JP6738514B2 - Inkjet head and inkjet device - Google Patents

Description

The present invention relates to an inkjet head that ejects ink on a surface to be printed and an inkjet device using the inkjet head.

An inkjet device is a device that ejects ink from an inkjet head to perform printing or drawing on a surface to be printed. An inkjet head mounted in an inkjet device includes a pressure chamber for filling ink, a nozzle connected to the pressure chamber, and an actuator that applies pressure to the ink filled in the pressure chamber. The ink filled in the pressure chamber is ejected from the nozzle by driving the actuator to increase the pressure in the pressure chamber.

Patent Document 1 discloses a configuration of an inkjet head capable of controlling the ejection direction and ejection amount of ink. In this configuration, the nozzle and the vibration plate are provided so as to sandwich the pressure chamber, and the plurality of piezoelectric elements are installed on the vibration plate so that the plurality of piezoelectric elements are arranged for one pressure chamber.

JP 2006-102976 A

However, in the configuration of Patent Document 1, since the position of the nozzle and the position of each piezoelectric element are distant from each other, even if the drive amount of each piezoelectric element is controlled to change the ink ejection direction, It is considered that the pressure waves are averaged in the pressure chamber and it is difficult to smoothly change the ink ejection direction to a desired direction.

In view of this problem, it is an object of the present invention to provide an inkjet head and an inkjet device that can eject ink smoothly from a nozzle in a desired direction.

A first aspect of the present invention relates to an inkjet head. The inkjet head according to the first aspect includes a nozzle for ejecting ink, an ink storage chamber to which the nozzle is joined, and a plurality of pressure chambers arranged around the ink storage chamber and connected to the ink storage chamber. A piezoelectric driving unit that is individually arranged in each of the plurality of pressure chambers and that changes the pressure in the pressure chamber , wherein the piezoelectric driving unit is provided on the nozzle side of the pressure chamber in the height direction of the inkjet head. that provided.

According to the inkjet head of this aspect, since the piezoelectric drive unit is provided for each pressure chamber, the pressures applied to the ink containing unit in different directions from the pressure chambers can be made different from each other. Therefore, by applying a negative pressure to the ink containing portion before the ink is ejected, the concave shape of the ink generated at the nozzle outlet can be adjusted to a meniscus shape that is concave in the side opposite to the direction in which the ink is desired to be ejected. This allows the ink to be smoothly ejected in a desired direction.

A second aspect of the present invention relates to an inkjet device. An inkjet device according to a second aspect includes the inkjet head according to the first aspect, an ink supply unit that supplies ink to the inkjet head, and a control unit that controls the inkjet head.

According to the inkjet device of the second aspect, since the inkjet head of the first aspect is used, the ink can be smoothly ejected from the nozzle in a desired direction.

As described above, it is possible to provide an inkjet head and an inkjet device that can smoothly eject ink from a nozzle in a desired direction.

The effects and significance of the present invention will be further clarified by the description of the embodiments below. However, the embodiment described below is merely an example for embodying the present invention, and the present invention is not limited to what is described in the embodiment below.

FIG. 1A is a diagram showing a configuration of an inkjet head according to an embodiment, and FIG. 1B is a diagram schematically showing a configuration in which a structure and a nozzle plate are combined with an actuator according to the embodiment. .. FIG. 2A is an enlarged view of a part of the actuator, the structure, and the nozzle plate according to the embodiment. FIG. 2B is a diagram schematically showing the configuration of the flow path section according to the embodiment. FIG. 2C is a diagram schematically showing the arrangement of nozzles in the structure according to the embodiment. FIG. 3 is a cross-sectional view showing a configuration around the pressure chamber and the ink containing chamber according to the embodiment. FIGS. 4A and 4B are diagrams schematically showing the ink ejection operation according to the embodiment. 5A and 5B are diagrams schematically showing the ink ejection operation according to the embodiment, respectively. FIG. 6 is a block diagram showing the configuration of the inkjet device according to the embodiment. FIGS. 7A and 7B are diagrams schematically showing the configuration of the flow path section according to the modification example. FIGS. 8A and 8B are diagrams schematically showing the configuration of the flow path section according to another modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. For the sake of convenience, the X, Y, and Z axes that are orthogonal to each other are added to each drawing. The Z-axis direction is the height direction of the inkjet head 1, and the Z-axis positive direction is the downward direction. The X-axis direction is the thickness direction of the inkjet head 1, and the Y-axis direction is the width direction of the inkjet head 1. The inkjet head 1 ejects ink in the Z-axis positive direction (downward direction).

