RU2664201C2 - Liquid ejection substrate, liquid ejection head and liquid ejection device - Google Patents

Abstract

FIELD: manufacturing technology.

SUBSTANCE: invention relates to a liquid ejection substrate, a liquid ejection head and a liquid ejection device, used to eject various fluids including ink. First duct layer comprises a plurality of feed ducts, each of which communicates with one part of each of the plurality of pressure chambers, and a plurality of ducts for collecting, each of which communicates with another part of each of the plurality of pressure chambers. Second duct layer comprises a common feed duct communicating with a plurality of feed paths and a common collection conduit communicating with a plurality of collection ducts.

EFFECT: liquid ejection substrate, a liquid ejection head, and a liquid ejection device are provided.

21 cl, 55 dwg

Description

State of the art

FIELD OF THE INVENTION

[0001] The present invention relates to a liquid ejection substrate, to a liquid ejection head, and to a liquid ejection device used to eject various liquids including ink.

Description of the Related Art

[0002] For example, in an inkjet printhead capable of selectively ejecting ink from a plurality of ejection openings, the ejection openings must be tightly placed to print a high quality image with high accuracy. Additionally, since the ink is thickened due to evaporation of moisture in the ink from the ejection openings, there is a need to provide resistance to the impact on the high-quality printing operation.

[0003] To address this need, Japanese Patent No. 4722826 discloses a method for circulating ink through a pressure chamber in such a way that ink condensed in a pressure chamber communicating with an ejection opening does not remain therein. Japanese Patent No. 4722826 discloses a configuration in which an element having a curved ink duct is formed by extruding aluminum, and the ink is finally forced to flow into a pressure chamber corresponding to each of the plurality of ejection openings through an ink duct formed in the element. Japanese Patent No. 5,264,000 discloses a configuration in which an element is formed having a three-dimensionally curved ink duct, and the ink is finally forced to flow into a pressure chamber corresponding to each of the plurality of ejection openings through an ink duct formed in the element.

[0004] However, in Japanese Patent No. 4722826 and Japanese Patent No. 5264000, the ink duct has a complex shape, and therefore, the plurality of ink ducts cannot be easily and tightly arranged so that the ink circulates through the pressure chamber, corresponding to each of a plurality of densely placed ejection openings.

SUMMARY OF THE INVENTION

[0005] The invention provides a fluid ejection pad, a fluid ejection head, and a fluid ejection device capable of circulating fluid through pressure chambers suitably corresponding to a plurality of ejection openings, even when the ejection openings are tightly placed.

[0006] In a first aspect of the present invention, there is provided a liquid ejection substrate including an ejection hole that ejects a liquid, an ejection energy generating element that generates energy used to eject the liquid, and a pressure chamber that has an provided in it there is an element of formation of energy of pushing

- wherein the substrate for expelling the liquid includes a first part and a second part deflected from each other in the thickness direction of the substrate for expelling the liquid,

- wherein the first part comprises a supply duct located on one side of the pressure chamber in order to supply fluid to the pressure chamber, and a collection duct located on the other side of the pressure chamber in order to collect fluid from the pressure chamber, and

- while the second part contains a common duct for supply, communicating with many ducts for supply, and a common duct for collection, communicating with many ducts for collection.

[0007] In a second aspect of the present invention, there is provided a liquid ejection substrate including an ejection hole that ejects the liquid, an ejection energy generating element that generates energy used to eject the liquid, and a pressure chamber that has an provided therein is an element for generating pushing energy, the substrate for pushing out the liquid contains:

- a supply duct, which is located on one side of the pressure chamber and extends in the direction crossing the surface containing the expulsion energy generating element;

- a duct for collection, which is located on the other side of the pressure chamber and passes in the direction crossing the surface containing the element of formation of the energy of the buoy;

- a common supply duct that communicates with a plurality of supply ducts; and

- a common duct for collection, which communicates with many ducts for collection,

- in this case, if the resistance, when passing per unit length from the end of the discharge of the flow channel for supply to the end of the flow of the flow channel for collection through the pressure chamber, is indicated by R, the consumed amount of liquid flowing through the pressure chamber at the time when the liquid is not pushed out from the ejection hole is indicated by Q1, and the maximum negative pressure allowing the liquid to be ejected from the ejection hole is indicated by P, the gap W between the end of the outlet I flow of the common duct for supply and the end of the flow of the common duct for collection satisfies the ratio W <(2 * P) / (Q1 * R).

[0008] In a third aspect of the present invention, there is provided a liquid ejection substrate including an ejection hole that ejects the liquid, an ejection energy generating element that generates energy used to eject the liquid, and a pressure chamber that has an provided therein is an element for generating pushing energy, the substrate for pushing out the liquid contains:

- a supply duct, which is located on one side of the pressure chamber and extends in the direction crossing the surface containing the expulsion energy generating element;

- a duct for collection, which is located on the other side of the pressure chamber and passes in the direction crossing the surface containing the element of formation of the energy of the buoy;

- a common supply duct that communicates with a plurality of supply ducts; and

- a common duct for collection, which communicates with many ducts for collection,

- in this case, if the resistance, when passing per unit length from the end of the duct flow outlet for supplying to the end of the flow duct for collection through the pressure chamber, is indicated by R, the maximum amount of liquid pushed out of the expulsion opening is indicated by Q2, and the maximum negative pressure allowing the liquid to be pushed out of the ejection hole is indicated by P, the gap W between the end of the flow outlet of the common supply duct and the end of the post the flow rate of the common duct for collection satisfies the ratio W <(2 * P) / (Q2 * R).

[0009] In a fourth aspect of the present invention, there is provided a liquid ejection head having a liquid ejection substrate, wherein the liquid ejection substrate includes an ejection hole that expels the liquid, an ejection energy generating element that generates energy used to in order to eject a liquid, and a pressure chamber, which has an element for generating ejection energy provided therein,

- wherein the substrate for expelling the liquid includes a first part and a second part deflected from each other in the thickness direction of the substrate for expelling the liquid,

- wherein the first part comprises a supply duct located on one side of the pressure chamber in order to supply fluid to the pressure chamber, and a collection duct located on the other side of the pressure chamber in order to collect fluid from the pressure chamber, and

- while the second part contains a common duct for supply, communicating with many ducts for supply, and a common duct for collection, communicating with many ducts for collection.

[0010] In a fifth aspect of the present invention, there is provided a device for ejecting a liquid, comprising:

- a head for ejecting liquid, including:

an ejection hole that ejects the liquid, an ejection energy generation element that generates energy used to eject the liquid, and a pressure chamber that has an ejection energy generation element provided therein, wherein the liquid ejection head comprises:

- a matrix of holes for pushing, in which there are many holes for pushing;

- the first duct, which communicates with one side of the pressure chamber;

- a second duct that communicates with the other side of the pressure chamber;

- a matrix of supply ducts in which a plurality of supply ducts supplying liquid to the first duct are arranged in a direction of arranging a plurality of ejection openings, wherein the plurality of supply ducts extend in a direction intersecting a surface containing an ejection energy generating element;

an array of collection ducts in which a plurality of collection ducts collecting liquid in a second duct are arranged in a direction of receiving a plurality of ejection openings, wherein the plurality of collection ducts extend in a direction of intersection;

- a common supply duct that extends in the direction of placement of the plurality of ejection openings and communicates with the plurality of supply ducts;

- a common duct for collection, which extends in the direction of placement of the plurality of ejection openings and communicates with the plurality of ducts for collection;

- a controller configured to control a plurality of push energy generation elements; and

- a differential pressure former configured to generate a differential pressure between the common supply duct and the common collection duct such that fluid flows through the common supply duct, the supply duct, the pressure chamber, the collection duct, and the common collection duct.

[0011] In a sixth aspect of the present invention, there is provided a head for ejecting a liquid, comprising:

- an ejection hole that ejects the liquid,

an ejection energy generating element that generates energy used to eject the liquid,

- a pressure chamber, which has an element for generating ejection energy provided therein, the head for ejecting liquid contains:

- a matrix of holes for pushing, in which there are many holes for pushing;

- the first duct, which communicates with one side of the pressure chamber;

- a second duct that communicates with the other side of the pressure chamber;

- a matrix of supply ducts in which a plurality of supply ducts supplying liquid to the first duct are arranged in a direction of arranging a plurality of ejection openings, wherein the plurality of supply ducts extend in a direction intersecting a surface containing an ejection energy generating element;

an array of collection ducts in which a plurality of collection ducts collecting liquid in a second duct are arranged in a direction of receiving a plurality of ejection openings, wherein the plurality of collection ducts extend in a direction of intersection;

- a common supply duct that extends in the direction of placement of the plurality of ejection openings and communicates with the plurality of supply ducts; and

- a common duct for collection, which extends in the direction of placement of the plurality of ejection openings and communicates with the plurality of ducts for collection.

[0012] Additional features of the present invention should become apparent from the following description of exemplary embodiments (with reference to the accompanying drawings).

Brief Description of the Drawings

[0013] FIG. 1 is an exploded perspective view illustrating a fluid ejection substrate of a first embodiment of the present invention;

[0014] FIG. 2 is an exploded plan view illustrating a fluid ejection substrate of FIG. one;

[0015] FIG. 3 is a plan view illustrating the main body of the fluid expulsion substrate of FIG. one;

[0016] FIG. 4 is a cross-sectional view along line IV-IV of FIG. 3;

[0017] FIG. 5 is a cross-sectional perspective view illustrating a main part of a fluid expelling substrate of FIG. one;

[0018] FIG. 6A is a longitudinal sectional view illustrating the main part of the fluid expulsion substrate of FIG. one;

[0019] FIG. 6B is a side view illustrating the main part of the fluid ejection substrate of FIG. one;

[0020] FIG. 7 is an explanatory diagram illustrating a main part of a fluid expelling substrate of FIG. one;

[0021] FIG. 8A and 8B are explanatory diagrams, respectively, illustrating an ink meniscus interface in an ejection opening;

[0022] FIG. 8c is an explanatory diagram illustrating the relationship between the hole diameter of the eject hole and the allowable pressure limit;

[0023] FIG. 9 is an explanatory diagram illustrating a positional relationship between a first common supply duct and a first common collection duct;

[0024] FIG. 10 is a flowchart illustrating a step of manufacturing a head for ejecting a liquid;

[0025] FIG. 11 is an exploded perspective view illustrating a liquid ejection substrate according to a second embodiment of the present invention;

[0026] FIG. 12 is an exploded plan view illustrating a fluid ejection substrate of FIG. eleven;

[0027] FIG. 13 is an exploded perspective view illustrating a liquid ejection substrate according to a third embodiment of the present invention;

[0028] FIG. 14 is an exploded plan view illustrating a fluid ejection substrate of FIG. 13;

[0029] FIG. 15 is an exploded perspective view illustrating a liquid ejection substrate according to a fourth embodiment of the present invention;

[0030] FIG. 16 is an exploded plan view illustrating a fluid ejection substrate of FIG. fifteen;

[0031] FIG. 17A is a plan view illustrating a main part of a fluid expelling substrate of FIG. fifteen;

[0032] FIG. 17B is an explanatory diagram illustrating an end of the ejection matrix of FIG. 17A;

[0033] FIG. 18A is an explanatory diagram illustrating forms of a first common duct for supply and a first common duct for collection;

[0034] FIG. 18B is an explanatory diagram illustrating the ends of a first common duct for supply and a first common duct for collection of FIG. 18A;

[0035] FIG. 19 is an exploded perspective view illustrating a liquid ejection substrate according to a fifth embodiment of the present invention;

[0036] FIG. 20 is an exploded plan view illustrating a fluid ejection substrate of FIG. 19;

[0037] FIG. 21 is an exploded perspective view illustrating a liquid ejection substrate according to a sixth embodiment of the present invention;

[0038] FIG. 22 is an exploded plan view illustrating a fluid ejection substrate of FIG. 21;

[0039] FIG. 23 is an explanatory diagram illustrating a relationship of a placement between a first ink flow and a second ink flow;

[0040] FIG. 24A, 24B, 24C, 24D and 24E are perspective views, respectively, illustrating configuration examples having various liquid ejection heads using the liquid ejection substrate of the present invention;

[0041] FIG. 25A and 25B are schematic perspective views, respectively, illustrating configuration examples having various inkjet printing apparatuses using the fluid ejection head of the present invention;

[0042] FIG. 25C is an explanatory diagram illustrating an ink supply system for a print head;

[0043] FIG. 26 is an explanatory diagram illustrating a printing apparatus according to a first example of an application of the present invention;

[0044] FIG. 27 is an explanatory diagram illustrating a first circulation configuration in a circulation path applied to the printing apparatus of FIG. 26;

[0045] FIG. 28 is an explanatory diagram illustrating a second circulation configuration in the circulation path applied to the printing apparatus of FIG. 26;

[0046] FIG. 29 is an explanatory diagram illustrating a circulating amount of ink in a first circulation configuration and a second circulation configuration;

[0047] FIG. 30A and FIG. 30B are perspective views respectively illustrating a fluid ejection head of FIG. 26;

[0048] FIG. 31 is an exploded perspective view illustrating a fluid ejection head;

[0049] FIG. 32 is a diagram illustrating the front and rear surfaces of the first, second, and third duct elements in a head for expelling fluid;

[0050] FIG. 33 is an enlarged perspective view illustrating ducts formed by gluing the first, second, and third duct elements;

[0051] FIG. 34 is a cross-sectional view along line XXXIV-XXXIV of FIG. 33;

[0052] FIG. 35A and 35B are perspective views, respectively, illustrating an ejection modulus;

[0053] FIG. 36A, 36B and 36C are explanatory diagrams, respectively, illustrating a board of printing elements;

[0054] FIG. 37 is a perspective view illustrating cross-sections of a printing element board along line XXXVII-XXXVII of FIG. 36A;

[0055] FIG. 38 is an enlarged plan view of an adjacent portion of two printed circuit boards;

[0056] FIG. 39A and 39B are perspective views, respectively, illustrating a liquid ejection head according to a second example of an application of the present invention;

[0057] FIG. 40 is an exploded perspective view illustrating a fluid ejection head;

[0058] FIG. 41 is an explanatory diagram illustrating a duct element constituting a head for expelling fluid;

[0059] FIG. 42 is a perspective view illustrating the relationship of fluid connections between a printed circuit board and a duct element in a head for expelling fluid;

[0060] FIG. 43 is a cross-sectional view along line XXXXII-XXXXII of FIG. 42;

[0061] FIG. 44A and 44B are perspective views illustrating a head ejection module for ejecting a liquid;

[0062] FIG. 45A and 45B are explanatory diagrams illustrating a board of printing elements;

[0063] FIG. 45C is an explanatory diagram illustrating a patch plate;

[0064] FIG. 46 is a diagram illustrating a second example of a printing apparatus to which the present invention is applied;

[0065] FIG. 47 is an explanatory diagram illustrating a printing apparatus of the present invention;

[0066] FIG. 48 is an explanatory diagram illustrating a third ink circulation circuit configuration;

[0067] FIG. 49A and 49B are explanatory diagrams illustrating a liquid ejection head of the present invention;

[0068] FIG. 50 is an exploded perspective view illustrating a fluid ejection head of the present invention;

[0069] FIG. 51 is a schematic explanatory diagram illustrating a duct element of the present invention;

[0070] FIG. 52 is an explanatory diagram illustrating a printing apparatus according to a third example of an embodiment of the present invention;

[0071] FIG. 53 is an explanatory diagram illustrating a fourth ink circulation circuit configuration;

[0072] FIG. 54A and 54B are explanatory diagrams, respectively, illustrating a head for ejecting a liquid according to a third example of an application of the present invention; and

[0073] FIG. 55A, 55B and 55C are explanatory diagrams, respectively, illustrating a head for ejecting a liquid according to a third example of an application of the present invention.

Detailed Description of Embodiments

[0074] The following describes embodiments of the present invention with reference to the drawings. A fluid ejection pad, a fluid ejection head, and a fluid ejection device of the following embodiments are examples of applications of an ink ejection substrate (inkjet print substrate), an inkjet printhead, and an inkjet printing apparatus ejecting ink as a liquid.

[0075] Further, the liquid ejection head and the liquid ejection device of the present invention can be applied to a printer, a copy machine, a fax machine having a communication system, a word processor having a printer, and an industrial printing apparatus combined with various processing devices. For example, a liquid ejection head and a liquid ejection device can be used to make a biocrystal or print an electronic circuit. Additionally, since the embodiments described below are detailed examples of the invention, various technical limitations may be made to them. However, embodiments of the present invention are not limited to embodiments or other detailed methods for describing in detail, and may be modified within the spirit of the present invention.

First Embodiment

[0076] FIG. 1-10 are explanatory diagrams illustrating a fluid ejection assembly 300 according to a first embodiment of the present invention. Here, the fluid ejection assembly 300 constitutes an inkjet printhead, and the printhead is mounted on the inkjet printing apparatus as described below.

[0077] As illustrated in FIG. 1 and 2, the fluid ejection assembly 300 of the embodiment has a six layered duct structure including a diaphragm 21, a first duct layer 22, a second duct layer 23, a third duct layer 24, a fourth duct layer 25, a fifth duct layer 26 and a layer 27 sixth duct. Layer 22 of the first duct comprises an ejection energy generating element 12 that generates ejection energy to eject ink as a liquid, and therefore, ink in the pressure chamber 13 can be ejected from the ejection hole 11 of the diaphragm 21 by the ejection energy. When the ink in the pressure chamber 13 is stationary, the pressure in the pressure chamber 13 is maintained equal to the negative pressure at which the meniscus of the ink is formed in the ejection hole 11. When a pressure change is generated in the pressure chamber 13, the ink ejection speed or the ejected amount (volume) of ink changes, and therefore the ink ejection characteristics are affected. In particular, when the pressure in the pressure chamber 13 becomes lower than a predetermined pressure, the ink cannot be easily expelled.

[0078] An electrothermal transducer element (heater) or a piezoelectric element can be used as the element 12 of energy generation of the buoyancy. In the case where a heater is used, the ink in the pressure chamber 13 is changed into bubbles by heat, and the ink can be pushed out of the ejection hole 11 by using the foaming energy.

