Manifold, head module, liquid ejection unit, and apparatus for ejecting liquid

Abstract

To provide a manifold which can achieve reduction of costs of a liquid discharge device, and to provide a head module, a liquid discharge unit, and the liquid discharge device.SOLUTION: In a manifold, a part of a wall which stores a liquid is formed by an elastic body such as a damper member 22. An orthogonal wall, which is orthogonal to the wall formed by the elastic body, has two head connection parts for connecting to a liquid discharge head. A facing wall facing the orthogonal wall has a tank connection part for connecting to a tank. The two head connection parts are disposed spaced apart from each other in a longitudinal direction of the orthogonal wall, and the elastic body has a shape which spreads from the facing wall to the orthogonal wall.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a manifold, a head module, a liquid ejection unit, and a device for ejecting a liquid.

Background Art

[0002] Conventionally, a manifold in which a part of a wall for storing a liquid is made of an elastic body and is connected to a plurality of liquid ejection heads is known.

[0003] Patent Document 1 describes a distribution tank as the above-mentioned manifold having a rectangular shape, and a flexible member which is an elastic body constituting a part of the wall of the distribution tank having a rectangular shape.

Summary of the Invention

Problems to be Solved by the Invention

[0004] To reduce the cost of the device.

Means for Solving the Problems

[0005] In order to solve the above-mentioned problems, the present invention provides a manifold in which a part of a wall for storing a liquid is made of an elastic body and is connected to a plurality of liquid ejection heads, the manifold having two head connection portions for connecting to the liquid ejection heads on an orthogonal wall orthogonal to the wall made of the elastic body, and a tank connection portion for connecting to a tank on an opposing wall opposing the orthogonal wall, the two head connection portions being spaced apart in the longitudinal direction of the orthogonal wall, and the elastic body having a shape that spreads from the opposing wall toward the orthogonal wall Yes, in the cross-section in the short side direction of the orthogonal wall, the edge of the elastic body is located outside the central part of the elastic body. characterized by the above.

Effects of the Invention

[0006] According to the present invention, the cost of the device can be reduced.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] [Embodiment 1] [Overall Description] FIG. 1 is a schematic diagram showing the schematic configuration of the inkjet recording apparatus in Embodiment 1 of the present invention. The inkjet recording apparatus 1 of the first embodiment mainly includes a paper feeding unit 100, an image forming unit 200, a drying unit 300, and a paper discharging unit 400. In the inkjet recording apparatus 1, an image is formed on a sheet P, which is a recording material and is fed from the paper feeding unit 100, with ink that is a liquid for image formation by the image forming unit 200. Then, after the ink adhering to the paper is dried in the drying unit 300, the paper is discharged from the paper discharging unit 400.

[0010] [Paper feeding unit] The paper feeding unit 100 mainly includes a paper feeding tray 110 on which a plurality of sheets P are stacked, a feeding device 120 that separates and feeds the sheets from the paper feeding tray 110 one by one, and a registration roller pair 130 that feeds the paper into the image forming unit 200. Any feeding device such as a device using rollers or cylinders or a device using air suction can be used for the feeding device 120. The paper fed from the paper feeding tray 110 by the feeding device 120 is fed into the image forming unit 200 when the leading edge thereof reaches the registration roller pair 130 and the registration roller pair 130 is driven at a predetermined timing. Note that in this embodiment, the configuration of the paper feeding unit 100 is not limited as long as it can feed the sheet P to the image forming unit 200.

[0011] [Image forming unit] The image forming unit 200 mainly includes a transfer cylinder 201 that receives the fed sheet P and passes it to a paper transfer drum 210, and the paper transfer drum 210 that carries and conveys the sheet P conveyed by the transfer cylinder 201 on its outer peripheral surface. Further, it includes a liquid ejection unit 230 that ejects ink toward the sheet P carried on the paper transfer drum 210, and a transfer cylinder 202 that passes the sheet P conveyed by the paper transfer drum 210 to the drying unit 300.

[0012] The sheet P conveyed from the sheet feeding unit 100 to the image forming unit 200 has its leading edge gripped by a sheet gripper provided on the surface of the transfer cylinder 201 and is conveyed as the surface of the transfer cylinder 201 moves. The sheet conveyed by the transfer cylinder 201 is delivered to the sheet transfer drum 210 at a position facing the sheet transfer drum 210.

[0013] Sheet grippers are also provided on the surface of the sheet transfer drum 210, and the leading edge of the sheet is gripped by the sheet grippers. Further, a plurality of suction holes are dispersedly formed on the surface of the sheet transfer drum 210, and a suction airflow directed toward the inside of the sheet transfer drum 210 is generated in each suction hole by a suction device 211. The sheet P delivered from the transfer cylinder 210 to the sheet transfer drum 210 has its leading edge gripped by the sheet grippers and is adsorbed to the surface of the sheet transfer drum 210 by the suction airflow and is conveyed as the surface of the sheet transfer drum 210 moves.

[0014] The liquid ejection unit 230 of the present embodiment ejects four colors of ink, namely C (cyan), M (magenta), Y (yellow), and K (black), to form an image. The liquid ejection unit 230 includes head devices 220C, 220M, 220Y, and 220K each having an individual liquid ejection head for each ink. The liquid ejection head is not limited in its configuration as long as it ejects liquid, and any configuration can be adopted. If necessary, a liquid ejection head for ejecting special inks such as white, gold, and silver may be provided, or a liquid ejection head for ejecting a liquid that does not constitute an image, such as a surface coating liquid, may be provided.