FIG. 1A is a diagram showing a configuration of the inkjet head 1, and FIG. 1B is a diagram schematically showing a configuration in which an actuator 40 is combined with a structure 30 and a nozzle plate 50.

As shown in FIG. 1A, the inkjet head 1 includes a storage box 10 and a head base 20. The storage box 10 is attachable to and detachable from the head base 20.

The storage box 10 is composed of a rectangular box body having an open lower surface. The upper surface of the storage box 10 is provided with a notch 10a connected to the inside thereof, and the circuit board 11 is stored in the storage box 10 through the notch 10a. A drive circuit for driving the actuator 40 is mounted on the circuit board 11. Circular holes 10b are provided on the Y-axis positive side and the Y-axis negative side of the notch 10a, respectively. The hole 10b is for guiding a tube (not shown) for supplying ink into the inside of the storage box 10.

The head base 20 is composed of a frame body having a rectangular opening 20a penetrating vertically in the center. The structure 30, the actuator 40, and the nozzle plate 50 shown in FIG. 1B are installed at the lower end of the opening 20a. The actuator 40 is electrically connected to the circuit board 11 in the opening 20a by FPC (Flexible Printed Circuits).

As shown in FIG. 1B, the actuator 40 is a plate body having a rectangular contour. The structure 30 is overlaid on the upper surface of the actuator 40. The structure 30 is a plate having a rectangular contour. Further, the structure 30 is formed with four main flow paths 31 arranged in the X-axis direction.

Four ink supply ports 30a are formed side by side in the X-axis direction at the Y-axis positive side end and the Y-axis negative side end of the structure 30, respectively. The two ink supply ports 30a lined up in the Y-axis direction are connected to one independent main flow path 31.

FIG. 2A is an enlarged view of the Y-axis positive side end of the configuration of FIG. 1B.

A groove is formed on the surface of the actuator 40 on the Z axis negative side. By stacking the structure 30 on the Z-axis negative side surface of the actuator 40, the flow path portion 41 is formed between the groove on the Z-axis negative side surface of the actuator 40 and the structure 30. The flow channel portion 41 is connected to the main flow channel 31. Further, the flow path portion 41 is connected to the nozzle 51 (see FIG. 2A and FIG. 3) on the lower surface of the nozzle plate 50. As described above, the main flow path 31 has its end connected to the ink supply port 30a. Ink is supplied to the flow path portion 41 via the main flow path 31.

A terminal group (not shown) for connecting the FPC of the circuit board 11 is provided at the end of the upper surface of the actuator 40 on the X axis positive side. This terminal group is for applying a voltage (driving signal) to the piezoelectric layer 431 (see FIG. 3) of the actuator 40.

Returning to FIG. 1B, pipes (not shown) are individually fitted into the eight ink supply ports 30a, and ink is supplied from the ink supply tubes (not shown) to the respective pipes. .. The tube is supported by a support member arranged in the opening 20a, and the tube that supplies ink to the tube is pulled out to the outside through the hole 10b. Ink is supplied to the ink supply port 30a via the ink supply tube and tube. As a result, the ink is supplied to the flow path portion 41 through the main flow path 31.

Inks of the same color are supplied to the two ink supply ports 30a arranged in the Y-axis direction, and inks of different colors are supplied to the four ink supply ports 30a arranged in the X-axis direction. Therefore, in the configuration of FIG. 1B, four color inks are supplied to the actuator 40. As a result, the pressure chambers 411 arranged in the Y-axis direction are filled with ink of the same color, and the pressure chambers 411 arranged in the X-axis direction are filled with inks of different colors. A combination of the actuator 40 and the structure 30 is installed at the lower end of the opening 20a of the head base 20. Therefore, the four color inks are ejected from the lower surface of the head base 20.