[0079] As illustrated in FIG. 3, a plurality of ejection holes 11 are arranged tightly so as to form a matrix of ejection holes 16. In this example, four arrays of 16 ejection holes are formed. As illustrated in FIG. 4, the first common duct 17 for supplying the second duct layer 23 is in communication with one side (left side in FIG. 4) of each pressure chamber 13 through a separate supply duct 14 and a duct 10 corresponding to each pressure chamber 13. Similarly, the first common duct 18 for collecting the layer 23, the second duct communicates with the other side (the right side in Fig. 4) of each pressure chamber 13 through the duct 10 and a separate duct 15 for collection from the pressure chamber 13. The plurality of supply ducts 14 and the plurality of collection ducts 15 extend towards layer thickness 22 first of the duct and are arranged in the direction of passage (first direction) of the arrays of 16 holes for pushing, so that a matrix of ducts for supply and a matrix of ducts for collection are formed. The thickness direction of the first duct layer 22 corresponds to the direction intersecting the surface of the liquid ejection substrate (in this example orthogonal to the surface) on which the ejection energy generating elements 12 are located. The first common supply duct 17 communicates with a first supply port 30 formed in the third duct layer 24 and receives ink supplied from the first supply port 30. Similarly, the first common collection duct 18 communicates with a first collection hole 31 formed in the layer 24 of the third duct. A plurality of first supply openings 30 are arranged along the direction of travel (first direction) of the ejection hole array 16 so as to form a matrix of first supply openings. Likewise, a plurality of first collection holes 31 are arranged along the direction of passage of the matrix of ejection holes 16 so as to form a matrix of first collection holes. In layer 24 of the third duct, four matrices of the first supply openings and four matrices of the first collection openings are alternately arranged in parallel. The fourth duct layer 25 contains the second common ducts 32 for supply and the second common ducts 33 for collection, and the layer 26 of the fifth duct contains second ducts 34 for supply and second collector holes 35. The sixth duct layer 27 comprises a third common duct 36 for supply and a third common duct 37 for collection.

[0080] The first common supply duct 17 has a configuration in which a side (side facing the first duct layer 22) in the thickness direction of the second duct layer 23 communicates with the plurality of ducts 14 for supply, and the other side (the side facing the layer 24 third duct) communicates with a plurality of first supply openings 30. Similarly, the first common collection duct 18 has a configuration in which a side in the thickness direction of the second duct layer 23 communicates with a plurality of collection ducts 15, and the other side communicates with a plurality of first collection openings 31. The second common supply duct 32 has a configuration in which a side in the thickness direction of the fourth duct layer 25 communicates with a plurality of first supply openings 30, and the other side communicates with a plurality of second supply openings 34. Similarly, the second common collection duct 33 has a configuration in which a side in the thickness direction of the fourth duct layer 25 communicates with the first collection opening 31, and the other side communicates with the second collection opening 35. Further, a third common supply duct 36 communicates with a plurality of second collection openings 34, and a third common collection duct 37 communicates with a plurality of second collection openings 35.

[0081] The density of the plurality of second second supply holes 34 and the density of the plurality of second collection holes 35 are lower than the density of the plurality of first supply holes 30 and the density of the plurality of first collection holes 31. Further, the density of the plurality of the first first supply openings 30 and the density of the plurality of the first collection openings 31 are lower than the density of the plurality of ducts 14 for supply and the density of the plurality of collection ducts 15. The first common duct 17 for supply and the first common duct 18 for collection is formed in parallel according to the first direction. A second common supply duct 32 and a second common collection duct 33 are formed in parallel according to the second direction. A third common supply duct 36 and a third common collection duct 37 are formed in parallel according to the first direction.

[0082] Thus, the fluid ejection assembly 300 of this example is formed by laminating a plurality of duct elements. The duct density in these duct layers increases in the order of the sixth duct layer 27, the fifth duct layer 26, the fourth duct layer 25, the third duct layer 24, the second duct layer 23 and the first duct layer 22. Accordingly, the fluid ejection assembly 300 may have a configuration in which a plurality of arrays of ejection apertures 16 are tightly coupled while suppressing an increase in the size of each of the substrate layers of the elements and duct elements.

[0083] The first duct layer 22 and the second duct layer 23 are formed in the substrate 100 for expelling liquid in this embodiment. In the present invention, the configurations of the third duct layer 24 — the sixth duct layer 27 are not particularly limited. In particular, the following first and second configuration examples may be approximately illustrated. In a first configuration example, a third duct layer 24 is formed in a patch plate 20 or 2020 (cap element) of the following embodiments of FIG. 36C or FIG. 45C, and a portion of the fourth duct layer 25 is formed in the support member 400 of the following embodiments of FIG. 24A-24E. Another part of the fourth duct layer 25 is formed in the first duct element 500 or 50 of the following embodiments of FIG. 24A-24E or FIG. 31, and a portion of the fifth duct layer 26 and the sixth duct layer 27 is formed in the second duct element 600 or 60 of the following embodiments of FIG. 24A-24E or FIG. 31. Another part of the sixth duct layer 27 is formed in the third duct element 370 of the embodiment of FIG. 31, which is described below. Meanwhile, in the second configuration example, the third duct layer 24 is formed in the patch plate 20 or 2020, and part of the fourth duct layer 25 is formed in the support member 400. Another part of the fourth duct layer 25 and the fifth duct layer 26 is formed in the first element 500 or 50 duct, and a layer of the sixth duct 27 is formed in the second duct element 600 or 60. Additionally, the second common supply duct 32, the second common collection duct 33, the second supply port 34 and the second collection port 35 are also not limited by the configuration of this example.

[0084] Inks that are supplied externally are drawn from the third common supply duct 36 communicating with the ink supply opening to the pressure chamber 13, while sequentially passing through the second supply opening 34, the second common supply duct 32, the first opening 30 for supply, a first common duct 17 for supply and a duct 14 for supply. Ink in the pressure chamber 13 flows outward from the collection opening in communication with the third common collecting duct 37, while passing through the collecting duct 15 sequentially, the first common collecting duct 18, the first collecting opening 31, the second common collecting duct 33, a second collection opening 35 and a third common collection duct 37. Since the ink is circulated in this way, thick ink, which is prone to remain in the pressure chamber 13, flows out. Accordingly, it is possible to suppress a change in the concentration of ink colors and a decrease in the ink ejection speed from the ejection hole 11. Hereinafter, such a forced ink flow is referred to as an “ink circulation flow”.

[0085] In this example, as illustrated in FIG. 3, 4 and 5, the supply duct 14 and the collection duct 15 are arranged so that they face each other with an ejection hole 11 located between them. Since the supply duct 14 and the collection duct 15 are facing each other in this manner, a highly efficient ink circulation stream is formed in the pressure chamber 13 and the ejection hole 11. Accordingly, it is possible to highly efficiently suppress a decrease in ink ejection speed and a change in the concentration of ink colors. Additionally, the supply duct 14 and the collection duct 15 are separately formed in a plurality of positions in a first direction corresponding to the direction of passage of the matrix of the ejection holes 16, so that they correspond to each of the pressure chambers 13. Since the supply duct 14 and the collection duct 15 are separately are formed in a variety of positions in such a way that the electric wire for driving the push energy generating element 12 can be located between adjacent supply ducts 14 and between adjacent ducts 15 d I collect. For this reason, it is not necessary to arrange the wire extending in the first direction between the supply duct 14 and the ejection hole 11 and between the collection duct 15 and the ejection hole 11. Accordingly, the portion between them can be further reduced in size. The number relationship between the supply duct 14 and the ejection hole 11 may be one-to-one, one-to-two, or one-to-five, and the number of pressure chambers 13 communicating with the duct 14 for filing is not limited to one, as indicated in this example.

[0086] In this example, since an ink circulation stream is formed in the pressure chamber 13 and the ejection hole 11, a duct is formed as explained below.

[0087] As illustrated in FIG. 2, a first common supply duct 17 extends in a first direction with the ability to communicate with a plurality of supply ducts 14 and communicates with a pressure chamber 13 through each supply duct 14. Similarly, the first common collection duct 18 extends in a first direction to communicate with a plurality of collection ducts 15 and communicates with a pressure chamber 13 through each collection duct 15.

[0088] Thus, the first duct layer 22 and the second duct layer 23 comprise a sequence of ink ducts including a supply duct 14, a collection duct 15, a first common supply duct 17 and a first common collection duct 18 and corresponding to the matrix 16 holes for pushing out. Through such ink ducts, an ink circulation stream may be formed in the pressure chamber 13 of the substrate 100 for ejecting liquid and the hole 11 for ejecting the diaphragm 21.

[0089] Additionally, as illustrated in FIG. 6A, the side walls forming the supply duct 14, the collection duct 15, the first common supply duct 17 and the first common collection duct 18 are substantially orthogonal to the front and rear surfaces (upper and lower surfaces of the drawing) of the first duct layer 22. Here, a substantially orthogonal state includes a conical inclination formed when the first duct layer 22 and the second duct layer 23 are processed. A supply duct 14, a collection duct 15, a first common supply duct 17 and a first common collection duct 18 may be formed, for example, by dry etching. Additionally, these ducts can be formed by laser treatment or a combination of dry etching and laser treatment. The depth direction (vertical direction in FIG. 6A) of each of the supply duct 14, the collection duct 15, the first common duct 17 for supply and the first common duct 18 for collection is substantially perpendicular to the front surface of the first duct layer 22. Accordingly, when the ink ducts are densely formed with high efficiency, the ink circulation flow can be formed highly efficiently in the pressure chamber 13 and the ejection hole 11 tightly formed in the first duct layer 22.

The relationship (1) between the first common duct 17 for supply and the first common duct 18 for collection

[0090] The first common supply duct 17 and the first common collection duct 18 are formed as explained below.

[0091] As illustrated in FIG. 6A and 6B, the gap (beam width) between the end of the flow outlet of the first common flow duct 17 for collection and the end of the flow of the second common flow duct 18 for collection is indicated by W1, and the distance between the supply duct 14 and the collection duct 15 is indicated by W2. Additionally, the resistance when passing per unit length from the end of the flow of the duct 14 for supply to the end of the flow of the duct 15 for collection through the duct 10, the pressure chamber 13 and the duct 10 is indicated by R, and the expendable amount of the ink circulation stream generated in each pressure chamber 13 is indicated by Q1. The resistance R during passage is expressed by an equation including a term (including a time component) representing the viscosity of the ink. Additionally, the maximum negative pressure in the pressure chamber 13 in the range in which the ink meniscus interface in the ejection hole 11 is not violated, or the maximum negative pressure in the pressure chamber 13 in the range in which the ink is properly ejected from the ejection hole 11, is indicated by Pmax. These components have the relationship of equation (1). The relative equation (1) is described below:

W2 <(2 * Pmax) / (Q1 * R) ········ Equation (1)

[0092] In the event that the meniscus interface is lowered by the influence of negative pressure, as illustrated in FIG. 8A, and the meniscus interface is destroyed in accordance with the increase in negative pressure, as illustrated in FIG. 8B, ink does not exist on the ejection energy generating element 12, and therefore, the ink cannot easily be ejected in the normal state. If the surface tension of the ink is 30 mN / m and 20 mN / m, the hole diameter of the ejection hole 11 and the allowable pressure limit in the ejection hole 11 have the relationship illustrated in FIG. 8C. Typically, the meniscus of the ink in the ejection hole depends on the hole diameter of the ejection hole and the surface tension of the ink. However, the meniscus interface is destroyed when a pressure of -1000 mm or more is not maintained. Thus, the maximum negative pressure in the range in which the meniscus interface is not destroyed is -1000 mm water column if the hole diameter of the ejection hole is 12 μm and the surface tension of the ink is 30 mN / m as an example. Additionally, even in a range in which the meniscus interface is not destroyed, the amount of ink ejected is reduced by lowering the meniscus interface, as illustrated in FIG. 8A. Accordingly, the ink ejection state is affected so that a plurality of secondary ink droplets (satellites) are formed.

[0093] Here, the corresponding ink ejection state indicates a state in which ink is satisfactorily ejected to the extent that distortion of the printed image is not visually recognized. In particular, it is desirable to use an ink ejection state in which a change in the ejected amount of ink is small and not visually recognized. Additionally, in the event that the main ink droplets and secondary ink drops (satellites) are formed during the ink ejecting operation, an ink ejection state is required in which at least a portion of the ink smudges formed by the satellites is in contact with the main ink point formed by the main drops and settles on the substrate.

[0094] Thus, the maximum negative pressure Pmax indicates the negative pressure at which the meniscus interface is destroyed or the ink cannot be properly ejected when the pressure becomes higher than the maximum negative pressure. Additionally, when the satellites are formed, it is desirable that the satellites are deposited on the recording medium so that the sub-points are located at the main point. For example, the maximum negative pressure Pmax is 500 mm Hg. Additionally, the expendable amount of Q1 in the ink circulation is an expendable amount capable of suppressing a decrease in the ink ejection speed and a change in the concentration of ink colors. Thus, the amount consumed can suppress the likelihood that the ink ejection speed decreases and the ink settling position changes in a recognizable degree due to evaporation of the ink moisture from the ejection hole 11. Additionally, the amount consumed can suppress the likelihood that the concentration of ink colors changes and the printed image becomes uneven in a recognizable degree due to evaporation of ink moisture from the ejection hole 11. For example, the amount of ink consumed Q1 during ink circulation indicates the amount of ink consumed during circulation, suppressing a reduction in ink ejection rate of 10% from the normal ejection state. In the experiment example, the amount of ink consumed during the circulation of the ink is calculated as a flow rate of 0.05 m / s or more in the pressure chamber 13. Additionally, the flow rate is 0.1 m / s in other examples of the experiment.

[0095] When the relationship of equation (1) is satisfied, the pressure in the first common supply duct 17 can be maintained equal to negative pressure. In an inkjet printhead, it is desirable that the pressure in the duct of the printhead is maintained equal to negative pressure. If the pressure is positive pressure, the following probabilities arise. Thus, in the event that the pressure in the flow path for the ink of the print head is a positive pressure, ink easily seeps out from the components of the print head. Additionally, ink easily seeps out of the ejection hole 11. For example, even when the pressure in the first common supply duct 17 is positive pressure and the pressure in the pressure chamber 13 is kept at a negative pressure due to a pressure loss caused by the ink circulation flow in the ink circulation state, there is such a problem that the pressure loss changes due to the change ink flow, and the pressure in the pressure chamber 13 may become a positive pressure. As an extreme example, when the ink circulation flow is stopped, the pressure of the pressure chamber 13 can become a positive pressure, similar to the first common supply duct. In order to prevent the pressure in the pressure chamber 13 from becoming positive, comprehensive control of the ink supply system is required.

Description of the relative equation (1)

[0096] Equation (1) is described in detail below to maintain the pressure of the first common duct 17 for supplying equal negative pressure.

[0097] The differential pressure ΔP between the supply duct 14 and the collection duct 15 is expressed by equation (2):

ΔP = Q1 * R * W2 ··········

[0098] Further, if the pressure of the supply duct 14 is indicated by Pin, and the pressure of the collection duct 15 is indicated by Pout, equation (3) is set. Additionally, in the case where the ejection hole 11 is located in an intermediate position between the supply duct 14 and the collection duct 15, the pressure Pn of the ejection hole 11 is expressed by equation (4):

ΔP = Pin-Pout

Pn = (Pin + Pout) / 2 ·········· (4)

[0099] From equations (3) and (4), equation (5) is established:

Pin = Pn + (ΔP / 2) ·········· (5)

[0100] To maintain the pressure of the first common duct 17 for supply equal to the negative pressure, equation (6) must be satisfied:

Pin = Pn + (ΔP / 2) <0 ········· Equation (6)

[0101] Equation (6) can be modified into equation (7):

-Pn> ΔP / 2 ··········

[0102] Since the equation Pn> -PMAX must be satisfied in order to normally eject ink, equation (8) is established:

Pmax> ΔP / 2 ··········· (8)

[0103] From equations (2) and (8), the above equation (1) can be extracted.

[0104] Additionally, W1 and W2 have a relationship of equation (9):

W1 <W2 ········ Equation (9)

[0105] From the relation of equation (9), equation (10) is established:

W1 <(2 * Pmax) / (Q1 * R) ········ Equation (10)

[0106] When the gap W1 is set in such a way that it satisfies the relation of equation (10), the pressure of the first common supply duct 17 can be maintained equal to negative pressure, and thereby the reliability of the substrate and the print head can be increased.

[0107] In particular, the clearance W1 (beam width) should be further reduced in the print head, in which the resistance when passing the pressure chamber 13 is high. In the print head in which the piezoelectric element is used as the ejection energy generating element 12, the gap W1 may increase as the resistance when passing the pressure chamber 13 is generally reduced. Meanwhile, in the print head in which the heater is used as the ejection energy generating element 12, the gap W1 must be further reduced since the resistance when passing the pressure chamber 13 generally increases.

Relationship (2) between the first common duct 17 for supply and the first common duct 18 for collection

[0108] In the case where the maximum ejected amount of ink ejected from the ejection hole 11 is indicated by Q2, it is desirable to define a first common supply duct 17 and a first common collection duct 18 so that they satisfy equation (11):

W1 <(2 * Pmax) / (Q2 * R) ········ Equation (11)

[0109] When the consumed amount of Q1 in the ink circulation is set to be greater than the maximum ejected amount of Q2, the countercurrent of the ink circulation flow can be suppressed even when the ink is ejected as much as possible. In the event that a countercurrent flow of the ink circulation is formed, the heat generated by the ink ejection is not released by the ink circulation flow. Additionally, the ink may become excessively hot due to the counterflow of heat ejected, and ink ejection failure may occur due to counterflow of deposits in the ink flow. However, since countercurrent flow of the ink circulation is suppressed, such conditions can be suppressed.

[0110] When the first common supply duct 17 and the first common acquisition duct 18 are set to satisfy equation (11), the pressure in the first common supply duct 17 can be kept at a negative pressure while the countercurrent of the circulation flow is suppressed. ink. As a result, the reliability of the substrate and the print head can be improved.

[0111] As a result of the experiment, when the height of the pressure chamber 13 is set to 20 μm, the ink viscosity is set to 10 CP, and the beam width W1 is set to 200 μm or less, the pressure in the first common supply duct 17 can be maintained equal to negative pressure, even when the ink circulation flow rate is 0.1 m / s to suppress countercurrent flow of the ink circulation. Additionally, when the beam width W is set to 100 μm or less, the pressure in the first common supply duct 17 can be maintained at a negative pressure, while the counterflow of the ink circulation flow is suppressed even when 10 pl ink is expelled with an expulsion frequency (excitation frequency printhead) at 30 kHz.

The relationship of the location between the ducts 17 and 14 and the relationship of the location between the ducts 18 and 15

[0112] Further, an arrangement relationship between the first common supply duct 17 and a supply duct 14 and an arrangement relationship between the first common acquisition duct 18 and the collection duct 15 may be defined below. Thus, as illustrated in FIG. 6B, the center L1 of the second flow duct 14 is set as a position near the ejection hole 11 with respect to the center L2 of the first common second flow duct 17. Likewise, the center L3 of the second collection duct 15 for collecting in the second direction is defined as a position near the ejection hole 11 relative to the center L4 of the first common collecting duct 18 in the second direction. Thus, when the supply duct 14 and the collection duct 15 are provided near the ejection hole 11, the width W2 is set smaller even when an identical beam width W1 is set, and therefore, the pressure in the ejection hole 11 can easily be maintained at the corresponding pressure.

The relationship of the placement between the duct 17 and duct 18

[0113] It is desirable to define a placement relationship between the first common supply duct 17 and the first common collection duct 18, as explained below.