[0015] The liquid ejection heads of the head devices 220C, 220M, 220Y, and 220K are each controlled to perform an ejection operation by a drive signal corresponding to image information. When the sheet P carried on the sheet conveyance drum 210 passes through the area facing the liquid ejection unit 230, inks of respective colors are ejected from the liquid ejection heads of the head devices 220C, 220M, 220Y, and 220K, and an image corresponding to the image information is formed. Note that in this embodiment, the image forming unit 200 is not limited in its configuration as long as it forms an image by attaching liquid onto the sheet P.

[0016] [Drying Unit] The drying unit 300 mainly includes a drying mechanism 301 for drying the ink attached onto the sheet P in the image forming unit 200, and a conveyance mechanism 302 for conveying the sheet P conveyed from the image forming unit 200. The sheet P conveyed from the image forming unit 200 is received by the conveyance mechanism 302 and then conveyed so as to pass through the drying mechanism 301, and is delivered to the paper discharge unit 400. When passing through the drying mechanism 301, the ink on the sheet P is subjected to a drying process, whereby liquid components such as moisture in the ink evaporate, the ink adheres to the sheet P, and curling of the sheet P is suppressed.

[0017] [Paper Discharge Unit] The paper discharge unit 400 mainly includes a paper discharge tray 410 on which a plurality of sheets P are stacked. The sheets P conveyed from the drying unit 300 are sequentially stacked and held on the paper discharge tray 410. Note that in this embodiment, the paper discharge unit 400 is not limited in its configuration as long as it discharges the sheet P.

[0018] [Other Functional Units] The inkjet recording apparatus 1 of this embodiment includes a paper feeding unit 100, an image forming unit 200, a drying unit 300, and a paper discharge unit 400, but other functional units may be appropriately added. For example, a preprocessing unit for performing preprocessing of image formation may be added between the paper feeding unit 100 and the image forming unit 200, or a postprocessing unit for performing postprocessing of image formation may be added between the drying unit 300 and the paper discharge unit 400.

[0019] Examples of the preprocessing unit include those that perform a treatment liquid application process of applying a treatment liquid that reacts with the ink to suppress bleeding to the paper P, but the content of the preprocessing is not particularly limited. Examples of the postprocessing unit include a paper reverse conveyance process for reversing the paper on which an image is formed by the image forming unit 200 and sending it back to the image forming unit 200 again to form an image on both sides of the paper. Examples of the postprocessing unit also include a process of binding a plurality of sheets of paper on which images are formed. However, the content of the postprocessing is not particularly limited either.

[0020] FIG. 2 is a schematic configuration diagram of the liquid ejection unit 230. In each of the head devices 220C, 220M, 220Y, and 220K of the liquid ejection unit 230 of the present embodiment, a plurality of liquid ejection heads 221C, 221M, 221Y, and 221K are arranged in a staggered manner in the main scanning direction (the axial direction of the paper conveyance drum 210). Specifically, it is composed of two head groups in which a plurality of liquid ejection heads are arranged at equal intervals in the main scanning direction, and the positions of the two head groups in the main scanning direction are made different from each other.

[0021] Each of the head devices 220C, 220M, 220Y, and 220K has two head modules 222 having two (a total of four) liquid ejection heads 221 from the two head groups arranged side by side in the main scanning direction.

[0022] FIG. 3 is a schematic perspective view of the head module 222, and FIG. 4 is an exploded perspective view of the manifold portion 223. As shown in FIG. 3, the head module 222 has a manifold portion 223. The manifold section 223 is provided with two supply-side manifolds 20 for supplying liquid to the two liquid ejection heads 221 and two discharge-side manifolds 30 from which liquid is discharged from the two liquid ejection heads 221, respectively. Among the two head groups, a supply-side manifold 20 for supplying liquid to the two liquid ejection heads of one head group and a supply-side manifold 20 for supplying liquid to the two liquid ejection heads of the other head group are provided back to back. A discharge-side manifold 30 from which liquid is discharged from the two liquid ejection heads of one head group and a discharge-side manifold 30 from which liquid is discharged from the two liquid ejection heads of the other head group are provided back to back.

[0023] The supply-side manifold 20 and the discharge-side manifold 30 have the same shape and include concave liquid storage portions 23, 33 provided in the base member 223a of the manifold section 223 and damper members 22, 32 as elastic bodies for sealing the liquid storage portions 23, 33. Further, the supply-side manifold 20 and the discharge-side manifold 30 are provided with a protective cover 21 for protecting the damper members 22, 32.

[0024] The damper members 22, 32 are thin film rubbers with a thickness of 1.0 mm or less, and the central portions 22a, 32a are shaped to protrude toward the liquid storage portions 23, 33, and a predetermined gap is formed between them and the protective cover 21.

[0025] On the upper part of the base member 223a, a liquid inlet 23a of the supply-side manifold 20 is provided. A supply pipe attachment member 24 to which the other end of a supply pipe having one end attached to the supply-side sub-tank 15 (see FIG. 5) is attached is attached to this liquid inlet 23a. Also, on the upper part of the base member 223a, a liquid outlet 33a of the discharge-side manifold 30 is provided. A discharge pipe attachment member 34 to which the other end of a discharge pipe having one end attached to the discharge-side sub-tank 16 (see FIG. 5) is attached is attached to this liquid outlet 33a.

