JP2017136774A - Inkjet head and inkjet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet head which inhibits a nozzle from being clogged by impurities mixed into an ink, and to provide an inkjet device.SOLUTION: An inkjet head 1 includes: a pressure chamber 52 which is filled with an ink; a main passage 51 for supplying the ink to the pressure chamber 52; an actuator 30 which changes a pressure of the ink filling the pressure chamber 52; a nozzle 41 which discharges the ink filling the pressure chamber 52 by the actuator 30 being driven; a communication passage 53 which connects the pressure chamber 52 with the main passage 51; and a filter 411c which is provided at a predetermined position between the nozzle 41 and an inlet of the communication passage 53 and used to remove impurities which are included in the ink and larger than a diameter of the nozzle 41.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an inkjet head that ejects ink onto a printing surface and an inkjet apparatus that uses the inkjet head.

  An inkjet apparatus is an apparatus that performs printing or drawing on a printing surface by ejecting ink from an inkjet head. An ink jet head mounted on an ink jet apparatus applies pressure to a pressure chamber for filling ink, a flow path for guiding ink to the pressure chamber, a nozzle connected to the pressure chamber, and ink filled in the pressure chamber. Actuator. By driving the actuator to increase the pressure in the pressure chamber, ink filled in the pressure chamber is ejected from the nozzle.

JP 2005-244174 A

  Generally, in an inkjet head, the nozzle diameter is set to about several tens of μm. For this reason, when impurities larger than the nozzle diameter are mixed in the ink, the impurities may clog the nozzle, and the ink may not be smoothly ejected from the nozzle.

  In view of such a problem, an object of the present invention is to provide an ink jet head and an ink jet apparatus capable of suppressing clogging of nozzles due to impurities mixed in ink.

  A first aspect of the present invention relates to an inkjet head. An inkjet head according to a first aspect includes a pressure chamber filled with ink, a main flow path for supplying ink to the pressure chamber, an actuator for changing the pressure of the ink filled in the pressure chamber, A nozzle that discharges the ink filled in the pressure chamber when the actuator is driven, a communication channel that connects the pressure chamber and the main channel, and the vicinity of the inlet of the nozzle and the communication channel And a filter for removing impurities larger than the diameter of the nozzle included in the ink.

  According to the ink jet head according to this aspect, impurities larger than the diameter of the nozzle included in the ink are removed by the filter before reaching the nozzle. Therefore, it is possible to prevent the nozzles from being clogged by impurities originally mixed in the ink or impurities mixed in the manufacture of the ink jet head.

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

  According to the ink jet apparatus according to the second aspect, since the ink jet head according to the first aspect is used, it is possible to prevent the nozzle from being clogged with impurities mixed in the ink, and to smoothly eject a predetermined amount of ink from the nozzle. it can. For this reason, the performance of an inkjet apparatus can be improved.

  As described above, according to the ink jet head and the ink jet apparatus according to the present invention, it is possible to suppress the nozzle from being clogged with impurities mixed in the ink.

  The effects and significance of the present invention will become more apparent from the following description of embodiments. However, the embodiment described below is merely an example when the present invention is implemented, and the present invention is not limited to what is described in the following embodiment.

FIG. 1A is a diagram illustrating a configuration of an ink jet head according to the embodiment, and FIG. 1B is a diagram schematically illustrating a configuration in which the actuator according to the embodiment and a structure are combined. FIG. 2A is an enlarged view of a part of the actuator and the structure according to the embodiment, and FIG. 2B is a diagram schematically showing the main flow path and the pressure chamber. FIG. 2C is a diagram schematically showing the arrangement of nozzles in the structure. FIG. 3 is a partial perspective view showing a configuration in the vicinity of the pressure chamber according to the embodiment. FIG. 4A is a cross-sectional view schematically showing the configuration near the pressure chamber and the flow of impurities according to the embodiment, and FIG. 4B shows the configuration near the pressure chamber according to the comparative example and the flow of impurities. It is sectional drawing shown typically. FIGS. 5A and 5B are diagrams schematically illustrating the overlap between the pressure chamber and the communication channel according to the comparative example, respectively. FIGS. 6A and 6B are diagrams schematically showing the overlap between the pressure chamber and the communication channel according to the embodiment, respectively. FIG. 7 is a block diagram illustrating a configuration of the ink jet apparatus according to the embodiment. FIGS. 8A and 8B are diagrams schematically illustrating the overlap between the pressure chamber and the communication channel according to the modified example, respectively. FIGS. 9A and 9B are cross-sectional views schematically showing a configuration of a communication channel according to another modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. For convenience, the X, Y, and Z axes that are orthogonal to each other are appended to each drawing. The Z-axis direction is the height direction of the inkjet head 1, and the positive Z-axis direction is the downward direction. Further, 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 positive Z-axis direction (downward). The X-axis direction corresponds to a “first direction” according to claim 6, and the Y-axis direction corresponds to a “second direction” according to claim 6.

