JP2016199033A - Liquid discharge head, liquid discharge unit, apparatus for discharging liquid, and image forming apparatus - Google Patents

Abstract

A liquid discharge head, a liquid discharge unit, an apparatus for discharging liquid, and an image forming apparatus capable of suppressing an increase in size in a nozzle arrangement direction are provided.
A nozzle row in which a plurality of nozzles for discharging liquid are arranged, a plurality of individual liquid chambers arranged in a nozzle arrangement direction leading to each nozzle of the nozzle row, and a liquid is supplied to the plurality of individual liquid chambers The common liquid chamber 12 that is long in the nozzle arrangement direction, the supply port 71 that supplies the liquid to the common liquid chamber, the circulating liquid chamber 43 that communicates with the plurality of individual liquid chambers, and the liquid discharged from the circulating liquid chamber In the liquid discharge head provided with the discharge port 72, the supply port is provided in the center of the common liquid chamber in the nozzle row arrangement direction, and the discharge port is provided outside the common liquid chamber in the nozzle arrangement direction. Provided.
[Selection] Figure 1

Description

  The present invention relates to a liquid ejection head, a liquid ejection unit, an apparatus for ejecting liquid, and an image forming apparatus.

  2. Description of the Related Art Conventionally, a circulating liquid discharge head that circulates liquid is known as a liquid discharge head that discharges liquid provided in an image forming apparatus.

  In the liquid ejection head described in Patent Document 1, a plurality of pressure generation chambers arranged in the nozzle arrangement direction leading to each nozzle of a nozzle row in which a plurality of nozzles are arranged, and a nozzle for supplying liquid to the plurality of pressure generation chambers A long common liquid chamber is provided in the arrangement direction. In addition, a supply port that communicates with the common liquid chamber and supplies ink to the common liquid chamber, and a discharge port that communicates with the circulation flow path leading to the plurality of pressure generation chambers and discharges ink from the circulation flow path are provided. It has been. The supply port is arranged so as to communicate with the upper part of the common liquid chamber on one end side in the nozzle arrangement direction. The discharge port is arranged on the side opposite to the supply port in the nozzle arrangement direction and outside the common liquid chamber.

  However, if the supply port is provided on one end side in the nozzle arrangement direction of the common liquid chamber and the discharge port is arranged on the side opposite to the supply port in the nozzle arrangement direction and outside the common liquid chamber, the nozzle arrangement direction of the liquid discharge head Increases the width of the liquid discharge head, leading to an increase in the size of the liquid discharge head.

  In order to solve the above problems, the present invention provides a nozzle row in which a plurality of nozzles for discharging liquid are arranged, a plurality of individual liquid chambers arranged in a nozzle arrangement direction leading to each nozzle of the nozzle row, and the plurality of the plurality of liquid chambers A common liquid chamber which is long in the nozzle arrangement direction for supplying liquid to the individual liquid chambers, a supply port for supplying liquid to the common liquid chamber, a circulating liquid chamber communicating with the plurality of individual liquid chambers, and the circulating liquid In a liquid discharge head having a discharge port for discharging liquid from the chamber, the supply port is provided in the center of the common liquid chamber in the nozzle array arrangement direction, and outside the common liquid chamber in the nozzle arrangement direction. The discharge port is provided.

  As described above, according to the present invention, there is an excellent effect that an increase in the size of the liquid ejection head in the nozzle arrangement direction can be suppressed.

FIG. 7 shows an example of a cross-sectional view along the A-A ′ cross section of FIG. 6. FIG. 3 is a cross-sectional view of the liquid ejection head according to Embodiment 1 cut along a direction orthogonal to the nozzle arrangement direction. FIG. 3 is a cross-sectional view of the liquid discharge head cut along a nozzle arrangement direction. Sectional drawing cut | disconnected along the liquid chamber plane direction of a liquid discharge head. 1 is a block diagram relating to an ink circulation system according to Embodiment 1. FIG. FIG. 6 is a cross-sectional view of the liquid discharge head cut along a direction orthogonal to the nozzle arrangement direction. FIG. 7 shows another example of a cross-sectional view along the A-A ′ cross section of FIG. 6. FIG. 10 is an external perspective view illustrating a liquid ejection head according to a second embodiment. Cross-sectional explanatory drawing of the direction orthogonal to the nozzle arrangement direction of a liquid discharge head. FIG. 6 is a partial cross-sectional explanatory diagram in a direction parallel to the nozzle arrangement direction of the liquid discharge head. FIG. 3 is an explanatory plan view of a nozzle plate of a liquid discharge head. FIG. 6 is an explanatory plan view of each member constituting the flow path member of the liquid discharge head. FIG. 6 is an explanatory plan view of each member constituting a common liquid chamber member of the liquid discharge head. FIG. 4 is a block diagram illustrating an example of a liquid circulation system according to a second embodiment. Sectional drawing along the A-A 'cross section of FIG. Sectional drawing along the B-B 'cross section of FIG. The principal part top explanatory drawing of an example of the apparatus which discharges a liquid. The principal part side surface explanatory view of the device which discharges liquid. FIG. 10 is a plan view illustrating a main part of another example of the liquid ejection unit according to the second embodiment.

[Embodiment 1]
FIG. 2 is a cross-sectional view of the liquid discharge head 434, which is an individual circulation type liquid discharge head according to this embodiment, cut along a direction orthogonal to the nozzle arrangement direction. FIG. 3 is a cross-sectional view of the liquid discharge head 434 cut along the nozzle arrangement direction. FIG. 4 is a cross-sectional view taken along the liquid chamber plane direction of the liquid discharge head 434.

  The liquid discharge head 434 according to the present embodiment includes the ink supply port 11 (see FIG. 4), the frame 1 in which the engraving that becomes the common liquid chamber 12 is formed, and the fluid resistance portion 21. Furthermore, the flow path plate 2 in which the engraving that becomes the pressure generation chamber 22 and the communication pipe portion 23 communicating with the nozzle 31 are formed, the nozzle plate 3 that forms the nozzle 31, the island-shaped convex portion 61, the diaphragm portion 62, and the ink flow A diaphragm 6 having an inlet 63 is provided. Furthermore, a laminated piezoelectric element 5 that is a pressure generating element joined to the vibration plate 6 via an adhesive layer 7 and a base 4 that fixes the laminated piezoelectric element 5 are provided.