[0026] The damper members 22 and 32 absorb vibrations caused by pressure fluctuations generated in the liquid chambers of the liquid discharge heads during the liquid discharge operation propagated in the liquid in the manifolds 20 and 30. Thereby, it suppresses the occurrence of so-called crosstalk in which the vibration of one liquid discharge head is propagated to the other liquid discharge head via the manifolds 20 and 30. In the present embodiment, although thin film rubber is used as the damper members 22 and 32, a resin film, thin film metal, or the like may be used.

[0027] Conventionally, there is a configuration in which a part of the wall constituting the common liquid chamber of each liquid discharge head is used as an elastically deformable damper portion to absorb vibrations caused by pressure fluctuations generated in the liquid chambers of the liquid discharge heads in the common liquid chamber of each liquid discharge head (for example, Japanese Patent No. 5047734 and Japanese Patent No. 5035486). However, in the configuration in which the damper portion is provided in the common liquid chamber of each liquid discharge head, the common liquid chamber becomes enlarged and each liquid discharge head becomes large-sized. On the other hand, in the present embodiment, by providing the damper members 22 and 32 in the manifolds 20 and 30, each liquid discharge head can be miniaturized, and the head module 222 can be miniaturized.

[0028] FIG. 5 is an explanatory diagram for explaining the configuration of the liquid circulation mechanism 10 that circulates the liquid. The liquid circulation mechanism 10 includes a main tank 11, an intermediate sub-tank 13, a supply-side sub-tank 15, and a discharge-side sub-tank 16 as means for storing the liquid discharged from the liquid discharge head 221. Further, the liquid circulation mechanism 10 includes a supply pump 14 that sends the liquid from the intermediate sub-tank 13 to the supply-side sub-tank 15. Further, the liquid circulation mechanism 10 includes a discharge pump 17 that sends the liquid from the discharge-side sub-tank 16 to the intermediate sub-tank 13, and a replenishment pump 12 that sends the liquid from the main tank 11 to the intermediate sub-tank 13. Further, the liquid circulation mechanism 10 includes a supply-side manifold 20 that supplies the liquid to the plurality of liquid discharge heads 221. Further, the liquid circulation mechanism 10 includes a discharge-side manifold 30 from which the liquid is discharged from the liquid discharge head 221.

[0029] The intermediate sub-tank 13 receives liquid replenishment from the main tank 11 by the liquid feeding operation of the replenishment pump 12. The replenishment pump 12 performs a liquid feeding operation so that the liquid level in the intermediate sub-tank 13 is maintained at a predetermined height based on the detection result of the liquid level detection means for detecting the liquid level position (liquid level height) in the intermediate sub-tank 13.

[0030] In this embodiment, the liquid circulates in a circulation path that returns to the intermediate sub-tank 13 from the intermediate sub-tank 13 through the supply-side sub-tank 15, the supply-side manifold 20, the liquid discharge head 221, the discharge-side manifold 30, and the discharge-side sub-tank 16.

[0031] Based on the detection results of the pressure sensor for detecting the pressure of the supply-side manifold 20 and the pressure sensor for detecting the pressure of the discharge-side manifold 30, the supply pump 14 and the discharge pump 17 are controlled to circulate the liquid so as to obtain a predetermined meniscus pressure.

[0032] Note that the configuration of the liquid circulation mechanism 10 shown in FIG. 5 is an example and is not limited thereto. For example, the intermediate sub-tank 13 may be eliminated, and the liquid in the discharge-side sub-tank 16 or the liquid in the main tank 11 may be directly transferred to the supply-side sub-tank 15.

[0033] Next, the characteristic parts of this embodiment will be described. Conventionally, the supply-side manifold 20 and the discharge-side manifold 30 (hereinafter, when the supply-side manifold 20 and the discharge-side manifold 30 are not particularly distinguished, simply referred to as the manifold) have a rectangular shape. And the damper member constituting a part of the wall portion of the manifold has a square shape. In such a conventional technique, there were the following problems.

[0034] That is, if there are bubbles in the manifold, there is a risk that these bubbles will flow into the liquid ejection head and cause problems such as ejection failure. Therefore, it is necessary to fill the manifold with liquid so that no bubbles remain in the manifold during the initial filling of the liquid. However, when the manifold has a rectangular shape, the air in the manifold may not escape well, and bubbles may remain at the upper four corners of the manifold.

[0035] Also, the manifolds 20 and 30 are set to a high pressure (the discharge-side manifold is set to a high negative pressure and the supply-side manifold is set to a high positive pressure) so as to obtain a predetermined meniscus pressure and to transfer the liquid against the flow path resistance due to the pressure difference between the supply-side manifold 20 and the discharge-side manifold 30. The damper members 22 and 32 need to prevent the liquid from leaking even at such a high pressure. On the other hand, the damper members 22 and 32 should preferably be as thin films as possible in order to satisfactorily absorb the vibrations of the liquid ejection head propagated to the manifolds 20 and 30. Thus, since the damper members 22 and 32 are made of a highly reliable material that is a thin film and can withstand high pressure, they are expensive, and it is preferable to make the area of the damper members 22 and 32 as small as possible.

[0036] In the present embodiment, the manifolds 20 and 30 are formed in a shape that allows air to escape easily and can reduce the area of the damper members 22 and 32 as much as possible. Hereinafter, the characteristic parts of the present embodiment will be described with reference to the drawings.