  Fig.1 (a) is a figure which shows the structure of the inkjet head 1 which concerns on embodiment, FIG.1 (b) shows typically the structure which combined the actuator 30 and structure 40 which concern on embodiment. FIG.

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

  The storage box 10 is a rectangular box whose bottom surface is open. A cutout 10a connected to the inside is provided on the upper surface of the storage box 10, and the circuit board 11 is stored in the storage box 10 through the cutout 10a. A drive circuit for driving the actuator 30 is mounted on the circuit board 11. Circular holes 10b are respectively provided on the Y axis positive side and the Y axis negative side of the notch 10a. The hole 10 b is for guiding an ink supply tube (not shown) to the inside of the storage box 10.

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

  As shown in FIG.1 (b), the actuator 30 consists of a plate body which has a rectangular outline. The actuator 30 is overlaid on the upper surface of the structure 40. The structure 40 is a plate having a rectangular outline. In the structure 40, four main flow paths 51 arranged in the X-axis direction are formed.

  Four ink supply ports 30a are formed side by side in the X-axis direction at the Y-axis positive end and the Y-axis negative end of the actuator 30, respectively. Each of the two ink supply ports 30a arranged in the Y-axis direction is connected to one independent main channel 51.

  Fig.2 (a) is the figure which expanded the edge part by the side of the Y-axis positive side of the structure of FIG.1 (b).

 A groove is formed on the back surface of the actuator 30. By overlapping the actuator 30 on the structure 40, a pressure chamber 52 is formed between the groove on the back surface of the actuator 30 and the upper surface of the structure 40. The pressure chamber 52 is connected to the main flow path 51 via a communication flow path 53 (see FIG. 2B) formed in the structure 40.

  Note that a terminal group (not shown) for connecting the FPC of the circuit board 11 is provided on each of the X-axis negative side end and the X-axis positive side end of the upper surface of the actuator 30. This terminal group is for applying a voltage (drive signal) to the piezoelectric layer 34 (see FIG. 2B) of the actuator 30.

  As described above, the end of the main channel 51 is connected to the ink supply port 30a. A large number of pressure chambers 52 are arranged along the main flow path 51, and each pressure chamber 52 is connected to the main flow path 51 by each communication flow path 53 (see FIG. 2B).

  Referring back to FIG. 1B, tubes (not shown) are individually fitted into the eight ink supply ports 30a, and ink is supplied to the tubes from ink supply tubes (not shown). . The tube is supported by a support member disposed in the opening 20a, and a tube for supplying ink to the tube is drawn out through the hole 10b. Ink is supplied to the ink supply port 30a through the ink supply tube and the tube. As a result, ink is supplied to the pressure chamber 52 through the main channel 51 and the communication channel 53.

  The same color ink is supplied to the two ink supply ports 30a arranged in the Y-axis direction, and different color inks are supplied to the four ink supply ports 30a arranged in the X-axis direction. Therefore, in the configuration shown in FIG. 1B, four colors of ink are supplied to the actuator 30. As a result, the pressure chambers 52 arranged in the Y-axis direction are filled with the same color ink, and the pressure chambers 52 arranged in the X-axis direction are filled with inks of different colors. A combination of the actuator 30 and the structure 40 is installed at the lower end of the opening 20 a of the head base 20. Therefore, four colors of ink are ejected from the lower surface of the head base 20.

  2B, the pressure chamber 52 in the vicinity of the X-axis positive side (right side) of FIG. 2A is cut along a plane parallel to the XZ plane at the center position in the Y-axis direction of the pressure chamber 52. It is sectional drawing which shows a cross section typically.

  The ink 60 that has flowed into the main channel 51 passes through the communication channel 53 and fills the pressure chamber 52. The structure 40 includes an upper member 40 a having a main channel 51 and communication channels 53 and 54 and a lower member 40 b having a nozzle 41. In the lower member 40b, a substantially circular hole serving as the nozzle 41 is formed in a portion of the communication channel 54 extending from the pressure chamber 52 in the positive Z-axis direction. The nozzle 41 gradually decreases in diameter toward the positive direction of the Z axis, and the diameter is uniform in the vicinity of the outlet.