  The base 4 is made of a barium titanate ceramic, and the laminated piezoelectric elements 5 are arranged in two rows and joined. The laminated piezoelectric element 5 includes a piezoelectric layer of lead zirconate titanate (PZT) having a thickness of 10 [μm] to 50 [μm] / 1 layer, and silver / palladium (AgPd) having a thickness of several [μm / 1 layer]. The internal electrode layers made of are stacked alternately. The internal electrode layer is connected to the external electrode at both ends. The laminated piezoelectric element 5 is divided into comb teeth by half-cut dicing and used as a drive unit 56 and a support unit 57 (non-drive unit) one by one. The length of the outer electrode is limited by cutting or the like so as to be divided by half-cut dicing, and these become a plurality of individual electrodes 54. The other is not divided in the dicing process and is conductive and becomes the common electrode 55.

  An FPC (flexible printed circuit) 8 is soldered to the individual electrode 54 of the drive unit 56. In addition, the common electrode 55 is provided with an electrode layer at the end of the laminated piezoelectric element 5 and is wound around to join the Gnd electrode of the FPC 8. A head driver 109 as a head control unit is mounted on the FPC 8, thereby controlling application of a driving voltage to the driving unit 56.

  The diaphragm 6 includes a thin film diaphragm portion 62, an island-shaped convex portion 61 that joins the laminated piezoelectric element 5 that forms the driving portion 56 formed at the center portion thereof, and a thick film portion that includes a beam joined to the frame 1. The opening serving as the ink inlet 63 is formed by stacking two Ni plating films by electroforming. The diaphragm 62 has a thickness of 3 [μm] and a width of 35 [μm] (one side). The island-shaped convex part 61 of the diaphragm 6 and the movable part (drive part) 56 of the laminated piezoelectric element 5 and the coupling of the diaphragm 6 and the frame 1 are bonded by patterning the adhesive layer 7 including the gap material. .

  The flow path plate 2 is formed by using a silicon single crystal substrate and patterning the engraving that becomes the fluid resistance portion 21 and the pressure generation chamber 22 and the through-hole that becomes the communication pipe portion 23 at a position relative to the nozzle 31 by an etching method. ing. The portion left by etching becomes the partition wall 24 of the pressure generating chamber 22. Further, the liquid discharge head 434 is provided with a portion for narrowing the etching width, and this is used as the fluid resistance portion 21.

  The nozzle plate 3 is formed of a metal material, for example, an Ni plating film by an electroforming method, and has a large number of nozzles 31 that are fine discharge ports for flying ink droplets. The internal shape (inner shape) of the nozzle 31 is formed in a horn shape (may be a substantially cylindrical shape or a substantially frustum shape). The diameter of the nozzle 31 is about 20 [μm] to 35 [μm] on the ink droplet outlet side. The nozzle pitch of each row was 150 [dpi].

  The ink ejection surface (nozzle surface side) of the nozzle plate 3 is provided with a water repellent treatment layer 32 subjected to a water repellent surface treatment. For example, PTFE-Ni eutectoid plating, fluororesin electrodeposition coating, evaporative fluororesin (e.g., fluorinated pitch, etc.), and baking after solvent application of silicon resin / fluorine resin, etc. A water repellent treatment layer 32 selected according to the ink physical properties is provided. As a result, the ink droplet shape and flight characteristics are stabilized, and high-quality image quality can be obtained. The frame 1 that forms the engraving that becomes the ink supply port 11 and the common liquid chamber 12 is manufactured by resin molding.

  In the liquid ejection head 434 configured as described above, a drive waveform (pulse voltage of 10 [V] to 50 [V]) configured by a drive pulse is applied to the drive unit 56 in accordance with a recording signal. As a result, displacement in the stacking direction occurs in the drive unit 56, the pressure generating chamber 22 is pressurized through the diaphragm 6, the pressure rises, and ink droplets are ejected from the nozzles 31. Thereafter, the ink pressure in the pressure generation chamber 22 decreases with the end of ink droplet ejection, and negative pressure is generated in the pressure generation chamber 22 due to the inertia of the ink flow and the discharge process of the drive voltage (drive pulse). The process proceeds to the ink filling process. At this time, the ink supplied from the ink tank flows into the common liquid chamber 12, passes from the common liquid chamber 12 through the ink inlet 63, passes through the fluid resistance portion 21, and is filled into the pressure generation chamber 22.

  The fluid resistance portion 21 is effective in damping the residual pressure vibration after ejection, but becomes resistant to the maximum filling (refill) due to surface tension. By appropriately selecting the fluid resistance portion 21, it is possible to balance the attenuation of the residual pressure and the refill time, and to shorten the time (drive cycle) until shifting to the next ink droplet ejection operation.

  Next, an example of an ink circulation system using the liquid ejection head 434 according to the present embodiment will be described with reference to FIG. FIG. 5 is a block diagram relating to the ink circulation system according to the present embodiment. As shown in FIG. 5, the ink circulation system includes a main tank 410, a liquid discharge head 434, a head tank 435, a supply side pump 438a, a circulation side pump 438b, a liquid feed pump 438c, a supply side pressure sensor 439a, and a circulation side pressure sensor. 439b or the like. The supply-side pressure sensor 439a is connected between the supply-side pump 438a and the liquid discharge head 434, and is connected to a supply flow path side connected to a supply port 71 (see FIG. 1) described later of the liquid discharge head 434. The circulation side pressure sensor 439b is connected between the liquid discharge head 434 and the circulation side pump 438b, and is connected to a circulation flow path side connected to a later-described circulation port 72 (see FIG. 1) of the liquid discharge head 434. Then, ink is supplied by the supply-side pump 438a and the circulation-side pump 438b so that a positive pressure is detected by the supply-side pressure sensor 439a and a negative pressure is detected by the circulation-side pressure sensor 439b. As a result, the ink circulates so as to flow from the head tank 435 through the supply port 71 into the liquid discharge head 434, to be discharged from the circulation port 72 and to return to the head tank 435.

  Further, the supply-side pump 438a and the circulation-side pump 438b are continuously controlled so that the supply-side pressure sensor 439a has a constant positive pressure and the circulation-side pressure sensor 439b has a constant negative pressure. Thereby, the negative pressure of the meniscus can be kept constant while circulating the ink through the liquid ejection head 434. Further, when droplets are ejected from the nozzles of the liquid ejection head 434, the amount of ink in the head tank 435 decreases, so the main tank 410 is appropriately transferred from the main tank 410 to the head tank 435 using the liquid feed pump 438c. It is desirable to replenish ink. The timing of ink replenishment from the main tank 410 to the head tank 435 is a liquid level sensor provided in the head tank 435, such as ink replenishment when the ink level in the head tank 435 falls below a predetermined level. It can control by the detection result.