[0037] FIG. 6 is a schematic cross-sectional view of the supply-side manifold 20 and the discharge-side manifold 30 in the main scanning direction (the longitudinal direction of the manifold). FIG. 6(a) is a cross-sectional view of the supply-side manifold 20, and FIG. 6(b) is a cross-sectional view of the discharge-side manifold 30. As shown in FIG. 6, the manifolds 20 and 30 of the present embodiment have a trapezoidal shape that widens from top to bottom. The supply-side manifold 20 has a concave-shaped supply-side liquid storage portion 23 provided in the base member 223a. At the center of the ceiling wall of the supply-side liquid storage portion 23 in the main scanning direction, there is a supply-side tank connection portion 26 connected to the supply-side sub-tank 15 via a supply pipe. The supply-side tank connection portion 26 is composed of a liquid inlet 23a and a supply pipe attachment member 24 attached to the liquid inlet 23a. Note that a plurality of supply-side tank connection portions 26 may be provided. Also, a plurality of tanks may be connected to the supply-side tank connection portion 26.

[0038] At both ends of the bottom wall of the supply-side liquid storage portion 23 in the main scanning direction, there are supply-side head connection portions 27 connected to the liquid ejection heads via head supply pipes. Each supply-side head connection portion 27 is composed of a liquid outlet 23b and a head supply pipe attachment member 25 attached to the liquid outlet 23b. The other end of the head supply pipe, one end of which is attached to the liquid ejection head, is attached to the head supply pipe attachment member 25.

[0039] By providing the supply-side head connection portions 27 at both ends of the bottom wall in the main scanning direction, the distance from one supply-side head connection portion to the other supply-side head connection portion can be maximally separated. Thereby, the vibration of the liquid ejection head propagated to the supply-side manifold from one supply-side head connection portion can be well suppressed from propagating to the other supply-side head connection portion. Thereby, the occurrence of crosstalk can be well suppressed.

[0040] Also, as shown in FIG. 6(a), it is preferable that the distance Y from the central position in the main scanning direction of the bottom wall of the supply-side manifold 20 to the supply-side head connection portion 27 is equal to or greater than the distance X from the supply-side head connection portion 27 to the end portion of the bottom wall of the supply-side manifold 20 in the main scanning direction (Y≧X). More preferably, Y = (2 to 20)X. By setting such a relationship, it is possible to suppress the vibration of the liquid ejection head propagated from one supply-side head connection portion 27 to the supply-side manifold 20 from propagating to the other supply-side head connection portion, and it is possible to suppress the occurrence of crosstalk.

[0041] The supply-side manifold 20 is supplied with liquid from the supply-side sub-tank 15 through the supply-side tank connection portion 26, and distributes and supplies the liquid from the supply-side head connection portion 27 to each liquid ejection head.

[0042] As shown in FIG. 6(b), the discharge-side manifold 30 has the same configuration as the supply-side manifold 20, and a discharge-side tank connection portion 36 connected to the discharge-side sub-tank 16 through a discharge pipe is provided at the center in the main scanning direction of the ceiling wall. The discharge-side tank connection portion 36 is composed of a liquid outlet 33a and a discharge pipe attachment member 34 attached to the liquid outlet 33a. One end of the discharge pipe is attached to the discharge pipe attachment member 34, and the other end of the discharge pipe is attached to the discharge-side sub-tank 16. Note that a plurality of discharge-side tank connection portions 36 may be provided. Also, a plurality of tanks may be connected to the discharge-side tank connection portion 36.

[0043] At both ends in the main scanning direction of the bottom wall of the discharge-side liquid storage portion 33, there are discharge-side head connection portions 37 connected to the liquid ejection heads through head discharge pipes. Each discharge-side head connection portion 37 is composed of a liquid inlet 33b and a head discharge pipe attachment member 35 attached to the liquid inlet 33b. The other end of the head discharge pipe, one end of which is attached to the liquid ejection head, is attached to the head discharge pipe attachment member 35.

[0044] By providing the discharge-side head connection parts 37 at both ends of the bottom wall in the main scanning direction, the distance from one discharge-side head connection part to the other discharge-side head connection part can be maximally increased. Thereby, the vibration of the liquid discharge head propagated from one discharge-side head connection part to the discharge-side manifold 30 can be favorably suppressed from propagating to the other discharge-side head connection part. Thereby, the occurrence of crosstalk can be favorably suppressed.

[0045] Also, regarding the discharge-side manifold 30 as well, it is preferable that the distance Y from the central position in the main scanning direction of the bottom wall of the discharge-side manifold 30 to the discharge-side head connection part 37 is equal to or greater than the distance X from the discharge-side head connection part 37 to the end in the main scanning direction of the bottom wall of the discharge-side manifold 30 (Y≧X). More preferably, Y = (2 to 20)X. By setting such a relationship, the vibration of the liquid discharge head propagated from one discharge-side head connection part to the discharge-side manifold 30 can be suppressed from propagating to the other discharge-side head connection part, and the occurrence of crosstalk can be suppressed.

[0046] Since the discharge-side manifold 30 tapers toward the discharge-side tank connection part 36, air in the discharge-side manifold during liquid filling gathers at the discharge-side tank connection part 36, and the air in the discharge-side manifold is favorably discharged from the discharge-side tank connection part 36. Thereby, it is possible to suppress air from remaining in the discharge-side manifold after liquid filling and forming bubbles.

[0047] The air (bubbles) remaining in the supply-side manifold after liquid filling gathers near the supply-side tank connection part 26. After liquid filling, an operation is performed to transfer the liquid in the supply-side manifold to the supply-side sub-tank 15 by the supply pump 14 (see FIG. 5) to remove the air in the supply-side manifold 20. During this operation, the bubbles gathered near the supply-side tank connection part 26 are discharged to the supply-side sub-tank 15 through the supply-side tank connection part 26. Thereby, the air remaining in the supply-side manifold can be favorably discharged, and the remaining of air in the supply-side manifold can be favorably suppressed.

