amount of droplets discharged can be increased.

Further, in the present embodiment, all the large diameter portions (holes 43E to 43I or 43F to 43G) are separated from the pressurizing chamber 17 and the discharge hole 9 in the extending direction of the partial flow path 19. From another viewpoint, the large diameter portion is located on the central side of the partial flow path 19 in the flow direction.

In this case, for example, as compared with a mode in which a large diameter portion is located adjacent to the pressurizing chamber 17 and / or the discharge hole 9 (the mode may also be included in the technique according to the present disclosure). Scattering of the pressure wave in the vicinity of the pressure chamber 17 and the vicinity of the discharge hole 9 in the plane direction is reduced, and the pressure wave can be efficiently used for discharging the droplets. From another viewpoint, it is possible to increase the discharge amount of the droplets in the vicinity of the pressurizing chamber 17 and the vicinity of the discharge hole 9 while realizing the same propagation mode of the pressure wave as in the case where the large diameter portion is not provided.

Further, in the present embodiment, the flow path member 5 has a plurality of plates 21 laminated from the discharge surface 5a to the pressure surface 5b. The discharge hole 9, the partial flow path 19, and the pressurizing chamber 17 are composed of holes included in the plurality of plates 21. The plurality of plates 21 have different thicknesses from each other, at least in a part thereof. Within the plurality of plates 21, all the plates 21E-21I or 21F-21H constituting the large diameter portion each have a thickness larger than the thickness of at least one other plate, and all the others. It has a thickness greater than the thickness of each plate.

In this case, for example, the decrease in rigidity of the plate 21 due to the formation of the large diameter portion (holes 43E to 43I or 43F to 43G) can be compensated by the thickness of the plate 21. As a result, the probability that the flow path member 5 is locally deformed is reduced. In other words, the rigidity of the flow path member 5 as a whole is improved.

Further, in the present embodiment, the partial flow path 19 has a shift portion (hole 43A) and a small diameter portion (43B). A part of the shift portion (hole 43A) protrudes from all the large diameter portions (holes 43E to 43I or 43F to 43G) in the plan view of the pressure surface 5b. The small diameter portion (43B) is located next to the large diameter portion side with respect to the shift portion (hole 43A) in the direction orthogonal to the pressure surface 5b. Further, in the plan view of the pressure surface 5b, a part of the small diameter portion protrudes from the shift portion on the side opposite to the side where the shift portion protrudes from the large diameter portion, and the small diameter portion fits in all the large diameter portions. There is. Further, the cross-sectional area of the small-diameter portion is smaller than the cross-sectional area and average area of the shift portion.

In this case, for example, a mode in which the shift portion (hole 43A) and the large diameter portion (holes 43E to 43I or 43F to 43G) are directly connected (the mode may also be included in the technique according to the present disclosure). ), It is easier to regulate the direction of the pressure wave propagating from the shift part to the large diameter part. As a result, the pressure wave can be easily guided to the discharge hole 9, although it depends on the overall configuration of the partial flow path 19. From another point of view, when it is necessary to shift a part (shift portion) of the partial flow path 19 with respect to the large diameter portion due to various circumstances, the pressure wave is not intended while increasing the deviation amount. The probability of propagating in the direction can be reduced.

Further, for example, focusing on the manufacturing process, it is possible to reduce the variation in the cross-sectional area of the partial flow path 19. Specifically, it is as follows. For example, in the hole 43D and the hole 43E, since the hole 43D is planned to fit in the hole 43E in plan perspective, the degree of the misalignment when the misalignment of the hole 43D and the hole 43E occurs in the plane direction. Although it depends on the above, the positional relationship in which the hole 43D fits in the hole 43E is maintained. As a result, the overlapping area of the two (the area of the cross section of the partial flow path 19 at the boundary between the two) does not change. On the other hand, in a hole 43 that partially overlaps with another hole 43, such as a shift portion (hole 43A), the overlapping area of the two changes when a misalignment occurs. That is, an error occurs in the cross section of the partial flow path 19. In the present embodiment, the small diameter portion (43B) is connected to the shift portion, so that the shift portion and the hole 43 connected to the shift portion are connected to each other as compared with the mode in which the shift portion and the large diameter portion are connected. The overlapping area becomes smaller. As a result, even if the plate 21 is displaced, the fluctuation of the overlapping area with respect to the displacement is also small. That is, the variation in the cross-sectional area of the partial flow path 19 is reduced. As a result, the accuracy of the discharge characteristics is improved.

Further, in the present embodiment, among the plurality of plates 21, the plate 21L constituting the small diameter portion (43B) has a thickness smaller than the thickness of at least one other plate 21, and all the others. It has a thickness equal to or less than the thickness of each of the plates 21.

In this case, for example, as compared with a mode in which the plate 21L is relatively thick (the mode may also be included in the technique according to the present disclosure), the opening area directly below the shift portion (hole 43A) is narrowed by the small diameter portion. However, the volume of the partial flow path 19 is secured. This facilitates, for example, adjusting the propagation direction of the pressure wave and increasing the discharge amount of the liquid droplets at the same time.

Further, for example, focusing on the manufacturing process, it is possible to reduce the variation in the overlapping volumes of the holes 43. Specifically, it is as follows. As inferred from the above-mentioned description of the action of reducing the variation in the overlapping area, for example, in a mode in which the hole 43B is contained in the hole 43A (the mode may also be included in the technique according to the present disclosure). Does not change the volume of the portion of the hole 43B that overlaps the hole 43A in planar perspective even if the position shift in the plane direction occurs. On the other hand, in the embodiment in which the hole 43A and the hole 43B partially overlap each other, the volume of the portion of the hole 43B overlapping the hole 43A changes when the misalignment occurs. In the present embodiment, the change in volume is reduced by the thinness of the plate 21L constituting the hole 43B.