[Configuration example 1]
Next, the configuration of the liquid ejection head 434 according to Configuration Example 1 will be described. FIG. 6 is a cross-sectional view of the liquid ejection head 434 cut along a direction orthogonal to the nozzle arrangement direction (liquid ejection head longitudinal direction). From the common liquid chamber 12 to the common circulation channel 41 via the introduction unit 20, the fluid resistance unit 21, the pressure generation chamber 22, the communication pipe unit 23, and the circulation resistance unit 42. In the middle of the circulation flow path, the nozzle 31 is disposed at the tip of the communication pipe portion 23. The common liquid chamber 12 is formed in the frame 1, and the flow path from the introduction unit 20 to the circulation flow path 41 is formed in the flow path plate 2. The flow path plate 2 has a configuration in which a plurality of plate-like members are laminated.

  FIG. 1 shows an example of a cross-sectional view along the A-A ′ cross section of FIG. 6. The supply port 71 of the frame 1 is connected to the common liquid chamber 12, and the supply port 71 is arranged at the center of the common liquid chamber 12 in the nozzle arrangement direction. The common liquid chamber 12 communicates with the circulation liquid chamber 43 in the flow path plate 2 via the circulation flow path described with reference to FIG. In addition, as shown in FIG. 1, the two circulation ports 72 are disposed on both sides of the common liquid chamber 12 on the outer side in the nozzle arrangement direction. By providing the supply port 71 and the two circulation ports 72 at the positions described above, the position of the circulation port 72 is the same, and the liquid is more liquid than when the supply port 71 is provided on the end side of the common liquid chamber 12 in the nozzle arrangement direction. The width of the ejection head 434 in the nozzle arrangement direction can be reduced. Therefore, the circulation flow path can be configured while suppressing the liquid discharge head 434 from increasing in size in the nozzle arrangement direction. Further, by arranging the supply port 71 in the center of the common liquid chamber 12 in the nozzle arrangement direction, the length of the liquid flow path from the supply port 71 to each circulation port 72 is the same in any pressure generation chamber 22. be able to. By making the lengths of the flow paths the same as described above, the sum of the pressure loss generated in the common liquid chamber 12 and the pressure loss generated in the circulating liquid chamber 43 can be obtained in any path passing through any pressure generation chamber 22. Can be the same. And since the sum of the pressure loss becomes the same, the characteristic difference due to the pressure loss can be eliminated.

[Configuration example 2]
Next, the configuration of the liquid ejection head 434 according to Configuration Example 2 will be described. FIG. 7 shows another example of a cross-sectional view taken along the line AA ′ of FIG. As in FIG. 1, the supply port 71 of the frame 1 is connected to the common liquid chamber 12, and the supply port 71 is arranged at the center of the common liquid chamber 12 in the nozzle arrangement direction (longitudinal direction of the liquid discharge head). The common liquid chamber 12 communicates with the circulation liquid chamber 43 in the flow path plate 2 via the circulation flow path described with reference to FIG. Further, as shown in FIG. 7, the two circulation ports 72 are disposed on both sides of the common liquid chamber 12 on the outer side in the nozzle arrangement direction.

  The liquid discharge head 434 according to this configuration example is configured such that the cross-sectional area of the common liquid chamber 12 in the direction orthogonal to the liquid flow direction is larger than the cross-sectional area of the circulating liquid chamber 43 in the direction orthogonal to the liquid flow direction. The fluid resistance value is also small. With this configuration, when the liquid is discharged while the liquid is circulated, both the circulating liquid and the discharged liquid flow in the common liquid chamber 12. By making the area larger than the cross-sectional area of the circulating fluid chamber 43, pressure loss in the common fluid chamber 12 can be suppressed.

  For example, when the liquid is circulated from the supply port 71 to the circulation port 72 at a flow rate of 400 [μl / s], the maximum discharge amount from all nozzles of the liquid discharge head 434 is 200 [μl / s]. . Since the liquid for ejection from all nozzles of the liquid ejection head 434 is supplied from the common liquid chamber 12 side, the maximum flow rate flowing through the supply port 71 and the common liquid chamber 12 is 600 [μl / s], and the circulating liquid chamber 43 and the maximum flow rate flowing through the circulation port 72 is 400 [μl / s]. In the common liquid chamber 12, a liquid having a flow rate up to 1.5 times that of the circulating liquid chamber 43 flows. Therefore, it is desirable that the cross-sectional area of the common liquid chamber 12 is 1.5 times larger than the cross-sectional area of the circulating liquid chamber 43.

[Configuration example 3]
Next, the configuration of the liquid ejection head 434 according to Configuration Example 3 will be described. In the liquid discharge head 434 according to the configuration example 2 described above, the cross-sectional area of the common liquid chamber 12 in the direction orthogonal to the liquid flow direction is larger than the cross-sectional area of the circulating liquid chamber 43 in the direction orthogonal to the liquid flow direction. Therefore, the fluid resistance value of the pipe line was reduced. On the other hand, depending on the shape of the pipe, even if the cross-sectional area in the direction perpendicular to the liquid flow direction of the common liquid chamber 12 is smaller than the cross-sectional area in the direction perpendicular to the liquid flow direction of the circulating liquid chamber 43, The fluid resistance value may be small. More specifically, for example, when the aspect ratio of the width and height of the pipe line is high, the fluid resistance value of the pipe line becomes high even if the common liquid chamber 12 and the circulating liquid chamber 43 have the same cross-sectional area. Therefore, when the aspect ratio of the width and height of the pipe line is close to 1, even if the common liquid chamber 12 and the circulating liquid chamber 43 have the same area, the fluid resistance value of the pipe line can be reduced. Thus, by making the fluid resistance value of the common liquid chamber 12 smaller than the fluid resistance value of the circulating liquid chamber 43, it is possible to suppress pressure loss due to the flow of liquid for circulation and discharge.

  For example, when the same fluid resistance value is used in a channel whose height is half that of the channel whose aspect ratio is 1: 1, the width needs to be increased to about 100 times. . That is, the aspect ratio is 200. As in the configuration example 2, if a liquid with a flow rate of 600 [μl / s] flows in the common liquid chamber 12 and a liquid with a flow rate of 400 [μl / s] flows in the circulating liquid chamber 43, the common liquid chamber 12 Is desired to be set to 2/3 or less of the fluid resistance value of the circulating fluid chamber 43. When the aspect ratio of the cross section of the common liquid chamber 12 is 1: 1 and the aspect ratio of the cross section of the circulating liquid chamber 43 is 0.6: 1.8, the fluid resistance value of the common liquid chamber 12 is approximately 2/3 that of the circulating liquid chamber 43. Thus, the cross-sectional area of the common liquid chamber 12 is about 91% of the cross-sectional area of the circulating liquid chamber 43. Thus, depending on the cross-sectional shape of the flow path, it is necessary to consider the fluid resistance value instead of the cross-sectional area.