[0048] FIG. 7 is a diagram for explaining the absorption of vibrations of the liquid ejection head propagated to the supply side manifold 20. Note that the supply side manifold 20 will be described, but the same applies to the discharge side manifold 30. As shown by the dashed-dotted line shown in FIG. 7, the area of the damper member 22 can be reduced compared to the case where the damper member 22, which is an elastic body, is square, and the material cost of the damper member 22 can be reduced. Thereby, the cost of the damper member 22 can be suppressed, and cost reduction of the apparatus can be achieved.

[0049] There is an area of the damper member 22 necessary for attenuating the vibrations propagated from the supply side head connection portion 27 to the supply side manifold 20. As shown in FIG. 7, when the shape of the damper size A necessary for attenuating the vibrations propagated from one supply side head connection portion 27 to the supply side manifold 20 and the shape of the damper size B necessary for attenuating the vibrations propagated from the other supply side head connection portion 27 to the manifold are parallelograms, a portion C where the damper sizes A and B overlap is generated at the upper part. On the other hand, at the lower part, a portion C' where the damper size A and the damper size B do not overlap is generated. The size of this overlapping portion C and the size of the portion C' where they do not overlap are the same. Therefore, by making the damper member trapezoidal, the overlapping portion C of the upper damper sizes A and B can be compensated for by the portion C' where they do not overlap. Thus, even if the damper member is trapezoidal, it is possible to secure the area of the damper member necessary for attenuating the vibrations of each supply side head connection portion 27.

[0050] FIG. 8 is a schematic cross-sectional view of the supply side manifold 20 in the sub-scanning direction (manifold short side direction). Note that the same applies to the discharge side manifold 30. As shown in FIG. 8, in the cross-section in the sub-scanning direction, the supply-side head connection portion 27 and the supply-side tank connection portion 26 are provided at the center O2 in the sub-scanning direction of the supply-side manifold 20. As described above, the damper member 22 has a shape in which the central portion 22a protrudes toward the liquid storage portion 23 side. Therefore, for the damper member 22 attached to the base member 223a, the edge portion 22b is located outside the central portion 22a of the damper member 22. As a result, a sufficient gap is formed between the central portion 22a of the damper member 22 and the protective cover 21. Thereby, it is possible to suppress the damper member 22 from hitting the protective cover 21 when the damper member 22 elastically deforms to absorb the vibration of the liquid discharge head propagated to the supply-side manifold 20. Thereby, the vibration of the liquid discharge head propagated well to the supply-side manifold 20 can be absorbed by the damper member 22, and crosstalk can be suppressed well.

[0051] Also, as shown in FIG. 8, the central portion 22a of the damper member 22 is preferably positioned in the sub-scanning direction between the center O2 in the sub-scanning direction of the supply-side manifold 20 and the line X1 connecting the damper member side end of the supply-side head connection portion 27 and the damper member side end of the supply-side tank connection portion 26. Thereby, compared with the case where the central portion 22a of the damper member 22 is located inside the center O2 in the sub-scanning direction of the supply-side manifold 20, it is possible to suppress the inhibition of the flow of the liquid in the supply-side manifold (the flow of the liquid from the supply-side tank connection portion 26 toward the supply-side head connection portion 27). Further, compared with the case where the central portion 22a of the damper member 22 is located outside the line X1, it is possible to preferably suppress the damper member 22 from hitting the protective cover 21 when the damper member 22 elastically deforms to absorb the vibration of the liquid discharge head propagated to the supply-side manifold 20.

[0052] That is, by positioning the central portion 22a of the damper member 22 between the center O2 in the sub-scanning direction of the supply-side manifold 20 and the line X1, it is possible to achieve both a high damper function and the ensuring of the flow of the liquid from the supply-side tank connection portion 26 toward the supply-side head connection portion 27.

[0053] Next, another example of the apparatus for discharging the liquid according to the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a plan explanatory view of the main part of the apparatus, and FIG. 10 is a side explanatory view of the main part of the apparatus. This apparatus is a serial type apparatus. By a main scanning movement mechanism 493, a carriage 403 reciprocates in the main scanning direction. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 is bridged between left and right side plates 491A and 491B and holds the carriage 403 movably. Then, by the main scanning motor 405, the carriage 403 is reciprocated in the main scanning direction via a timing belt 408 bridged between a driving pulley 406 and a driven pulley 407.

[0054] This carriage 403 is equipped with a liquid discharge unit 440 in which a head device 404 and a head tank 441 according to the present invention are integrated. The liquid discharge unit 440 includes, for example, head devices 404 for yellow (Y), cyan (C), magenta (M), and black (K), similar to the above-described embodiment. The head device 404 includes at least one head module 222 similar to the above-described embodiment.

[0055] A supply mechanism 494 for supplying the liquid stored outside the head device 404 to the head device 404 supplies the liquid stored in a liquid cartridge 450 to the head tank 441.

[0056] The supply mechanism 494 includes a cartridge holder 451 which is a filling part for mounting the liquid cartridge 450, a tube 456, a liquid feed unit 452 including a liquid feed pump, and the like. The liquid cartridge 450 is detachably mounted on the cartridge holder 451. The liquid in the liquid cartridge 450 is fed to the head tank 441 by the liquid feed unit 452 via the tube 456.