[0114] Thus, as illustrated in FIG. 9, in the case where the width of the beam between the first common duct 17 for supply and the first common duct 18 for collection, located between adjacent matrices 16 of ejection holes, is indicated by W3, the width W3 of the beam is set greater than the width W1 of the beam. When the beam width W3 is set large, the strength of the substrate can increase. FIG. 9 is a diagram illustrating a liquid ejection substrate when viewed from the rear surface side in a state in which the ejection hole 11 is clearly visible. Thus, the first common duct 17 for supply and the first common duct 18 for collection, communicating with the identical matrix 16 of ejection holes, are formed close to each other, so that the width W1 of the beam is set small. Meanwhile, the first common supply duct 17 communicating with one of the adjacent matrix of ejection holes 16 is separated from the first common collection duct 18 communicating with the other one, so that the beam width W2 is large. Accordingly, the strength of the substrate can increase, while the countercurrent of the ink circulation flow is suppressed, so that the pressure in the first common supply duct 17 is maintained equal to the negative pressure.

Design (1) to suppress changes in the amount consumed during ink circulation and pressure

[0115] Additionally, in an embodiment, the following construction is provided in order to suppress a change in the amount consumed during ink circulation and a change in pressure of each pressure chamber 13.

[0116] Thus, as illustrated in FIG. 1 and 2, a plurality of first supply openings 30 communicate with one first common supply duct 17. Similarly, a plurality of first collection openings 31 are in communication with one first common collection duct 18. The first supply opening 30 and the first collection opening 31 are arranged such that a change in the amount consumed by the ink circulation and a change in pressure of each pressure chamber 13 fall into a range in which the ink ejection characteristics are not affected. In particular, the first supply opening 30 and the first collection opening 31 are alternately arranged in a first direction in which the ejection hole array 16 extends. Accordingly, the gap between the first supply opening 30 and the first collection opening 31 in the first direction can be further reduced. Thus, even if the width of the duct of each of the first common duct 17 for supply and the first common duct 18 for collection is relatively small, the change in the amount consumed during ink circulation and the change in pressure of each pressure chamber 13 can be suppressed.

Design (2) to suppress changes in the amount consumed during ink circulation and pressure

[0117] Furthermore, in an embodiment, the structure below is provided in order to suppress a change in the amount consumed during ink circulation and a change in pressure of each pressure chamber 13.

[0118] Thus, as illustrated in FIG. 1 and 2, a second common supply duct 32 extends in a second direction and communicates with a plurality of first supply openings 30 arranged in a second direction. Similarly, the second common collection duct 33 extends in a second direction and communicates with a plurality of first collection holes 31 arranged in the second direction. Additionally, a plurality of second common supply ducts 32 communicate with one third common supply duct 36 together through second supply ports 34. Similarly, a plurality of second common collection ducts 33 communicate with one third common collection duct 37 together through second collection openings 35.

[0119] When the ink ducts communicate with each other through a six-layer structure in this manner, a plurality of first common supply ducts 17 that are formed in a narrow pitch so that they match a plurality of arrays 16 of ejection holes that are tightly seated are ultimately grouped into one third common supply duct 36 through the plurality of first supply openings 30. Similarly, a plurality of first common collection ducts 18 that are formed in a narrow pitch so that they match a plurality of arrays 16 of ejection holes that are tightly seated are ultimately grouped into one third common collection duct 37 through the plurality of first collection ports . Thus, a plurality of arrays of ejection holes 16 can be tightly placed without increasing the width of the duct of each of the first common duct 17 for supply and the first common duct 18 for collection. Additionally, it is possible to suppress the change in the amount consumed during ink circulation and the pressure in each pressure chamber 13 corresponding to each opening 11 for ejecting a plurality of arrays 16 of ejecting holes that are tightly packed in this way. Additionally, it is possible to supply ink from the ink tank (not illustrated) and cause the ink to collect in the ink tank while suppressing a change in the amount consumed by the ink circulation and pressure of the pressure chamber 13 relative to the ejection holes 11 that are tightly seated. Accordingly, not only a print head and a printing device including it, but also various liquid ejection heads and liquid ejection devices including them can be provided with a compact size.

Design (3) to suppress changes in the amount consumed during ink circulation and pressure

[0120] Additionally, the design below is required to suppress a change in the amount consumed during ink circulation and a change in pressure of each pressure chamber 13.

[0121] Thus, the first supply openings 30 and / or the first collection openings 31 located at both ends of the ejection hole array 16 are formed so that they are smaller than the first supply openings 30 and / or the first collection openings 31 located in a position different from both ends. Thus, openings from among the first supply openings 30 and / or first collection openings 31 of the first one are formed so that they are smaller than openings from among the first supply openings 30 / or first collection openings 31 of the second of the specified. Near the first supply holes 30 located at both ends of the ejection hole array 16, the ejection hole 11 is located on only one side in a first direction of the first supply holes 30 located at both ends of the ejection hole array 16. Therefore, the amount of ink consumed by the first supply openings 30 located at both ends of the matrix of ejection openings 16 is less than the amount of ink consumed by the other first supply openings 30. Similarly, near the first collection holes 31 located at both ends of the ejection hole array 16, the ejection hole 11 is located on only one side in a first direction of the first collection holes 31 located at both ends of the opening array of 16 pushing out. Therefore, the amount of ink consumed by the first collection holes 31 located at both ends of the matrix of ejection holes 16 is less than the amount of ink consumed by the other first collection holes 31.

[0122] Thus, the shapes of the first supply openings 30 and / or the first collection openings 31 formed at both ends of the matrix of the ejection openings 16 are formed with a small size, so that the passage resistance increases. Accordingly, the pressure losses that are formed in the first supply openings 30 and / or the first collection openings 31 formed at both ends of the matrix of the ejection openings 16 can be controlled so that they are similar to the pressure losses that form in the other first openings 30 for supply and / or first collection openings 31. Thus, it is possible to reduce the difference between the amount of ink used for ink flowing in the pressure chamber 13 through the first supply openings 30 and / or the first openings 31 for collecting ejection holes at both ends of the matrix 16 and the amount of ink used for ink flowing in the pressure chamber 13 through the other first supply openings 30 and / or other first collection openings 31. As a result, the difference in the amount consumed during ink circulation in each pressure chamber 13 can be further suppressed.

Design (4) to suppress changes in the amount consumed during ink circulation and pressure

[0123] Additionally, the design below is required in order to suppress a change in the amount consumed during ink circulation and a change in pressure of each pressure chamber 13.

[0124] Thus, as illustrated in FIG. 7 (a), the region “a” between the end of the ejection hole array 16 and the end of the liquid ejection substrate 100 is large. For example, region "a" can be used as a space for accommodating drive circuits of the push energy generation element 12 and the connecting contact pad 150 that transmit and receive electrical signals to / from the fluid push substrate 100. Additionally, it is desirable to position the first collection opening 31 by using the area “a” as indicated in perspective views of part (b) and (c) of FIG. 7 illustrating a liquid ejection substrate 100 when viewed from an ejection hole 11. Thus, the first collection hole 31 is positioned so that it overlaps an ejection hole 11 located at the end of the ejection hole matrix 16 in a first direction in which the ejection hole matrix 16 extends. In part (b) of FIG. 7, the left end of the first common collection duct 18 and the left end of the first collection opening 31 are located at an identical position. Additionally, in part (c) of FIG. 7, the left ends of the first common collection duct 18 and the left ends of the first collection opening 31 increase greatly to the left relative to the collection duct 15 located on the left end.

[0125] In parts (a) and (b) of FIG. 7, ink that passes through a pressure chamber 13 located at the end of the ejection hole array 16 first flows from the first supply opening 30 into the first common supply duct 17 and the supply duct 14, as indicated by arrow A1. Then, ink flows from the first collecting opening 31 after passing through the pressure chamber 13, the collecting duct 15 and the first common collecting duct 18 located at the end of the ejection hole array 16, as indicated by arrow A2. Part (d) of FIG. 7 is a comparative example if the first collection hole 31 is positioned so that it does not overlap the ejection hole 11 located at the end of the matrix of the ejection holes 16 in the first direction. In part (d) of FIG. 7, ink that passes through a pressure chamber 13 located at the end of the ejection hole array 16 first flows from the first supply opening 30 into the first common supply duct 17 and the supply duct 14, as indicated by arrow A1. Then, the ink passes through the pressure chamber 13 and the collection duct 15 located at the end of the matrix 16 of ejection holes, as indicated by arrow A2, and flow from the first collection hole 31 after passing through the first common collection duct 18, as indicated by arrows A3.

[0126] In parts (b) and (c) of FIG. 7, the length of the ink flow for the ink flowing from the first supply opening 30 located at the end of the first direction and flowing from the first collection opening 31 through the pressure chamber 13 can be shortened compared to the configuration of part (d) of FIG. 7. Thus, since the maximum pressure loss in the first common supply duct 17 and the first common collection duct 18 located near the end of the matrix of the ejection holes 16 is reduced, the variation in the amount consumed during ink circulation in each pressure chamber 13 can be suppressed. if the first supply hole 30 is located at the end of the first direction instead of the first collection hole 31, the first supply hole 30 may be located so that it overlaps the hole 11 for ejecting disposed on the end of the matrix of holes 16 for ejecting a first direction.

Design to suppress temperature distribution

[0127] In an embodiment, the following construction is provided in order to suppress the temperature distribution in the print head.

[0128] Thus, as illustrated in FIG. 1 and 2, a first collection hole 31 is located at both ends of the ejection hole array 16. In the event that the ink is forcedly circulated through each pressure chamber 13, as indicated in this example, the heat generated from the ejection energy generating element 12 or the like is collected by ink. For this reason, the temperature of the ink in the duct on the ink collection side is higher than the temperature of each pressure chamber 13.

[0129] Further, even when a sufficient expendable amount is provided during ink circulation in order to suppress the effect caused by the evaporation of moisture in the ink from the ejection hole 11, a case arises when the ejected amount of ink ejected simultaneously from the plurality of ejection holes 11, becomes more than is consumed by ink circulation. In this case, ink is also supplied from the second common duct 37 for collection to the pressure chamber 13. Thus, ink is supplied from the second common duct 37 for collection to the pressure chamber 13 through the second collection port 35, the second common duct 33 for collection, the first a collection opening 31, a first common collection duct 18 and a collection duct 15. For this reason, there is a case where the high temperature ink in the first collection opening 31 is supplied to the pressure chamber 13 when the ink is simultaneously ejected from the plurality of ejection holes 11. In this case, since the temperature of the ink near the first collection hole 31 becomes higher than the temperature of the ink near the first supply hole 30, there is such a problem that a difference in ink ejection speed may occur between the ejection hole 11 near the first supply hole 30 and the opening 11 for pushing near the first collection hole 31. Additionally, in the case where the first supply hole 30 is located on one end side of both ends of the ejection hole array 16 and the first collection hole 31 is located on the other end side, a temperature distribution tilt in the direction of placement of the ejection holes 11 occurs in the entire matrix 16 ejection holes, and therefore the width of the temperature distribution in the entire print head increases. As a result, there is such a problem that a change in the ink ejection characteristic can occur in each ejection hole 11.

[0130] In an embodiment, since the first collection hole 31 is located at both ends of the ejection hole array 16, such a slope in the temperature distribution is suppressed, and therefore, a change in the ink ejection characteristic can be suppressed. Additionally, an identical advantage can be obtained even when the first supply opening 30 is located at each of both ends of the ejection hole array 16. However, as indicated in the embodiment, it is desirable to position the first collection opening 31 at each of both ends of the matrix of ejection openings 16.

[0131] Thus, in the liquid ejection substrate 100, as described above, a region “a” without placement with the ejection hole 11 is mainly defined between each of both ends of the ejection hole array 16 and the end of the liquid ejection substrate 100, and therefore, the heat generated by the ink ejecting operation is emitted from the region “a”. For this reason, in the case where a plurality of ejection holes 11 ejects ink, there is a tendency that the temperature values of both ends of the ejection hole array 16 become lower than the temperatures of the other parts. Since the first collection hole 31 is located at each of both ends of the ejection hole array 16, high temperature ink can be supplied to both ends of the ejection opening array 16 in such a case. Thus, since the temperature values of both ends of the matrix 16 of the ejection holes are set higher, the temperature difference relative to other parts can be reduced. As a result, since the width of the temperature distribution throughout the print head is reduced, a change in ink ejection characteristic can be suppressed.

[0132] FIG. 10 is a flowchart illustrating an example of a step for manufacturing a head for ejecting a liquid of an embodiment.

[0133] First, nozzles are formed on the liquid ejection substrate 100 having an ejection energy generating element 12 and a necessary pattern formed thereon by the nozzle forming step S1. The nozzle is a part that ejects ink through the use of an ejection energy generating element 12, and includes an ejection hole 11 and a pressure chamber 13. Then, a first common supply duct 17 and a first common collection duct 18 are formed on the back surface of the substrate 100 for ejecting the liquid through the step S2 of forming the supply path on the rear surface. Then, the patch plate 20 or 2020 (cover element) of the embodiment illustrated in FIG. 36C or 45C is formed on the back surface of the liquid ejection substrate 100 by a cap member forming step S3. Then, the shape of the liquid ejection substrate 100 is processed from the shape of the laminate plate to the crystal shape by the cutting step S4. Then, the fluid ejection substrate 100 adheres to the support member 400 and the first duct member 500 of the embodiments of FIG. 24A-24E by gluing step S5.

[0134] Thus, since the patch plate serving as the third duct layer is formed on the back surface of the liquid ejection substrate 100 by the cap element forming step S3 before the gluing step S5, the first supply hole 30 and the first collection hole 31 can be formed in the substrate 100 for ejecting liquid in the form of a layered plate. Since the patch plate is machined when the liquid ejection substrate 100 is in the form of a layered plate, the machining accuracy is improved compared to machining or molding, and therefore, microscopic holes can be formed with greater accuracy. Additionally, the patch plate may be formed so that it is thinner. Thus, the ejection holes 11 can be placed with greater accuracy. Additionally, since the resistance when passing through the first supply opening 30 and the first collecting hole 31 decreases with a slight change in the passage resistance, the differential pressure for forming the ink circulation stream can be stabilized, and therefore, the change in the amount consumed during circulation can be suppressed in this way that it is small.

[0135] The patch plate may be formed by means of a silicon substrate. Thus, since the patch plate formed as a silicon substrate in the form of a layered plate is bonded to the substrate 100 for ejecting liquid in the form of a layered plate, the number of steps can be reduced compared to the case in which the patch plate is glued to the substrate 100 for ejecting liquid into crystal shape. Additionally, the patch plate may be formed from a resin-based film. As in the case of the silicon substrate, since the patch plate can be glued so that the film-shaped resin is laminated to the substrate 100 to eject the liquid in the form of a layered plate, the number of steps can be reduced compared to the case in which the patch plate is glued to each substrate 100 for ejecting a liquid in the form of a crystal.

[0136] The sequence and content of the steps of FIG. 10 are merely examples and do not limit the present invention. For example, the sequences of the nozzle forming step S1, the backflow forming path S2 of the back surface, the cap element forming step S3, and the cutting step S4 are not limited to the examples of FIG. 10 provided that the step S3 of forming the cap member can be performed before the gluing step S5.

Second Embodiment

[0137] FIG. 11 and 12 are explanatory diagrams illustrating a fluid ejection unit 300 according to the second embodiment of the present invention, and a description identical to that of the above-described embodiment is omitted, with identical reference numbers assigned to the indicated one. FIG. 11 is an exploded perspective view illustrating a fluid ejection assembly 300, and FIG. 12 is an exploded plan view illustrating a fluid ejection assembly 300.

[0138] In an embodiment, the first common supply duct 17 and the second common supply duct 32 communicate with each other on one end side of the ejection hole array 16, and the first common collection duct 18 and the second common collection duct 33 communicate with each other on the other end side. In an embodiment, since the third duct layer 24 of the first embodiment is not provided, and the first supply opening 30 and the first collection opening 31 can be lowered, the duct structure can be simplified.

Third Embodiment

[0139] FIG. 13 and 14 are explanatory diagrams illustrating a fluid ejection unit 300 according to the third embodiment of the present invention, and a description identical to that of the above embodiment is omitted, with identical reference numbers assigned to the indicated one. FIG. 13 is an exploded perspective view illustrating a fluid ejection assembly 300, and FIG. 14 is an exploded plan view illustrating a fluid ejection assembly 300.

[0140] In an embodiment, on one end side of the ejection hole array 16, the first common supply duct 17 and the first supply opening 30 communicate with each other, and the first common collection duct 18 and the first collection opening 31 communicate with each other. Similarly, also on the other end side of the matrix of ejection holes 16, the first common supply duct 17 and the first supply opening 30 communicate with each other, and the first common collection duct 18 and the first collection opening 31 communicate with each other. When the first supply hole 30 and the first collection hole 31 are located at both ends of the ejection hole array 16, it is possible to suppress a pressure change in each pressure chamber 13 and a change in the amount consumed during ink circulation in the first direction in which the ejection hole array 16 extends , compared with the second embodiment. Additionally, each of the second common duct 32 for supply and the second common duct 33 for collection can be located in two positions.

[0141] Thus, in the embodiment, since the number of the first supply holes 30 and the second collection holes 31 is reduced, the construction of the ink flow can be simplified.

Fourth Embodiment

[0142] FIG. 15 to 18B are explanatory diagrams illustrating a fluid ejection unit 300 according to a fourth embodiment of the present invention, and a description identical to that of the above-described embodiment is omitted, with identical reference numerals being assigned to the aforesaid. FIG. 15 is an exploded perspective view illustrating a fluid ejection assembly 300, and FIG. 16 is an exploded plan view illustrating a fluid ejection assembly 300. In an embodiment, the planar shape of the fluid ejection assembly 300 is in the form of a parallelogram (parallelogram without rectangular adjacent sides), but to simplify the description, the planar shape is illustrated as a rectangular shape. FIG. 17A is a plan view illustrating a liquid ejection substrate 100 according to an embodiment, and FIG. 17B is a perspective view illustrating an end structure of an ejection hole array 16.

[0143] As illustrated in FIG. 17A, the planar shape of the liquid ejection substrate 100 of the embodiment is parallelogram-shaped, and the region “a” between the end of the ejection hole array 16 and the end of the element layer substrate is smaller than the region “a” of the liquid ejection substrate 100 of part (a) of FIG. 7 of the first embodiment. In an embodiment, a connecting pad 150 for transmitting and receiving electrical signals between a liquid ejection substrate 100 and an external medium, and drive circuits of the ejection energy generating element 12 or the like. are located on the long side of the fluid ejection substrate 100, as illustrated in FIG. 17A. In the event that an elongated printhead (line head) is obtained by a combination of liquid ejection substrates 100, the liquid ejection substrates 100 can be arranged in substantially the same matrix form, as illustrated in FIG. 17A, instead of a zigzag shape. Through this arrangement, the ends of the matrix 16 of the ejection holes adjacent to the liquid ejection substrates 100 can easily overlap each other in the second direction, as illustrated in FIG. 17A. Here, “placement in substantially the same matrix form” indicates a state in which adjacent liquid ejection substrates 100 partially overlap each other in both the first direction and the second direction.