  In the above embodiment, the configuration of the flow path component is taken as an example, but the configuration of the flow path component is not limited to the above embodiment. In general, as a printer, a fax machine, a copier, a plotter, or an image forming apparatus that combines a plurality of these functions, for example, a droplet discharge head that discharges ink droplets (hereinafter referred to as ink droplets) is used. There is an inkjet recording apparatus provided. In an ink jet recording apparatus, an image is formed by adhering ink droplets to a sheet by a droplet discharge head while conveying the sheet as a medium. The medium here is also referred to as “paper”, but the material is not limited, and a recording medium, a recording medium, a transfer material, a recording paper, and the like are also used synonymously. The image forming apparatus means an apparatus for forming an image by ejecting liquid droplets on a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramic. The image formation is not only giving an image having a meaning such as a character or a figure to the medium but also giving an image having no meaning such as a pattern to the medium (simply ejecting a droplet). Also means. The ink is not limited to so-called ink, and is not particularly limited as long as it becomes a droplet when ejected. For example, the ink is a generic term for liquids including DNA samples, resists, pattern materials, and the like. Used as

[Embodiment 2]
Hereinafter, a second embodiment will be described with reference to the accompanying drawings. First, an example of the liquid discharge head 504 according to the present embodiment will be described with reference to FIGS. FIG. 8 is an external perspective view illustrating the liquid discharge head 504 according to the present embodiment. FIG. 9 is a cross-sectional explanatory diagram in a direction orthogonal to the nozzle arrangement direction of the liquid ejection head 504 according to the present embodiment. FIG. 10 is an explanatory cross-sectional view in a direction parallel to the nozzle arrangement direction of the liquid ejection head 504 according to the present embodiment. FIG. 11 is an explanatory plan view of the nozzle plate of the liquid ejection head 504 according to the present embodiment. FIG. 12 is an explanatory plan view of each member constituting the flow path member of the liquid ejection head 504 according to the present embodiment. FIG. 13 is an explanatory plan view of each member constituting the common liquid chamber member of the liquid discharge head 504 according to this embodiment.

  The liquid discharge head 504 is a common liquid chamber member and a piezoelectric actuator 13 that displaces the vibration plate 6 by laminating and joining the nozzle plate 3, the flow path plate 2, and the vibration plate 6 as a wall surface member. A frame 1 and a cover 29 are provided. The nozzle plate 3 has a plurality of nozzles 31 for discharging liquid, and the plurality of nozzles 31 are arranged in a staggered manner as shown in FIG. The flow path plate 2 includes a pressure generation chamber 22 that is an individual liquid chamber that communicates with the nozzle 31, a fluid resistance portion 21 that communicates with the pressure generation chamber 22, and an introduction portion 20 that communicates with the fluid resistance portion 21. The flow path plate 2 is formed by laminating and joining a plurality of plate-like members 2a, 2b, 2c, 2d, 2e from the nozzle plate 3 side, and these plate-like members 2a, 2b, 2c, 2d, 2e. And the diaphragm 6 are laminated and joined to form a flow path member 40.

  The diaphragm 6 has a filter portion 9 as an opening through the introduction portion 20 and the common liquid chamber 12 formed by the frame 1. The diaphragm 6 is a wall surface member that forms the wall surface of the pressure generation chamber 22 of the flow path plate 2. The diaphragm 6 has a two-layer structure, and is formed of a first layer that forms a thin portion from the flow path plate 2 side and a second layer that forms a thick portion, and the first layer corresponds to the pressure generation chamber 22. A deformable vibration region 30 is formed in the portion to be deformed. The diaphragm 6 is not limited to a two-layer structure.

  As shown in FIG. 12A, the plate-like member 2a constituting the flow path plate 2 includes a through groove portion (meaning a groove-shaped through hole) 22a constituting the pressure generating chamber 22, a fluid resistance portion 51, Through grooves 51 a and 52 a constituting the circulating fluid chamber 43 are formed. As shown in FIG. 12B, the plate-like member 2 b is formed with a through groove 22 b that constitutes the pressure generating chamber 22 and a through groove 52 b that constitutes the circulating fluid chamber 43. As shown in FIG. 12C, the plate-like member 2 c is formed with a through groove portion 22 c constituting the pressure generating chamber 22 and a through groove portion 53 a having the nozzle arrangement direction constituting the circulation flow channel 53 as the longitudinal direction. ing. As shown in FIG. 12 (d), the plate-like member 2 d includes a through groove portion 22 d constituting the pressure generating chamber 22, a through groove portion 21 a constituting the fluid resistance portion 21, a through groove portion 20 a constituting the introduction portion 20, and A through-groove portion 53 b is formed with the nozzle arrangement direction constituting the circulation channel 53 as a longitudinal direction. As shown in FIG. 12 (e), the plate-like member 2 e becomes a through groove portion 22 e constituting the pressure generating chamber 22 and a filter downstream side liquid chamber having the nozzle arrangement direction constituting the introduction portion 20 as a longitudinal direction. A through groove portion 20 b and a through groove portion 53 c having the nozzle arrangement direction constituting the circulation channel 53 as a longitudinal direction are formed. As shown in FIG. 12 (f), the vibration plate 30 is formed with a vibration region 30, a filter portion 9, and a through groove portion 53 d whose longitudinal direction is the nozzle arrangement direction constituting the circulation flow path 53. . As described above, by forming the flow path member 40 by laminating and joining the plurality of plate-like members 2a, 2b, 2c, 2d, and 2e, a complicated flow path can be formed with a simple configuration.

  With the above configuration, the flow path member 40 including the flow path plate 2 and the vibration plate 6 includes the fluid resistance portion 51, the circulating liquid chamber 43, and the circulating liquid along the surface direction of the flow path plate 2 leading to each pressure generation chamber 22. A circulation channel 53 in the thickness direction of the channel member 40 communicating with the chamber 43 is formed. The circulation channel 53 communicates with a circulation common liquid chamber 50 described later.