[0057] This device is equipped with a transport mechanism 495 for transporting the paper P. The transport mechanism 495 includes a transport belt 412 which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

[0058] The transport belt 412 adsorbs the paper P and transports it to a position facing the head device 404. This transport belt 412 is an endless belt and is stretched between a transport roller 413 and a tension roller 414. The adsorption can be performed by electrostatic adsorption or air suction, etc.

[0059] Then, the transport belt 412 moves in a circular motion in the sub-scanning direction by the transport roller 413 being rotationally driven via a timing belt 417 and a timing pulley 418 by the sub-scanning motor 416.

[0060] Furthermore, on one side of the carriage 403 in the main scanning direction, a maintenance and recovery mechanism 420 for maintaining and recovering the head device 404 is arranged on the side of the transport belt 412.

[0061] The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 for capping the nozzle surface (the surface on which the nozzles are formed) of the head device 404, a wiper member 422 for wiping the nozzle surface, etc.

[0062] The main scanning movement mechanism 493, the supply mechanism 494, the maintenance and recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A, 491B and a back plate 491C.

[0063] In this device configured as described above, the paper P is fed onto the transport belt 412 and adsorbed, and the paper P is transported in the sub-scanning direction by the circular movement of the transport belt 412.

[0064] Therefore, while moving the carriage 403 in the main scanning direction, the head device 404 is driven according to the image signal, so that liquid is discharged onto the stationary paper P to form an image.

[0065] Thus, since this apparatus includes the liquid ejection head according to the present invention, a high-quality image can be stably formed.

[0066] Next, another example of the liquid ejection unit will be described with reference to FIG. 11. FIG. 11 is a plan explanatory view of the main part of the unit.

[0067] This liquid ejection unit includes a housing portion composed of side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a head device 404 among the members constituting the apparatus that ejects the liquid.

[0068] Note that a liquid ejection unit can also be configured by further attaching at least one of the above-described maintenance and recovery mechanism 420 and supply mechanism 494 to, for example, side plate 491B of this liquid ejection unit.

[0069] Next, still another example of the liquid ejection unit according to the present invention will be described with reference to FIG. 12. FIG. 12 is a front explanatory view of the unit.

[0070] This liquid ejection unit 440 includes a head device 404 to which a flow path component 444 is attached and a tube 456 connected to the flow path component 444.

[0071] Note that the flow path component 444 is disposed inside a cover 442. Instead of the flow path component 444, a head tank 441 can also be included. Further, a connector 443 for making an electrical connection with the head device 404 is provided above the flow path component 444.

[0072] In the present application, the “apparatus that ejects liquid” includes a liquid ejection head, a liquid ejection head device, or a head device, and is an apparatus that drives the liquid ejection head to eject liquid. The apparatus that ejects liquid includes not only an apparatus that can eject liquid onto an object to which the liquid can adhere but also an apparatus that ejects liquid into the air or into a liquid.

[0073] This "device for discharging liquid" can also include means related to the feeding, conveying, and paper discharging of objects to which liquid can adhere, as well as other pretreatment devices, post-treatment devices, and the like.

[0074] For example, as the "device for discharging liquid", there are an image forming device that discharges ink to form an image on paper, and a three-dimensional modeling device (three-dimensional shaping device) that discharges a shaping liquid onto a powder layer formed by powder in layers to model a three-dimensional object (three-dimensional shaped object).

[0075] Also, the "device for discharging liquid" is not limited to those in which a significant image such as characters or figures is visualized by the discharged liquid. For example, those that form a pattern or the like having no meaning by itself, and those that model a three-dimensional image are also included.

[0076] The "object to which liquid can adhere" means an object to which liquid can adhere at least temporarily, such as an object to which liquid adheres and adheres firmly, or an object to which liquid adheres and penetrates. Specific examples include recording materials such as paper, recording paper, recording sheet, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, media such as inspection cells, and include all objects to which liquid adheres as long as it is not particularly limited.

[0077] The material of the "object to which liquid can adhere" may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and floor materials, textile for clothing, etc., as long as liquid can adhere temporarily.

[0078] Also, "liquid" includes ink, treatment liquid, DNA sample, resist, pattern material, binder, shaping liquid, or solutions and dispersions containing amino acids, proteins, calcium, etc.

[0079] In addition, the "liquid discharging device" includes, but is not limited to, a device in which a liquid discharging head and an object to which liquid can adhere move relative to each other. Specific examples include a serial type device that moves the liquid discharging head and a line type device that does not move the liquid discharging head.

[0080] In addition, the "liquid discharging device" includes a treatment liquid coating device that discharges a treatment liquid onto a sheet to coat the surface of the sheet for the purpose of modifying the surface of the sheet, an injection granulation device that injects a composition liquid in which raw materials are dispersed in a solution from a nozzle to granulate fine particles of the raw materials, and the like.

[0081] The "liquid discharging unit" is an integrated unit of functional components and mechanisms with a liquid discharging head, and is an assembly of components related to liquid discharging. For example, the "liquid discharging unit" includes at least one of a head tank, a carriage, a supply mechanism, a liquid circulation mechanism, a maintenance and recovery mechanism, and a main scanning movement mechanism combined with the liquid discharging head.

[0082] Here, the integration includes, for example, those in which the liquid discharging head and the functional components and mechanisms are fixed to each other by fastening, adhesion, engagement, etc., and those in which one is movably held with respect to the other. Also, the liquid discharging head and the functional components and mechanisms may be configured to be detachable from each other.