FIG. 2B is a diagram schematically showing the configuration of the flow path section 41. FIG. 2B shows a view of the flow path portion 41 seen from the Z axis positive side. For the sake of convenience, in FIG. 2B, a piezoelectric drive unit 430 for changing the pressure in the pressure chamber 411 is shown by a solid line together with the flow passage unit 41, and ink is introduced from the main flow passage 31 into the pressure chamber 411. The supply port 32 of is shown by the broken line.

The flow path unit 41 has a structure in which eight flow path units 410 are arranged radially around the ink storage chamber 420. One flow path unit 410 includes a pressure chamber 411 and a communication flow path 412. The eight flow path units 410 have the same shape and the same size as each other. The eight flow path units 410 are arranged around the ink containing chamber 420 at substantially equal intervals, that is, at intervals of about 45 degrees. Therefore, the eight pressure chambers 411 and the communication channels 412 are also arranged around the ink containing chamber 420 at substantially equal intervals, that is, at intervals of about 45 degrees.

The ink storage chamber 420 has a regular octagonal outline in a plan view. The nozzle 51 is joined to the surface of the ink containing chamber 420 on the Z axis positive side. The pressure chamber 411 has a rectangular contour in a plan view. A piezoelectric drive unit 430 that changes the pressure inside the pressure chamber 411 is arranged on the Z axis positive side of the pressure chamber 411. The communication channel 412 has a trapezoidal outline in a plan view. The communication channel 412 has a cross-sectional area that decreases toward the ink containing chamber 420. The communication channel 412 connects the pressure chamber 411 and the ink containing chamber 420.

FIG. 2C is a diagram schematically showing the arrangement of the nozzles 51 on the nozzle plate 50.

As shown in FIG. 2C, the nozzle plate 50 has a plurality of nozzles 51 arranged in a line. On the nozzle plate 50, rows L1 to L4 of four nozzles 51 are arranged. For example, 50 nozzles 51 are provided at regular intervals in each of the rows L1 to L4. The number of nozzles 51 in each row is not limited to this. One nozzle 51 of the nozzle plate 50 is joined to one ink storage chamber 420 shown in FIG.

FIG. 3 is a cross-sectional view showing the configuration around the pressure chamber 411 and the ink containing chamber 420. FIG. 3 is a cross section of the structure 30, the actuator 40, and the nozzle plate 50 taken along a plane parallel to the XZ plane at the position A-A′ in FIG. A cross-section obtained by cutting the structure 30, the actuator 40, and the nozzle plate 50 at a position rotated clockwise by 45°, 90°, and 135° from the position AA′ in FIG. It is the same.

As shown in FIG. 3, the actuator 40 has a structure in which a piezoelectric layer 431, a diaphragm layer 432, and an electrode layer 433 are laminated. The piezoelectric layer 431, the diaphragm layer 432, and the electrode layer 433 are formed by a vacuum film forming technique such as a sputtering method. These layers may be formed by another film forming technique such as coating. The piezoelectric layer 431, the vibrating plate layer 432, and the electrode layer 433 form a piezoelectric drive unit 430 shown in FIG. 2B. The electrode layer 433 is an upper electrode of the piezoelectric layer 431, and the diaphragm layer 432 also serves as a lower electrode of the piezoelectric layer 431.

A flow path layer 440 is formed on the Z axis negative side of the diaphragm layer 432. The flow path layer 440 is formed by a thick film forming technique such as a plating technique or a metal plate etching technique. Grooves for forming the pressure chambers 411 and the communication channels 412 are formed in the channel layer 440. By mounting the structure 30 on the lower surface of the flow path layer 440, the pressure chamber 411 and the communication flow path 412 are formed by the groove of the flow path layer 440, and further, the ink containing chamber 420 is formed. The structure 30 is attached to the lower surface of the actuator 40 with an adhesive, for example.