  On the other hand, the common liquid chamber 12 and the circulation common liquid chamber 50 to which the liquid is supplied from the supply circulation mechanism 594 are formed in the frame 1. As shown in FIG. 13A, the first common liquid chamber member 1a constituting the frame 1 includes a piezoelectric actuator through hole 25a, a through groove portion 10a serving as a downstream common liquid chamber 12A, and a circulating common liquid chamber. A groove portion 50a having a bottom that is 50 is formed. Similarly, as shown in FIG. 13B, the second common liquid chamber member 1b is formed with a piezoelectric actuator through hole 25b and a groove portion 10b that becomes the upstream common liquid chamber 12B.

  Referring also to FIG. 8, the second common liquid chamber member 1 b is formed with a through hole 71 a serving as a supply port through the central portion of the common liquid chamber 12 in the nozzle arrangement direction and the supply port 71. . Similarly, the first common liquid chamber member 1 a and the second common liquid chamber member 1 b are formed with through holes 72 a that pass through both ends of the circulation common liquid chamber 50 in the nozzle arrangement direction and the circulation port 72. In FIG. 13, the groove portion having the bottom is shown with surface coating (the same applies to the following drawings).

  Thus, the frame 1 is constituted by the first common liquid chamber member 1a and the second common liquid chamber member 1b, and joins the first common liquid chamber member 1a to the diaphragm 6 side of the flow path member 40, A second common liquid chamber member 1b is stacked and joined to the common liquid chamber member 1a. The frame 1 forms a common liquid chamber 12 and a circulation common liquid chamber 50 to which liquid is supplied from a head tank or a liquid cartridge.

  Here, the first common liquid chamber member 1 a forms a downstream common liquid chamber 12 </ b> A that is a part of the common liquid chamber 12 that communicates with the introduction unit 20, and a circulation common liquid chamber 50 that communicates with the circulation flow path 53. Yes. Further, the second common liquid chamber member 1 b forms an upstream common liquid chamber 12 </ b> B that is the remaining part of the common liquid chamber 12. At this time, the downstream common liquid chamber 12A, which is a part of the common liquid chamber 12, and the circulation common liquid chamber 50 are arranged side by side in a direction orthogonal to the nozzle arrangement direction, and the circulation common liquid chamber 50 is arranged in the common liquid chamber 12. It is arranged at the position projected inside. Thereby, the dimension of the circulation common liquid chamber 50 is not restricted by the dimensions required for the flow path including the pressure generation chamber 22, the fluid resistance part 21, and the introduction part 20 formed by the flow path member 40. The circulation common liquid chamber 50 and a part of the common liquid chamber 12 are arranged side by side, and the circulation common liquid chamber 50 is arranged at a position projected into the common liquid chamber 12 so as to be orthogonal to the nozzle arrangement direction. The width of the liquid discharge head 504 in the direction can be suppressed. Therefore, the increase in the size of the liquid discharge head 504 can be suppressed accordingly.

  On the other hand, the piezoelectric actuator 13 including an electromechanical conversion element as a driving unit that deforms the vibration region 30 of the diaphragm 6 is disposed on the opposite side of the diaphragm 6 from the pressure generation chamber 22. As shown in FIG. 10, the piezoelectric actuator 13 has a laminated piezoelectric element 5 bonded on a base 4. The laminated piezoelectric element 5 is grooved by half-cut dicing, and a required number of columnar piezoelectric elements 5A and 5B are formed in a comb-like shape at a predetermined interval with respect to one laminated piezoelectric element 5.

  Here, the piezoelectric element 5A of the laminated piezoelectric element 5 is a piezoelectric element that is driven by giving a driving waveform, and the piezoelectric element 5B is used as a simple support without giving a driving waveform, but all the piezoelectric elements 5A and 5B are used. It can also be used as a piezoelectric element to be driven. The piezoelectric element 5 </ b> A is joined to a convex portion 30 a that is an island-shaped thick portion formed in the vibration region 30 of the diaphragm 6. Further, the piezoelectric element 5 </ b> B is bonded to the convex portion 30 b which is a thick portion of the diaphragm 6. The laminated piezoelectric element 5 is formed by alternately laminating piezoelectric layers and internal electrodes, and the internal electrodes are drawn out to the end surfaces to provide external electrodes, and the flexible wiring member 15 is connected to the external electrodes.

  In the liquid discharge head 504 configured as described above, for example, the voltage applied to the piezoelectric element 5A is lowered from the reference potential, so that the piezoelectric element 5A contracts, the vibration region 30 of the diaphragm 6 is lowered, and the volume of the pressure generating chamber 22 is reduced. The liquid flows into the pressure generation chamber 22 by expanding. Thereafter, the voltage applied to the piezoelectric element 5A is increased to extend the piezoelectric element 5A in the stacking direction, and the vibration region 30 of the diaphragm 6 is deformed in the direction toward the nozzle 31 to contract the volume of the pressure generating chamber 22. Thereby, the liquid in the pressure generation chamber 22 is pressurized, and the liquid is discharged from the nozzle 31. Then, the liquid is drawn from the common liquid chamber 12 by the surface tension and filled with the liquid. Eventually, the meniscus surface is stabilized by the balance between the negative pressure defined by the supply tank 531 and the circulation tank 532 and the water head difference and the surface tension of the meniscus, so that it is possible to shift to the next discharge operation.

  Note that the driving method of the liquid discharge head 504 is not limited to the above example (pull-push), and it is also possible to perform strike or push according to the direction to which the drive waveform is given. In the above-described embodiment, the laminated piezoelectric element has been described as the pressure generating means for giving the pressure fluctuation to the pressure generating chamber 22, but the present invention is not limited to this, and a thin film piezoelectric element can also be used. . Furthermore, a heating resistor can be provided in the pressure generating chamber 22 to generate a bubble by the heat generation of the heating resistor to give a pressure fluctuation, or to generate a pressure fluctuation by using electrostatic force. .

  Next, an example of the liquid circulation system 530 using the liquid discharge head 504 according to the present embodiment will be described with reference to FIG. FIG. 14 is a block diagram showing a liquid circulation system 530 according to this embodiment. As shown in FIG. 14, the liquid circulation system 530 includes a main tank 502, a liquid discharge head 504, a supply tank 531, a circulation tank 532, a compressor 533, a vacuum pump 534, a first liquid feed pump 535, and a second liquid feed pump 536. , A supply side pressure sensor 537, a circulation side pressure sensor 538, regulators (R) 539a, 539b, and the like. The supply-side pressure sensor 537 is connected between the supply tank 531 and the liquid discharge head 504 and on the supply flow path side connected to the supply port 71 (see FIG. 8) of the liquid discharge head 504. The circulation side pressure sensor 538 is connected between the liquid discharge head 504 and the circulation tank 532 and on the circulation channel side connected to the circulation port 72 (see FIG. 8) of the liquid discharge head 504.