[0083] For example, as a liquid discharging unit, there is one in which a head device 404 and a head tank are integrated, such as the liquid discharging unit 440 shown in FIG. 10. Also, there are those in which they are connected to each other by a tube or the like and the head device and the head tank are integrated. Here, a unit including a filter can also be added between the head tank and the head device of these liquid discharging units.

[0084] In addition, as a liquid discharging unit, there is one in which a head device and a carriage are integrated.

[0085] In addition, as a liquid ejection unit, there is one in which a head device is movably held by a guide member that forms part of a scanning movement mechanism, and the head device and the scanning movement mechanism are integrated. Also, as shown in FIG. 11, as a liquid ejection unit, there is one in which a head device, a carriage, and a main scanning movement mechanism are integrated.

[0086] In addition, as a liquid ejection unit, there is one in which a cap member that is part of a maintenance and recovery mechanism is fixed to a carriage to which a head device is attached, and the head device, the carriage, and the maintenance and recovery mechanism are integrated.

[0087] In addition, as a liquid ejection unit, as shown in FIG. 12, there is one in which a tube is connected to a head device to which a head tank or a flow path component is attached, and the head device, a supply mechanism, and a circulation mechanism are integrated.

[0088] The main scanning movement mechanism shall include a single guide member. Also, the supply mechanism shall include a single tube and a single loading unit.

[0089] In addition, the "liquid ejection head" is not limited to the actuator used. For example, in addition to the piezoelectric element (a laminated piezoelectric element may be used) as described in the above embodiment, a thermal actuator using an electrothermal conversion element such as a heating resistor, an electrostatic actuator composed of a diaphragm and a counter electrode, etc. may be used.

[0090] In addition, in the terms of the present application, image formation, recording, printing, imprinting, printing, shaping, etc. are all synonymous.

[0091] Finally, the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. Each of these novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. Such embodiments and modifications of the embodiments are included in the scope and gist of the invention and are included in the invention described in the claims and the equivalent scope thereof.

[0092] What has been described above is an example, and each of the following aspects has a specific effect. (Aspect 1) A part of the wall for storing the liquid is made of an elastic body such as a damper member. In a manifold connected to a plurality of liquid ejection heads, there are two head connection portions for connecting to the liquid ejection heads on an orthogonal wall (in this embodiment, the bottom walls of the liquid storage portions 23 and 33) orthogonal to the wall made of the elastic body, and a tank connection portion for connecting to a tank (in this embodiment, the supply-side sub-tank 15 or the discharge-side sub-tank 16) on an opposing wall (in this embodiment, the ceiling walls of the liquid storage portions 23 and 33) facing the orthogonal wall. The two head connection portions are arranged at intervals in the longitudinal direction of the orthogonal wall (the main scanning direction in this embodiment), and the elastic body has a shape that spreads from the opposing wall toward the orthogonal wall. In order to satisfactorily exhibit the damper function of attenuating the vibration in the liquid chamber generated by the liquid ejection head propagated to the liquid in the manifold through the head connection portion with the elastic body, it is necessary to make the elastic body thin. However, with a thin elastic body, liquid leakage is likely to occur. An elastic body having a function that satisfies both thinness and liquid leakage is expensive, which has caused an increase in the cost of the device. Therefore, as a result of intensive studies by the applicant, it has been found that when the elastic body has a shape that spreads from the opposing wall toward the orthogonal wall, the damper function does not deteriorate even if the area on the tank connection portion side is narrower than the area on the head connection portion side. In Mode 1, based on such findings, the elastic body is shaped to spread from the opposing wall toward the orthogonal wall. As a result, without reducing the damper function of the elastic body, it is possible to reduce the area of the elastic body compared to the case of a square shape and reduce the cost of the device.

[0093] (Mode 2) In Mode 1, when the opposing wall is the upper wall, in the longitudinal cross-section such as the main scanning direction, the shape of the liquid storage part such as the liquid storage parts 23 and 33 for storing liquid is a shape that spreads from the upper part to the lower part. According to this, as described in the embodiment, the bubbles in the manifold can be collected near the center in the longitudinal direction of the opposing wall. Therefore, if the tank connection part is provided at the center in the longitudinal direction of the opposing wall, the bubbles in the manifold can be discharged well from the tank connection part.

[0094] (Mode 3) In Mode 2, the tank connection part is provided at the center in the longitudinal direction such as the main scanning direction of the opposing wall. According to this, as described in the embodiment, the bubbles in the manifold can be discharged well from the tank connection part.

[0095] (Mode 4) In any one of Modes 1 to 3, head connection parts are provided at both ends in the longitudinal direction of the orthogonal wall. According to this, as described in the embodiment, the one head connection part and the other head connection part can be separated to the maximum extent, and the so-called crosstalk in which the vibration of the liquid discharge head propagated into the manifold from one head connection part is propagated to another liquid discharge head through the other head connection part can be suppressed well.

[0096] (Mode 5) In any one of Modes 1 to 4, in the cross-section in the short-side direction of the orthogonal wall, the edge part of the elastic body such as the damper member is located outside the central part of the elastic body. According to this, as described in the embodiment, when the central portion of the elastic body is at the same position as the edge portion, the gap between the central portion of the elastic body and the member facing the outer surface of the elastic body (the protective cover 21 in this embodiment) can be widened compared to the case where the central portion of the elastic body is at the same position as the edge portion. Thereby, when the elastic body elastically deforms and absorbs the vibration of the liquid ejection head propagated to the manifold, it is possible to suppress the elastic body from hitting the member facing the outer surface of the elastic body, and it is possible to suppress the elastic deformation of the elastic body from being inhibited. Thereby, the vibration of the liquid ejection head propagated well to the manifold can be absorbed by the elastic body.