The piezoelectric layer 431 is formed of, for example, lead zirconate titanate (PZT). The film thickness of the piezoelectric layer 431 is about several μm. The electrode layer 433 is formed of a conductive material. The electrode layer 433 is formed of, for example, titanium containing a noble metal. The thickness of the electrode layer 433 is about 0.2 μm. Each of the piezoelectric layer 431, the diaphragm layer 432, and the electrode layer 433 is not necessarily a single layer, and may be formed of a plurality of layers. Further, another layer may be arranged between each layer.

As shown in FIG. 3, the nozzle plate 50 is mounted on the surface of the actuator 40 on the Z axis positive side. The nozzle plate 50 has a substantially circular hole that serves as the nozzle 51. The nozzle 51 has a diameter that gradually decreases toward the Z-axis positive direction up to the outlet. That is, the nozzle 51 has a conical inclined surface. When the nozzle plate 50 is mounted on the surface of the actuator 40 on the Z axis positive side, the nozzles 51 of the nozzle plate 50 are joined to the ink containing chamber 420. The nozzle plate 50 is attached to the surface of the actuator 40 on the Z axis positive side with an adhesive, for example.

When a voltage is applied to the electrode layer 433, the piezoelectric layer 431 is deformed in the Z-axis direction, and the diaphragm layer 432 is deformed accordingly. When the diaphragm layer 432 is deformed upward, the volume of the pressure chamber 411 increases and the pressure of the ink with which the pressure chamber 411 is filled decreases. As a result, an ink depression occurs at the outlet of the nozzle 51. When the vibration plate layer 432 is deformed downward, the volume of the pressure chamber 411 decreases and the pressure of the ink 60 filled in the pressure chamber 411 increases. As a result, ink droplets are ejected from the nozzle 51.

In the present embodiment, as shown in FIG. 2B, eight pressure chambers 411 are arranged around the ink containing chamber 420 at substantially equal intervals, and each pressure chamber 411 is individually provided with a piezoelectric drive unit 430. Is provided. As described above, in the present embodiment, since the piezoelectric drive unit 430 is provided for each pressure chamber 411, the pressure applied from each pressure chamber 411 to the ink containing chamber 420 can be made different from each other. Therefore, by applying a negative pressure to the ink containing chamber 420 before the ink is ejected, the concave shape of the ink generated at the outlet of the nozzle 51 can be adjusted to a meniscus shape which is concave in the direction opposite to the direction of ejecting the ink. This allows the ink to be smoothly ejected in a desired direction.

The ink ejection operation in this embodiment will be described below.

4A and 4B are diagrams schematically showing the operation when ejecting ink in the Z axis positive direction, respectively. Similar to FIG. 3, in FIGS. 4A and 4B, the structure 30, the actuator 40, and the nozzle plate 50 are shown in a plane parallel to the XZ plane at the position AA′ in FIG. The cross-section when cut is shown.

When the droplets 62 of the ink 60 are ejected in the Z-axis positive direction, first, a negative pressure is applied to the ink containing chamber 420. That is, the eight piezoelectric driving units 430 of FIG. 2B are driven by the same driving force to evenly displace the diaphragm layer 432 of each piezoelectric driving unit 430 in the Z-axis positive direction. As a result, the ink 60 in the ink containing chamber 420 is evenly drawn in the direction of the eight communication channels 412. As a result, as shown in FIG. 4A, a meniscus-shaped recess 61 recessed in the Z-axis negative direction is formed at the outlet of the nozzle 51.

Then, a positive pressure is applied to the ink containing chamber 420. That is, the eight piezoelectric driving units 430 of FIG. 2B are driven by the same driving force to uniformly displace the diaphragm layer 432 of each piezoelectric driving unit 430 in the Z axis negative direction. As a result, the ink 60 is evenly pushed out of the eight communication channels 412 into the ink containing chamber 420. As a result, as shown in FIG. 4B, the droplet 62 of the ink 60 is ejected from the nozzle 51 in the Z-axis positive direction.

FIGS. 5A and 5B are diagrams schematically showing the operation when ejecting ink in the direction inclining from the Z axis positive direction to the X axis negative side, respectively. Similar to FIG. 3, in FIGS. 5A and 5B, the structure 30, the actuator 40, and the nozzle plate 50 are arranged in a plane parallel to the XZ plane at the position AA′ in FIG. 2B. The cross-section when cut is shown.