  The actuator 30 is configured by laminating a diaphragm layer 32, an insulating layer 33, a piezoelectric layer 34, and an electrode layer 35 on the pressure chamber layer 31. The diaphragm layer 32, the insulating layer 33, the piezoelectric layer 34, and the electrode layer 35 are formed by a vacuum film forming technique such as sputtering. These layers may be formed by other film forming techniques such as coating. The pressure chamber layer 31 is formed by a thick film forming technique such as a plating method or a metal plate etching method. By attaching the upper member 40 a to the lower surface of the pressure chamber layer 31, the pressure chamber 52 is formed. The diaphragm layer 32 is made of a conductive metal material and also serves as a lower electrode (common electrode) of the piezoelectric layer 34. The insulating layer 33 insulates the diaphragm layer 32 from the piezoelectric layer 34. That is, the insulating layer 33 shields voltage application to the piezoelectric layer 34 other than the piezoelectric functional region R1.

  The piezoelectric layer 34 is made of, for example, lead zirconate titanate (PZT). The film thickness of the piezoelectric layer 34 is about several μm. The electrode layer 35 is formed of a conductive material. The electrode layer 35 is formed from titanium containing a noble metal, for example. The film thickness of the electrode layer 35 is about 0.2 μm.

  When a voltage is applied to the electrode layer 35, the piezoelectric layer 34 is deformed in the Z-axis direction in the piezoelectric functional region R1, and accordingly, the diaphragm layer 32 is deformed. When the diaphragm layer 32 is deformed downward in the piezoelectric function region R1, the volume of the pressure chamber 52 is reduced, and the pressure of the ink 60 filled in the pressure chamber 52 is increased. Thereby, the droplet 61 of the ink 60 is ejected from the nozzle 41.

  Each of the pressure chamber layer 31, the diaphragm layer 32, the insulating layer 33, the piezoelectric layer 34, and the electrode layer 35 is not necessarily a single layer, and may be formed of a plurality of layers. Further, another layer may be disposed between the layers.

  FIG. 2C is a diagram schematically showing the arrangement of the nozzles 41 in the structure 40.

  As shown in FIG. 2C, the structure 40 has a plurality of nozzles 41 arranged in a line. In the structure 40, rows L1 to L4 of four nozzles 41 are arranged. For example, 200 nozzles 41 are provided at regular intervals in each of the rows L1 to L4. The number of nozzles 41 in each row is not limited to this.

  FIG. 3 is a partial perspective view showing a cross section of the configuration in the vicinity of the pressure chamber 52.

  As shown in FIG. 3, the upper member 40 a of the structure 40 is configured by stacking plate-like bodies 411 and 412, seven plate-like bodies 413, and a plate-like body 414. Each of the plate-like bodies 411 to 414 has a predetermined thickness, and has the same contour as that of the structure body 40 in plan view. The seven plate-like bodies 413 have the same structure. A thin damper 415 is sandwiched between the first and second plate-like bodies 413 from the bottom. The damper 415 is for absorbing a pressure wave applied from the communication channel 53 to the main channel 51 when the actuator 30 is driven and the diaphragm layer 32 is displaced downward (Z-axis positive direction). is there.

  In the plate-like bodies 411 and 412, long holes 411 a and 412 a for forming the communication channel 54 are formed, respectively. In the long holes 411a and 412a, the X-axis direction is the longitudinal direction. In plan view, each of the long holes 411a and 412a has an oval outline that is long in the X-axis direction. More specifically, the long hole 411a has an outline in which the ends of two semicircular arcs facing each other are connected by a straight line. The long hole 412a has an outline in which two semicircular arcs similar to the long hole 411a are connected by a straight line shorter than the long hole 411a.

  The seven plate-like bodies 413 are formed with holes 413 a for forming the communication channel 54. The hole 413a is substantially circular. The plate-like body 414 and the damper 415 are also formed with holes 414a and 415a for forming the communication channel 54, respectively. The diameters of the holes 414a and 415a are substantially the same as the diameter of the hole 413a. The seven holes 413a have the same center. The centers of the holes 414a and 415a coincide with the center of the hole 413a. The center of the nozzle 41 coincides with the center of the holes 413a, 414a, 415a.

  The center of the long hole 412a coincides with the center of the hole 413a in the Y-axis direction, and deviates in the X-axis negative direction from the center of the hole 413a in the X-axis direction. Further, the center of the long hole 411a coincides with the center of the long hole 412a in the Y-axis direction, and is shifted from the center of the long hole 412a in the X-axis negative direction in the X-axis direction. In plan view, the X-axis positive side edge of each of the long holes 411a and 412a coincides with the X-axis positive side edge of the hole 413a.