  One of the circulation tanks 532 is connected to the supply tank 531 via the first liquid feed pump 535, and the other of the circulation tanks 532 is connected to the main tank 502 via the second liquid feed pump 536. As a result, the liquid flows from the supply tank 531 through the supply port 71 into the liquid discharge head 504, discharged from the circulation port 72, and discharged to the circulation tank 532. Further, the liquid is circulated by sending the liquid from the circulation tank 532 to the supply tank 531 by the first liquid feed pump 535. Further, a compressor 533 is connected to the supply tank 531 and is controlled so that a predetermined positive pressure is detected by the supply side pressure sensor 537. On the other hand, a vacuum pump 534 is connected to the circulation tank 532 and is controlled so that a predetermined negative pressure is detected by the circulation side pressure sensor 538. Thereby, the negative pressure of the meniscus can be kept constant while circulating the liquid through the liquid discharge head 504.

  Further, when droplets are ejected from the nozzle 31 of the liquid ejection head 504, the amount of liquid in the supply tank 531 and the circulation tank 532 decreases. Therefore, it is desirable to replenish liquid from the main tank 502 to the circulation tank 532 using the second liquid feeding pump 536 from the main tank 502 as appropriate. The timing of liquid replenishment from the main tank 502 to the circulation tank 532 is a liquid level sensor provided in the circulation tank 532, such as liquid replenishment when the liquid level of ink in the circulation tank 532 falls below a predetermined height. It can control by the detection result.

  Next, the circulation of the liquid in the liquid discharge head 504 will be described. FIG. 15 is a cross-sectional view along the A-A ′ cross section of FIG. 9. 16 is a cross-sectional view taken along the B-B ′ cross section of FIG. 9. As shown in FIG. 8, the liquid discharge head 504 is provided with a supply port 71 communicating with the common liquid chamber and a circulation port 72 communicating with the circulation common liquid chamber 50 at the end of the frame 1. The supply port 71 and the circulation port 72 are connected to a supply tank 531 and a circulation tank 532 (see FIG. 14) that store liquid via tubes, respectively. Then, the liquid stored in the supply tank 531 is supplied to the pressure generation chamber 22 through the supply port 71, the common liquid chamber 12, the introduction portion 20, and the fluid resistance portion 21. Further, while the liquid in the pressure generation chamber 22 is discharged from the nozzle 31 by driving the piezoelectric elements 5A and 5B, a part or all of the liquid remaining in the pressure generation chamber 22 without being discharged is a fluid resistance portion. 51, the circulation channels 52 and 53, the circulation common liquid chamber 50, and the circulation port 72 are circulated to the circulation tank 532.

  The liquid circulation can be performed not only when the liquid discharge head 504 is operating but also when the operation is stopped. By circulating at the time of operation stop, the liquid in the pressure generating chamber 22 is always refreshed, and aggregation and sedimentation of components contained in the liquid can be suppressed, which is preferable.

  Also in the present embodiment, as the liquid discharge head, the liquid discharge heads 434 having the respective configurations described in the configuration example 1, the configuration example 2, and the configuration example 3 of the first embodiment with reference to FIG. 1, FIG. 6, FIG. By adopting, the same effect as described above can be obtained. Further, the size of the device for ejecting liquid can be reduced by downsizing the liquid ejection head.

  Next, an example of a device that ejects liquid to which the liquid ejection heads 434 and 504 according to each embodiment can be applied will be described with reference to FIGS. 17 and 18 in which the liquid ejection head 504 is applied. FIG. 17 is an explanatory plan view of a main part of a device for ejecting liquid according to the present embodiment, and FIG. The apparatus for discharging the liquid is a serial type apparatus, and the carriage 503 is reciprocated in the main scanning direction by the main scanning moving mechanism 593. The main scanning movement mechanism 593 includes a guide member 501, a main scanning motor 505, a timing belt 508, and the like. The guide member 501 is bridged between side plates 591A and 591B provided on both sides in the apparatus longitudinal direction, and holds the carriage 503 in a movable manner. The carriage 503 is reciprocated by a main scanning motor 505 in the main scanning direction, which is the longitudinal direction of the apparatus, via a timing belt 508 spanned between the driving pulley 506 and the driven pulley 507.

  The carriage 503 is provided with a liquid discharge unit 540 on which a liquid discharge head 504 is mounted. The liquid discharge head 504 of the liquid discharge unit 540 discharges, for example, yellow (Y), cyan (C), magenta (M), and black (K) liquids. The liquid discharge head 504 is mounted with a nozzle row composed of a plurality of nozzles arranged in the sub-scanning direction orthogonal to the main scanning direction and the discharge direction facing downward. The liquid is supplied and circulated in the liquid discharge head 504 by a supply circulation mechanism 594 for supplying the liquid stored outside the liquid discharge head 504 to the liquid discharge head 504. In the present embodiment, the supply circulation mechanism 594 includes a supply tank 531, a circulation tank 532, a compressor 533, a vacuum pump 534, a first liquid feed pump 535, a second liquid feed pump 536, regulators (R) 539a and 539b, and the like. Consists of. The supply pressure sensor 537 is connected between the supply tank 531 and the liquid discharge head 504 and on the supply flow path side connected to the supply port 71 of the liquid discharge head 504. The circulation side pressure sensor 538 is connected between the liquid discharge head 504 and the circulation tank 532 and on the circulation channel side connected to the circulation port 72 of the liquid discharge head 504.

  The apparatus for ejecting liquid includes a transport mechanism 595 for transporting the paper 510. The transport mechanism 595 includes a transport belt 512 serving as transport means, a sub-scanning motor 516 for driving the transport belt 512, and the like. The conveyance belt 512 sucks the sheet 510 and conveys it at a position facing the liquid ejection head 504. The transport belt 512 is an endless belt and is stretched between the transport roller 513 and the tension roller 514. The sheet 510 can be attracted to the transport belt 512 by electrostatic suction or air suction. The conveyance belt 512 rotates in the sub-scanning direction when the conveyance roller 513 is rotationally driven by the sub-scanning motor 516 via the timing belt 517 and the timing pulley 518.

  On one side of the carriage 503 in the main scanning direction, a maintenance / recovery mechanism 520 that performs maintenance / recovery of the liquid ejection head 504 is disposed on the side of the transport belt 512. The maintenance / recovery mechanism 520 includes, for example, a cap member 521 for capping the nozzle surface (surface on which the nozzle is formed) of the liquid discharge head 504, a wiper member 522 for wiping the nozzle surface, and the like.