[0144] Thus, in the embodiment, the ejection holes 11 are located in the vicinity of the end of the liquid ejection substrate 100. In such an embodiment, it is difficult to locate the first supply opening 30 or the first collection opening 31 at a position overlapping the end of the matrix of holes 16 for ejecting the substrate 100 for ejecting liquid, as illustrated in parts (b) and (c) of FIG. 7 of the first embodiment. Thus, in the embodiment, the first supply openings 30 or the first collection openings 31 are located at a position offset from the center relative to the end of the ejection hole array 16, as illustrated in FIG. 17B.

[0145] In an embodiment, in order to suppress the change in the amount consumed during ink circulation and the pressure change of each pressure chamber 13 and suppress the temperature distribution in the liquid ejection substrate 100, a first supply opening 30 is located near each of both ends of the ejection hole array 16, as illustrated in FIG. 15 and 16.

[0146] As indicated in the embodiment, in the case where the first supply opening 30 is located near the end of the ejection hole array 16, the differential pressure between the first common supply duct 17 and the first common collection duct 18 located at the end of the opening matrix 16 ejection is large during the ink ejection operation compared to the ink circulation operation using the initial differential pressure. Meanwhile, in the event that the first collection hole 31 is located at the end of the ejection hole matrix 16, similarly to the first embodiment, the differential pressure between the first common supply duct 17 and the first common collection duct 18 at the end of the ejection hole matrix 16 is small during the ink ejecting operation compared to the ink circulation operation using the initial differential pressure. When the differential pressure decreases between the first common supply duct 17 and the first common collection duct 18, the amount of ink consumed during circulation is reduced. Accordingly, the advantage of suppressing the effect caused by the evaporation of moisture in the ink from the ejection hole 11 is reduced. Thus, the advantage of suppressing a decrease in ink ejection speed and a change in the concentration of ink colors is reduced. For this reason, the differential pressure is preferably set large. As indicated in the embodiment, since the first supply opening 30 is located near both ends of the ejection hole array 16, the effect of changing the amount consumed during ink circulation can be reduced.

[0147] Since the pressure in the first supply opening 30 is set higher than the pressure in the first collection opening 31 to form an ink circulation stream, ink is easily supplied to the pressure chamber 13 through the first supply opening 30 during the ink ejecting operation. Thus, since the first ink supply hole 30, which is easy to supply, is located near the end of the ejection hole array 16, the pressure loss formed between the first common supply duct 17 and the first common collection duct 18 can be reduced when the ink is simultaneously ejected from the plurality holes 11 for pushing.

[0148] Additionally, in the embodiment as described above, since the region “a” between the end of the matrix of the ejection holes 16 and the end of the substrate of the element layer is small, the degree to which the heat generated by the ink ejection operation is emitted from the region “a” "is small. Since the region "a" is small, a portion of the first common supply duct 17 from the first supply opening 30 to the end of the matrix of ejection openings 16 increases in length, as illustrated in FIG. 17B. Similarly, a portion of the first common collection duct 18 from the first collection hole 31 to the end of the matrix of ejection holes 16 is extended in length. Thus, ink passing through portions of the first common flow duct 17 for supply and the first common flow duct 18 for collection easily accepts heat from the substrate 100 for expelling liquid. For this reason, when ink is simultaneously ejected from a plurality of ejection holes 11, there is a tendency that the temperature of the end of the ejection hole matrix 16 becomes higher than the temperature of other parts. Further, the pressure loss generated in each ink flow increases during the ink ejecting operation, and therefore, the pressure at the end of the ejection hole matrix 16 becomes uneven.

[0149] However, in the embodiment as described above, since the first supply hole 30 is located at each of both ends of the ejection hole array 16, a large amount of ink is supplied to the ejection hole 11 near the end of the array of ejection holes 16 a first feed hole 30 located in its vicinity. As a result, when ink is simultaneously ejected from the plurality of ejection holes 11, the amount of high-temperature ink supplied from the first supply hole 30 is reduced, and therefore, an increase in the temperature of the end of the ejection hole matrix 16 can be reduced.

[0150] In particular, ink supplied from the first supply opening 30 flows first from the first common supply duct 17 into the supply duct 14, as indicated by arrow B1 of FIG. 17B. Then, ink passes through the pressure chamber 13 and the collection duct 15 located at the end of the matrix of ejection holes 16, as indicated by arrow B2, and flows from the first collection hole 31 through the first common collection duct 18, as indicated by arrow B3 .

[0151] Thus, in the embodiment, since the first supply hole 30 is located at each of both ends of the ejection hole array 16, the change in the amount consumed during ink circulation and pressure can be suppressed, and the temperature distribution in the print head can be suppressed in this way that it is small. Thus, it is possible to print a high-quality image with greater accuracy by suppressing a decrease in the ink ejection speed, changing the concentration of ink colors and changing the ejection characteristic caused by the evaporation of moisture in the ink from the ejection hole 11. Additionally, it is desirable that the first common duct 17 for supply and the first common duct 18 for collecting an embodiment have the form illustrated in FIG. 18B. FIG. 18A is a diagram illustrating a liquid ejection substrate 100 when viewed from the rear surface, and FIG. 18B is an enlarged view illustrating the ends of the first common duct 17 for supply and the first common duct 18 for collecting in the longitudinal direction of FIG. 18A. Both ends of the first common duct 17 for supply and the first common duct 18 for collection, communicating with the identical matrix 16 of holes for pushing in the longitudinal direction, are provided in the identical position illustrated in FIG. 18B. Additionally, as illustrated in FIG. 18A, in two arrays 16 of ejection holes provided in parallel so that they are adjacent to each other, a first common duct 17 for supply and a first common duct 18 for collecting on one side of adjacent arrays 16 of ejection holes and a first common duct 17 for the feed and the first common duct 18 for collecting on the other side of adjacent matrices 16 of ejection holes have a positional relationship, as explained below. Thus, both ends of the first common duct 17 for supply and the first common duct 18 for collection, communicating with one side of adjacent matrices 16 of holes for pushing in the longitudinal direction, and both ends of the first common duct 17 for supply and the first common duct 18 for collection, communicating with its other side in the longitudinal direction, deviate at an angle.

[0152] By means of the ducts 17 and 18 having such a shape, the width between each of the ends of the ducts 17 and 18 and the end of the liquid ejection substrate 100 is increased to provide strength to the liquid ejection substrate 100, while ink is reliably supplied to the openings 11 for ejection, located at both ends of the matrix 16 holes for ejection. More specifically, as illustrated in FIG. 18A, the distance between the right end of the duct 17 and the right end of the fluid ejection substrate 100 can be set large, and the distance between the left end of the duct 18 and the left end of the fluid ejection substrate 100 can be large. Additionally, as illustrated in FIG. 18B, both ends of the first common duct 17 for supply and the first common duct 18 for collecting in the longitudinal direction have a shape in which the angle is excluded. In the case of this example, a beveled shape is illustrated, but a round shape can be used. With this form, it is possible to suppress the likelihood that stress is concentrated at both ends of the first common duct 17 for supply and the first common duct 18 for collection when external force or deformation is caused by heat, and thereby suppress damage to the substrate 100 for expelling fluid caused by a crack or the like

Fifth Embodiment

[0153] FIG. 19 and 20 are explanatory diagrams illustrating a fluid ejection unit 300 according to a fifth embodiment of the present invention, and a description identical to that of the above-described embodiment is omitted, with identical reference numerals being assigned to the indicated one. FIG. 19 is an exploded perspective view illustrating a fluid ejection assembly 300, and FIG. 20 is an exploded plan view illustrating a fluid ejection assembly 300.

[0154] In the example, as illustrated in FIG. 19, the first three common ducts 17 (17A, 17B and 17C) for supply and the first two common ducts 18 (18A and 18B) for collection are located relative to the four arrays 16 (16A, 16B, 16C and 16D) of the ejection holes. As illustrated in FIG. 20, a collection duct 15 common to these matrices 16A and 16B is located between the matrices 16A and 16B of the pop-up openings, and the collection duct 15 communicates with the first common collection duct 18A. Additionally, between the ejection hole matrices 16B and 16C, a supply duct 14 common to these dies 16B and 16C is located, and the supply duct 14 communicates with the first common supply duct 17A. Additionally, between the ejection hole arrays 16C and 16D, a collection duct 15 common to these arrays 16C and 16D is located, and the collection duct 15 is in communication with the first common collection duct 18B. The duct 14 for supplying the matrix 16A of ejection openings communicates with the first common duct 17A for supply, and the duct 14 for supplying the matrix 16D of ejection openings communicates with the first common duct 17C for supply.

[0155] Thus, one first common supply duct 17B communicates with the pressure chambers 13 of the openings for the ejection ports 16B and 16C through the supply duct 14 common to these matrices 16B and 16C. Additionally, one first common collection duct 18A communicates with the pressure chambers 13 of the openings for the ejection holes 16A and 16B through the collection duct 15 common to these matrices 16A and 16B. Similarly, one first common collection duct 18B communicates with the pressure chambers 13 of the openings 15 through 16 of the collection ducts 16C and 16D, common to these matrices 16C and 16D.

[0156] According to an embodiment, the following advantage may be obtained, in addition to the advantage of the above-described embodiment.

[0157] Thus, since two adjacent arrays of ejection openings share the first common duct 17 for supply and the first common duct 18 for collection, the number of dividing walls between the ink ducts and the number of ink ducts can be reduced. Thus, the gap between the matrices 16 of the ejection openings may narrow, and the width of the ink duct may increase. As a result, the change in the amount consumed during the circulation of the ink and the change in pressure of each pressure chamber 13 are further suppressed. Then, the arrays 16 of the ejection holes are even more densely arranged as compared with the above embodiment, so that the size of the substrate and the print head can be reduced. Additionally, if the density of the arrays 16 of the ejection holes is identical, the change in the amount consumed during ink circulation and the pressure change of each pressure chamber 13 are further suppressed, and in addition, the number of the first supply holes 30 and the first collection holes 31 can be reduced. Therefore, the design of the flow path for the ink substrate can be simplified.

Sixth Embodiment

[0158] FIG. 21-23 are explanatory diagrams illustrating a fluid ejection unit 300 according to a sixth embodiment of the present invention, and a description identical to that of the above-described embodiment is omitted, with identical reference numbers assigned to the indicated one. FIG. 21 is an exploded perspective view illustrating a fluid ejection assembly 300, and FIG. 22 is an exploded plan view illustrating a fluid ejection assembly 300.

[0159] In an embodiment, an ejection hole array having ejection holes 51 for the first ink and an ejection hole array having ejection holes 61 for the second ink are formed to eject various ink colors or a plurality of types of ink into one substrate . Layer 23 of the second duct comprises a first common duct 52 for supplying the first ink, a first common duct 62 for supplying the second ink, a first common duct 53 for collecting the first ink and a first common duct 63 for collecting the second ink. The third duct layer 24 includes a supply hole 54 for the first ink, a supply hole 64 for the second ink, a collection hole 55 for the first ink, and a collection hole 65 for the second ink. The fourth duct layer 25 comprises a second common duct 56 for supplying the first ink, a second common duct 66 for supplying the second ink, a third common duct 57 for collecting the first ink and a third common duct 67 for collecting the second ink. The fifth duct layer 26 comprises a second supply hole 58 for the first ink, a second supply hole 68 for the second ink, a second collection hole 59 for the first ink and a second collection hole 69 for the second ink. The sixth duct layer 27 comprises a third common duct 70 for supplying the first ink, a third common duct 80 for supplying the second ink, a third common duct 71 for collecting the first ink and a third common duct 81 for collecting the second ink.

[0160] Similar to the first embodiment, the first and second ink, respectively, are supplied from the third common supply ducts 70 and 80, pass through the respective pressure chambers 13, and then flow from the third common collection ducts 71 and 81.

[0161] Similar to the fifth embodiment, one first common supply duct can typically communicate with pressure chambers of two arrays of ejection openings. Similarly, one first common collection duct may typically communicate with the pressure chambers of the two arrays of ejection openings. Additionally, the width of the sixth duct layer 27 in the second direction can be set greater than the width of the first duct layer 22 in the second direction.

[0162] Thus, even in the print head for a plurality of ink colors or a plurality of ink types, a change in the circulating amount of ink and a pressure change in each pressure chamber can be suppressed, while the widths of the first common supply duct and the first common collection duct do not increase . Thus, it is possible to print a high-quality image with greater accuracy by suppressing a decrease in the ink ejection speed and a change in the concentration of ink colors caused by the evaporation of moisture in the ink from the ejection opening.

The relationship of the placement between the ducts 52 and 53 and the ducts 62 and 63

[0163] It is desirable to define a placement relationship between the first common supply duct 52 and the first common collection duct 53 for the first ink and the first common supply duct 62 and the first common collection duct 63 for the second ink, as explained below.

[0164] Thus, as illustrated in FIG. 23, the width W4 of the beam between the first common duct 53 for collection and the first common duct 62 for supplying between the matrix 16 (1) of the ejection holes for the first ink and the matrix 16 (2) of the ejection holes for the second ink is set greater than the width W1 of the beam. When the beam width W4 is set large, ink leakage between the first common collection duct 53 and the first common supply duct 62 can be suppressed so that the ink colors do not mix with each other. Beam width W3 and beam width W4 may be equal to or different from each other. In particular, if the width W3 of the beam between the ducts for identical inks is set to be smaller than the width W4 of the beam between the ducts for different inks, the pressure loss of the duct for the ink flow is reduced, and therefore ink ejection characteristics can be improved. Thus, since the counterflow of the ink circulation flow is suppressed, it is possible to suppress the mixing of the ink colors with each other while maintaining the pressure in the first common duct 17 for supplying a negative pressure.

Examples of fluid ejection configurations

[0165] FIG. 24A-24E are perspective views illustrating configuration examples having various inkjet printheads serving as a fluid ejection head of the present invention.

[0166] The print head of FIG. 24A includes one fluid ejection substrate 100, and the support member 400 and the fluid ejection substrate 100 are sequentially disposed in the first duct element 500. The print head is used in the so-called sequential scanning inkjet printing device. The printing apparatus prints the image on the recording medium by repeating the printing operation of ejecting ink from the ejecting hole by moving the print head in the main scanning direction indicated by the arrow X, and the transportation operation for transporting the printing medium in the sub-scanning direction indicated by the arrow X crossing (in this example, orthogonal to) the direction of the main scan. The direction of the main scan is the direction crossing (in this example, orthogonal to) the first direction in which the matrix of holes 16 for pushing.

[0167] The print heads of FIG. 24B and 24C are elongated string heads in which a plurality of liquid ejection substrates 100 are arranged in a zigzag shape. In the configuration of FIG. 24B, the first duct member 500 is typically located on a plurality of fluid expelling substrates 100. In the configuration of FIG. 24C, the first duct element 500 is separately located on each of the liquid ejection substrates 100. The first duct element 500 is located on the second duct element 600. Such printheads are used in the so-called full-line inkjet printing apparatus. The printing apparatus continuously prints the image on the recording medium by ejecting ink from the print head in a fixed position while continuously transporting the recording medium in the direction indicated by the arrow Y crossing (in this example, orthogonal to) the first direction in which the matrix 16 passes ejection holes.

[0168] The print heads of FIG. 24D and 24E are elongated string heads in which the liquid ejection substrate 100 is arranged in a single matrix shape and is used in a so-called full-line inkjet printing apparatus. In the configuration of FIG. 24D, the first duct member 500 is typically located on a plurality of fluid expelling substrates 100. In the configuration of FIG. 24E, the first duct member 500 is separately located on each of the liquid ejection substrates 100. The first duct element 500 is located on the second duct element 600. It is desirable to form a substrate 100 for ejecting a liquid of such a print head in the form of a fourth embodiment.

[0169] In such various printheads, by generating an ink circulation stream as described above, a high-quality image can be printed with high accuracy, while the reduction in ink ejection rate and the change in ink color concentration caused by the evaporation of moisture in the ink from the hole are suppressed. for pushing out.

Examples of fluid ejection device configurations

[0170] FIG. 25A-25C are diagrams illustrating configuration examples having various inkjet printing apparatuses using the fluid ejection device of the present invention.

[0171] The inkjet printing apparatus of FIG. 25A is a sequential scanning printing apparatus that uses a print head having the configuration of FIG. 24A, as the print head 43. The frame 47 is formed by a plurality of plate-shaped metal elements having a predetermined stiffness, and forms the frame of the printing apparatus. The feed unit 41, the transport unit 42 and the carriage 46, equipped with a print head 43 and movable in the main scanning direction indicated by the arrow X, are assembled in the frame 47. The main scanning direction is the direction crossing (in this example, orthogonal to) the direction of the matrix ejection holes in the print head 43. The feeding unit 41 automatically feeds a sheet-like printing medium (not illustrated) to the printing device, and the conveying unit 42 conveys the wearer eh for printing fed one by one from a supply unit 41, a sub-scanning direction indicated by the arrow Y. subscan direction is a direction crossing (in this example, orthogonal to) the main scanning direction. Such a printing apparatus prints the image on the recording medium by repeating the printing operation of ejecting ink from the ejection hole of the print head 43 by moving the print head 43 in the main scanning direction along with the carriage 46 and the transportation operation for transporting the print medium in the sub-scanning direction. Ink is supplied from the ink tank (not illustrated) to the print head 43.

[0172] The inkjet printing apparatus of FIG. 25B is a full-line scanning printing apparatus that uses an elongated print head 120 described in FIG. 24B, 24C, 24D and 24E, and includes a conveyance mechanism 202 that continuously conveys the sheet 201 (recording medium) in the direction shown by the arrow Y. As the conveyance mechanism 202, a construction using a conveyor roller or the like can be used. P. instead of constructing this example using a shipping belt. In this example, four printheads 120Y, 120M, 12 ° C, and 120B ejecting inks of yellow (Y), magenta (M), cyan (C), and black (Bk) are provided as printhead 120. Corresponding ink is supplied to the print heads 120 (120Y, 120M, 120C, 120B). When ink is ejected from the print head 120 in a fixed position, while the sheet 201 is continuously transported in the direction shown by the arrow Y, a color image can be continuously printed on the sheet 201.

[0173] FIG. 25C is an explanatory diagram illustrating an ink supply system for printheads 43 and 120. Ink in a first ink tank 44 is supplied to a third common duct 36 for supplying a printhead 43 or 120, passes through a pressure chamber 13, and is collected from a third common duct 37 for collecting in the second tank 45 with ink. As a method for generating an ink circulation stream in a print head 43 or 120, for example, a method is known for using the difference in water pressure between the first ink tank 44 and the second ink tank 45. Alternatively, a method is known for generating a pressure difference between the first ink tank 44 and the second ink tank 45 by controlling pressures in the first ink tank 44 and the second ink tank 45. In addition, a method of forming an ink circulation stream by using a pump and the like is known. The configuration of the ink supply system and the method of forming the ink circulation flow are not limited to this example and can be arbitrarily set. The configuration and method do not matter, provided that the differential pressure driver, allowing the formation of a difference in pressure, necessary for the circulation of ink in the pressure chamber, can be configured.