  In the plate-like bodies 412, 413, openings 412b, 413b are formed in regions corresponding to the main flow paths 51, respectively. The opening 412b is narrower in the X-axis direction than the opening 413b. In plan view, the edge on the X axis positive side of the opening 412b coincides with the edge on the X axis positive side of the opening 413b. The main flow path 51 is partitioned by a damper 415.

  The plate-like body 411 has an opening 411 b in a region corresponding to the communication channel 53. A filter 411 c is formed at the bottom of the opening 411 b, that is, at the inlet of the communication channel 53. The filter 411c is provided with a large number of holes H1 having a diameter of about several μm. The diameter of the hole H1 provided in the filter 411c is slightly smaller than the diameter of the outlet of the nozzle 41. For example, the diameter of the outlet of the nozzle 41 is 20 μm, and the diameter of the hole H1 of the filter 411c is 15 μm. In plan view, the opening 411b has a hexagonal outline that is long in the X-axis direction. In addition, the opening 411b may have an oval outline that is long in the X-axis direction, for example, an outline in which the ends of two semicircular arcs facing each other are connected by a straight line.

  The long hole 411a, the hole 412a, and the opening 411b described above may have a large circular shape. However, the pitch of the nozzles 41 cannot be reduced and hinders high-density printing. It is preferable to do.

  The opening 411b is arranged so as to be shifted from the pressure chamber 52 in the X-axis direction so that the X-axis positive side overlaps the pressure chamber 52 and the X-axis negative side does not overlap the pressure chamber 52. Further, the filter 411 c is disposed in the entire area of the inlet of the communication channel 53. As a result, a gap is formed between the X-axis negative side portion of the filter 411c and the lower surface of the pressure chamber layer 31, and this gap is also an ink flow path.

  On the X-axis negative side of the opening 411b, the ink that has passed through the filter 411c from the main channel 51 passes through the gap between the filter 411c and the lower surface of the pressure chamber layer 31, and then the pressure chamber from the X-axis positive side of the opening 411b. Enter 52. When the actuator 30 is driven to increase the pressure in the pressure chamber 52, the ink filled in the pressure chamber 52 passes through the communication channel 54 constituted by the long holes 411a, 412a and the holes 413a, 414a, 415a, and the nozzle 41 It is discharged from.

  As shown in FIG. 3, in this embodiment, the upper member 40a of the structure 40 is configured by stacking a plurality of plate-like bodies 411, 412, 413, 414, and the lower member 40b is formed on the lower surface of the upper member 40a. Bonded or bonded using a thermal diffusion method. Further, the upper member 40 a is bonded to the lower surface of the pressure chamber layer 31, and the structure 40 including the upper member 40 a and the lower member 40 b is attached to the actuator 30. That is, the pressure chamber 52 and the communication channel 54 are connected by bonding the structure 40 having the communication channel 54 to the actuator 30. At the same time, the pressure chamber 52 and the communication channel 53 are connected.

  By the way, in the ink jet head, impurities such as fine dust attached to the main flow path 51 of the structure 40 and fragments of the structure 40 may be mixed into the ink flowing through the main flow path 51. Also, the ink may originally contain impurities. In such a case, if the size of the impurity is larger than the diameter of the outlet of the nozzle 41, the nozzle 41 may be clogged by the impurity reaching the nozzle 41, and ink may not be ejected smoothly from the nozzle 41.

  On the other hand, in the present embodiment, since the filter 411c is provided at the inlet of the communication channel 53, even if an impurity larger than the diameter of the nozzle 41 is mixed into the ink flowing through the main channel 51, The nozzle 41 is prevented from clogging. Hereinafter, the effect of the filter 411c will be described.

  FIG. 4A is a cross-sectional view schematically showing the configuration near the pressure chamber 52 and the flow of impurities according to the embodiment. FIG. 4B shows the configuration near the pressure chamber 52 according to the comparative example. It is sectional drawing which shows the flow of an impurity typically. 4 (a) and 4 (b) show cross sections obtained by cutting the actuator 30 and the structure 40 along a plane parallel to the XZ plane at the central position of the width of the pressure chamber 52 in the Y-axis direction.

  In the comparative example shown in FIG. 4B, the configurations of the uppermost plate 411 ′ and the second plate 412 ′ are different from the configuration of the embodiment shown in FIG. . That is, in the comparative example, circular holes 411a ′ and 412a ′ having the same diameter as the hole 413a formed in the plate-like body 413 are provided in the uppermost plate and the second-stage plate-like bodies 411 ′ and 412 ′, respectively. The centers of these holes 411a ′ and 412a ′ coincide with the center of the hole 413a. Thereby, the communication flow path 54 is comprised. In the comparative example, circular holes 411 b ′ and 412 b ′ constituting the communication channel 53 are provided in the uppermost plate and the second plate 411 ′ and 412 ′, respectively. Here, the diameter of the hole 412b 'is set smaller than the diameter of the hole 411b'.