[0097] (Aspect 6) In Aspect 5, the elastic body such as a damper member has a shape in which the central portion protrudes toward the inner side of the manifold. According to this, when the elastic body is attached to the manifold, in the cross section in the short side direction, the edge portion of the elastic body can be positioned outside the central portion of the elastic body.

[0098] (Aspect 7) In Aspect 5 or 6, in the cross section in the short side direction, the head connection portion and the tank connection portion are provided at the center in the short side direction, and the central portion of the elastic body such as a damper member is between the line X1 connecting the elastic body side end portion of the head connection portion and the elastic body side end portion of the tank connection portion and the center in the short side direction. According to this, as described in the embodiment, it is possible to suppress the elastic body from inhibiting the flow of the liquid between the head connection portion and the tank connection portion in the manifold, and it is possible to sufficiently provide a gap between the central portion of the elastic body and the member facing the outer surface of the elastic body (the protective cover 21 in this embodiment).

[0099] (Aspect 8) The head module 222 includes a plurality of liquid ejection heads and a manifold according to any one of Aspects 1 to 7. According to this, cost reduction of the head module 222 can be achieved. Further, by providing the manifold with a damper function, the size of the apparatus can be reduced compared to the case where each liquid ejection head is provided with a damper function.

[0100] (Aspect 9) In Aspect 8, the manifold is a supply manifold that transfers liquid to a plurality of liquid ejection heads and / or a discharge manifold from which liquid is transferred from the plurality of liquid ejection heads.

[0101] (Aspect 10) The liquid ejection unit includes the manifold of any one of Aspects 1 to 7 or the head module of Aspect 8 or 9. According to this, cost reduction of the liquid ejection unit can be achieved. Also, compared with providing a damper function to each liquid ejection head, downsizing of the apparatus can be achieved.

[0102] (Aspect 11) The apparatus that ejects liquid includes the liquid ejection unit described in Aspect 10. According to this, cost reduction of the apparatus can be achieved.

Explanation of Reference Numerals

[0103] 1: Inkjet recording apparatus 10: Liquid circulation mechanism 11: Main tank 12: Supply pump 13: Intermediate sub-tank 14: Supply pump 15: Supply-side sub-tank 16: Discharge-side sub-tank 17: Discharge pump 20: Supply-side manifold 21: Protection cover 22: Damper member 22a: Central portion 22b: Edge portion 23: Supply-side liquid storage portion 23a: Liquid inlet 23b: Liquid outlet 24: Supply pipe attachment member 25: Head supply pipe attachment member 26: Supply-side tank connection portion 27: Supply-side head connection part 30: Discharge-side manifold 32: Damper member 32a: Central part 33: Discharge-side liquid storage part 33a: Liquid outlet 33b: Liquid inlet 34: Discharge pipe attachment member 35: Head discharge pipe attachment member 36: Discharge-side tank connection part 37: Discharge-side head connection part 200: Image forming unit 220: Head device 221: Liquid ejection head 222: Head module 223: Manifold part 223a: Base member 230: Liquid ejection unit P: Paper

Prior Art Documents

Patent Documents

[0104]

Patent Document 1

Claims

1. In a manifold having a part of a wall for storing a liquid made of an elastic body and connected to a plurality of liquid ejection heads, it has two head connection parts for connecting to the liquid ejection heads on an orthogonal wall orthogonal to the wall made of the elastic body, and a tank connection part for connecting to a tank on an opposing wall opposing the orthogonal wall, the two head connection parts are arranged spaced apart in the longitudinal direction of the orthogonal wall, the elastic body has a shape that spreads from the opposing wall toward the orthogonal wall, In a cross-section in the short direction of the orthogonal wall, an edge portion of the elastic body is located outside the central portion of the elastic body, characterized in that the manifold.

2. In the manifold according to Claim 1, the opposing wall is an upper wall, In the longitudinal cross-section, the shape of the liquid storage part for storing a liquid is a shape that spreads from the upper part to the lower part, characterized in that the manifold.

3. In the manifold according to Claim 2, the tank connection part is provided at the longitudinal center of the opposing wall, characterized in that the manifold.

4. In the manifold according to any one of Claims 1 to 3, the head connection parts are provided at both ends in the longitudinal direction of the orthogonal wall, characterized in that the manifold.

5. In the manifold according to any one of Claims 1 to 4, the elastic body has a shape in which the central part protrudes toward the inner side of the manifold, characterized in that the manifold.

6. In the manifold according to any one of Claims 1 to 5, in the cross-section in the short direction, the head connection part and the tank connection part are provided at the center in the short direction, the central part of the elastic body is located between a line connecting the elastic body side end of the head connection part and the elastic body side end of the tank connection part and the center in the short direction, characterized in that the manifold.

7. A head module characterized by comprising a plurality of liquid ejection heads and the manifold according to any one of Claims 1 to 6.

8. In the head module according to Claim 7, the manifold is a supply manifold for transferring a liquid to a plurality of liquid ejection heads and / or a discharge manifold from which a liquid is transferred from a plurality of liquid ejection heads, characterized in that the head module.

9. A liquid discharge unit comprising the manifold according to any one of claims 1 to 8, or the head module according to claim 7 or 8.

10. An apparatus for discharging a liquid, comprising the liquid discharge unit according to claim 9.

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