Even when the droplet 62 of the ink 60 is ejected in the direction inclined from the Z axis positive direction to the X axis negative side, first, a negative pressure is applied to the ink containing chamber 420. In this case, among the eight piezoelectric drive units 430 of FIG. 2B, the drive force of the three piezoelectric drive units 430 on the X-axis positive side is higher than the drive force of the three piezoelectric drive units 430 on the X-axis negative side. The six piezoelectric drive units 430 are driven so that At this time, the two piezoelectric driving units 430 located symmetrically in the Y-axis direction are driven by the same driving force.

In this way, each piezoelectric drive unit 430 is driven to displace the diaphragm layer 432 of each piezoelectric drive unit 430 unevenly in the Z axis positive direction. As a result, the direction in which the ink 60 in the ink containing chamber 420 is drawn is biased toward the X-axis positive direction. As a result, as shown in FIG. 5A, the shape of the depression 61 of the ink 60 generated at the outlet of the nozzle 51 becomes a meniscus shape inclined from the negative direction of the Z axis to the positive side of the X axis.

Then, a positive pressure is applied to the ink containing chamber 420. That is, the eight piezoelectric driving units 430 of FIG. 2B are driven by the same driving force to uniformly displace the diaphragm layer 432 of each piezoelectric driving unit 430 in the Z axis negative direction. As a result, the ink 60 is evenly pushed out of the eight communication channels 412 into the ink containing chamber 420. As a result, as shown in FIG. 5B, a droplet 62 of the ink 60 is ejected from the nozzle 51 in a direction inclined from the Z axis positive direction to the X axis negative side.

The ejection direction of the ink 60 can be roughly defined by the direction of the recess 61 of the ink 60 formed at the outlet of the nozzle 51 before ejecting the ink 60, as described above. That is, by inclining the meniscus shape of the recess 61 in the direction opposite to the direction of ejecting the droplet 62, the droplet 62 can be ejected in a desired ejection direction.

According to the present embodiment, as shown in FIG. 2B, eight flow path units 410 are provided so as to surround the ink containing chamber 420, and each flow path unit 410 is provided with a piezoelectric drive unit 430 individually. Therefore, the negative pressure applied to the ink containing chamber 420 can be biased in a desired direction by adjusting the driving force of each piezoelectric drive unit 430. Thereby, the direction of the recess 61 of the ink 60 formed at the outlet of the nozzle 51 can be adjusted to a desired direction. Therefore, according to this embodiment, the droplets 62 of the ink 60 can be ejected from the nozzle 51 in a desired direction.

Further, according to the present embodiment, the size (liquid amount) of the droplet 62 of the ink 60 can be changed by adjusting the driving force of the eight piezoelectric drive units 430. Therefore, by adjusting the size (liquid amount) of the liquid droplets 62 while adjusting the direction in which the liquid droplets 62 of the ink 60 are ejected, a region where the small liquid droplets 62 are dispersed and the color is spread lightly, Regions of various colors can be created on the surface to be printed, such as regions in which large droplets 62 are concentrated and the color is dense and dense. Therefore, it is possible to draw on the surface to be printed with various expressions.

FIG. 6 is a block diagram showing the configuration of the inkjet device according to the embodiment.

The inkjet device includes an inkjet head 1 having the above-described configuration, an ink supply unit 2, a control unit 3, and an interface 4.

The ink supply unit 2 includes the above-mentioned tube for supplying ink to the inkjet head 1, an ink tank connected to the tube, and a pump for supplying ink from the ink tank to the tube. The control unit 3 includes a CPU and a memory, and controls the inkjet head 1 and the ink supply unit 2 according to a program stored in the memory. The interface 4 accepts input of drawing information such as characters and figures to be printed, and outputs the drawing information to the control unit 3.

The control unit 3 controls the inkjet head 1 according to the input drawing information, and prints or draws on the surface to be printed. At this time, the control unit 3 controls the ejection direction of the ink 60 ejected from the nozzle 51 by adjusting the driving force of the eight piezoelectric drive units 430 shown in FIG. 2B as described above. In this way, ink is ejected from the nozzles 51 corresponding to the print image in a desired direction onto the print surface, and printing or drawing is performed on the print surface.

