JP4983765B2 - Droplet ejector - Google Patents

Description

  The present invention relates to a droplet ejecting apparatus capable of adjusting the temperature of a jetting liquid.

  Conventionally, as a droplet ejecting apparatus, a droplet ejecting apparatus that includes a droplet ejecting head that ejects droplets toward a printing medium such as paper and prints an image, a character, a wiring pattern, or the like on the printing medium is known. Yes. The droplet ejecting head includes energy applying means for applying ejecting energy to the liquid stored in the head when ejecting droplets onto the print medium.

  When the droplet ejecting head continuously ejects a large number of droplets, for example, for solid printing, heat is generated by continuously driving the energy applying means, and the droplet ejecting head has heat. End up. Further, in a situation where the temperature is very low, the droplet ejecting head is cooled by the outside air while it is left without printing. In a situation where the temperature of the droplet ejecting head fluctuates greatly, the liquid temperature changes as the ejecting liquid stored in the droplet ejecting head is heated or cooled. The viscosity will change. If the viscosity changes greatly, there is a problem in that droplets are not ejected even when ejection energy is applied, or that even if ejected, the amount of droplets becomes abnormal.

  Therefore, in order to solve such a problem, the liquid droplet ejecting apparatus described in Patent Document 1 includes an ink jet head that ejects ink as an ejecting liquid, and the stored ink is cooled inside the head. Thus, a water cooling mechanism capable of adjusting the temperature is provided. This water cooling mechanism includes a refrigerant recess formed in the head and supply means for supplying the refrigerant into the refrigerant recess. The refrigerant recess is provided in the orifice plate. In the orifice plate, a nozzle capable of ejecting ink and an ink flow path communicating with the nozzle are formed. Since the orifice plate can be cooled by the coolant supplied to the recess for coolant, the ink in the ink flow path is cooled more efficiently than when cooling by natural heat radiation alone. Further, the temperature of the ink can be adjusted by adjusting the time for supplying the refrigerant and changing the cooling time of the orifice plate.

In general, in addition to a liquid droplet ejecting head in which a liquid channel is formed on a single plate, a plurality of plates each having a liquid recess formed as a part of the liquid channel are stacked to form a liquid channel. There is a droplet ejecting head that constitutes. In the droplet ejecting apparatus described in Patent Document 2, the droplet ejecting head includes a plurality of stacked plates. Each plate is formed with a nozzle, a pressure chamber, or a part of a liquid flow path that connects the nozzle and the pressure chamber. When the water cooling mechanism of Patent Document 1 is adopted in the droplet jet head of Patent Document 2, a concave portion for refrigerant is formed on each plate.
JP 2006-7498 JP 2007-245394

  However, in the case where a refrigerant recess is formed in each plate, each plate has a coolant recess in addition to the liquid recess in the nozzle or pressure chamber. For this reason, the plate in which the refrigerant recess is formed has a wider area with a smaller dimension (thickness) in the direction orthogonal to the plane than the case where there is no refrigerant recess. Wide plates with thin regions are more likely to bend in the stacking direction than plates with narrow or no thin regions. When the plates are stacked and assembled, if the plates are curved, a gap is formed between the plates during joining, or the plates are joined while being displaced from their normal positions. When assembling the plate in which the concave portion for the refrigerant is formed, the plate must be assembled in consideration of deformation in the stacking direction. Therefore, it is necessary to use a device for preventing such deformation and to carry out a manufacturing process for preventing deformation, which causes a problem that the manufacturing process becomes complicated.

  Accordingly, an object of the present invention occurs in the stacking direction at the time of manufacturing when a configuration for adjusting the temperature of the liquid flowing in the liquid channel is adopted in the channel unit configured by stacking a plurality of plates. An object of the present invention is to provide a liquid droplet ejecting apparatus that can suppress the deformation of each plate as much as possible, can be manufactured without considering such deformation, and can adjust the temperature of the liquid.

According to a first aspect of the present invention, a liquid droplet ejecting apparatus includes a flow channel structure in which a liquid channel including a pressure chamber is formed and a plurality of plates are stacked in a predetermined stacking direction, and the flow channel structure in the stacking direction. And a flow path unit having a nozzle plate formed with nozzles communicating with the pressure chambers, and an ejection unit for ejecting liquid droplets from the nozzles to the liquid in the pressure chambers. Energy applying means for applying energy, circulation paths formed in each of at least two circulation plates adjacent to each other in the stacking direction among the plurality of plates constituting the flow path structure, and the liquid flow Supply means for supplying a circulation fluid different from the liquid in the liquid flow path to the circulation path in order to adjust the temperature of the liquid in the path, and the circulation path is spaced from each of the circulation plates. Leave It has a plurality of formed recesses, and an end of the recess formed in one circulation plate communicates with an end of the recess formed in another circulation plate in the stacking direction and is tubular The concave portion formed in the one circulation plate and the concave portion formed in the other circulation plate overlap each other only in the stacking direction. is there.

  “Energy imparting means” refers to energy that is injected into the liquid in the pressure chamber, such as a heating resistor that applies heat to the surface that defines the pressure chamber, or a member made of a piezoelectric material that is separate from the flow path structure. Means to give. “Circulating fluid” refers to any gas or gel-like fluid that can flow in the circulation path. The “concave portion” includes not only a shape having a bottom in the stacking direction but also a through shape penetrating the circulation plate in the stacking direction.

  According to this configuration, the plurality of recesses are arranged at intervals in each circulation plate, and only a part of the circulation path is formed for each plate. In each circulation plate, the total volume of the recesses per sheet is reduced and a region having a small dimension (thickness) in the stacking direction is reduced as compared with the case where all the circulation paths are formed on one plate. Therefore, it becomes difficult to bend in the stacking direction as compared with the case where all circulation paths are formed on each circulation plate. Compared to the circulation plate with all circulation paths formed, it is assembled in consideration of deformation in the stacking direction at the time of manufacturing, and special manufacturing processes and equipment are used to prevent such deformation. As a result, the circulation plate can be assembled without any trouble. Thereby, deformation in the stacking direction of each plate can be suppressed as much as possible at the time of manufacturing, and the droplet ejecting apparatus can be manufactured without considering such deformation, and the temperature of the liquid in the liquid channel can be adjusted.

  In the liquid droplet ejecting apparatus according to a second aspect of the present invention, in the first aspect of the invention, the liquid channel has a liquid storage chamber for storing a liquid to be supplied to the pressure chamber, and the liquid storage chamber is It overlaps at least a part of the pressure chamber in the stacking direction and the direction orthogonal to the direction in which the circulation path extends, and is positioned between the pressure chamber and the nozzle in the stacking direction, At least a part of the liquid storage chamber is formed on the plate.