[0174] In such a printing apparatus, by generating an ink circulation flow in the print head, a high-quality image can be printed with high accuracy, while the decrease in ink ejection speed and the change in ink color concentration caused by evaporation of moisture in the ink from the ejection hole are suppressed. .

First application example

[0175] FIG. 26-38 are diagrams illustrating a first example of an application to which the present invention is applicable.

Description of Inkjet Printer

[0176] FIG. 26 is a diagram illustrating a schematic configuration of a liquid ejection device in the present invention that ejects a liquid, and in particular an inkjet printing device 1000 (hereinafter, also referred to as a “printing device”) that prints an image by ink ejection. The printing apparatus 1000 includes a conveying unit 1 that conveys the recording medium 2, and a line-by-line (page-by-page) liquid ejection head 3, which is positioned so that it is substantially orthogonal to the direction of transport of the recording medium 2. Then, the printing apparatus 1000 is a line-by-line printing apparatus that continuously prints an image in a single pass by ejecting ink onto relatively movable printing substrates 2 while continuously or intermittently transporting the recording substrates 2. The liquid ejection head 3 includes a negative pressure control unit 230 that controls the pressure (negative pressure) in the circulation path, a liquid supply unit 220 that communicates with the negative pressure control unit 230, a fluid connection part 111 that serves as an opening for the ink supply and ink supply openings of the fluid supply unit 220, and the housing 380. The recording medium 2 is not limited to sheet paper and may also be a continuous roll medium. The liquid ejection head 3 can print a full color image using cyan (C), magenta (M), yellow (Y) and black (K) inks and has a fluid connection to the fluid supply element, main tank and buffer tank (see Fig. 27, which is described below), which serve as a supply path supplying fluid to the head 3 for expelling the fluid. Additionally, a control unit that supplies power and transmits an ejection control signal to the liquid ejection head 3 is electrically connected to the liquid ejection head 3. The fluid path and the electrical signal path in the head 3 for expelling the fluid are described below.

[0177] The printing apparatus 1000 is an inkjet printing apparatus that circulates a liquid, such as ink, between a tank, which is described below, and a head 3 for ejecting liquid. The circulation configuration includes a first circulation configuration in which liquid is circulated by activating two circulation pumps (for high and low pressures) on the discharge side of the head 3 for ejecting liquid, and a second circulation configuration in which liquid is circulated by activating two circulation pumps ( for high and low pressures) on the inlet side of the flow of the head 3 to eject the liquid. Hereinafter, the first circulation configuration and the second circulation configuration for circulation are described in this document.

Description of the first circulation configuration

[0178] FIG. 27 is a circuit diagram illustrating a first circulation configuration in a circulation path applied to a printing apparatus 1000 of an example application. The liquid ejection head 3 is fluidly connected to a first circulation pump 1001 (on the high pressure side), a first circulation pump 1002 (on the low pressure side) and a buffer tank 1003. Further, in FIG. 27, to simplify the description, a path through which ink of the same color from cyan (C), magenta (M), yellow (Y) and black (K) is illustrated. However, in fact, four colors of the circulation paths are provided in the head 3 for ejecting liquid and the housing of the printing apparatus.

[0179] In the first circulation configuration, ink in the main tank 1006 is supplied to the buffer tank 1003 by a make-up pump 1005 and then supplied to the liquid supply unit 220 of the head 3 to eject the liquid through the liquid connection part 111 by the second circulation pump 1004. Then, the ink, which are regulated to two different negative pressures (high and low pressures) through the negative pressure control unit 230 connected to the liquid supply unit 220, circulate when divided into two ducts having high and low pressure. The ink in the liquid ejection head 3 is circulated in the liquid ejection head by the operation of the first circulation pump 1001 (on the high pressure side) and the first circulation pump 1002 (on the low pressure side) on the discharge side of the liquid ejection head 3, are dispensed from the head 3 to eject the liquid into the fluid connection part 111 and return to the buffer tank 1003.

[0180] The buffer tank 1003, as an auxiliary tank, is connected to the main tank 1006 and includes a hole for communicating with the atmosphere (not illustrated), which communicates the inside of the tank 1003 with the external environment, and therefore can release ink bubbles to the outside. A make-up pump 1005 is provided between the buffer tank 1003 and the main tank 1006. The make-up pump 1005 delivers ink from the main tank 1006 to the buffer tank 1003 after the ink is consumed by ejecting (dispensing) ink from the ejection hole of the head 3 for ejecting liquid during the printing operation and suction recovery operations.

[0181] The first two circulation pumps 1001 and 1002 draw liquid from the liquid connection portion 111 of the head 3 to expel the liquid, so that the liquid flows into the buffer tank 1003. As the first circulation pump, a displacement pump having a quantitative liquid delivery capacity is required. In particular, a tubular pump, a gear pump, a diaphragm pump and a syringe pump can be roughly illustrated. However, for example, a common constant flow control valve or a common safety valve may be located in the outlet of the pump to provide a predetermined flow. When the liquid ejection head 3 is energized, the first circulation pump 1001 (on the high pressure side) and the first circulation pump 1002 (on the low pressure side) are controlled so that ink flows at a predetermined flow rate through the common supply duct 211 and the common duct 212 to collect. Since the ink flows in this manner, the temperature of the liquid ejection head 3 is maintained at the optimum temperature during the printing operation. The predetermined flow rate when the liquid ejection head 3 is excited is preferably set equal to or higher than the flow rate in which the temperature difference between the printed circuit boards 10 of the printing elements of the inside of the liquid ejection head 3 does not affect the print quality. First of all, when the flow rate is set too high, the difference in negative pressure between the boards 10 of the printing elements increases due to the influence of the flow pressure loss in the fluid ejection unit 300, and therefore a density inhomogeneity is caused. For this reason, it is desirable to set the flow rate taking into account the difference in temperature and the difference in negative pressure between the boards 10 of the printing elements.

[0182] A negative pressure control unit 230 is provided in the path between the second circulation pump 1004 and the fluid ejection unit 300. The negative pressure control unit 230 is controlled to maintain pressure on the discharge side (i.e., the pressure near the fluid ejection unit 300) of the negative pressure control unit 230 equal to a predetermined pressure, even when the ink flow in the circulation system due to the difference in the ejected the amount of ink per unit area. Any mechanism can be used as the two negative pressure control mechanisms constituting the negative pressure control unit 230, provided that the pressure on the discharge side of the negative pressure control unit 230 can be controlled in a predetermined range or less relative to the desired predetermined pressure. As an example, a mechanism such as the so-called “pressure reducing regulator” can be used. In the circulation flow of an example application, the flow side of the negative pressure control portion 230 is sealed by a second circulation pump 1004 through the fluid supply portion 220. With this configuration, since the influence of the water pressure of the buffer tank 1003 with respect to the liquid ejection head 3 can be suppressed, the degree of freedom in the arrangement of the buffer tank 1003 of the printing apparatus 1000 can increase.

[0183] As the second circulation pump 1004, a turbopump or a displacement type pump may be used provided that a predetermined pressure in the head or more can be shown in the flow range of the ink circulation used when the head 3 is driven to eject the liquid. In particular, a diaphragm pump may be used. Additionally, for example, a water tank arranged in such a way that it has a certain water pressure difference with respect to the negative pressure control unit 230 can also be used instead of the second circulation pump 1004. As illustrated in FIG. 27, the negative pressure control unit 230 includes two negative pressure control mechanisms, respectively, having different control pressures. Of the two negative pressure control mechanisms, the relatively high pressure side (indicated by “H” in FIG. 27) and the relatively low pressure side (indicated by “L” in FIG. 27) are respectively connected to a common supply duct 211 and a common a duct 212 for collecting fluid in the node 300 ejection through the node 220 fluid supply. The fluid ejection assembly 300 includes a common supply duct 211, a common collection duct 212, and separate ducts 215 (separate supply ducts 213 and separate collection ducts 214) communicating with the printing element board. The negative pressure control mechanism H is connected to a common supply duct 211, the negative pressure control mechanism L is connected to a common collection duct 212, and differential pressure is generated between the two common ducts 211 and 212. Then, since a separate duct 215 communicates with the common supply duct 211 and a common collection duct 212, a flow is formed (the flow indicated by the direction of the arrow in FIG. 27), in which part of the fluid flows from the common duct 211 for supplying to the common collection duct 212 by an eye formed in the board 10 printing elements.

[0184] Thus, the fluid ejection assembly 300 has a flow in which a portion of the fluid passes through the printed circuit boards 10 while the fluid flows in such a way that it passes through the common supply duct 211 and the common collection duct 212. For this reason, the heat generated by the printing element boards 10 can be released outside the printing elements board 10 by ink flowing through a common supply duct 211 and a common collection duct 212. With this configuration, ink can be formed even in the pressure chamber or the ejection opening without ejecting the liquid when the image is printed by the liquid ejection head 3. Accordingly, the thickening of the ink can be suppressed in such a way that the viscosity of the ink thickened in the ejection hole is reduced. Additionally, condensed ink or ink admixture may be discharged in the direction of the common collection duct 212. For this reason, the liquid ejection head 3 of an example application can print a high-quality image at high speed.

Description of the second circulation configuration

[0185] FIG. 28 is a circuit diagram illustrating a second circulation configuration, which is a circulation configuration different from a first circulation configuration in a circulation path applied to a printing apparatus of an example application. The main difference from the first circulation configuration is that the two negative pressure control mechanisms constituting the negative pressure control unit 230 control the pressure on the flow side of the negative pressure control unit 230 in a predetermined range relative to the desired predetermined pressure. Additionally, another difference from the first circulation configuration is that the second circulation pump 1 004 serves as a negative pressure source that reduces pressure on the downstream side of the negative pressure control unit 230. Additionally, another other difference is that the first circulation pump 1001 (on the high pressure side) and the first circulation pump 1002 (on the low pressure side) are located on the flow side of the head 3 for ejecting liquid, and the negative pressure control unit 230 is located on the side of the discharge flow of the head 3 to eject the liquid.

[0186] In the second circulation configuration, ink in the main tank 1006 is supplied to the buffer tank 1003 by the make-up pump 1005. Then, the ink is divided into two ducts and circulated in two ducts on the high pressure side and on the low pressure side under the influence of the negative control unit 230 the pressure provided in the head 3 to eject the liquid. Ink, which is divided into two ducts on the high pressure side and on the low pressure side, is supplied to the head 3 to eject fluid through the fluid connection part 111 by the first circulation pump 1001 (on the high pressure side) and the first circulation pump 1002 (on the low side pressure). Then, the ink circulating in the head for expelling the liquid under the action of the first circulation pump 1001 (on the high pressure side) and the first circulation pump 1002 (on the low pressure side) are issued from the head 3 for expelling the liquid through the negative pressure control unit 230 and part 111 fluid connection. The dispensed ink is returned to the buffer tank 1003 by means of a second circulation pump 1004.

[0187] In the second circulation configuration, the negative pressure control unit 230 stabilizes the pressure change on the inlet side of the flow (ie, on the side of the fluid ejection unit 300) of the negative pressure control unit 230 in a predetermined range relative to the predetermined pressure, even when the flow rate changes caused by changing the ejected amount of ink per unit area. In the circulation flow of an example application, the downstream side of the negative pressure control portion 230 is sealed by a second circulation pump 1004 through the fluid supply portion 220. With this configuration, since the influence of the pressure of the water of the buffer tank 1003 relative to the head 3 for ejecting liquid can be suppressed, the location of the buffer tank 1003 in the printing device 1000 can have many options. Instead of the second circulation pump 1004, for example, a water tank may also be used so that it has a predetermined difference in water head relative to the negative pressure control unit 230. Similar to the first circulation configuration, in the second circulation configuration, the negative pressure control unit 230 includes two negative pressure control mechanisms, respectively, having different control pressures. Of the two negative pressure control mechanisms, the high pressure side (indicated by “H” in FIG. 28) and the low pressure side (indicated by “L” in FIG. 28) are respectively connected to a common supply duct 211 and a common duct 212 for collecting in the node 300 ejecting fluid through the node 220 of the fluid supply. When the pressure of the common supply duct 211 is set above the pressure of the common duct 212 for collection by two negative pressure control mechanisms, a fluid flow is formed from the common duct 211 for supplying the common duct 212 for collection through a separate duct 215 and ducts formed in the printed circuit boards 10 .

[0188] In such a second circulation configuration, a fluid flow identical to the fluid flow of the first circulation configuration can be obtained in the fluid ejection unit 300, but has two advantages that differ from the advantages of the first circulation configuration. As a first advantage, in the second circulation configuration, since the negative pressure control unit 230 is located on the discharge side of the liquid ejection head 3, there is virtually no problem that impurity or debris formed from the negative pressure control unit 230 flows into the head 3 for ejecting fluid. As a second advantage, in the second circulation configuration, the maximum flow rate required for the liquid supplied from the buffer tank 1003 to the head 3 to eject the liquid is less than the value of the first circulation configuration. The reason is explained below.

[0189] In the case of circulation in the idle state of printing, the sum of the flow rates of the common supply duct 211 and the total collection duct 212 is set to the flow rate A. The flow rate A is set as the minimum flow rate necessary to adjust the temperature of the head 3 for ejecting liquid into the print standby state so that the temperature difference in the fluid ejection unit 300 falls within the required range. Additionally, the ejection rate obtained when ink is ejected from all the ejection openings of the liquid ejecting unit 300 (in the full ejection state) is defined as the flow rate F (ejected amount per ejection opening * ejection frequency per unit time * number of holes for pushing out).

[0190] FIG. 29 is a circuit diagram illustrating a difference in the flowing amount of ink into the head 3 for ejecting liquid between the first circulation configuration and the second circulation configuration. Part (a) of FIG. 29 illustrates a standby state in a first circulation configuration, and part (b) of FIG. 29 illustrates a full ejection state in a first circulation configuration. Parts (c) to (f) of FIG. 29 illustrate a second circulation configuration. Here, parts (c) and (d) of FIG. 29 illustrate a case in which the flow rate F is lower than the flow rate A, and part (e) and (f) of FIG. 29 illustrates a case in which the flow rate F is higher than the flow rate A. Thus, the flow rates in the standby state and the full ejection state are illustrated.

[0191] In the case of the first circulation configuration (parts (a) and (b) of FIG. 29), in which the first circulation pump 1001 and the first circulation pump 1002 having a quantitative liquid delivery capacity are arranged on the discharge side of the head flow 3 for ejection of liquid, the total flow rate of the first circulation pump 1001 and the first circulation pump 1002 becomes flow A. By flow A, the temperature in the standby unit 300 can be controlled. Then, in the case of the full ejection state of the head 3 for ejecting the liquid, the total flow rate of the first circulation pump 1001 and the first circulation pump 1002 becomes the flow rate A. However, the maximum flow rate of the liquid supplied to the head 3 for ejecting the liquid is obtained so that the flow rate F, consumed by full ejection, is added to the flow rate A from the total flow rate under the influence of negative pressure generated by ejecting the head 3 to eject the liquid. Thus, the maximum value of the quantity supplied to the head 3 for expelling the liquid satisfies the relation {(flow A) + (flow F)}, since the flow F is added to the flow A (part (b) of FIG. 29).

[0192] Meanwhile, in the case of the second circulation configuration (parts (c) and (d) of FIG. 29) in which the first circulation pump 1001 and the first circulation pump 1002 are located on the inlet side of the flow of the head 3 for ejecting liquid, the supplied amount into the head 3 for ejecting the liquid necessary for the print standby state becomes the flow rate A, similarly to the first circulation configuration. Thus, when the flow rate A is higher than the flow rate F (parts (c) and (d) of FIG. 29) in the second circulation configuration in which the first circulation pump 1001 and the first circulation pump 1002 are located on the inlet side of the flow of the head 3 for ejecting liquid, the amount supplied to the head 3 for expelling the liquid becomes sufficiently the flow rate A even in the state of full expulsion. At this time, the flow rate when the head 3 for expelling the liquid is dispensed satisfies the relation {(flowrate A) - (flowrate F)} (part (d) of FIG. 29). However, when the flow rate F is higher than the flow rate A (parts (e) and (f) of FIG. 29), the flow rate becomes insufficient when the flow rate of the liquid supplied to the liquid ejection head 3 becomes the flow rate A in the full ejection state. For this reason, when the flow rate F is higher than the flow rate A, the amount supplied to the liquid ejection head 3 must be set equal to the flow rate F. At this time, since the flow rate F is consumed by the liquid ejection head 3 in the full ejection state, the liquid flow rate discharged from the head 3 to expel the fluid, becomes almost zero (part (f) of FIG. 29). In addition, if the liquid is ejected, but not ejected in a state of full ejection, when the flow rate F is higher than the flow rate A, the liquid that is attracted in the amount consumed by the flow rate pushing F is discharged from the head 3 to eject the liquid. A liquid that is reduced by the amount consumed by expulsion from the flow F is dispensed from the head 3 to expel the fluid. Further, when the flow rate A and the flow rate F are equal, the flow rate A (or the flow rate F) is supplied to the head 3 for ejecting the liquid, and the flow rate F is consumed by the head 3 for ejecting the liquid. For this reason, the flow rate discharged from the head 3 for expelling the liquid becomes almost zero.

[0193] Thus, in the case of the second circulation configuration, the cumulative flow rate set for the first circulation pump 1001 and the first circulation pump 1002, i.e. the maximum value of the required flow rate becomes a large value between the flow rate A and the flow rate F. For this reason, provided that the fluid ejecting unit 300 having the identical configuration is used, the maximum value (flow rate A or flow rate F) of the supplied quantity required for the second configuration circulation, becomes less than the maximum value {(flow A) + (flow F)} flow rate required for the first circulation configuration.

[0194] For this reason, in the case of the second circulation configuration, the degree of freedom of the applicable circulation pump is increased. For example, a circulation pump having a simple configuration and low costs can be used, or the load of the cooler (not illustrated) provided in the path on the side of the main body can be reduced. Accordingly, such an advantage is provided that the costs of the printing apparatus can be reduced. This advantage is high in a string head having a relatively large flow rate A or flow rate F. Accordingly, a string head having a large longitudinal length from among the string heads is advantageous.

[0195] Meanwhile, the first circulation configuration has more advantages than the second circulation configuration. Thus, in the second circulation configuration, since the flow rate of the fluid flowing through the fluid ejection unit 300 in the idle state of printing becomes maximum, a higher negative pressure is applied to the ejection holes as the ejected amount per unit image area (hereinafter, this document, also called the “low-intensity image) becomes smaller. For this reason, when the duct width is small and the negative pressure is high, you Okoye negative pressure is applied to the ejection opening in the low-intensity image in which nonuniformity easily occurs. Accordingly, there exists a problem that the print quality may be degraded in accordance with the increasing number of so-called satellite droplets ejected together with the main ink droplet.

[0196] Meanwhile, in the case of the first circulation configuration, since a high negative pressure is applied to the ejection hole when an image is formed (hereinafter, also referred to as a “high intensity image”) having a large ejected amount per unit area, such is provided the advantage is that the effect of satellite drops on the image is small, even when a plurality of satellite drops are formed. Two circulation configurations can preferably be selected taking into account the technical requirements (flow rate F when pushing out, minimum flow rate A when circulating and resistance when passing through the head) of the head for ejecting liquid and the housing of the printing apparatus.