<Effects of the embodiment>
As described above, according to this embodiment, the following effects can be obtained.

As shown in FIG. 2B, since the piezoelectric drive section 430 is provided for each pressure chamber 411, the pressures applied from the pressure chambers 411 to the ink containing chamber 420 in eight different directions are different from each other. Can be made Therefore, by applying a negative pressure to the ink containing chamber 420 before the ink is ejected, the concave shape of the ink generated at the outlet of the nozzle 51 can be adjusted to a meniscus shape which is concave in the direction opposite to the direction of ejecting the ink. This allows the ink to be smoothly ejected in a desired direction.

As shown in FIG. 2B, a communication channel 412 is provided between each pressure chamber 411 and the ink accommodating chamber 420, the cross-sectional area of which becomes smaller toward the ink accommodating chamber 420. As a result, the volume of the ink storage chamber 420 can be reduced, and the pressure generated by the piezoelectric drive unit 430 can be efficiently applied to the ink storage chamber 420. Therefore, the ink ejection direction can be smoothly controlled.

As shown in FIG. 2B, the eight pressure chambers 411 are provided radially around the ink storage chamber 420. Therefore, the pressure generated in each pressure chamber 411 can be applied to the inside of the ink containing chamber 420 in the direction orthogonal to the direction of the nozzle 51. Therefore, the ink ejection direction can be smoothly controlled.

As shown in FIG. 2B, eight pressure chambers 411 are arranged around the ink containing chamber 420 at substantially equal intervals so as to surround the ink containing chamber 420. As a result, pressure can be applied from each pressure chamber 411 to the ink containing chamber 420 at substantially equal intervals. Therefore, it is possible to easily control the uneven distribution of pressure in the ink containing chamber 420.

<Example of change>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

For example, in the above-described embodiment, the eight flow passage units 410 (pressure chambers 411, communication flow passages 412) are arranged at approximately equal intervals around the ink containing chamber 420, but the flow passage units 410 (pressure chambers 411, The number and layout of the communication channels 412) are not limited to this.

For example, as shown in FIG. 7A, four flow path units 410 (pressure chamber 411, communication flow path 412) may be arranged around the ink containing chamber 420 at intervals of approximately 90 degrees, or As shown in FIG. 7B, two flow channel units 410 (pressure chamber 411 and communication flow channel 412) may be arranged with the ink storage chamber 420 interposed therebetween.

Alternatively, as shown in FIG. 8A, three flow passage units 410 (pressure chambers 411, communication flow passages 412) may be arranged around the ink containing chamber 420 at intervals of approximately 120 degrees. As shown in FIG. 8B, 38 flow path units 410 (pressure chambers 411, communication flow paths 412) may be arranged at uneven intervals around the ink containing chamber 420. In the example of FIG. 8B, the interval between the two flow path units 410 (pressure chamber 411, communication flow path 412) on the Y axis negative side is approximately 90 degrees, and these two flow path units 410 (pressure chamber 411). The communication channel 412) and the remaining channel unit 410 (the pressure chamber 411, the communication channel 412) have an interval of approximately 135 degrees.

In the configuration of FIG. 7B, it is possible to tilt the ink ejection direction only in the Y-axis direction. In this case, the two flow path units 410 (the pressure chamber 411 and the communication flow path 412) are moved relative to each other between the inkjet head 1 and the printing surface (X-axis direction) as shown in FIG. ) Are preferably sandwiched in between. Accordingly, the ink adhesion position in the X-axis direction on the print surface can be adjusted by controlling the speed or position of the relative movement between the inkjet head 1 and the print surface, and the X-axis direction on the print surface can be adjusted. The ink adhesion position in each direction can be adjusted by controlling the driving force of the two piezoelectric drive units 430 to change the ink ejection direction from the nozzle 51.

In this case, the two flow path units 410 (the pressure chamber 411 and the communication flow path 412) do not necessarily sandwich the relative movement direction (X-axis direction) between the inkjet head 1 and the printing surface vertically. It does not need to be arranged, and may be arranged so as to sandwich the relative movement direction (X-axis direction) between the inkjet head 1 and the printing surface obliquely.