  According to this configuration, at least a part of the liquid storage chamber is formed on the circulation plate. The circulation path and the liquid storage chamber are formed on separate plates, and the circulation path and the liquid storage chamber are formed on the same plate as compared with the case where another plate is sandwiched between the plates. Therefore, it is possible to exchange heat with the liquid in the liquid storage chamber while reducing the chance that the circulating fluid wastefully exchanges heat with other plates. As a result, the circulation fluid and the liquid in the liquid storage chamber can be heat exchanged without waste, and the temperature of the liquid in the liquid storage chamber can be adjusted efficiently.

  According to a third aspect of the present invention, in the first or second aspect of the invention, at least a part of the pressure chamber is formed on the circulation plate.

  According to this configuration, at least a part of the pressure chamber is formed in the circulation plate. Compared to the case where the temperature is adjusted only upstream of the pressure chamber, the temperature of the liquid can be adjusted immediately before jetting, and droplets can be jetted using the liquid whose temperature has been reliably adjusted. Thereby, the change of the ejection performance due to the temperature change of the liquid is prevented, and stable droplet ejection is enabled.

  According to a fourth aspect of the present invention, in any one of the first to third inventions, the flow path structure includes a supply port and a discharge port communicating with the circulation path, and further the circulation. A plurality of the pressure chambers are formed in the direction in which the passage extends, and the circulation passages are provided on both sides of the pressure chamber in a direction orthogonal to the stacking direction and the direction in which the circulation passage extends, The circulation passages arranged on both sides of the pressure chamber are arranged at intervals larger than the interval between the supply port and the discharge port in the orthogonal direction.

  The “interval between the supply port and the discharge port” refers to the distance between the edge portions that define the shape of the supply port and the discharge port in the orthogonal direction. Further, the “circulation path interval” refers to the distance between edge portions that define the shape of the circulation path in the orthogonal direction.

  According to this configuration, since the interval between the supply port and the discharge port is smaller than the interval between two adjacent circulation paths, the two circulation paths are close to each other in the orthogonal direction so as to be connected to the supply port and the discharge port, respectively. . By reducing the distance between the two circulation paths, the area in the region surrounded by the circulation paths is reduced. Thereby, it is easy to perform heat exchange between the liquid in the pressure chamber and the circulating fluid, and temperature adjustment can be performed efficiently.

  According to a fifth aspect of the present invention, in any one of the first to third aspects, the flow path structure includes a supply port and a discharge port communicating with the circulation path, and further includes the pressure A plurality of chambers are formed side by side in the direction in which the circulation path extends, and a plurality of pressure chamber arrays are arranged in a direction orthogonal to the stacking direction and the direction in which the circulation path extends. The circulation path has an inter-row circulation path arranged in the orthogonal direction, and the inter-row circulation path is disposed between the plurality of pressure chamber rows in the orthogonal direction; Further, it is directly connected to the supply port without passing through the other circulation path.

  According to this configuration, the circulation fluid flows directly into the inter-row circulation path without passing through the other circulation paths. Since the circulation fluid exchanges heat with the liquid in the liquid flow path and the pressure chamber while flowing through the circulation path toward the discharge port, the temperature changes compared to immediately after flowing in from the supply port. Close to the liquid temperature. In the circulation fluid in which the temperature difference with the liquid in the liquid channel is small, heat exchange with the liquid in the liquid channel is difficult compared to the case where the temperature difference between the two liquids is large. However, the inter-row circulation path is directly connected to the supply port without passing through other circulation paths, and the circulation fluid is directly flowed in without passing through the other circulation paths. Thereby, heat exchange is reliably performed between the circulation fluid in the circulation path between the columns and the liquid in the liquid flow path, and the temperature in the liquid flow path can be adjusted efficiently.

According to a sixth aspect of the present invention, in the first to fifth inventions, the circulation path is the circulation plate in a direction perpendicular to the stacking direction and the direction in which the circulation path extends. is arranged in a region between the pressure chamber and the outermost end of a length of definitive in the orthogonal direction, it is characterized in that longer than the length in the stacking direction.

  According to this structure, since the recessed part is arrange | positioned at each circulation plate at intervals, the location which supports the area | region of the inner side in which the pressure chamber was formed in the orthogonal direction can be ensured. In addition, since the circulation path is longer in the orthogonal direction than the stacking direction, the flow path area of the circulation path can be secured.

  In any one of the first to sixth inventions, the flow path structure includes at least three circulation plates, and the at least three circulations. An intermediate circulation plate having both sides in the laminating direction in the laminating plate sandwiched between other circulating plates, and the end portions of the concave portions of the intermediate circulating plate are adjacent to each other on both sides in the laminating direction. The end portions of the recesses formed in the circulation plate respectively communicate with each other in the stacking direction.

  According to this structure, the edge part of a recessed part is branched and communicated in both directions in the lamination direction. Since one concave portion communicates with the concave portions on both sides in the laminating direction, the circulating fluid can flow on both sides in the laminating direction as compared with the case where the concave portion communicates with only one direction in the laminating direction. Circulating fluid is created in the liquid flow path as evenly as possible to exchange heat with the liquid in the liquid flow path, and avoids adjusting the liquid temperature locally in the liquid flow path. Heat exchange with the liquid in the entire path is possible. This avoids local heat exchange between the circulating fluid and the liquid in the liquid flow path as much as possible, and allows heat exchange with the liquid in the entire liquid flow path.

According to an eighth aspect of the present invention, in the seventh aspect of the invention, the concave portion is formed to have the same length as the concave portion formed in the same plate in the direction in which the circulation path extends. An interval between two adjacent concave portions formed on the same plate is also equally arranged.

  According to this configuration, the length of each recess is equal in the extending direction, and the distance from each recess is constant. In the extending direction, opportunities for the circulating fluid to flow on both sides in the stacking direction are provided at regular intervals. Thereby, compared with the case where the opportunity which flows to both sides in a lamination direction is non-uniform | heterogenous, local temperature adjustment of a liquid can be avoided.

  In the present invention, when the configuration for adjusting the temperature of the liquid flowing in the liquid flow path is adopted in the flow path unit configured by laminating a plurality of plates, the deformation of each plate occurring in the stacking direction at the time of manufacture Can be manufactured without considering such deformation, and the temperature of the liquid can be adjusted.

  Next, an embodiment of the present invention will be described. In the present embodiment, the present invention is applied to a printer that prints desired characters, images, and the like on a printing paper by ejecting ink droplets onto the printing paper from an inkjet head.