Description of the third circulation configuration

[0197] FIG. 48 is a circuit diagram illustrating a third circulation configuration, which is one of the circulation paths used in a printing apparatus of an embodiment. A description of the functions and configurations identical to the functions and configurations of the first and second circulation paths is omitted, and only the difference is described.

[0198] In the circulation path, liquid is supplied to the head 3 for ejecting liquid from three positions, including two positions of the central part of the head 3 for ejecting liquid and one end face of the head 3 for ejecting liquid. The liquid flowing from the common duct 211 for supplying to each pressure chamber 23 is collected by means of the common duct 212 for collecting and is collected externally from the collecting hole at the other end of the head 3 for ejecting liquid. A separate duct 215 communicates with a common duct 211 for supply and a common duct 212 for collection, and the board 10 of the printing elements and the pressure chamber 23 located in the board 10 of the printing elements are provided in the path of the separate duct 215. Accordingly, a portion of the liquid flowing from the first circulation pump 1002, flows from the common duct 211 for supplying to the common duct 212 for collection when passing through the pressure chamber 23 of the board 10 of the printing elements (see arrow in Fig. 48). This is because a differential pressure is generated between the pressure control mechanism H connected to the common supply duct 211 and the pressure control mechanism L connected to the common collection duct 212, and the first circulation pump 1002 is connected only to the common collection duct 212.

[0199] Thus, in the fluid ejection unit 300, a fluid flow is formed passing through the common collection duct 212 and a fluid flow flowing from the common duct 211 to be supplied to the common collection duct 212 when passing through the pressure chamber 23 inside each circuit board 10 printing elements. For this reason, the heat generated by each printing element board 10 can be released outside the printing element board 10 by a stream from the common duct 211 for supplying to the common duct 212 for collection while pressure loss is suppressed. Additionally, according to the circulation path, the number of pumps that are fluid transport units may be reduced compared to the first and second circulation paths.

Description of fluid ejection head configuration

[0200] The following describes the configuration of the head 3 for ejecting liquid according to the first example application. FIG. 30A and 305 are perspective views illustrating a liquid ejection head 3 according to an example application. The liquid ejection head 3 is a line-by-line liquid ejection head in which there are fifteen printed circuit boards 310 that allow four ink colors to be ejected from cyan (C), magenta (M), yellow (Y) and black (K) placed sequentially (linear placement). As illustrated in FIG. 30A, the fluid ejection head 3 includes printing element boards 310 and an input signal terminal 91 and a terminal 92 for supplying power. These terminals 91 and 92 are electrically connected to the printing element board 310 through the flexible circuit board 40 and the electrical wiring board 90. The input signal terminal 91 and the power terminal 92 are electrically connected to the control unit of the printing apparatus 1000 so that the drive signal the ejection and the power required for ejection are supplied to the circuit board 310 of the printing elements. When the interconnects are integrated by the circuitry in the electrical circuit board 90, the number of input signal contact pins 91 and the contact pins 92 for supplying power may be reduced compared with the number of printed circuit boards 310. Accordingly, the number of electrical connection components to be separated when the liquid ejection head 3 is collected in the printing apparatus 1000, or the liquid ejection head is replaced, is reduced. As illustrated in FIG. 30B, fluid connection portions 111 that are provided at both ends of the fluid ejection head 3 are connected to a fluid supply system of the printing apparatus 1000. Accordingly, ink of four colors including cyan (C), magenta (M), yellow (Y) and black color (K) are supplied from the feeding system of the printing apparatus 1000 to the liquid ejection head 3, and ink passing through the liquid ejecting head 3 is collected by the feeding system of the printing apparatus 1000. Thus, the ink various colors can be circulated through the path of the printing apparatus 1000 and path the head 3 for ejecting liquid.

[0201] FIG. 31 is an exploded perspective view illustrating components or assemblies constituting a liquid ejection head 3. The fluid ejection assembly 300, the fluid supply assembly 220, and the electrical mounting plate 90 are connected to the housing 380. The fluid connection portions 111 (see FIG. 28) are provided in the fluid supply assembly 220. In addition, to remove impurities in the ink supplied, filters 221 (see FIGS. 27 and 28) for various colors are provided in the fluid supply unit 220 in communication with the openings of the fluid connection portions 111. Two fluid supply assemblies 220 respectively comprise filters 221 corresponding to two colors. In the first circulation configuration, as illustrated in FIG. 27, the fluid passing through the filter 221 is supplied to the negative pressure control portion 230 located on the fluid supply portion 220 arranged so that it matches each color. The negative pressure control unit 230 is a unit that includes negative pressure control valves corresponding to various colors. By the function of the spring element or valve provided therein, the change in pressure loss in the feed system (feed system on the inlet side of the flow head 3 for ejecting liquid) of the printing apparatus 1000 is substantially reduced due to a change in the liquid flow rate. Accordingly, the negative pressure control unit 230 can stabilize the negative pressure change on the discharge side (on the side of the fluid ejection unit 300) of the negative pressure control unit in a predetermined range. As described in FIG. 27, two negative pressure control valves corresponding to each color are arranged in the negative pressure control unit 230. Two negative pressure control valves, respectively, are set equal to different control pressures. Here, the high pressure side of the two negative pressure control valves communicates with the common supply duct 211 (see FIG. 27) in the fluid ejection unit 300 through the fluid supply unit 220, and the low pressure side of the two negative pressure control valves communicates with the common duct 212 for collection (see Fig. 27) through the node 220 fluid supply.

[0202] The housing 380 includes a support portion 381 of the fluid ejection assembly and a support portion 82 of the electrical circuit board and provides rigidity to the fluid ejection head 3 with support of the fluid ejection assembly 300 and the electrical circuit board 90. The electrical circuit board support portion 82 is used to to support the electrical circuit board 90, and is attached to the support portion 381 of the fluid ejection assembly by screws. The support portion 381 of the fluid ejection assembly is used to correct warpage or deformation of the fluid ejection assembly 300 to ensure accuracy of the relative position between the printed circuit boards 310. Accordingly, the stripes and heterogeneity of the image printed on the medium are suppressed. For this reason, it is desirable that the support portion 381 of the fluid ejection assembly has sufficient rigidity. As a material, metal, for example, SUS or aluminum, or ceramics, for example, aluminum oxide, is required. The support portion 381 of the fluid ejection assembly includes openings 83 and 84 into which the connecting rubber pad 100 is inserted. The fluid supplied from the fluid supplying unit 220 is drawn into the third duct element 370 constituting the fluid ejecting unit 300 through the rubber connecting pad 100.

[0203] The fluid ejection unit 300 includes a plurality of ejection modules 200 and a flow element 210, and the lid element 130 is attached to a surface near the recording medium in the fluid ejection unit 300. Here, the lid member 130 is an element having a surface in the form of a frame for the original, and has an elongated hole 131, as illustrated in FIG. 31, and the printing element board 310 and the sealing element 110 (see FIG. 35A, which will be described later) included in the eject module 200 are accessible from the opening 131. The peripheral frame of the opening 131 serves as the contact surface of the plug element that overlaps the head 3 to expel fluid in the idle state of printing. For this reason, it is desirable to form an enclosed space in the closed state by applying glue, a sealing material and a filler along the periphery of the hole 131 to fill the inhomogeneity or gap on the surface of the hole for pushing out the fluid ejection unit 300.

[0204] The following describes the configuration of the duct element 210 included in the fluid ejection assembly 300. As illustrated in FIG. 31, the duct element 210 is obtained by layering the first duct element 50, the second duct element 60, and the third duct element 370 and distributes the fluid supplied from the fluid supply unit 220 to the eject modules 200. Additionally, the duct element 210 is a duct element that returns fluid recirculated from the eject module 200 to the fluid supply unit 220. The duct element 210 is attached to the support portion 381 of the fluid ejection assembly by means of screws, and thereby warping or deformation of the duct element 210 is suppressed.

[0205] Parts (a) to (f) of FIG. 32 are diagrams illustrating the front and rear surfaces of the first to third duct elements. Part (a) of FIG. 32 illustrates the surface of the first duct member 50 on which the eject module 200 is mounted, and part (f) of FIG. 32 illustrates the surface of the third duct element 370 with which the support portion 381 of the fluid expulsion assembly contacts. The first duct element 50 and the second duct element 60 are glued together so that the parts illustrated in parts (b) and (c) of FIG. 32, corresponding to the contact surfaces of the duct elements 50 and 60, face each other. The second duct element 60 and the third duct element 370 are glued together so that the parts illustrated in parts (d) and (e) of FIG. 32, corresponding to the contact surfaces of the duct elements 60 and 370, face each other. When the second duct element 60 and the third duct element 370 are glued together, eight common ducts (211a, 211b, 211c, 211d, 212a, 212b, 212c, 212d) extending in the longitudinal direction of the duct element are formed by grooves 362 and 371 of the common ducts duct elements. Accordingly, a set of a common supply duct 211 and a common collection duct 212 is formed in the duct element 210 so that it matches each color. Ink is supplied from a common duct 211 for supplying to the liquid ejection head 3, and ink supplied to the liquid ejection head 3 is collected through a common collection duct 212. The communication hole 72 (see part (f) of FIG. 32) of the third duct element 370 communicates with the corresponding hole of the rubber connection pad 100 and is fluidly connected to the fluid supply unit 220 (see FIG. 31). The lower surface of the common channel groove 362 of the second duct element 60 comprises a plurality of communication holes 361 (a communication hole 361-1 communicating with a common supply duct 211 and a communication hole 361-2 communicating with a common collection duct 212). These communication holes 361 communicate with one end of the corresponding groove 352 of the separate duct of the first duct member 50. The other end of the separate duct groove 352 of the first duct member 50 includes a communication hole 351 and is fluidly connected to the eject modules 200 through the communication hole 351. By means of a separate duct groove 352, ducts can be tightly provided in the central side of the duct element.

[0206] It is desirable that the first to third duct elements are formed from a material having corrosion resistance to a liquid and having a low coefficient of linear expansion. As the material, for example, a composite material (resin) obtained by adding an inorganic filler, such as fiber particles or fine silica, to a substrate material such as alumina, LCP (liquid crystal polymer), PPS (polyphenyl sulfide) can be suitably used. , PSF (polysulfone) or modified PPE (polyphenylene ether). As a method of forming the duct element 210, the three duct elements can be layered and adhered to each other. When the polymer composite material is selected as the material, a joining method using welding can be used.

[0207] FIG. 33 is a partial enlarged perspective view illustrating part α of part (a) of FIG. 32 and illustrating the ducts in the duct element 210 formed by gluing the first to third duct elements together when viewed from a surface onto which the eject module 200 in the first duct element 50 is mounted. A common supply duct 211 and a common collection duct 212 are formed so that the common supply duct 211 and the common collection duct 212 are alternately arranged with respect to the ducts of both ends. Here, the relationship of the connections between the ducts in the duct element 210 is described.

[0208] In the duct element 210, a common supply duct 211 (211a, 211b, 211c, 211d) and a common collection duct 212 (212a, 212b, 212c, 212d) extending in the longitudinal direction of the fluid expelling head 3 are provided for each color. Separate supply ducts 213 (213a, 213b, 213c, 213d), which are formed by grooves 352 of individual ducts, are connected to common ducts 211 for supplying various colors through communication openings 361. Additionally, individual collection ducts 214 (214a, 214b, 214c, 214d) formed by grooves 352 of individual ducts are connected to common ducts 212 for collecting various colors through communication openings 361. With this configuration of ducts, ink can be intensively supplied to a printed circuit board 310 located in the central part of the duct element from the common ducts 211 for supplying to the individual supply ducts 213. Additionally, ink can be collected from the printed circuit board 310 into common collection ducts 212 through separate collection ducts 214.

[0209] FIG. 34 is a cross-sectional view along line XXXIV-XXXIV of FIG. 33. The individual collection ducts (214a, 214c) communicate with the eject module 200 through communication openings 351. In FIG. 34, only the individual collection ducts (214a, 214c) are illustrated, but in a different cross section, the individual supply ducts 213 and the eject module 200 communicate with each other, as illustrated in FIG. 33. The support member 330 and the printing element board 310, which are included in each eject module 200, comprise ducts that supply ink from the first flow element 50 to the printing element 315 provided in the printing element board 310. Additionally, the support member 330 and the printing element board 310 comprise ducts that collect (provide recirculation) a portion or all of the fluid supplied to the printing element 315 to the first duct member 50.

[0210] Here, a common duct 211 for supplying each color is connected to the negative pressure control unit 230 (on the high pressure side) of the corresponding color through the liquid supply unit 220, and a common collection duct 212 is connected to the negative pressure control unit 230 (on the low side pressure) through the fluid supply unit 220. By the negative pressure control unit 230, a differential pressure (pressure difference) is formed between the common supply duct 211 and the common collection duct 212. For this reason, as illustrated in FIG. 33 and 34, a liquid flow of each color is formed in the order of a common supply duct 211, a separate supply duct 213, a printing element board 310, a separate collection duct 214, and a common duct 212 to collect an example application having ducts in a fluid ejection head interconnected.

Eject Module Description

[0211] FIG. 35A is a perspective view illustrating one eject module 200, and FIG. 35B is an exploded view thereof. As a manufacturing method of the eject module 200, firstly, the printing element board 310 and the flexible printed circuit board 40 are adhered to the support member 330 comprising a fluid communication hole 31. Then, the terminal 316 on the printed circuit board 310 and the terminal 341 on the flexible circuit board 40 are electrically connected to each other by wire mounting, and the part after the wire installation (electrical connection part) is sealed by the sealing element 110. The terminal 342, which is opposed to the board 310 of the printing elements of the flexible circuit board 40 is electrically connected to the connection terminal 93 (see FIG. 31) of the electrical circuit board 90. Since the support element 330 serves as a support body that supports the printing element board 310 and a duct element that provides fluid communication between the printing element board 310 and the duct element 210 to each other, it is desirable that the supporting element 330 has high evenness and sufficiently high reliability when glued to the printing element board. As the material, for example, alumina or resin is required.

Description of the design of the printed circuit board

[0212] FIG. 36A is a plan view illustrating a surface comprising an ejection hole 313 for ejecting the printing element board 310, FIG. 36B is an enlarged view of part A of FIG. 36A, and FIG. 36C is a plan view illustrating the rear surface of FIG. 36A. Here, the configuration of the printing element board 310 of an example application is described. As illustrated in FIG. 36A, the ejection hole forming member 312 31 of the printing element board 310 comprises four arrays of ejection openings corresponding to different ink colors. Further, the direction of passage of the matrixes of the ejection holes 313 is called the "direction of the matrixes of ejection holes". As illustrated in FIG. 36B, a printing member 315 serving as an ejection energy generating element for ejecting liquid by thermal energy is located at a position corresponding to each ejection hole 313. A pressure chamber 323 providing the printing element 315 is defined by a dividing wall 22. The printing element 315 is electrically connected to the contact terminal 316 by an electric wire (not illustrated) provided in the printing element board 310. Then, the printing element 315 boils the liquid when heated based on the pulse signal input from the control circuit of the printing device 1000 through the electrical circuit board 90 (see FIG. 31) and the flexible circuit board 40 (see FIG. 35B). The fluid is ejected from the ejection hole 313 by the foaming force caused by boiling. As illustrated in FIG. 36B, a fluid supply path 318 extends on one side along each matrix of ejection openings, and a fluid collection path 319 extends on the other side along the matrix of ejection openings. The liquid supply path 318 and the liquid collection path 319 are ducts that extend in the direction of the matrix of ejection holes provided in the printing element board 310 and communicate with the ejection hole 313 through the supply hole 317a and the collection hole 317b. [0213] As illustrated in FIG. 36C, a sheet-like overlay plate 20 (cover member) is layered on the back surface for a surface having an ejection hole 313 for ejecting the printing element board 310, and the overlay plate 20 comprises a plurality of holes 20A in communication with the liquid supply path 318 and the liquid collection path 319. In an example application, the patch plate 20 comprises three holes 20A for each fluid path 318 and two holes 20A for each fluid path 319. As illustrated in FIG. 36B, the openings 20A of the patch plate 20 are in communication with the communication openings 351 illustrated in part (a) of FIG. 32. It is desirable that the patch plate 20 has sufficient corrosion resistance for the liquid. In terms of preventing mixed colors, the shape of the hole and the position of the hole for the hole 20A should have high accuracy. For this reason, it is desirable to form a hole 20A by using a photosensitive polymer material or a silicon wafer as the material of the patch plate 20 through photolithography. Thus, the patch plate 20 changes the pitch of the ducts through the hole 20A. Here, it is desirable to form the patch plate 20 by means of a film-shaped element with a small thickness taking into account pressure loss.

[0214] FIG. 37 is a perspective view illustrating cross-sections of a printing board 310 and a patch plate 20 along line XXXVII-XXXVII of FIG. 36A. Here, the fluid flow in the printed circuit board 310 is described. The patch plate 20 serves as a cover that is part of the walls of the fluid supply path 318 and the fluid collection path 319 formed on the substrate 311 of the printing element board 310. A printing element board 310 is formed by laminating a substrate 311 formed from Si and an ejection hole forming member 312 formed from a photosensitive resin, and the patch plate 20 is adhered to the back surface of the substrate 311. One surface of the substrate 311 comprises a printing element 315 (see FIG. 36B), and its rear surface comprises grooves forming a fluid supply path 318 and a fluid collection path 319 extending along the matrix of ejection openings. The liquid supply path 318 and the liquid collection path 319, which are formed by the substrate 311 and the patch plate 20, respectively, are connected to a common supply duct 211 and a common collection duct 212 in each duct element 210, and a differential pressure is formed between the liquid supply path 318 and a fluid collection path 319. When the liquid is pushed out of the ejection hole 313 to print an image, in the ejection hole not ejecting liquid, the liquid in the liquid supply path 318 provided in the substrate 311 flows in the direction of the liquid collection path 319 through the supply hole 317a, the pressure chamber 323 and a collection hole 317b by differential pressure (see arrow C of FIG. 37). By flow, impurities, bubbles and thickened ink formed by evaporation from the ejection hole 313, in the ejection hole 313 or a pressure chamber 323 not included in the printing operation, can be collected via a liquid collection path 319. Additionally, ink thickening in the ejection aperture 313 or the pressure chamber 323 can be suppressed. The fluid that collects in the fluid collection path 319 is collected in the order of the communication aperture 351 in the duct element 210, a separate collection duct 214, and a common collection duct 212 through the hole 20A of the patch plate 20 and the liquid communication hole 31 (see FIG. 35B) of the support member 330. Then, the liquid is collected through the collection path of the printing apparatus 1000. Thus, the liquid supplied from the printing device body CTBA in head 3 for ejecting liquid takes place in the following order for delivery and collection.