  In the configuration of the comparative example, when the impurity 62 is mixed into the ink flowing through the main flow channel 51, the impurity 62 enters the pressure chamber 52 through the communication flow channel 53 including the holes 411b 'and 412b', and then communicates. The nozzle 41 is reached through the flow path 54. As a result, the nozzle 41 may be blocked by the impurity 62 and ink may not be ejected from the nozzle 41.

  On the other hand, in the present embodiment, as shown in FIG. 4A, a filter 411c having a large number of circular holes H1 is provided at the inlet of the communication channel 53 over the entire area of the inlet. Yes. The diameter of the hole H1 provided in the filter 411c is set smaller than the diameter of the outlet of the nozzle 41. For this reason, even if the impurity 62 larger than the diameter of the outlet of the nozzle 41 is mixed into the ink flowing through the main flow channel 51, the impurity 62 is stopped by the filter 411c and does not enter the pressure chamber 52. For this reason, the nozzle 41 is prevented from being clogged with the impurities 62.

  The impurity 62 smaller than the diameter of the hole H1 of the filter 411c passes through the filter 411c and reaches the nozzle 41. However, since the impurity 62 is smaller than the diameter of the outlet of the nozzle 41, when the ink is ejected from the nozzle 41, it is contained in the ink and discharged to the outside.

  Thus, according to the present embodiment, the nozzle 41 is reliably prevented from being clogged with the impurities 62.

  In the present embodiment, long holes 411a and 412a are formed in the first plate-like body 411 from the pressure chamber 52 side and the plate-like body 412 therebelow, and holes 413a in the other plate-like bodies 413 and 414 are formed. It is wider in the X-axis direction than 414a. As a result, even when a slight displacement occurs between the structure 40 and the actuator 30 when the structure 40 is bonded to the actuator 30, the area of the communication channel 54 that overlaps the pressure chamber 52 is significantly reduced. Can be suppressed.

  Similarly, the opening 411b formed in the communication channel 53 also has a long hole shape that is long in the X-axis direction. For this reason, even when a slight displacement occurs between the structure 40 and the actuator 30 when the structure 40 is bonded to the actuator 30, the area of the communication channel 53 that overlaps the pressure chamber 52 is significantly reduced. Can be suppressed.

  FIGS. 5A and 5B are diagrams schematically showing the overlap between the pressure chamber 52 and the communication channels 53 and 54 according to the comparative example, respectively. 5A and 5B show a state in which the pressure chamber 52 is seen through from the Z axis positive side. For convenience, FIGS. 5A and 5B show the overlap of the three pressure chambers 52 and the communication channels 53 and 54.

  As shown in FIG. 5A, in the configuration of the comparative example, when the structure 40 is bonded to the actuator 30 without misalignment, the area S1 of the communication channel 54 that overlaps the pressure chamber 52 is appropriately secured, and The area S2 of the communication channel 53 that overlaps the pressure chamber 52 is ensured appropriately.

  However, in the configuration of the comparative example, as illustrated in FIG. 5B, when a positional shift in the Y-axis direction occurs between the structure 40 and the actuator 30 when the structure 40 is bonded to the actuator 30, the pressure The area S3 of the communication channel 54 that overlaps the chamber 52 decreases from the normal area S1, and the area S4 of the communication channel 53 that overlaps the pressure chamber 52 decreases from the normal area S2. For this reason, it is difficult for ink to flow from the communication channel 53 to the pressure chamber 52, and it is difficult for ink to flow from the pressure chamber 52 to the communication channel 54.

  FIGS. 6A and 6B are diagrams schematically illustrating the overlap between the pressure chamber 52 and the communication flow paths 53 and 54 according to the embodiment, respectively. Like FIGS. 5A and 5B, FIGS. 6A and 6B show a state in which the pressure chamber 52 is seen through from the Z-axis positive side. The overlap with the inlet of the communication channel 54 is shown. 6A and 6B, a region where the hole 413 a constituting the communication flow channel 54 and the pressure chamber 52 overlap each other is surrounded by a broken line, so that the communication flow channel 54 is configured. The area where the long hole 411a and the pressure chamber 52 overlap is hatched.