(Schematic configuration of the printer)
FIG. 1 is a perspective view illustrating a schematic configuration of a printer 1 according to the present embodiment. In addition, the up-down direction, the left-right direction, and the front-rear direction in this specification and drawings are the up-down direction, the left-right direction, and the front-rear direction perpendicular to the up-down direction and the left-right direction shown by the arrows in FIG. As shown in FIG. 1, the printer 1 includes a main body frame 2 and a conveyance roller 3 attached to the main body frame 2 and extending in the left-right direction. The main body frame 2 has a guide shaft 4 extending in the left-right direction, and a carriage 5 is attached to the guide shaft 4. An ink jet head 6 is attached to the lower surface of the carriage 5.

  The carriage 5 is connected to an endless scanning belt (not shown), and the endless belt is attached to a driving shaft of a driving motor (not shown). The drive motor is disposed on the main body frame. The endless belt travels in the left-right direction as the drive shaft rotates. Following the travel of the endless belt, the carriage 5 reciprocates in the left-right direction.

(Configuration of inkjet head)
Next, the inkjet head 6 will be described in detail with reference to FIGS. 2 is a top view of the inkjet head 6, FIG. 3 is a cross-sectional view taken along line II of the inkjet head 6 shown in FIG. 2, and FIG. 4 is a cross-sectional view taken along line II-II of the inkjet head 6 shown in FIG. It is.

  As shown in FIG. 2, the inkjet head 6 includes a flow path unit 10 including a nozzle 28 and a piezoelectric actuator 30. The piezoelectric actuator 30 imparts ejection energy for ejecting ink from the nozzles 28 to the ink in the inkjet head 6.

  As shown in FIG. 2, in the flow path unit 10, a plurality of nozzles 28 are arranged in the front-rear direction to form a nozzle row, and a plurality of such nozzle rows are arranged in the left-right direction. The plurality of nozzles 28 communicate with the plurality of pressure chambers 26 through the plurality of descenders 27. The plurality of pressure chambers 26 are substantially elliptical as shown in FIG. The plurality of pressure chambers 26 are arranged in the front-rear direction to form pressure chamber rows 26a, 26b, and the pressure chamber rows 26a, 26b are arranged in the left-right direction.

  As shown in FIG. 2, the manifold 24 extends in the front-rear direction across the plurality of pressure chambers 26. The manifold 24 communicates with the pressure chamber 26 through the aperture hole 25.

  The piezoelectric actuator 30 has a plurality of individual electrodes 32 arranged in the front-rear direction, as shown in FIG. The individual electrode 32 has a substantially oval shape that is slightly smaller than the pressure chamber 26, and is disposed at the center of the pressure chamber 26 in plan view.

As shown in FIG. 2, the terminal 35 is provided at the tip 32 a of the individual electrode 32. The terminal 35 is connected to a wiring member such as a flexible printed board (not shown). The flexible printed circuit board is also connected to a print control circuit (not shown), and connects the print control circuit and the individual electrode 32. The print control circuit applies a predetermined drive voltage only to the selected individual electrode 32 with respect to the plurality of individual electrodes 32. The print control circuit controls a printing operation related to printing by the printer 1.

  As shown in FIG. 3, the flow path unit 10 includes a nozzle plate 11 on which the nozzles 28 are formed, and a flow path structure 12 joined to the upper surface 11 a of the nozzle plate 11.

  The nozzle plate 11 is formed of a resin material such as polyimide resin. The flow channel structure 12 includes a pressure chamber plate 14, a cavity plate 15, and manifold plates 16 and 19. The pressure chamber plate 14, the cavity plate 15, and the manifold plates 16 and 19 are made of metal such as stainless steel. Further, the pressure chamber plate 14, the cavity plate 15, and the manifold plates 16 and 19 are joined in a stacked state in the vertical direction.

The plurality of pressure chambers 26 are formed through the pressure chamber plate 14 in the vertical direction. The manifold 24 is constituted by manifold holes 24a and 24b formed in the manifold plates 16 and 19, respectively. The aperture hole 25 is formed through the cavity plate 15. The descender 27 includes a through hole 27a formed in the cavity plate 15 and through holes 27b and 27c formed in the manifold plates 16 and 19, respectively.

The piezoelectric actuator 30 is joined to the upper surface 14a of the pressure chamber plate 14 as shown in FIG. The piezoelectric actuator 30 includes a plurality of piezoelectric layers 31, a plurality of individual electrodes 32, a common electrode 33, and a diaphragm 34. The plurality of piezoelectric layers 31 are joined in a stacked state in the vertical direction. A plurality of individual electrodes 32 and a common electrode 33 are disposed on the piezoelectric layer 31. The individual electrode 32 is connected to a terminal 35 exposed on the upper surface 31 a of the piezoelectric layer 31.

  The piezoelectric layer 31 is a mixed crystal of lead titanate and lead zirconate, and is made of a piezoelectric material mainly composed of lead zirconate titanate having ferroelectricity. Similarly, the diaphragm 34 is formed of a piezoelectric material. However, the diaphragm 34 is not sandwiched between the individual electrode 32 and the common electrode 33 in the vertical direction, and an electric field in the vertical direction is not generated in the diaphragm 34.

  The operation principle of the piezoelectric actuator 30 having the above configuration will be described. The common electrode 33 is connected to a ground terminal (not shown) of the piezoelectric actuator 30 and has a ground potential. The individual electrode 32 to which no voltage is applied has no potential difference with the common electrode 33. When a predetermined drive voltage is applied to the individual electrode 32, a potential difference is generated between the individual electrode 32 and the common electrode 33. When a potential difference is generated between the individual electrode 32 and the common electrode 33, an electric field in the vertical direction is generated in the piezoelectric layer 31. When the polarization direction of the piezoelectric layer 31 is equal to the direction of the electric field, the piezoelectric layer 31 extends in the vertical direction and contracts in the horizontal direction perpendicular to the vertical direction. Along with the contraction deformation of the piezoelectric layer 31, the vibration plate 34 is convexly deformed in the vertical direction (unimorph deformation).