[0215] First, the fluid flows from the fluid communication portion 111 of the fluid supply unit 220 to the head 3 to expel the fluid. The liquid is then sequentially supplied through a connecting rubber pad 100, a communication hole 72 and a common duct groove 371 provided in the third duct element, a common duct groove 362 and a communication hole 361 provided in the second duct element, and a separate duct groove 353 and the hole 351 for messages provided in the first element of the duct. Then, liquid is supplied to the pressure chamber 23, while successively passing through the fluid communication hole 31 provided in the support member 330, the hole 20A provided in the patch plate 20 and the liquid supply path 318, and the supply hole 317a provided in the substrate 311. In the liquid supplied to the pressure chamber 23, the liquid that is not ejected from the ejection hole 313 sequentially flows through the collection hole 317b and the liquid collection path 319 provided in the substrate 311, the hole 20A, provided located in the patch plate 20 and a fluid communication hole 31 provided in the support member 330. Then, the liquid flows sequentially through the communication hole 351 and the separate duct groove 352 provided in the first duct element, the communication hole 361 and the common duct groove 362 provided in the second duct element, a common duct groove 371 and a communication hole 72 provided in the third duct element 370, and a hole of the connecting rubber pad 100. Then, the fluid flows from part 111 fluid connection provided in the node 220 of the fluid supply, outside the head 3 to push the liquid.

[0216] In the first circulation configuration illustrated in FIG. 27, the liquid that flows from the fluid connection portion 111 is supplied to the hole of the rubber connecting pad 100 through the negative pressure control unit 230. Additionally, in the second circulation configuration illustrated in FIG. 28, the fluid that is collected from the pressure chamber 323 passes through the opening of the connecting rubber pad 100 and flows from the fluid connection portion 111 beyond the head to expel the fluid through the negative pressure control unit 230. All liquid that flows from one end of the common duct 211 to supply the fluid ejection assembly 300 is not supplied to the pressure chamber 323 through a separate supply duct 213a. Thus, liquid that flows from one end of the common supply duct 211 can flow from the other end of the common duct 211 to be supplied to the fluid supply unit 220, without flowing into a separate supply duct 213a. Thus, since the path is provided in such a way that fluid flows through it without passing through the printing element board 310, a countercurrent of the liquid circulation can be suppressed even in the printing element board 310 including a small duct with high hydraulic resistance, as indicated in the example example application. Thus, since thickening of the liquid near the ejection hole and the pressure chamber 23 can be suppressed in the head 3 for ejecting the liquid of an example application, dripping or non-ejection of the liquid can be suppressed. As a result, a high quality image can be printed.

Description of the positional relationship between the printed circuit boards

[0217] FIG. 38 is a partial enlarged plan view illustrating an adjacent portion of a printing element board in two adjacent ejection modules. In an example application, a board of printing elements is used in the form of a parallelogram. The ejection hole arrays (14a-14d) having ejection holes 313 located on each printing element board 310 are arranged so that they are inclined with a predetermined angle relative to the longitudinal direction of the liquid ejection head 3. Then, the matrix of ejection openings in the adjacent portion between the printing element boards 310 is formed so that at least one ejection opening overlaps in the direction of transport of the recording medium. In FIG. 38, two ejection holes on line D overlap each other. With this arrangement, even when the position of the printing element board 310 is slightly deviated from the predetermined position, black bars or skipping of the printed image may become less noticeable by controlling the driving of overlapping ejection holes. Even when the printed circuit boards 310 are arranged in a straight linear shape (linear shape) instead of a zigzag shape, black bars or a gap in the connecting portion between the printed circuit boards 10 can be processed, while increasing the length of the head 3 for ejecting liquid in the direction of transporting the medium for printing is suppressed by the configuration illustrated in FIG. 38. Additionally, in the example application, the main plane of the board of the printing elements has the shape of a parallelogram, but the present invention is not limited to this. For example, even when printed circuit boards having a rectangular shape, a trapezoidal shape and other shapes are used, the configuration of the present invention can preferably be used.

Description of a modified example of the configuration of the head for ejecting fluid

[0218] A modified example of a configuration of a head for ejecting a fluid illustrated in FIG. 47 and FIG. 49-51. A description of the configuration and function identical to the configuration and function of the above example is omitted, and mainly only the difference is described. In a modified example, as illustrated in FIG. 47, 49A and 49B, the fluid connection portions 111 between the fluid ejection head 3 and the external environment are intensively disposed on one end face of the fluid ejection head in the longitudinal direction. The negative pressure control units 230 are intensively located on the other end side of the head 3 for ejecting liquid (FIG. 50). The fluid supply unit 220, which belongs to the fluid ejection head 3, is configured as an elongate assembly corresponding to the length of the fluid ejection head 3, and includes ducts and filters 221 that suitably correspond to the fluids of four colors to be supplied. As illustrated in FIG. 50, the positions of the openings 83-86 provided in the support portion of the fluid ejection assembly 81 are also at positions different from the positions of the fluid ejection head 3.

[0219] FIG. 51 illustrates the layering state of duct elements 50, 60, and 70. The circuit boards 10 of the printing elements are linearly arranged on the upper surface of the duct element 50, which is the outermost layer of the duct elements 50, 60 and 70. As a duct that communicates with a hole 20A (FIG. 36C) of a cover member 20 positioned on a back surface side of each printing element board 10, two separate supply ducts 213 and one separate collection duct 214 are provided for each liquid color. Accordingly, as an opening 21 that is formed in the cover member 20 provided on the rear surface of the printing element board 10, two supply openings 20A and one collection opening 20A are provided for each liquid color. As illustrated in FIG. 51, a common supply duct 211 and a common collection duct 212 extending along the longitudinal direction of the fluid ejection head 3 are alternately arranged.

Second application example

[0220] Hereinafter, the configurations of an inkjet printing apparatus 2000 and a liquid ejection head 2003 according to a second example of an application of the present invention are described with reference to the drawings. In the description below, only the difference from the first example of the application is described, and the description of components identical to the components of the first example of the application is omitted.

Description of Inkjet Printer

[0221] FIG. 46 is a diagram illustrating an inkjet printing apparatus 2000 according to an exemplary application used to eject liquid. The printing apparatus 2000 of the example application differs from the first example of the application in that the full-color image is printed on the recording medium by means of a configuration in which four monochromatic heads 2003 for ejecting the liquid, correspondingly to the cyan ink (C), magenta (M) , yellow (Y) and black (K), are parallel. In a first example application, the number of ejection hole arrays that can be used for one color is one. However, in the example application, the number of ejection hole arrays that can be used for one color is twenty. For this reason, when the printed data is appropriately distributed across a plurality of ejection hole arrays to print an image, the image can be printed at a higher speed. Further, even when there are ejection openings that do not eject the liquid, the liquid is complementary ejected from the ejection openings of other matrices located at positions corresponding to the non-ejection openings in the transport direction of the recording medium. Reliability is enhanced, and therefore a commercial image can be properly printed. Similar to the first example application, the supply system, the buffer tank 1003 (see FIGS. 27 and 28) and the main tank 1006 (see FIGS. 27 and 28) of the printing apparatus 2000 are fluidly connected to the heads 2003 for expelling the liquid. Further, an electrical control unit that transmits power and ejection control signals to the liquid ejection head 2003 is electrically connected to the liquid ejection heads 2003.

Description of the circulation path

[0222] Similar to the first example application, the first and second circulation configurations illustrated in FIG. 27 or 28 may be used as a fluid circulation configuration between the printing apparatus 2000 and the head 2003 for ejecting the fluid.

(Description of fluid ejection head design)

[0223] FIG. 39A and 39B are perspective views illustrating a liquid ejection head 2003 according to an example application. Here, the construction of a head 2003 for ejecting a liquid according to an example application is described. The liquid ejection head 2003 is a line-by-line inkjet printhead that includes sixteen printing element boards 2010 arranged linearly in the longitudinal direction of the liquid ejection head 2003, and can print an image by one type of liquid. Similar to the first example application, the liquid ejection head 2003 includes a liquid connection portion 111, an input signal terminal 91 and a terminal 92 for supplying power. However, since the fluid ejection head 2003 of the example application includes a plurality of ejection hole arrays as compared with the first application example, the input signal terminal 91 and the power supply terminal 92 are located on both sides of the liquid ejection head 2003 . This is because the voltage reduction or delay in signal transmission caused by the part of the interconnects provided in the printed circuit board 2010 should be reduced.

[0224] FIG. 40 is an oblique exploded view illustrating a liquid ejection head 2003 and components or assemblies constituting the liquid ejection head 2003 according to their functions. The function of each of the nodes and elements or the sequence of the fluid flow in the head to eject the liquid is essentially the same as the function or sequence of the first example application, but the function of guaranteeing the rigidity of the head to eject the liquid is different. In the first example application, the rigidity of the head for ejecting liquid is mainly guaranteed by the support portion 381 of the fluid ejection unit, but in the head 2003 for ejecting the liquid of the second example application, the rigidity of the head 2003 for ejecting fluid is guaranteed by the second duct element 2060 included in the assembly 2300 fluid expulsion. The support portion 381 of the fluid ejection unit of an example application is connected to both ends of the second duct element 2060, and the fluid ejection unit 2300 is mechanically connected to the carriage of the printing apparatus 2000 to position the head 2003 for ejecting the liquid. An electrical mounting plate 90 and a fluid supply assembly 2220 including a negative pressure control assembly 2230 are connected to a support portion 381 of the fluid ejection assembly. Each of the two fluid supply units 2220 includes a filter (not illustrated) arranged therein.

[0225] Two nodes 2230 negative pressure control are set so that they control the pressure for various relatively high and low negative pressures. Additionally, as shown in FIG. 39A, 39B, and 40, when the negative pressure control units 2230 on the high pressure side and the low pressure side are provided at both ends of the head 2003 for ejecting liquid, liquid flows in a common supply duct and a common collection duct extending in the longitudinal direction of the head 2003 to push the liquid, facing each other. In this configuration, heat transfer between the common supply duct and the common collection duct is stimulated, and thereby the temperature difference in the two common ducts decreases. Accordingly, the temperature difference of the printed circuit boards 2010 provided along the common duct is reduced. As a result, such an advantage is provided that the heterogeneity in the print is not easily caused by the difference in temperature.

[0226] The following describes the detailed configuration of the duct element 2210 of the fluid ejection unit 2300. As illustrated in FIG. 40, the duct element 2210 is obtained by layering the first duct element 2050 and the second duct element 2060 and distributes the liquid supplied from the fluid supply unit 2220 to the eject modules 2200. The duct element 2210 serves as a duct element that returns fluid circulating from the eject module 2200 to the fluid supply unit 2220. The second duct element 2060 for the duct element 2210 is a duct element having a common supply duct and a common collection duct formed therein, and increasing the rigidity of the liquid ejection head 2003. For this reason, it is desirable that the material of the second duct element 2060 has sufficient corrosion resistance for the fluid and high mechanical strength. In particular, SUS, Ti or alumina may be used.

[0227] Part (a) of FIG. 41 is a diagram illustrating the surface of a first duct element 2050 on which an eject module 2200 is mounted, and part (b) of FIG. 41 is a diagram illustrating a back surface thereof and a surface in contact with a second duct element 2060. Unlike the first example application, the first duct element 2050 of the example application has a configuration in which a plurality of elements corresponding to the eject modules 2200 are arranged side by side. By using such a separate structure, a plurality of modules can be arranged so that they correspond to the length of the liquid ejection head 2003. Accordingly, this design can be appropriately used, in particular, in a relatively long head for ejecting a fluid corresponding, for example, to a sheet having a size B2 or more. As illustrated in part (a) of FIG. 41, an opening 351 for communicating the first duct element 2050 is in fluid communication with the eject module 2200. As illustrated in part (b) of FIG. 41, a separate opening 353 for communicating the first duct element 2050 has fluid communication with an opening 361 for communicating the second duct element 2060. Part (c) of FIG. 41 illustrates the contact surface of the second duct element 60 with respect to the first duct element 2050, part (d) of FIG. 41 illustrates a cross section of the center portion of the second duct element 60 in the thickness direction, and part (e) of FIG. 41 is a diagram illustrating a contact surface of a second duct element 2060 with respect to a fluid supply unit 2220. The function of the communication hole and duct for the second duct element 2060 is similar for each color of the first example application. The common duct groove 371 of the second duct element 2060 is formed so that one side thereof is a common supply duct 2211, illustrated in FIG. 42, and its other side is a common duct 2212 for collection. These ducts 2211 and 2212, respectively, are provided along the longitudinal direction of the head 2003 to expel the fluid so that fluid is supplied from one end to the other. The example application differs from the first example application in that the directions of fluid flow in the common supply duct 2211 and the common collection duct 2212 are opposite to each other.

[0228] FIG. 42 is a perspective view illustrating the relationship of fluid connections between the printing element board 2010 and the duct element 2210. A pair of the common supply duct 2211 and the common collection duct 2212 extending in the longitudinal direction of the fluid ejection head 2003 is provided in the duct member 2210. An opening 361 for communicating the second duct element 2060 is connected to a separate opening 353 for communicating the first duct element 2050 so that both positions coincide. Also, by virtue of this, a fluid supply duct is formed, communicating with the opening 351 for communicating the first duct element 2050 through the communication opening 361 from the common duct 2211 for supplying the second duct element 2060. Similarly, a fluid supply path is also formed that communicates with an opening 351 for communicating the first duct element 2050 through a common duct 2212 to collect from the communication port 72 for the second duct element 2060.

[0229] FIG. 43 is a cross-sectional view along line XLIII-XLIII of FIG. 42. A common supply duct 2211 is connected to the eject module 2200 through a communication hole 361, a separate communication hole 353, and a communication hole 351. Although not illustrated in FIG. 43, it is apparent that a common collection duct 2212 is connected to the eject module 2200 via an identical path in another cross section in FIG. 42. Similar to the first example application, each of the eject module 2200 and the printing element board 2010 includes a duct communicating with each eject hole, and therefore, part or all of the supplied liquid can circulate when passing through the eject hole, which does not perform the operation pushing out. Additionally, similar to the first example of the application, the common supply duct 2211 is connected to the negative pressure control unit 2230 (on the high pressure side), and the common collection duct 2212 is connected to the negative pressure control unit 2230 (on the low pressure side) through the supply unit 2220 liquids. Thus, the flow is formed in such a way that fluid flows from the common duct 2211 for supplying to the common duct 2212 for collecting printing elements through the pressure chamber of the printed circuit board 2010 by means of differential pressure.

Eject Module Description

[0230] FIG. 44A is a perspective view illustrating one eject module 2200, and FIG. 44B is an exploded view of it. The difference from the first example application is that the contact terminals 316, respectively, are located on both sides (parts of the long side of the printed circuit board 2010) in the directions of the ejection hole arrays on the printed circuit board 2010. Accordingly, two flexible printed circuit boards 40 electrically connected to the printing element board 2010 are arranged for each printing element board 2010. Since the number of ejection hole arrays provided in the printing board 2010 is twenty, the ejection opening arrays are more than eight ejection opening arrays of the first example application. Here, since the maximum distance from the terminal 316 to the printing element is reduced, the voltage reduction or signal delay generated in the interconnects portion of the printing element board 2010 is reduced. Additionally, the fluid communication hole 31 of the support member 2030 is open along the entire matrix of ejection holes provided in the printing element board 2010. Other configurations are similar to the configurations of the first example application.

Description of the design of the printed circuit board

[0231] FIG. 45A is a circuit diagram illustrating a surface of a printing element board 2010 on which an ejection hole 313 is located, and FIG. 45C is a circuit diagram illustrating a rear surface for the surface of FIG. 45A. FIG. 45B is a schematic diagram illustrating the surface of the printing element board 2010 when the patch plate 2020 provided on the rear surface of the printing board 2010 in FIG. 45C, extracted. As illustrated in FIG. 45B, the fluid supply path 318 and the fluid collection path 319 are alternately provided along the direction of the ejection hole arrays on the rear surface of the printing element board 2010. The number of ejection hole matrices exceeds the number of the first example application. However, the main difference from the first example application is that the contact terminal 316 is located on both sides of the board of the printing elements in the direction of the matrix of holes for pushing, as described above. The basic configuration is similar to the first example of an application in that steam from the liquid supply path 318 and the liquid collection path 319 is provided in each matrix of ejection openings, and the patch plate 2020 includes an opening 20A in communication with the liquid opening 31 of the support member 2030.

[0232] In addition, the description of the above example application example does not limit the scope of the present invention. As an example, in an example application, a thermal type is described in which bubbles are formed by a heating element to expel a liquid. However, the present invention can also be applied to a fluid ejection head that uses a piezotype and various other types of fluid ejection.

[0233] In an example application, an inkjet printing device (printing device) is described in which a liquid, such as ink, circulates between a tank and a head for ejecting liquid, but other example applications can also be used. In other exemplary applications, for example, a configuration may be used in which ink is not circulated and two tanks are provided on the flow inlet side and the discharge side of the head to eject the liquid so that ink flows from one tank to another tank. Thus, ink may leak in the pressure chamber.

[0234] In an example application, an example of using a so-called line head having a length corresponding to the width of a recording medium is described, but the present invention can also be applied to a so-called sequential head for ejecting a liquid that prints an image on a recording medium when scanning the medium for print. As a sequential head for ejecting a liquid, for example, a head for ejecting a liquid may be equipped with a board of printing elements that eject black ink, and a board of printing elements that eject color ink, but the present invention is not limited to this. Thus, a head for ejecting a liquid that is smaller than the width of the recording medium can be provided and includes a plurality of printing boards arranged so that the ejection holes overlap each other in the direction of the matrix of the ejection holes, and the head for ejecting the liquid can be scanned relative to the substrate.

Third application example

[0235] The following describes the configuration of an inkjet printing apparatus 1000 and a head 3 for ejecting liquid according to a third example of an application of the present invention. The fluid ejection head of the third example application is a page in which an image is printed on a size B2 printing medium through a single scan. Since the third example of the application is similar to the second example of the application in many respects, the description below mainly explains the only difference from the second example of the application, and the description of the configuration identical to the configuration of the second example of the application is omitted.

Description of Inkjet Printer

[0236] FIG. 52 is a circuit diagram illustrating an inkjet printing apparatus according to an example application. The printing apparatus 1000 has a configuration in which an image is not printed directly onto the recording medium by means of a fluid ejected from the head 3 to eject the liquid. Thus, the liquid is first pushed into the intermediate transfer member 1007 (intermediate transfer drum) so as to form an image thereon, and the image is transferred to the recording medium 2. In the printing apparatus 1000, the liquid ejection heads 3, appropriately corresponding to the four ink colors (C, M, Y, K), are arranged along the intermediate transfer drum 1007 in a circular arcuate shape. Accordingly, the full-color printing process is performed on the intermediate transfer element, the printed image is properly dried on the intermediate transfer element, and the image is transferred to the recording medium 2 transported by the sheet conveying roller 1009 of the transfer portion 1008. The sheet transport system of the second example application is mainly used to transport sheet paper in a horizontal direction. However, the sheet transport system of this example application can also be applied to a continuous sheet fed from a main roller (not illustrated). In such a drum transport system, since the sheet is easily transported at a time when a predetermined tension is applied to it, a jam during transportation almost never occurs even during a high-speed printing operation. For this reason, the reliability of the device is increased, and therefore, the device is suitable for the purpose of commercial printing. Similar to the first and second examples of the application, the feeding system of the printing apparatus 1000, the buffer tank 1003, and the main tank 1006 are fluidly connected to each head 3 for expelling liquid. Additionally, an electrical control unit that transmits an ejection control signal and power to the liquid ejection head 3 is electrically connected to each liquid ejection head 3.