Further, in the present embodiment, the shift portion (43A) and the small diameter portion (43B) are located on the pressurizing chamber 17 side with respect to all the large diameter portions (holes 43E to 43I or 43F to 43G).

In this case, for example, at a position where the pressure applied by the pressurizing element 38 is relatively high, the effect of the above-mentioned pressure propagation regulation and / or the effect of reducing manufacturing variation is exhibited. As a result, for example, it is easy to improve the accuracy of the discharge characteristics.

Further, in the present embodiment, in the plan view of the pressurizing surface 5b, each of the large diameter portions is contained in the pressurizing chamber 17.

In this case, the probability that the pressure applied to the pressurizing chamber 17 in the vertical direction (direction intersecting the pressurizing surface 5b) escapes in the plane direction (direction along the pressurizing surface 5b) is further reduced.

In the above embodiment, the head 2 or the head body 2a is an example of a liquid discharge head. The printer 1 is an example of a recording device. Ink is an example of a liquid. The printing paper P is an example of a recording medium. Each or all of the holes 43E to 43I, or each or all of the holes 43F to 43H are examples of the large diameter portion. Hole 43A is an example of a shift portion. The hole 43B is an example of a small diameter portion.

The technique according to the present disclosure is not limited to the above-described embodiment, and may be implemented in various embodiments.

The head may have a common flow path for collecting the liquid from the individual flow paths. The partial flow path may be connected to a common flow path for recovery. The partial flow path may have a portion connected to the pressurizing chamber or the discharge hole having a large diameter portion, or may not have a hole in which the centroids are displaced from each other in plan perspective. Alternatively, the structure may be such that the entire surface fits in the pressurizing chamber in plan perspective.

The plurality of holes constituting the partial flow path are not limited to those each formed on one plate. For example, two holes having different diameters and / or positions in the plane direction may be formed on one side and the other side in the thickness direction of one plate. For example, a shift portion may be formed on the surface of the plate located below the pressurization chamber on the pressurization chamber side, and a small diameter portion may be formed on the surface on the opposite side.

1 ... Printer (recording device), 2 ... Liquid discharge head, 2a ... Head body (liquid discharge head), 5a ... Discharge surface, 5b ... Pressurized surface, 9 ... Discharge hole, 17 ... Pressurized chamber, 19 ... Partial flow path , 43E to 43I ... Hole (large diameter part), R1 ... Range, 38 ... Pressurizing element.

Claims (10)

The discharge surface, the pressure surface on the back surface of the discharge surface, the discharge hole opened in the discharge surface, the pressure chamber located on the pressure surface side of the discharge hole, and the discharge from the pressure chamber. A flow path member having a partial flow path extending to the hole,
A pressurizing element that overlaps the pressurizing surface and is displaced in the direction toward the pressurizing chamber and in the opposite direction to pressurize the liquid in the pressurizing chamber.
Have and
The partial flow path has one or more large diameter portions in which the area of the cross section parallel to the pressure plane is larger than the average area of the cross section in the partial flow path.
In the plan view of the pressurizing surface, each of the large diameter portions has an outer edge that is 10% of the maximum diameter of the partial flow path and is separated from the outer edge of the pressurizing chamber. Liquid discharge head that fits inside. The liquid discharge head according to claim 1, wherein all the large diameter portions are separated from the pressurizing chamber and the discharge hole in the extending direction of the partial flow path. The flow path member has a plurality of plates laminated from the discharge surface to the pressure surface.
The discharge hole, the partial flow path, and the pressurizing chamber are composed of holes included in the plurality of plates.
The plurality of plates have different thicknesses, at least in part from each other.
Within the plurality of plates, each of the plates constituting the one or more large diameter portions has a thickness larger than the thickness of at least one other plate, and each of the other plates has a thickness larger than that of the other plates. The liquid discharge head according to claim 1 or 2, which has a thickness equal to or greater than the thickness. The partial flow path
In the planar perspective of the pressurized surface, the shift portion that partially protrudes from all the large diameter portions and the shift portion
It is located next to the large-diameter portion with respect to the shift portion in a direction orthogonal to the pressure surface, and in the plan view of the pressure surface, the shift portion is located on the large-diameter portion with respect to the shift portion. On the other hand, a part of the portion protrudes to the side opposite to the protruding side and fits in all the large diameter portions, and the area of the cross section is smaller than the area of the cross section and the average area of the shift portion. The liquid discharge head according to claim 1 or 2, which has a small diameter portion. The flow path member has a plurality of plates laminated from the discharge surface to the pressure surface.
The discharge hole, the partial flow path, and the pressurizing chamber are composed of holes included in the plurality of plates.
The plurality of plates have different thicknesses, at least in part from each other.
Among the plurality of plates, the plate constituting the small diameter portion has a thickness smaller than the thickness of at least one other plate and a thickness equal to or less than the thickness of each of the other plates. The liquid discharge head according to claim 4. The liquid discharge head according to claim 4 or 5, wherein the shift portion and the small diameter portion are located on the pressurizing chamber side with respect to all the large diameter portions in the extending direction of the partial flow path. In the plan view of the pressurized surface, each of the large diameter portions is a liquid discharge head housed in the pressurized chamber. The liquid discharge head according to any one of claims 1 to 7.
A moving unit that relatively moves the liquid discharge head and the recording medium,
A recording device that has. The liquid discharge head according to any one of claims 1 to 7.
A coating machine that applies a coating agent to printing paper,
A recording device that has. The liquid discharge head according to any one of claims 1 to 7.
A dryer that dries the printing paper,
A recording device that has.

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