  The operation when the piezoelectric actuator 30 ejects ink will be described. The piezoelectric actuator 30 continues to apply a drive voltage to the individual electrode 32 in a state where ink is not ejected. For this reason, the piezoelectric layer 31 and the diaphragm 34 stand by in a state of being convexly deformed downward on the pressure chamber 26 side. When ink is ejected, the print control circuit stops applying the drive voltage to the individual electrode 32, and the individual electrode 32 becomes the ground potential accordingly. When the individual electrode 32 becomes the ground potential, the diaphragm 34 is deformed from a convex shape to a planar shape, the volume in the pressure chamber 26 is increased, and a pressure wave is generated in the pressure chamber 26. The pressure wave propagates in one direction of the pressure chamber 26 in the left-right direction. The propagated pressure wave collides with the inner wall of the pressure chamber 26 after a predetermined time, and the phase is reversed. The pressure in the pressure chamber 26 changes from a negative pressure to a positive pressure by reversing the phase of the pressure wave. Therefore, the print control circuit applies the drive voltage to the individual electrode 32 again at the timing when the pressure in the pressure chamber 26 becomes positive. The pressure wave generated when the volume of the pressure chamber 26 is increased and the pressure wave generated when the diaphragm 34 is convexly deformed toward the pressure chamber 26 are combined, and the combined pressure wave is ejected onto the ink in the pressure chamber 26. Ink is ejected as energy. As a result, two pressure waves can be synthesized and applied to the ink in the pressure chamber 26, so that a much larger pressure can be applied compared to the case where one pressure wave is applied to the ink in the pressure chamber 26. .

(Configuration of circulation path and circulation mechanism)
By the way, the temperature of the ink inside the conventional inkjet head becomes non-uniform due to changes in the surrounding environment and usage conditions. The viscosity of the ink changes greatly as the temperature of the ink changes. When the viscosity changes, the flow of ink in the flow path changes, and even if jet energy is applied to the ink, it does not flow normally. Therefore, the ink jet head cannot eject ink droplets from the nozzles or cannot eject a desired ejection amount when the ink viscosity is changed. However, the conventional inkjet head does not include a temperature adjustment unit that adjusts the temperature of the ink, and the ink ejection performance cannot be adjusted due to a change in the temperature of the ink.

  The ink jet head 6 of this embodiment includes a temperature adjustment unit 40 that adjusts the temperature of ink. The temperature adjustment unit 40 will be described with reference to FIGS. As shown in FIGS. 2 to 4, the temperature adjustment unit 40 includes a circulation path 50, a supply port 46 and a discharge port 47, a circulation mechanism 41, and tubes 48 a and 48 b.

  As shown in FIG. 2, the circulation path 50 is disposed between the outermost end portion of the flow path structure 10 and the pressure chamber 26 so as to extend in the front-rear and left-right directions. Moreover, the circulation path 50 has the supply port 46 and the discharge port 47, as shown in FIG. The supply port 46 and the discharge port 47 are formed through the pressure chamber plate 14. As shown in FIG. 3, in the circulation path 50, the left circulation path 50 is formed only in the cavity plate 15, and the right circulation path 50 is formed in the cavity plate 15 and the manifold plate 16.

As shown in FIG. 4, a groove 51, a groove 52, and a groove 53 are formed in the cavity plate 15, and have a predetermined length in the front-rear direction. The grooves 61 and 62 are formed in the manifold plate 16 and have a predetermined length in the front-rear direction. In the front-rear direction, the groove 51 and the groove 61 communicate with each other by overlapping the end portion 51b and the end portion 61a to form a pipe line 60a. Further, the groove 61 and the groove 52 communicate with each other in such a manner that the end portion 61b and the end portion 52a overlap each other in the front-rear direction, thereby forming a pipe line 60b. In the front-rear direction, the groove 52 and the groove 62 are communicated with each other by overlapping the end portion 52b and the end portion 62a to form a pipe line 60c. Further, the groove 62 and the groove 53
Means that the end portion 62b and the end portion 53a overlap and communicate with each other to form a pipe line 60d.

  As an example, the circulation mechanism 41 has the configuration of the circulation mechanism described in Japanese Patent Application Laid-Open No. 2008-123488. The circulation mechanism 41 includes a circulation pump 42, a temperature adjustment unit 43, a temperature sensor 44, and a circulation control circuit 45. The circulation pump 42 supplies the circulation fluid to the supply port 46, and flows the circulation fluid discharged from the discharge port 47 into the supply port 46 again. The temperature adjusting unit 43 includes a heater (not shown) that heats the circulation fluid and a cooler (not shown) that cools the circulation fluid, and can heat or cool the circulation fluid. The temperature sensor 44 is mounted on the inkjet head 6 and measures the temperature of the inkjet head 6. The circulation control circuit 45 is connected to the circulation pump 42, the temperature adjustment unit 43, and the temperature sensor 44.

  Here, a control operation in which the circulation control circuit 45 controls the circulation mechanism 41 to heat or cool the circulation fluid will be described. The circulation control circuit 45 estimates the temperature of the ink in the inkjet head 6 based on the temperature of the inkjet head 6 measured by the temperature sensor 44. When the circulation control circuit 45 determines that the temperature of the ink is lower than the desired temperature, the circulation control circuit 45 activates the heater provided in the temperature adjustment unit 43 to heat the circulation fluid. The circulation control circuit 45 heats the circulation fluid and drives the circulation pump 42. As a result, the heated circulation fluid flows in the circulation path 50 and warms the ink in the inkjet head 6.

  When the circulation control circuit 45 determines that the temperature of the ink is higher than the desired temperature, the circulation control circuit 45 operates the cooler provided in the temperature adjustment unit 43 to cool the circulation fluid. The circulation control circuit 45 drives the circulation pump 42 so that the cooled circulation fluid flows through the circulation path 50. As a result, the cooled circulation fluid flows through the circulation path 50 and cools the ink in the inkjet head 6.

  The circulation fluid is not limited to a liquid such as water or a gas such as air, but may be any fluid that can be adjusted in temperature and that flows through the circulation path 50, such as a gel fluid.

(Description of the plate constituting the channel structure)
Next, a plurality of plates constituting the flow path structure 10 will be described with reference to FIGS. 5 is a top view of the pressure chamber plate 14, FIG. 6 is a top view of the cavity plate 15, FIG. 7 is a top view of the manifold plate 16, and FIG. 8 is a top view of the manifold plate 19.

As shown in FIG. 5, the pressure chamber plate 14 has a plurality of pressure chambers 26. The plurality of pressure chambers 26 constitute a pressure chamber row 26a and a pressure chamber row 26b side by side in the front-rear direction. The pressure chamber row 26a and the pressure chamber row 26b are arranged in the left-right direction. The ink supply port 29a is formed on the front side of the pressure chamber plate 14 in plan view. The supply port 46 and the discharge port 47a are formed on both sides of the ink supply port 29a.