  The main scanning movement mechanism 593, the supply circulation mechanism 594, the maintenance / recovery mechanism 520, and the transport mechanism 595 are attached to a housing composed of side plates 591A, 591B, a back plate 591C, and the like. In the liquid ejecting apparatus configured as described above, the paper 510 is fed and sucked onto the transport belt 512, and the paper 510 is transported in the sub-scanning direction by the circular movement of the transport belt 512. Then, the liquid ejection head 504 is driven according to the image signal while moving the carriage 503 in the main scanning direction, thereby ejecting liquid onto the stopped paper 510 to form an image. As described above, since the apparatus for ejecting liquid includes the liquid ejection head 504, a high-quality image can be stably formed.

  Next, another example of the liquid discharge unit 540 will be described with reference to FIG. FIG. 19 is an explanatory plan view of the main part of the unit. The liquid discharge unit 540 includes a housing portion composed of side plates 591A and 591B and a back plate 591C among members constituting the device for discharging the liquid, a main scanning moving mechanism 593, a carriage 503, And a liquid discharge head 504. In addition, for example, the liquid discharge unit 540 in which at least one of the maintenance and recovery mechanism 520 and the supply circulation mechanism 594 described above is further attached to, for example, the side plate 591B of the liquid discharge unit 540 can be configured.

  In the present embodiment, the “liquid ejection head” is a functional component that ejects and ejects liquid from a nozzle. The liquid to be ejected is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 [mPa · s] or less at normal temperature, normal pressure, or by heating and cooling. It is preferable. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. And edible materials such as natural pigments, solutions, suspensions, emulsions and the like. These can be used, for example, in applications such as inkjet inks, surface treatment liquids, components for electronic elements and light emitting elements, liquids for forming electronic circuit resist patterns, and three-dimensional modeling material liquids. As energy generation sources for discharging liquid, piezoelectric actuators (laminated piezoelectric elements and thin film piezoelectric elements), thermal actuators using electrothermal transducers such as heating resistors, electrostatic actuators consisting of a diaphragm and counter electrode are used. To be included.

  A “liquid ejection unit” is a unit in which functional parts and mechanisms are integrated with a liquid ejection head, and is an assembly of parts related to liquid ejection. For example, the “liquid discharge unit” includes a combination of at least one of a supply circulation mechanism, a carriage, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head. Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a supply circulation mechanism are integrated. Also, there are some in which the liquid discharge head and the supply circulation mechanism are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the supply circulation mechanism of these liquid discharge units and the liquid discharge head. In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated. In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. . Some liquid discharge units have a tube connected to a liquid discharge head to which a supply circulation mechanism or a flow path component is attached, and the liquid discharge head and the supply mechanism are integrated. The liquid from the liquid storage source is supplied to the liquid discharge head via this tube. The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  The “device that discharges liquid” is a device that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge the liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid. This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer. Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to. The material of the above-mentioned “material to which liquid can adhere” is not limited as long as liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics can be adhered even temporarily.

  The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, but the viscosity is 30 [mPa · s] or less at normal temperature, normal pressure, or by heating and cooling. It is preferable that More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. And edible materials such as natural pigments, solutions, suspensions, emulsions and the like. These can be used, for example, in applications such as inkjet inks, surface treatment liquids, components for electronic elements and light emitting elements, liquids for forming electronic circuit resist patterns, and three-dimensional modeling material liquids.

  In addition, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like. In addition, as the “device for discharging liquid”, there is a processing liquid application device that discharges a processing liquid onto a sheet in order to apply the processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet. is there. Further, there is an injection granulating apparatus for granulating raw material fine particles by spraying a composition liquid in which raw materials are dispersed in a solution through a nozzle. In addition, the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
A nozzle row in which nozzles such as a plurality of nozzles 31 for discharging liquid such as ink are arranged; individual liquid chambers such as a plurality of pressure generating chambers 22 arranged in the nozzle arrangement direction leading to each nozzle of the nozzle row; A common liquid chamber such as a common liquid chamber 12 elongated in the nozzle arrangement direction for supplying liquid to the plurality of individual liquid chambers, a supply port such as a supply port 71 for supplying liquid to the common liquid chamber, and the plurality of individual liquid chambers In a liquid discharge head such as a liquid discharge head 434 having a circulating liquid chamber such as a circulating liquid chamber 43 communicating with the liquid chamber and a discharge port such as a circulation port 72 for discharging liquid from the circulating liquid chamber, The supply port is provided in the center of the common liquid chamber in the arrangement direction, and the discharge port is provided outside the common liquid chamber in the nozzle arrangement direction.
In (Aspect A), in the nozzle array arrangement direction, a supply port is provided in the center of the common liquid chamber, and a discharge port is provided outside the common liquid chamber. As a result, the supply port is provided on the end side of the common liquid chamber in the nozzle arrangement direction, and the width of the liquid discharge head in the nozzle arrangement direction is larger than the case where the discharge port is provided outside the common liquid chamber in the nozzle arrangement direction. Can be small. Therefore, it is possible to suppress an increase in the size of the liquid discharge head in the nozzle arrangement direction.
(Aspect B)
In (Aspect A), the discharge ports are respectively provided on the outer side on one end side and the outer side on the other end side of the common liquid chamber in the nozzle arrangement direction. According to this, as described in the above embodiment, the length of the liquid flow path from the supply port to the discharge port can be made the same in any individual liquid chamber.
(Aspect C)
In (Aspect A) or (Aspect B), the cross-sectional area in the direction orthogonal to the liquid flow direction of the common liquid chamber is larger than the cross-sectional area in the direction orthogonal to the liquid flow direction of the circulating liquid chamber. According to this, as described in the above embodiment, the pressure loss in the common liquid chamber can be suppressed.
(Aspect D)
In any one of (Aspect A) to (Aspect C), the fluid resistance value of the common liquid chamber is smaller than the fluid resistance value of the circulating liquid chamber. According to this, as described in the above embodiment, it is possible to suppress pressure loss due to the flow of liquid for circulation and discharge.
(Aspect E)
Head tank such as supply tank 531 and circulation tank 532, carriage such as carriage 503, supply mechanism such as supply circulation mechanism 594, maintenance and recovery mechanism such as maintenance and recovery mechanism 520, and main scanning movement mechanism such as main scanning movement mechanism 593 In a liquid discharge unit including at least one of the above and a liquid discharge head, any one of (Aspect A) to (Aspect D) is used as the liquid discharge head. According to this, as described in the above embodiment, the size of the liquid discharge unit can be reduced by downsizing the liquid discharge head.
(Aspect F)
In the apparatus for discharging a liquid including the liquid discharge head, any one of the liquid discharge heads of (Aspect A) to (Aspect D) is used as the liquid discharge head. According to this, as described in the above embodiment, the size of the apparatus can be reduced by downsizing the liquid discharge head.
(Aspect G)
In the apparatus for discharging a liquid including the liquid discharge unit, the liquid discharge unit described in (Embodiment E) is used as the liquid discharge unit. According to this, as described in the above embodiment, the size of the apparatus can be reduced by downsizing the liquid discharge unit.
(Aspect H)
In an image forming apparatus such as a printer that forms an image by discharging liquid droplets from a liquid discharge head such as the liquid discharge head 434, the liquid discharge head according to any one of (Aspect A) to (Aspect D) is used as the liquid discharge head. Was used. According to this, as described in the above embodiment, the size of the image forming apparatus can be reduced by downsizing the liquid discharge head.
(Aspect I)
In an image forming apparatus that forms an image by discharging droplets from a liquid discharge head provided in a liquid discharge unit, the liquid discharge unit described in (Embodiment E) is used as the liquid discharge unit. According to this, as described in the above embodiment, the size of the image forming apparatus can be reduced by downsizing the liquid discharge unit.