  In the configuration of the embodiment, when the structure 40 is bonded to the actuator 30 without displacement, a large area of the communication channel 54 that overlaps the pressure chamber 52 is secured as shown in FIG. Here, the area S1 where the holes 413a, 414a, and 415a continuing to the nozzle 41 shown in FIG. 3 overlap the pressure chamber 52 is the same as the area S1 of the comparative example shown in FIG. However, as described above, in the embodiment, since the first and second elongated holes 411a and 412a from the pressure chamber 52 side are expanded in the X-axis direction as compared with the hole 413a, the elongated hole 411a is formed in the pressure chamber. The area S5 overlapping with 52 is wider than the area S1 of the comparative example shown in FIG. In the embodiment, since the opening 411b is expanded in the X-axis direction, the area S6 where the opening 411b overlaps the pressure chamber 52 is larger than the area S2 of the comparative example shown in FIG.

  For this reason, in the configuration of the embodiment, as shown in FIG. 6B, when the structure 40 is bonded to the actuator 30, a positional shift in the Y-axis direction occurs between the structure 40 and the actuator 30. In this case, the area S3 where the main flow portion of the communication channel 54 overlaps the pressure chamber 52 decreases from the normal area S1, but the area where the communication channel 54 (long hole 411a) overlaps the pressure chamber 52, that is, the long hole 411a. An area S7 that overlaps the pressure chamber 52 is secured widely, and an area S8 that the communication channel 53 (opening 411b) overlaps the pressure chamber 52 is secured widely. Therefore, the ink is smoothly guided from the communication channel 53 to the pressure chamber 52, and the ink is smoothly guided from the pressure chamber 52 to the communication channel 54. Therefore, even when such a positional deviation occurs, a predetermined amount of ink can be smoothly ejected from the nozzle 41.

  In the above description, it is assumed that the pressure chamber 52 is displaced in the Y direction. However, the same effect can be obtained when the pressure chamber 52 is displaced in the X direction perpendicular to the above.

  FIG. 7 is a block diagram illustrating a configuration of the ink jet apparatus according to the embodiment.

  The ink jet apparatus includes an ink supply unit 2, a controller 3, and an interface 4 in addition to the ink jet head 1 having the above configuration.

  The ink supply unit 2 includes the above-described 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 controller 3 includes a CPU and a memory, and controls the inkjet head 1 and the ink supply unit 2 in accordance with a program held in the memory. The interface 4 receives input of drawing information such as characters and graphics to be printed and outputs the drawing information to the controller 3.

  The controller 3 controls the inkjet head 1 according to the input drawing information, and performs printing or drawing on the printing surface. In this way, ink is ejected from the nozzle 41 corresponding to the print image onto the printing surface, and printing or drawing is performed on the printing surface.

<Effect of embodiment>
As described above, according to the present embodiment, the following effects are exhibited.

  As described with reference to FIG. 4A, when the ink includes an impurity 62 larger than the diameter of the nozzle 41, the impurity 62 is removed by the filter 411 c before reaching the nozzle 41. Therefore, it is possible to prevent the nozzle 41 from being clogged by the impurities 62 originally mixed in the ink or the impurities 62 mixed in the head manufacturing.

  As shown in FIG. 3, the filter 411 c has a large number of holes H <b> 1 having a diameter smaller than the diameter of the nozzle 41, so that impurities 62 larger than the diameter of the nozzle 41 can be reliably blocked.

  In addition, when the impurity 62 is contained in the ink, the impurity 62 may be attached to the lower surface of the filter 411c. However, according to the present embodiment, a part of the ink in the pressure chamber 52 is transferred from the communication channel 53 to the main channel 51 by the pressure applied by the actuator 30 when the ink is ejected from the nozzle 41. Backflow. Due to this ink flow, the impurities 62 adhering to the lower surface of the filter 411c are peeled off from the filter 411c. Accordingly, the filter 411 c is prevented from being clogged by the impurities 62, and the ink flow from the main channel 51 to the pressure chamber 52 is ensured.

  In the present embodiment, the filter 411 c becomes resistant to the ink flow that flows backward from the pressure chamber 52 to the main flow path 51, so that the pressure in the pressure chamber 52 flows through the communication flow path 53 to the main flow. It becomes difficult to escape to the road 51. For this reason, as shown in FIG. 3 and FIG. 4A, the pressure in the pressure chamber 52 can be appropriately applied to the nozzle 41 even if the cross-sectional area of the communication channel 53 is increased. Therefore, by expanding the area of the communication channel 53 and increasing the area of the filter 411c, ink is smoothly supplied from the main channel 51 to the pressure chamber 52 while maintaining the pressure applied to the nozzle 41 appropriately. be able to.