As shown in FIG. 6, the cavity plate 15 includes a plurality of aperture holes 25 arranged in the front-rear direction to form aperture hole rows 25a and 25b. A plurality of through holes 27a are arranged in the front-rear direction. Grooves 51 to 55 are formed in the cavity plate 15, and the grooves 51 and 52 are disposed between the left outermost end portion of the cavity plate 15 in the left-right direction and the aperture hole row 25 a. Yes. Further, the groove 54 and the groove 55 are disposed between the rightmost outermost end portion of the cavity plate 15 in the left-right direction and the aperture hole 25b. The groove 53 is disposed between the outermost end portion on the front side in the front-rear direction of the cavity plate 15 and the aperture hole 25 and the through hole 27a. The cavity plate 15 includes an ink supply port 29b and a discharge port 46b on the front side.

As shown in FIG. 7, the manifold plate 16 has a manifold hole 24a extending in the front-rear direction. The manifold hole 24a includes manifold holes 241a and 242a which are divided into two portions with a space in the left-right direction. A plurality of through holes 27b are formed between the manifold hole 241a and the manifold hole 242a. Grooves 61 to 65 are formed in the manifold plate 16, and the grooves 61 and 62 are disposed between the leftmost outermost end portion of the manifold plate 16 and the manifold hole 241 a. Also, groove 64
The groove 65 is disposed between the outermost end portion on the right side of the manifold plate 16 and the manifold hole 242a. The groove 63 is disposed between the uppermost outermost end portion of the cavity plate 15 and the manifold hole 242a.

  As shown in FIG. 8, the manifold plate 19 has a manifold hole 24b. The manifold hole 24b includes bifurcated manifold holes 241b and 242b with a space in the left-right direction. A plurality of through holes 27c are formed between the manifold hole 241b and the manifold hole 242b.

(Manufacturing / Assembly)
Next, the manufacturing method of the inkjet head 6 of this embodiment is demonstrated. The pressure chamber 26, the aperture hole 25, and the like are formed in the pressure chamber plate 14, the cavity plate 15, and the manifold plates 16 and 19 by a manufacturing method similar to the manufacturing method disclosed in Japanese Patent Laid-Open No. 2006-305948. At the time of manufacture, first, manifold holes 24a, 2
4b, and through holes 27b and 27c, and mask patterns corresponding to the grooves 51 to 55 and the grooves 61 to 65 are formed on the manifold plates 16 and 19, respectively. Next, portions where the mask pattern is not formed are removed by etching, and the manifolds 24a, 24 are removed.
b, through-holes 27b and 27c, grooves 51 to 55, and grooves 61 to 65 are formed in the manifold plates 16 and 19, respectively. Further, the nozzle 28 is formed on the nozzle plate 11 by a manufacturing method similar to the manufacturing method disclosed in Japanese Patent Laid-Open No. 2006-305948.

The cavity plate 15 is arranged and joined so that the lower surface 14b of the pressure chamber plate 14 and the upper surface 16a of the manifold plate 16 shown in FIG. The manifold plate 19 is joined to the lower surface 16b of the manifold plate 16 shown in FIG. 3, and the nozzle plate 11 is joined to the lower surface 19b of the manifold plate 19. Thereby, the flow path unit 10 is comprised. The piezoelectric actuator 30 is joined to the upper surface 14a of the pressure chamber plate 14 after the flow path unit 10 is formed. Thereafter, the tube 48 a and the tube 48 b are connected to the supply port 46 and the discharge port 47 that open in the pressure chamber plate 21, respectively. The tube 48a and the tube 48b are connected to the circulation mechanism 41, respectively.

(Comparison of the laminated structure in which the circulation path of the entire surface is formed on the plate and the laminated structure of this embodiment)
In order to quickly adjust the temperature of the ink, it is desirable that the circulation path be configured to have as large a volume as possible in the flow path structure. In order to increase the volume of the circulation path, the entire plate of the plate constituting the flow path structure is formed with the circulation path passing through the plate. Here, the cavity plate 115 and the manifold plate 116 in which the circulation path of the entire surface is formed will be described with reference to FIGS. 9 and 10. FIG. 9 is a top view of the cavity plate 115 in which the groove 151 corresponding to the entire circulation path is formed, and FIG. 10 is a top view of the manifold plate 116 in which the groove 161 corresponding to the entire circulation path is formed.

As shown in FIG. 9, the cavity plate 115 is formed with a groove 151, and has an inner region 115 a inside the groove 151. In the inner region 115a, an aperture hole 125a and a through hole 127a are formed. Further, the gap region 115 b exists between the end portion 151 a of the groove 151 and the ink supply port 129, and the gap region 115 c exists between the end portion 151 e of the groove 151 and the ink supply port 129. The gap regions 115b and 115c are regions connected to the inner region 115a in the cavity plate 115. The inner region 115a is supported only on the lower side connected to the gap regions 115b and 115c, and is in a cantilever state. The inner region 115a is easily bent in the stacking direction due to its own weight with the gap regions 115b and 115c serving as fulcrums. For example, when the assembly operation is performed by gripping only the outer edge portion 115d of the cavity plate 115 during manufacturing, the inner region 115a is bent in the vertical direction by its own weight. In some cases, the inner region 115a may not return from the bent state, or the gap region 115b and the gap region 115c may break.

As shown in FIG. 10, the manifold plate 116 has a groove 161, and has an inner region 116 a inside the groove 161. A manifold hole 124 and a plurality of through holes 127b are formed in the inner region 116a. The manifold hole 124 includes manifold holes 1241a and 1242a. A gap region 116b exists between the end 161a of the groove 161 and the manifold hole 124, and a gap region 116c exists between the end 161e of the groove 161 and the manifold hole 124a. Further, the gap region 116d exists between the manifold hole 1241a and the circulation path 161, and the gap region 116e becomes the manifold hole 1242a.
And the circulation path 161. The gap area 116b and the gap area 116e have elongated shapes in plan view and are easily bent in the vertical direction. The manifold plate 116 has almost no area to be gripped by an arm or the like used during manufacture, and the gap area 116b and the gap area 116e are easily bent in the vertical direction, and thus are difficult to handle during manufacture.

  On the other hand, as shown in FIGS. 6 and 7, the cavity plate 15 and the manifold plate 16 of the present embodiment include a plurality of grooves 51 to 55 and grooves 61 to 65 that define the circulation path 50 with a space therebetween. Is formed. The cavity plate 15 does not have a region that is cantilevered in the front-rear direction, and is difficult to deform downward due to its own weight. The manifold plate 16 has a wider area for gripping the arm at the time of manufacture than the manifold plate 116 and is easy to handle at the time of manufacture. Further, the manifold plate 16 does not have the gap regions 116b and 116c like the manifold plate 116, and is difficult to deform downward due to its own weight. The gap regions 116b and 116c support the inner region 116a in a cantilever state.