When three or more flow passage units 410 (pressure chambers 411, communication flow passages 412) are arranged, these flow passage units 410 surround the ink containing chamber 420, that is, the space between adjacent flow passage units 410. Are preferably arranged so that each of them is less than 180 degrees. Accordingly, by controlling the driving force of each piezoelectric drive unit 430, the ink ejection direction can be tilted in any direction.

In addition, in the example of FIG. 2B, the shape of the pressure chamber 411 in a plan view is rectangular, but the shape of the pressure chamber 411 in a plan view may be a trapezoid having the communication channel 412 side as an upper bottom. Alternatively, other shapes such as an ellipse and a track shape may be used. Similarly, the shape of the communication channel 412 in plan view does not necessarily have to be a trapezoid, and may be another shape such as a shape in which the hypotenuse of the trapezoid is replaced with an arc.

Further, in the above-described embodiment, the width of the communication channel 412 in the XY plane is narrowed toward the ink containing chamber 420, so that the cross-sectional area of the communication channel 412 is reduced toward the ink containing chamber 420. However, with this configuration or in place of this configuration, the width of the communication channel 412 in the Z-axis direction is made smaller toward the ink containing chamber 420, so that the cross-sectional area of the communication channel 412 becomes the ink containing chamber 420. It may be made smaller as it goes.

Further, the communication channel 412 is not always necessary, and the pressure chamber 411 may be directly connected to the ink containing chamber 420. For example, the shape of the pressure chamber 411 in a plan view may be a trapezoid having the ink storage chamber 420 side as an upper bottom, and the pressure chamber 411 may be directly connected to the ink storage chamber 420.

In addition, the configurations of the inkjet head 1 and the actuator 40, and the configuration of the piezoelectric drive unit 430 are not limited to those of the above-described embodiment. For example, the piezoelectric drive unit 430 does not necessarily have to be configured by stacking thin films as in the above-described embodiment, and may be configured by mounting a ceramic piezoelectric body.

Further, the arrangement position of the main flow path 31 and the arrangement position of the piezoelectric drive unit 430 are not limited to those in the above embodiment, and can be changed as appropriate. Further, in the above-described embodiment, the ink is supplied from the two ink supply ports 30a arranged in the Y-axis direction to one main flow path, but one ink supply port 30a is provided to one main flow path. It may be provided.

In addition, the embodiment of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims.

1... Inkjet head 2... Ink supply part 3... Control part 30... Structure 40... Actuator 50... Nozzle plate 51... Nozzle 411... Pressure chamber 412... Communication channel 420... Ink storage chamber 430... Piezoelectric drive part

Claims (7)

A nozzle for ejecting ink,
An ink storage chamber to which the nozzle is joined,
A plurality of pressure chambers arranged around the ink storage chamber and connected to the ink storage chamber;
An ink jet head comprising: a piezoelectric drive unit that is individually arranged in each of the plurality of pressure chambers and that changes the pressure in the pressure chambers ,
The piezoelectric drive unit is provided on the nozzle side of the pressure chamber in the height direction of the inkjet head .
An inkjet head characterized in that The inkjet head according to claim 1,
Between each of the pressure chambers and the ink containing chamber, a communication channel having a cross-sectional area that decreases toward the ink containing chamber is provided.
An inkjet head characterized in that. The inkjet head according to claim 1 or 2,
The plurality of pressure chambers are provided radially around the ink storage chamber,
An inkjet head characterized in that. The inkjet head according to claim 3,
At least three pressure chambers are arranged so as to surround the ink containing chamber,
An inkjet head characterized in that. The inkjet head according to claim 4,
The at least three pressure chambers are arranged at substantially equal intervals around the ink containing chamber,
An inkjet head characterized in that. The inkjet head according to claim 3,
The two pressure chambers are arranged so as to sandwich a relative movement direction between the inkjet head and the printing surface.
An inkjet head characterized in that. An inkjet head according to any one of claims 1 to 6,
An ink supply unit for supplying ink to the inkjet head;
An inkjet device, comprising: a controller that controls the inkjet head.

Images