1 frame 1a first common liquid chamber member 1b second common liquid chamber member 2 flow path plate 2a plate member 2b plate member 2c plate member 2d plate member 2e plate member 3 nozzle plate 4 base 5 laminated piezoelectric element 5A Piezoelectric element 5B Piezoelectric element 6 Diaphragm 7 Adhesive layer 9 Filter portion 10a Through groove portion 10b Groove portion 11 Ink supply port 12 Common liquid chamber 12A Downstream common liquid chamber 12B Upstream common liquid chamber 13 Piezoelectric actuator 15 Flexible wiring member 20 Introducing portion 20a Through groove portion 20b Through groove portion 21 Fluid resistance portion 21a Through groove portion 22 Pressure generating chamber 22b Through groove portion 22c Through groove portion 22d Through groove portion 22e Through groove portion 23 Communication pipe portion 24 Partition 25a Piezoelectric actuator through hole 25b Piezoelectric actuator through hole 29 Cover 30 Vibration Region 30a Convex 30b Convex 31 32 Water repellent treatment layer 40 Channel member 41 Circulation channel 42 Circulation resistance part 43 Circulation liquid chamber 50 Circulation common liquid chamber 50a Groove part 51 Fluid resistance part 51a Through groove part 52 Circulation channel 52a Through groove part 52b Through groove part 53 Circulation channel 53a Through groove portion 53b Through groove portion 53c Through groove portion 53d Through groove portion 54 Individual electrode 55 Common electrode 56 Drive portion 57 Support portion 61 Island-shaped convex portion 62 Diaphragm portion 63 Ink inlet 71 Supply port 71a Through hole 72 Circulation port 72a Through hole 72b Through hole Hole 109 Head driver 410 Main tank 434 Liquid discharge head 435 Head tank 438a Supply side pump 438b Circulation side pump 438c Liquid supply pump 439a Supply side pressure sensor 439b Circulation side pressure sensor 501 Guide member 502 Main tank 503 Carry 504 Liquid discharge head 505 Main scanning motor 506 Driving pulley 507 Driven pulley 508 Timing belt 510 Paper 512 Conveying belt 513 Conveying roller 514 Tension roller 516 Sub-scanning motor 517 Timing belt 518 Timing pulley 520 Maintenance / recovery mechanism 521 Cap member 530 Wiper member 530 Liquid circulation system 531 Supply tank 532 Circulation tank 533 Compressor 534 Vacuum pump 535 First liquid feed pump 536 Second liquid feed pump 537 Supply side pressure sensor 538 Circulation side pressure sensor 540 Liquid discharge unit 591A Side plate 591B Side plate 591B Side plate 591C Back plate 593C Main scanning movement mechanism 594 Supply circulation mechanism 595 Conveyance mechanism

JP 2012-143948 A

Claims (9)

A nozzle row in which a plurality of nozzles for discharging liquid are arranged;
A plurality of individual liquid chambers arranged in a nozzle arrangement direction leading to each nozzle of the nozzle row;
A common liquid chamber elongated in the nozzle array direction for supplying liquid to the plurality of individual liquid chambers;
A supply port for supplying liquid to the common liquid chamber;
A circulating fluid chamber communicating with the plurality of individual fluid chambers;
In a liquid discharge head comprising a discharge port for discharging liquid from the circulating liquid chamber,
The supply port is provided in the center of the common liquid chamber in the nozzle array arrangement direction,
A liquid discharge head, wherein the discharge port is provided outside the common liquid chamber in a nozzle arrangement direction. The liquid discharge head according to claim 1,
The liquid discharge head according to claim 1, wherein the discharge ports are respectively provided on an outer side on one end side and an outer side on the other end side of the common liquid chamber in a nozzle arrangement direction. The liquid discharge head according to claim 1 or 2,
The liquid discharge head according to claim 1, wherein a cross-sectional area of the common liquid chamber in a direction orthogonal to the liquid flow direction is larger than a cross-sectional area of the circulating liquid chamber in a direction orthogonal to the liquid flow direction. The liquid discharge head according to claim 1 or 2,
The liquid discharge head according to claim 1, wherein a fluid resistance value of the common liquid chamber is smaller than a fluid resistance value of the circulating liquid chamber. In a liquid ejection unit including at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism, and a liquid ejection head,
A liquid discharge unit using the liquid discharge head according to claim 1 as the liquid discharge head. In a device for discharging a liquid provided with a liquid discharge head,
An apparatus for ejecting liquid, wherein the liquid ejection head according to claim 1 is used as the liquid ejection head. In an apparatus for discharging a liquid provided with a liquid discharge unit,
An apparatus for discharging liquid, wherein the liquid discharge unit according to claim 5 is used as the liquid discharge unit. In an image forming apparatus for forming an image by discharging droplets from a liquid discharge head,
An image forming apparatus using the liquid discharge head according to claim 1 as the liquid discharge head. In an image forming apparatus that forms an image by discharging droplets from a liquid discharge head provided in a liquid discharge unit,
An image forming apparatus using the liquid discharge unit according to claim 5 as the liquid discharge unit.

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