(Relationship between printing operation and circulation operation)
Next, the relationship between the printing operation of the inkjet head 6 of this embodiment and the circulation operation of the circulation mechanism 41 will be described. The circulation control circuit 45 outputs a print command to the print control circuit by operating an external input device (PC or the like) connected to the printer 1 or pressing a print switch provided in the printer 1. Then, the circulation mechanism 41 is driven to adjust the ink temperature before printing. Specifically, after receiving the print command, the circulation control circuit 45 confirms the temperature measured by the temperature sensor 44 and compares the ink temperature at the time of confirmation with a desired temperature. When it is determined that the temperature of the ink at the time of confirmation is lower than the desired temperature, the circulation control circuit 45 heats the circulation fluid by the temperature adjustment unit 44, and uses the heated circulation fluid to the circulation pump 42. To the circulation path 50. While supplying the circulation fluid to the circulation path 50, the circulation control circuit 45 confirms the temperature of the ink in the inkjet head 6. When it is confirmed that the ink temperature has reached the desired temperature, the circulation control circuit 45 stops the circulation pump 42 and also stops the temperature adjustment unit 43. Thereafter, when the circulation control circuit 45 inputs a temperature adjustment end signal to the print control circuit, the print control circuit drives the inkjet head 6 to execute a printing operation.

  When the circulation control circuit 45 determines that the temperature measured by the temperature sensor 44 is higher than the desired temperature, the circulation fluid is cooled by the temperature adjusting unit 43 and the cooled circulation fluid is circulated. It is supplied to the circulation path 50 by the pump 42. When the circulation control circuit 45 confirms that the ink temperature has reached a desired temperature, the circulation control circuit 45 stops the circulation pump 42 and also stops the temperature adjustment unit 43. Thereafter, when the circulation control circuit 45 inputs a temperature adjustment end signal to the print control circuit, the print control circuit drives the inkjet head 6 to execute a printing operation.

(Heat exchange between circulating fluid and ink and outside air)
The heat exchange between the circulation fluid and the ink and the heat exchange between the circulation fluid and the outside air will be described with reference to FIGS. FIG. 11 is an enlarged view of the periphery of the groove 51 including a part of the manifold 24 and the pressure chamber 26, and FIG. 12 is an enlarged view of the periphery of the pipe line 60a including a part of the manifold 24 and the pressure chamber 26. 13 is an enlarged view of the periphery of the groove 61 including a part of the manifold 24 and the pressure chamber 26.

As shown in FIG. 11, the groove 51 and the aperture hole 25 are partitioned by the inner wall 15a. The circulation fluid heat J1 is transmitted to the ink in the aperture hole 25 through the inner wall 15a. Therefore, the circulation fluid exchanges heat with the ink in the aperture hole 25 through the inner wall 15a. Further, as shown in FIG. 12, the pipe line 60a, the aperture hole 25, and the manifold 24 are partitioned by an inner wall 15b and an inner wall 16b. Circulating fluid heat J
2 and heat J3 are transferred to the ink in the aperture hole 25 and the manifold 24 through the inner wall 15b and the inner wall 16b. As shown in FIG. 13, the groove 61 and the manifold 24 are partitioned by an inner wall 16c. The circulation fluid heat J4 is transmitted to the ink in the manifold 24 through the inner wall 16a.

The circulating fluid is the ink stored in the aperture hole 25 and the manifold 24 through the pipe line 60 a without exchanging heat with only the ink in the aperture hole 25 or only the ink in the manifold 24. Heat can be exchanged between the two. Therefore, the circulation fluid can exchange heat evenly with the ink in the inkjet head 6 without exchanging heat locally.

(Function and effect)
With the printer 1 configured as described above, the following operational effects can be obtained. In the present embodiment, the circulation path 50 is formed in the cavity plate 15 and the manifold plate 16. The cavity plate 15 has some grooves 51 to 55 of the circulation path 50, and the manifold plate 16 has some grooves 61 to 65 of the circulation path 50. The grooves 51 to 55 are formed in the cavity plate 15 at intervals, and the grooves 61 to 65 are also formed in the manifold plate 16 at intervals. Therefore, the cavity plate 15 and the manifold plate 16 can be prevented from being bent in the vertical direction due to their own weight when lifted during manufacturing, for example, compared to the cavity plate 115 and the manifold 116 in which the circulation path of the entire surface is formed. it can. Therefore, although the circulation path 50 is mounted, it is possible to manufacture without considering the vertical deformation, and to adjust the ink temperature.

(Correspondence between this embodiment and the present invention)
The correspondence between the inkjet head 6 of the present embodiment and the present invention will be described. The manifold 24, the aperture hole 25, the pressure chamber 26, and the descender 27 of this embodiment are an example of the “liquid channel” of the present invention. The vertical direction of this embodiment corresponds to the “stacking direction” of the present invention. The piezoelectric actuator 30 according to the present embodiment is an example of the “energy applying unit” in the present invention. The cavity plate 15 and the manifold plate 16 of this embodiment are examples of the “circulation plate” of the present invention. The temperature adjustment unit 40 of the present embodiment is an example of the “supplying unit” in the present invention. The groove 51 to the groove 55 and the groove 61 to the groove 65 of the present embodiment are an example of the “concave portion” of the present invention.

Further, the manifold 24 of the present embodiment is an example of the “liquid storage chamber” in the present invention. The front-rear direction of the present embodiment corresponds to the “direction in which the circulation path extends” of the present invention. The front-rear direction of the present embodiment corresponds to the “perpendicular direction” of the present invention.

(Modification)
Next, modified embodiments in which various modifications are made to the embodiment will be described. However, components having the same configuration as in the above embodiment are given the same reference numerals and description thereof is omitted as appropriate.

(Modification 1)
In the embodiment, the circulation path 50 is formed in the two plates of the cavity plate 15 and the manifold plate 16, but the manifold plate 217 is a part of the circulation path 250 as in the flow path unit 210 shown in FIG. 14. The circulation path 250 may be configured together with the cavity plate 215 and the manifold plate 216.

As shown in FIG. 14, the cavity plate 215 has a groove 251 and a groove 252, and the manifold plate 216 has a groove 261 and a groove 262. The manifold plate 217 has a groove 271. The end portion 251 b of the groove 251 communicates with the end portion 261 a of the groove 261. The pipe line 260a includes an end portion 251b and an end portion 261a. Further, the end portion 261b of the groove 261 and the end portion 271a of the groove 271 are connected to the pipe line 260b.
And the conduit 260b communicates the groove 261 and the groove 271 in the vertical direction. Further, the end portion 271b of the groove 270 and the end portion 262a of the groove 262 constitute a pipe line 260c, and the pipe line 260c communicates the groove 271 and the groove 262 in the vertical direction. Thereby, since the cavity plate 215 and the manifold plates 216 and 217 can be configured by reducing the grooves formed in each, the vertical deformation due to its own weight can be further suppressed.