  In the present embodiment, when the actuator 30 is driven, the pressure wave from the pressure chamber 52 toward the main flow path 51 is buffered by the filter 411c. For this reason, it can suppress more effectively that this pressure wave rebounds by the damper 415, and enters the pressure chamber 52 again. For this reason, undesired pressure fluctuations in the pressure chamber 52 due to the pressure wave can be prevented, whereby the ink ejection operation by the actuator 30 can be performed with higher accuracy.

  As shown in FIGS. 3 and 4A, the communication channel 53 has a pressure chamber 52 in the X-axis direction so that the X-axis positive side overlaps the pressure chamber 52 and the X-axis negative side does not overlap the pressure chamber 52. The filter 411c is disposed in the entire region of the inlet of the communication channel 53. As a result, a gap can be formed between the X-axis negative side portion of the filter 411c and the lower surface of the pressure chamber layer 31, and ink can be guided from the filter 411c to the pressure chamber 52 via this gap. it can. Further, the area of the communication channel 53 that overlaps the pressure chamber 52 is suppressed and the pressure in the pressure chamber 52 is reduced from the communication channel 53 while ensuring a large area of the filter 411c and increasing the flow rate of the ink passing through the filter 411c. Escape to the main flow path 51 can be suppressed. Thereby, both the smooth guiding of ink from the main channel 51 to the pressure chamber 52 and the proper ejection of ink by the pressure applied to the pressure chamber 52 can be realized simultaneously.

  As shown in FIGS. 6A and 6B, the pressure chamber 52 and the communication channel 53 both have the width in the X-axis direction (first direction) orthogonal to the X-axis direction (first direction). The connecting flow path 53 is shifted from the pressure chamber 52 in the X-axis direction (first direction) and is wider than the width in the Y-axis direction (second direction). As a result, as shown in FIG. 6B, even if a positional shift in the Y-axis direction occurs between the structure 40 and the actuator 30 when the structure 40 is bonded to the actuator 30, the communication channel 53. An area S8 where the (opening 411b) overlaps the pressure chamber 52 is ensured widely, and also when the positional deviation in the X-axis direction occurs, a wide area where the communication channel 53 (opening 411b) overlaps the pressure chamber 52 is ensured. The Therefore, the ink is smoothly guided from the communication channel 53 to the pressure chamber 52, and the ink is smoothly guided from the pressure chamber 52 to the communication channel 54. Therefore, even when such a positional deviation occurs, a predetermined amount of ink can be smoothly ejected from the nozzle 41.

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

  For example, in the above embodiment, the width of the communication channel 53 is expanded in the X-axis direction (first direction), but as shown in FIGS. 8A and 8B, the communication channel 53 (opening 411b). ) May be widened in the Y-axis direction (second direction).

  Also in this modified example, as shown in FIG. 8B, a positional shift in the Y-axis direction occurred between the communication flow path 53 and the pressure chamber 52 as the structural body 40 and the actuator 30 were displaced. In this case, it is possible to suppress the area where the communication channel 53 overlaps the pressure chamber 52 from being reduced. Therefore, the effect that the ink flow can be secured with respect to such misalignment can be achieved as in the above embodiment.

  However, in this modified example, since the opening direction of the opening 411b is the Y-axis direction, as shown in FIGS. 8A and 8B, the gap between the adjacent openings 411b becomes considerably narrow. For this reason, when a positional deviation in the Y-axis direction occurs between the structure 40 and the actuator 30, as shown in FIG. 8B, the pressure chamber 52 approaches the adjacent communication channel 53 considerably, and the pressure chamber 52 and the adjacent communication channel 53 are easily communicated with each other.

  On the other hand, in the above embodiment, since the opening direction of the opening 411b is the X-axis direction (first direction), as shown in FIGS. 6 (a) and 6 (b), the gap between the adjacent openings 411b. Can be secured widely. For this reason, even if a slight displacement in the Y-axis direction occurs between the structure 40 and the actuator 30, the pressure chamber 52 and the adjacent communication channel 53 do not communicate with each other. Therefore, the ink filled in the pressure chamber 52 can be properly discharged. For this reason, the expansion of the opening 411b is preferably in the X-axis direction (first direction) as in the above embodiment.

  In the above embodiment, the filter 411c is provided at the inlet of the communication channel 53. However, the filter 411c may be provided at another position between the nozzle 41 and the vicinity of the inlet of the communication channel 53. . For example, as shown in FIG. 9A, the filter 411 d may be provided at the inlet of the communication channel 54 or may be provided at another position of the communication channel 54.