  In addition, the groove | channel which comprises a circulation path may be formed in four or more plates.

(Modification 2)
Further, in the embodiment, the grooves 51 to 55 and the grooves 61 to 65 penetrate the cavity plate 15 and the manifold plate 16 in the vertical direction, respectively, but like the flow path unit 310 shown in FIG. The cavity plate 315 has concave grooves 351 and 352 that do not penetrate in the vertical direction, and the manifold plate 316 has concave grooves 361 and 362.

  Since the concave grooves 351 and 352 and the concave grooves 361 and 362 do not penetrate the cavity plate 315 and the manifold plate 316, respectively, the concave grooves 351 and 352 are less likely to bend in the vertical direction compared to the plate in which the grooves penetrating in the vertical direction are formed.

  In addition, the concave grooves 351 and 352 and the concave grooves 361 and 362 of the modified embodiment 2 are examples of the “concave portion” of the present invention.

(Modification 3)
As in the flow path unit 410 shown in FIG. 16, the circulation path 450 includes four plates 415 to 418. The groove 451 of the plate 415 and the groove 471 of the plate 417 are disposed so as to overlap in the front-rear direction and communicate with each other through the pipe line 490a. Further, the groove 451 and the groove 471 are connected by the groove 461 of the plate 416, the groove 481 of the plate 418, and the pipe line 490b. The groove 461 and the groove 481, and the groove 452 and the groove 472 are connected by a pipe line 490c, and the groove 452 and the groove 472, and the groove 462 and the groove 482 communicate with each other through a pipe line 490d. Further, the groove 462 and the groove 482 communicate with each other through the pipe line 490e.

  The circulating fluid can flow through the plates 415 and 417 and the plates 416 and 418 as evenly as possible in the vertical direction. Therefore, the circulation fluid can be prevented from flowing locally in the flow path structure 410.

  Further, when the pipe lines 490a to 490e are arranged at a constant interval in the front-rear direction, it is possible to prevent the circulation fluid from flowing locally biased in the vertical direction.

(Modification 4)
As shown in FIG. 17, in the inkjet head 504, a plurality of pressure chambers 526 are arranged in the transport direction to constitute a pressure chamber row 526a to a pressure chamber row 526h, and the pressure chamber row 526a to the pressure chamber row 526h are arranged in the left-right direction. Multiple sequences are arranged. A circulation path 600 is formed between the pressure chamber row 526b and the pressure chamber row 526c.

The circulation path 550 a and the circulation path 600 are directly connected to the supply port 546 and the circulation mechanism 54.
The circulating fluid is directly supplied from 1. The circulation mechanism 541 includes a circulation pump 542, a temperature adjustment unit 543, and a temperature sensor 544, as in the present embodiment. The circulation path 550 b extends from a pipe line 690 connected to the circulation path 550 a and the circulation path 600 to the discharge port 547. The flow path area of the circulation path 550b is larger than that of the circulation path 550a and the circulation path 600. When the circulation pump 542 is driven by the circulation control circuit 545, the circulation fluid flows through the supply port 546 to the circulation path 550a and the circulation path 600 as indicated by the arrows V1 and V2. Then, the circulation fluid flows into the circulation path 550b through the pipe line 690. The pipe line 690 and the circulation path 550b have a larger cross-sectional area than the circulation path 550a and the circulation path 600. Therefore, the circulation fluid can surely flow into the circulation path 550b via the circulation path 550a and the circulation path 600. The circulation fluid flows into the circulation path 600 in an optimum temperature state for adjusting the ink temperature. Therefore, the circulation fluid can efficiently exchange heat with the ink as compared with the case where the circulation fluid passes through the circulation path 550a.

A plurality of circulation paths 600 may be formed in the inkjet head 504. The circulation path 600 may be disposed between the pressure chamber row 526d and the pressure chamber row 526e, or between the pressure chamber row 526f and the pressure chamber row 526g. Furthermore, for example, two or more plural circulation paths 600 may be disposed between the pressure chamber row 526b and the pressure chamber row 526c. Similarly, the circulation path 600 has a pressure chamber row 526f between the pressure chamber row 526d and the pressure chamber row 526e.
Two or more of them may be arranged between the pressure chamber row 526g and the pressure chamber row 526g.

  The circulation path 600 of the modified embodiment 6 is an example of the “inter-row circulation path” in the present invention.

(Modification 5)
As shown in FIG. 18, the inkjet head 604 is configured such that the circulation path 650 is disposed below the pressure chamber 626 in the vertical direction.

  Since the circulation path 650 overlaps the pressure chamber 626 in the vertical direction, the circulation fluid can exchange heat with the ink in the pressure chamber 626 in addition to the manifold 624.

  In each of the above embodiments, the groove may have a shape penetrating the plate in the vertical direction or a concave shape having a bottom. You may make it comprise a circulation path combining a groove | channel of a penetration shape and a concave groove | channel of a concave shape.

  The piezoelectric actuator 30 according to the present embodiment performs a jetting operation to stop the drive voltage applied to the individual electrode 32 by the print control circuit when jetting ink and to apply jetting energy to the ink in the pressure chamber 26. However, for example, a printing control circuit that applies a driving voltage to the individual electrodes and performs an ejection operation that imparts ejection energy to the ink in the pressure chamber is also included in the present invention. In this embodiment, the case where the piezoelectric actuator 30 is used as the means for applying the ink ejection energy has been described. However, the present invention is not limited to this. For example, the present invention can be applied to a thermal ink jet printer in which a heating resistor is disposed in the pressure chamber to apply pressure to ink.

  In the present embodiment, the grooves 51 to 55 and the grooves 61 to 65 are formed in the pressure chamber plate 15 and the manifold plate 16 that constitute the circulation path 50, respectively. If so, the circulation path may be formed on any plate. In addition to the plate in which the liquid flow path is formed, a single plate in which only the circulation path is formed or a large number of the plates may be stacked.

  In the present embodiment, the fluid for circulation is a fluid different from the ink, but ink may be used.

  In the present embodiment, the serial type inkjet head 6 in which the carriage 3 reciprocates in the left-right direction along the guide shaft 5 has been described. For example, the line type extends so as to overlap all the sheets in the left-right direction. The present invention can also be applied to an inkjet head of this type.

  In the embodiment described above, the present invention is applied to an ink jet printer that performs printing by ejecting ink onto paper. However, the application target of the present invention is not limited to an ink jet printer. That is, the present invention can also be applied to various droplet ejecting apparatuses that eject various droplets to a target according to the application.

1 is a schematic perspective view according to an embodiment of the present invention. It is a top view of the inkjet head 6 of FIG. It is sectional drawing cut | disconnected by the II line | wire of the inkjet head 6 shown in FIG. It is sectional drawing cut | disconnected by the II-II line | wire of the inkjet head 6 shown in FIG. 4 is a top view of a pressure chamber plate 14 that constitutes the inkjet head 6. FIG. 3 is a top view of a cavity plate 15 that constitutes the inkjet head 6. FIG. 4 is a top view of a manifold plate 16 that constitutes the inkjet head 6. FIG. 4 is a top view of a manifold plate 19 that constitutes the inkjet head 6. FIG. It is a top view of the cavity plate 115 in which the circulation path of the whole surface was formed. It is a top view of the manifold plate 116 in which the circulation path of the whole surface was formed. 3 is an enlarged cross-sectional view of a periphery of a groove 51 including a part of a manifold 24 and a pressure chamber 26. FIG. 4 is an enlarged cross-sectional view of a periphery of a pipe line 60a including a part of a manifold 24 and a pressure chamber 26. FIG. 4 is an enlarged cross-sectional view of the periphery of a groove 61 including a part of a manifold 24 and a pressure chamber 26. FIG. FIG. 5 is a cross-sectional view of Modification 1 corresponding to the cross-sectional view of the inkjet head 6 shown in FIG. 4. FIG. 6 is a cross-sectional view of a modified embodiment 2 corresponding to the cross-sectional view of the inkjet head 6 shown in FIG. 4. FIG. 6 is a cross-sectional view of a modified embodiment 3 corresponding to the cross-sectional view of the inkjet head 6 shown in FIG. 4. It is a schematic top view of the inkjet head 504 of the modified form 4. FIG. 6 is a cross-sectional view of a modified embodiment 5 corresponding to the cross-sectional view of the inkjet head 6 shown in FIG. 3.

DESCRIPTION OF SYMBOLS 1 Printer 6 Inkjet head 10 Flow path unit 11 Nozzle plate 12 Flow path structure 14, 214, 314, 414 Pressure chamber plate 15, 115, 215, 315, 415 Cavity plate 16, 116, 216, 316, 416 Manifold plate 19 219, 419 Manifold plate 24, 524, 624 Manifold 25 Aperture hole 26, 526, 626 Pressure chamber 27 Decender 28 Nozzle 30 Piezo actuator 40 Temperature adjustment unit 41, 541 Circulation mechanism 50, 250, 350, 450, 550 Circulation path 51 -55 Grooves 61-65 Grooves 46, 546 Supply port 47, 547 Discharge port 217 Manifold plate 418 Manifold plate 449 Communication path 526a-526h Pressure chamber row 650 Circulation path

Claims (8)

A flow channel structure in which a liquid channel including a pressure chamber is formed and a plurality of plates are stacked in a predetermined stacking direction, and a nozzle that is stacked on the flow channel structure in the stacking direction and communicates with the pressure chamber A flow path unit having a nozzle plate formed with
Energy application means provided in the flow path unit for applying injection energy for injecting liquid droplets from the nozzle to the liquid in the pressure chamber;
A circulation path formed in each of at least two circulation plates adjacent in the stacking direction among the plurality of plates constituting the flow path structure;
Supply means for supplying a circulation fluid different from the liquid in the liquid flow path to the circulation path in order to adjust the temperature of the liquid in the liquid flow path;
The circulation path has a plurality of recesses formed at intervals in each of the circulation plates, and an end of the recess formed in one circulation plate is formed in another circulation plate. The end of the recess is formed in a tubular shape in communication with the stacking direction ,
The droplet ejecting apparatus , wherein the recess formed in the one circulation plate and the recess formed in the other circulation plate overlap each other only in the stacking direction . The liquid flow path has a liquid storage chamber for storing liquid to be supplied to the pressure chamber,
The liquid storage chamber overlaps at least a part of the pressure chamber in the stacking direction and the direction orthogonal to the direction in which the circulation path extends, and is sandwiched between the pressure chamber and the nozzle in the stacking direction. And
The droplet ejecting apparatus according to claim 1, wherein at least a part of the liquid storage chamber is formed on the circulation plate.   The droplet ejecting apparatus according to claim 1, wherein at least a part of the pressure chamber is formed in the circulation plate. The flow path structure includes a supply port and a discharge port communicating with the circulation path, and a plurality of the pressure chambers are formed in a direction in which the circulation path extends, and the stacking direction and the circulation path Having the circulation path on both sides of the pressure chamber in a direction orthogonal to the extending direction of
The said circulation path arrange | positioned at the both sides of the said pressure chamber is arrange | positioned by the space | interval larger than the space | interval of the said supply port and the said discharge port in the said orthogonal direction. A liquid droplet ejecting apparatus according to claim 1. The flow channel structure includes a supply port and a discharge port communicating with the circulation path, and a plurality of the pressure chambers are arranged in a direction in which the circulation path extends, and a pressure chamber row is formed. A plurality of pressure chamber rows are arranged side by side in a direction perpendicular to the stacking direction and the direction in which the circulation path extends,
The circulation path has inter-row circulation paths arranged in the orthogonal direction,
The inter-row circulation path is arranged between the plurality of pressure chamber rows in the orthogonal direction, and further directly connected to the supply port without passing through the other circulation path. Item 4. The droplet ejection device according to any one of Items 1 to 3. The circulation path is disposed in a region between the outermost end portion of the circulation plate and the pressure chamber in a direction orthogonal to the stacking direction and a direction in which the circulation path extends, and in the orthogonal direction The droplet ejecting apparatus according to claim 1, wherein a length of the droplet ejecting apparatus is longer than a length in the stacking direction. The flow path structure has at least three circulation plates, and further, for intermediate circulation in which both sides of the at least three circulation plates are sandwiched between other circulation plates in the stacking direction. With plates,
The end of the recess of the intermediate circulation plate communicates with the end of the recess formed in each of the circulation plates on both sides adjacent to each other in the stacking direction in the stacking direction. Item 7. A droplet ejecting apparatus according to any one of Items 1 to 6. The concave portion is formed to have the same length as the concave portion formed in the same plate in the direction in which the circulation path extends, and the interval between two adjacent concave portions formed in the same plate is also arranged equally. The liquid droplet ejecting apparatus according to claim 7, wherein:

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