  However, in the modified example of FIG. 4A, the filter 411d becomes resistant to the flow of ink from the pressure chamber 52 toward the nozzle 41, and therefore the ink in the pressure chamber 52 is smoothly guided to the nozzle 41. For this purpose, it is necessary to considerably increase the area of the filter 411d. Further, in this configuration, since the impurity 62 adheres to the upper surface of the filter 411d, the action of separating the impurity 62 from the filter 411d by the flow of ink generated when the actuator 30 is driven is lower than that in the above embodiment, and therefore Impurities 62 are easily deposited on the upper surface of the filter 411d. For these reasons, it is preferable to provide the filter 411d toward the communication channel 53 as in the above embodiment.

  Further, in the above embodiment, the filter 411c is provided on the plate-like body 411 constituting the communication flow path 53, but the filter 411c is provided on a member different from the member constituting the communication flow path 53, and the filter 411c is provided. You may arrange | position in a flow path. For example, the member in which the filter 411c is formed may be installed from the main channel 51 side, and the filter 411c may be disposed near the inlet of the communication channel 53. In this case, the filter 411c may be fitted into the inlet of the communication channel 53, or a position displaced slightly from the inlet of the communication channel 53 to the main channel 51 side so as to cover the inlet of the communication channel 53. May be arranged.

  In addition, the arrangement position of the communication channel 53 is not limited to the position shown in the above embodiment, and for example, as shown in FIG. 9B, the entire range of the communication channel 53 in the X-axis direction. The communication channel 53 may be disposed so that the pressure channel 52 overlaps the pressure chamber 52. Further, the arrangement position of the filter 411d in the Z-axis direction in the connecting flow path 53 is not limited to the position shown in the above embodiment, and for example, as shown in FIG. The filter 411c may be provided at a position displaced to the Z-axis negative side, or the filter 411c may be provided at the outlet of the communication flow path 53.

  However, if the opening 411b and the filter 411c are arranged as shown in FIG. 4A, the pressure chamber can be secured while ensuring a large area of the filter 411c and increasing the flow rate of ink passing through the filter 411c as described above. The effect that the area of the communication channel 53 that overlaps 52 can be suppressed and the pressure in the pressure chamber 52 can be prevented from escaping from the communication channel 53 to the main channel 51 is achieved. Therefore, from this effect, the opening 411b and the filter 411c are preferably arranged as shown in FIG.

  Moreover, in the said embodiment, although the upper member 40a of the structure 40 was comprised by overlapping the some plate-shaped body 411, 412, 413, 414, the structure method of the structure 40 is limited to this. It is not something. For example, the upper six plate-like bodies 413 of the seven plate-like bodies 413 shown in FIG. 3 may be integrally formed by one member.

  In addition, the configurations of the inkjet head 1 and the actuator 30 and the shapes and configurations of the main flow path 51, the pressure chamber 52, and the communication flow path 53 are not limited to those of the above embodiment. In the above embodiment, ink is supplied from two ink supply ports 30a arranged in the Y-axis direction with respect to one main flow path, but one ink supply port 30a is provided for one main flow path. It may be provided.

  The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims.

DESCRIPTION OF SYMBOLS 1 ... Inkjet head 2 ... Ink supply part 30 ... Actuator 41 ... Nozzle 53 ... Communication flow path 411b ... Opening 411c, 411d ... Filter H1 ... Hole

Claims (7)

A pressure chamber filled with ink;
A main flow path for supplying ink to the pressure chamber;
An actuator for changing the pressure of the ink filled in the pressure chamber;
A nozzle that ejects the ink filled in the pressure chamber when the actuator is driven;
A communication channel connecting the pressure chamber and the main channel;
A filter that is provided at a predetermined position between the nozzle and the vicinity of the inlet of the communication flow path, and removes impurities larger than the diameter of the nozzle included in the ink.
An inkjet head characterized by that. The inkjet head according to claim 1,
The filter has a large number of holes having a diameter smaller than the diameter of the nozzle.
An inkjet head characterized by that. The inkjet head according to claim 1 or 2,
The filter is provided in the communication channel,
An inkjet head characterized by that. The inkjet head according to claim 3,
The communication channel is arranged so that a part thereof overlaps the pressure chamber and the other part does not overlap the pressure chamber,
The filter is disposed on the inlet side of the communication channel.
An inkjet head characterized by that. The inkjet head according to claim 4,
The filter is disposed in the entire region of the communication channel,
An inkjet head characterized by that. The inkjet head according to claim 4 or 5,
Each of the pressure chamber and the communication channel has a width in a first direction wider than a width in a second direction orthogonal to the first direction,
The communication flow path is arranged to be shifted from the pressure chamber in the first direction.
An inkjet head characterized by that. An ink jet head according to any one of claims 1 to 6;
An ink jet apparatus comprising: an ink supply unit that supplies ink to the ink jet head.

Images