Description of the fourth circulation configuration

[0237] Similar to the second example application, the first and second circulation paths illustrated in FIG. 27 or 28 can also be used as a fluid circulation path between the fluid ejection head 3 and the tank of the printing apparatus 1000, but a circulation path illustrated in FIG. 53. The main difference from the second circulation path of FIG. 28 is that a bypass valve 1010 is additionally provided to communicate with each of the ducts of the first circulation pumps 1001 and 1002 and the second circulation pump 1004. The bypass valve 1010 has a function (first function) for reducing the pressure at the inlet of the bypass valve 1010 through an opening valve when the pressure exceeds a predetermined pressure. Additionally, the bypass valve 1010 has a function (second function) of opening and closing the valve at an arbitrary time by means of a signal from the control substrate of the printing device body.

[0238] By the first function, it is possible to suppress the application of large or small pressure to the discharge side of the first circulation pumps 1001 and 1002 or to the intake side of the stream of the second circulation pump 1004. For example, when the functions of the first circulation pumps 1001 and 1002 are not performed properly, arises a case where a high flow rate or pressure can be applied to the head 3 to expel the fluid. Accordingly, there is such a problem that liquid may leak from the ejection opening of the head 3 to eject the liquid, or each bonding part in the head 3 to eject the liquid may break. However, when the bypass valves 1010 are added to the first circulation pumps 1001 and 1002, as indicated in the example application, the bypass valve 1010 opens in case of high pressure. Accordingly, since the liquid path is open to the flow inlet side of each circulation pump, the above-described difficulty can be suppressed.

[0239] Further, by the second function, when the actuation of the circulation actuation is stopped, all bypass valves 1010 quickly open based on a control signal of the printing apparatus body after the operation of the first circulation pumps 1001 and 1002 and the second circulation pump 1004 are stopped. Accordingly, high negative pressure (for example, from several to several tens of kPa) in the part of the discharge flow (between the negative pressure control unit 230 and the second circulation pump 1004) liquid ejection heads 3 can be discharged for a short time. When a displacement pump, such as a diaphragm pump, is used as a circulation pump, the check valve is normally assembled in the pump. However, when the bypass valve 1010 is open, the pressure in the discharge portion of the fluid ejection head 3 can also be relieved from the drainage portion of the buffer tank 1003. Although the pressure in the discharge portion of the fluid ejection head 3 can only be released from the inlet side, pressure loss exists in the duct at the inlet of the head to eject the fluid and in the duct inside the head to eject the fluid. For this reason, since some time is wasted when the pressure is relieved, the pressure in the common duct in the head 3 for expelling the liquid decreases too much momentarily. Accordingly, there is such a problem that the meniscus in the ejection hole may be damaged. However, since the pressure at the outlet of the liquid ejection head is further relieved when the bypass valve 1010 on the discharge side of the liquid ejection head 3 is open, the risk of damage to the meniscus in the ejection hole is reduced.

Description of fluid ejection head design

[0240] The construction of a head 3 for ejecting a liquid according to a third example of an embodiment of the present invention is described below. FIG. 54A is a perspective view illustrating a liquid ejection head 3 according to an example application, and FIG. 54B is an exploded perspective view thereof. The liquid ejection head 3 is a page inkjet printhead that includes thirty-six print element boards 10 arranged in a line shape (linear shape) in the longitudinal direction of the liquid ejection head 3, and prints an image in a single color. Similar to the second example application, the liquid ejection head 3 includes a shield plate 132 that protects the rectangular side surface of the head, in addition to the signal input contact terminal 91 and the contact terminal 92 for supplying power.

[0241] FIG. 54B is an exploded perspective view illustrating a liquid ejection head 3. In FIG. 54B, the components or assemblies constituting the liquid ejection head 3 are separated according to their functions and are illustrated (wherein the shield plate 132 is not illustrated). The functions of the nodes and elements and the sequence of fluid circulation in the head 3 for ejecting the liquid are similar to the functions and sequences of the second example application. The main difference from the second example application is that the separate electrical circuit boards 90 and the negative pressure control unit 230 are in different positions, and the first duct element has a different shape. As indicated in this example application, for example, in the case of a liquid ejection head 3 having a length corresponding to a B2 size recording medium, the power consumption by the liquid ejection head 3 is large, and therefore eight electrical wiring boards 90 are provided. Four electrical mounting boards 90 are attached to each of both side surfaces of the elongated supporting portion 82 of the electrical mounting board connected to the supporting portion of the fluid ejection assembly 81.

[0242] FIG. 55A is a side view illustrating a liquid ejection head 3 including a liquid ejection unit 300, a liquid supply unit 220, and a negative pressure control unit 230, FIG. 55B is a circuit diagram illustrating a fluid flow, and FIG. 55C is a perspective view illustrating a cross section along the line LVC-LVC of FIG. 55A. To easily understand the drawings, part of the configuration is simplified.

[0243] A fluid connection portion 111 and a filter 221 are provided in the fluid supply portion 220, and the negative pressure control portion 230 is integrally formed on the lower side of the fluid supply portion 220. Accordingly, the distance between the negative pressure control portion 230 and the printing element board 10 in the height direction becomes small compared to the second example application. With this configuration, the number of duct connecting parts in the fluid supply unit 220 is reduced. As a result, such an advantage is provided that the reliability of preventing leakage of printing fluid is increased, and the number of components or assembly steps is reduced.

[0244] Further, since the difference in water pressure between the negative pressure control portion 230 and the surface for forming the ejection openings of the liquid ejection head 3 is relatively reduced, this configuration can be appropriately applied to a printing apparatus in which the angle of inclination of the liquid ejection head 3 illustrated in FIG. 52 is different for each of the heads for ejecting liquid. Since the difference in water pressure can be reduced, the difference in negative pressure applied to the ejection holes of the printed circuit boards of the printing elements can be reduced even when the heads 3 for ejecting liquid having different angles of inclination are used. Further, since the distance from the negative pressure control unit 230 to the printed circuit board 10 is reduced, the flow resistance between them is reduced. Accordingly, the difference in pressure loss caused by the change in fluid flow is reduced, and therefore, the negative pressure can more preferably be controlled.

[0245] FIG. 55B is a schematic diagram illustrating a flow of printing fluid in the head 3 for ejecting liquid. Although the circulation path is similar to the circulation path illustrated in FIG. 53, from the point of view of its circuit, FIG. 55B illustrates fluid flow in components of an actual fluid expelling head 3. A pair of the common supply duct 211 and the common collection duct 212 extending in the longitudinal direction of the fluid ejection head 3 is provided in an elongated second duct member 60. A common supply duct 211 and a common collection duct 212 are formed in such a way that liquid flows in them in opposite directions, and a filter 221 is provided on the inlet side of the flow of each duct in order to capture impurities penetrating from the connecting portion 111, etc. P. Thus, since the fluid flows through the common supply duct 211 and the common duct 212 for collecting in opposite directions, the temperature gradient in the head 3 for expelling the fluid in the longitudinal direction can preferably be reduced. To simplify the description of FIG. 53, flows in a common supply duct 211 and a common collection duct 212 are indicated by the same direction.

[0246] The negative pressure control unit 230 is connected to a discharge side of each of the common supply duct 211 and the common collection duct 212. Additionally, a branch portion is provided in the path of the common supply duct 211 so that it connects to the individual supply ducts 213a, and a branch portion is provided in the path of the common supply duct 212 in such a way that it connects to the separate collection ducts 213b. A separate supply duct 213a and a separate collection duct 213b are formed in the first duct elements 50, and each individual duct communicates with an opening 10A (see FIG. 36C) of the lid member 20 provided on the rear surface of the printing element board 10.

[0247] The negative pressure control units 230 indicated by "H" and "L" of FIG. 55B are nodes on the high pressure side (H) and on the low pressure side (L). The negative pressure control units 230 are back pressure-based pressure control mechanisms that control the inlet pressures of the negative pressure control units 230 by means of a relatively high negative pressure (H) and relatively low negative pressure (L). The common supply duct 211 is connected to the negative pressure control unit 230 (on the high pressure side), and the common collection duct 212 is connected to the negative pressure control unit 230 (on the low pressure side), so that a differential pressure is formed between the common supply duct 211 and a common duct 212 for collection. By means of differential pressure, fluid flows from a common duct 211 for supplying to a common duct 212 for collecting, sequentially passing through a separate duct 213a for feeding, a hole 11 for pushing out (pressure chamber 23) in the circuit board 10 of the printing elements and a separate duct 213b for collecting.

[0248] FIG. 55C is a perspective view illustrating a cross section along the line LVC-LVC of FIG. 55A. In an example application, each eject module 200 includes a first duct element 50, a printing element board 10, and a flexible printed circuit board 40. In an example application, the support member 2030 (FIG. 43) described in the second example application does not exist , and a printing element board 10 including a lid member 20 is directly glued to the first duct member 50. Liquid is supplied from a communication port 61 formed on the upper surface of the common supply duct 211 provided in the second duct member 60 to a separate duct 213a for supplying through a separate communication port 53 formed on the bottom surface of the first duct member 50. Then, the fluid passes through the pressure chamber 23 and passes through a separate collection duct 213b, a separate communication port 53 and a communication port 61 to collect in a common collection duct 212.

[0249] Here, in contrast to the second example application, illustrated in FIG. 40, a separate communication hole 53 formed on the lower surface of the first duct element 50 (surface near the second duct element 60) is large enough with respect to the communication hole 61 formed on the upper surface of the second duct element 50. With this configuration, the first duct element and the second duct element reliably have fluid communication with each other, even when a positional deviation occurs when the eject module 200 is mounted on the second duct element 60. As a result, the yield of finished products in the manufacturing process of heads increases, and therefore, cost reduction can be realized.

Other options for implementation

[0250] The present invention is not limited to an ink ejection substrate, an inkjet printhead, and an inkjet printing device, and can be widely applied to a liquid ejection substrate, a liquid ejection head, and a liquid ejection device used to eject various liquids. The invention can also be applied to various types of printing devices, for example, with full-line scanning and sequential scanning.

[0251] Additionally, the present invention can be widely applied to a liquid ejection device that uses a liquid ejection head capable of ejecting various liquids, in addition to an inkjet printing device that prints an image by using an ink ejection printhead. For example, the present invention can be applied to a printer, a copier, a fax machine having a communication system, a word processor having a printer, and an industrial printing device combined with various processing devices. Additionally, the present invention can be used to make a biocrystal or print an electronic circuit.

[0252] According to the present invention, a plurality of supply ducts, a plurality of collection ducts, a first common supply duct and a first common collection duct can be formed with high accuracy. Thus, even when the plurality of ejection openings are tightly placed, fluid can circulate through the pressure chambers appropriately corresponding to the ejection openings. As a result, satisfactory ejection performance for ejecting liquid from the ejection opening can be maintained. For example, in the case where ink is ejected from an ejection opening to print an image, a high-quality image can be printed with high accuracy by suppressing a decrease in ink ejection speed caused by evaporation of moisture in the ink from the ejection opening.

[0253] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be accorded the broadest interpretation so that it encompasses all such modifications and equivalent structures and functions.

Claims (69)

1. A liquid ejection support including an ejection opening through which liquid is ejected, an ejection energy generating element that generates energy used to eject the liquid, and a pressure chamber that has an ejection energy generating element provided therein, wherein the liquid ejection substrate includes a first part and a second part deflected from each other in the thickness direction of the liquid ejection substrate, wherein the first part comprises a supply duct located on one side of the pressure chamber in order to supply fluid to the pressure chamber, and a collection duct located on the other side of the pressure chamber in order to collect fluid from the pressure chamber, and wherein the second part comprises a common supply duct communicating with a plurality of supply ducts and a common collection duct communicating with a plurality of collection ducts. 2. The substrate for ejecting a liquid according to claim 1, wherein the supply duct and the collection duct extend in a direction intersecting the surface containing the ejection energy generating element, and in this case, if the resistance, when passing per unit length from the end of the discharge of the flow channel for supply to the end of the flow of the flow channel for collection through the pressure chamber, is indicated by R, the consumed amount of fluid flowing through the pressure chamber while the fluid is not expelled from the ejection hole is indicated by Q1 and the maximum negative pressure allowing the liquid to be ejected from the ejection hole is indicated by P, the width W of the beam between the common With a feed window and a common collection duct, it satisfies the ratio W <(2 * P) / (Q1 * R). 3. The substrate for ejecting a liquid according to claim 1, wherein the supply duct and the collection duct extend in a direction intersecting the surface containing the ejection energy generating element, and in this case, if the resistance when passing per unit length from the end of the flow duct discharge for supply to the end of the flow of the duct for collection through the pressure chamber is indicated by R, the maximum ejected amount of fluid ejected from the ejection hole is indicated by Q2 and the maximum negative the pressure allowing the liquid to be pushed out of the ejection hole is indicated by P, the beam width W between the common supply duct and the common collection duct creates the relation W <(2 * P) / (Q2 * R). 4. A liquid ejection substrate including an ejection opening through which liquid is ejected, an ejection energy generating element that generates energy used to eject the liquid, and a pressure chamber that has an ejection energy generating element provided therein, moreover, the substrate for expelling the liquid contains: a supply duct that is located on one side of the pressure chamber and extends in a direction intersecting the surface containing the expulsion energy generating element; a collection duct, which is located on the other side of the pressure chamber and extends in a direction crossing the surface containing the expulsion energy generating element; a common supply duct that communicates with a plurality of supply ducts, and a common collection duct that communicates with a plurality of collection ducts, in this case, if the resistance when passing per unit length from the end of the discharge of the flow channel for supply to the end of the flow of the flow channel for collection through the pressure chamber is indicated by R, the consumed amount of fluid flowing through the pressure chamber while the fluid is not expelled from the ejection hole is indicated by Q1 and the maximum negative pressure allowing the liquid to be ejected from the ejection hole is indicated by P, the gap W between the end of the outlet the flow of the common duct for supply and the end of the flow of the common duct for collection satisfies the ratio W <(2 * P) / (Q1 * R). 5. A substrate for ejecting a liquid, including an ejection hole through which the liquid is ejected, an ejection energy generating element that generates energy used to eject the liquid, and a pressure chamber that has an ejection energy generating element provided therein, moreover, the substrate for expelling the liquid contains: a supply duct that is located on one side of the pressure chamber and extends in a direction intersecting the surface containing the expulsion energy generating element; a collection duct, which is located on the other side of the pressure chamber and extends in a direction crossing the surface containing the expulsion energy generating element; a common supply duct that communicates with a plurality of supply ducts, and a common collection duct that communicates with a plurality of collection ducts, in this case, if the resistance when passing per unit length from the end of the flow duct discharge for supply to the end of the flow of the duct for collection through the pressure chamber is indicated by R, the maximum ejected amount of fluid ejected from the ejection hole is indicated by Q2 and the maximum negative the pressure allowing the liquid to be pushed out of the ejection hole is indicated by P, the gap W between the end of the flow outlet of the common supply duct and the end of the post Lenia common flow duct for collecting satisfies the relation W <(2 * P) / (Q2 * R). 6. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, wherein a plurality of ejection openings is configured to form a matrix of ejection openings extending in a first direction, wherein the width of the duct for feeding in the second direction orthogonal to the first direction is less than the width of the common duct for feeding in the second direction, and wherein the width of the duct for collection in the second direction is less than the width of the common duct for collection in the second direction. 7. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, wherein the common supply duct and the common collection duct extend along each other and the gap W between the common supply duct and the common collection duct is 200 μm or less. 8. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, in which the gap between the supply duct and the collection duct is less than the gap between the common supply duct and the common collection duct. 9. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, wherein a plurality of ejection openings is configured to form a matrix of ejection openings extending in a first direction, wherein the center of the supply duct in a second direction orthogonal to the first direction is located near the push hole relative to the center of the common duct for supply in the second direction, and however, the center of the duct for collection in the second direction is near the opening for pushing relative to the center of the common duct for collection in the second direction. 10. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, in which many of the holes for pushing made with the possibility of forming a matrix of holes for pushing, extending in the first direction, and wherein the common duct for supply and the common duct for collection pass in the first direction. 11. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, wherein the supply duct and the collection duct extend in a direction intersecting the surface containing the ejection energy generating element of the substrate for ejecting the liquid, and the common supply duct and the common collection duct extend in a direction along the surface. 12. The substrate for ejecting a liquid according to any one of paragraphs. 1-5, while the substrate for ejecting the liquid has the form of a practically parallelogram, wherein, both ends of the first common supply duct communicating with the first matrix of ejection openings having a plurality of ejection openings arranged therein in the first direction, and both ends of the second common supply duct communicating with the second matrix of ejection openings provided in parallel the first matrix of ejection holes deviate in the first direction. 13. The substrate for pushing the liquid according to p. 12, in which both ends of at least one of the common supply duct and the common collection duct communicating with the first matrix of ejection holes in the first direction have a beveled shape or a circular shape. 14. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, in which if the width of the beam between the common supply duct and the common collection duct communicating with the first matrix of ejection openings having a plurality of ejection openings disposed therein is indicated by W1 and the width of the beam between the common supply duct communicating with a first matrix of ejection holes and a common collection duct communicating with a second matrix of ejection holes provided parallel to the first matrix of ejection holes is indicated by W3, the relationship W1 <W3 is satisfied. 15. A substrate for ejecting a liquid according to any one of paragraphs. 1-5, wherein the fluid ejection substrate ejects many kinds of liquid, and in this case, if the width of the beam between the common supply duct and the common collection duct located between adjacent matrices of ejection holes that eject an identical type of liquid is indicated by W3 and the width of the beam between the common supply duct and the common collection duct located between adjacent matrices of ejection holes ejecting various types of liquid is indicated by W4, the relationship W3 <W4 is satisfied. 16. A head for ejecting a liquid containing a substrate for ejecting a liquid according to any one of paragraphs. 1-5. 17. The head for ejecting a liquid according to p. 16, in which fluid in the pressure chamber circulates outside the pressure chamber. 18. A fluid ejection device, comprising: a head for ejecting a liquid according to claim 16; a controller configured to control a plurality of push energy generation elements, and a differential pressure generator configured to generate differential pressure between the common supply duct and the common collection duct such that liquid flows through the common supply duct, the supply duct, the pressure chamber, the collection duct and the common collection duct. 19. A liquid ejection head including an ejection opening through which liquid is ejected, an ejection energy generating element that generates energy used to eject the liquid, and a pressure chamber that has an ejection energy generating element provided therein, moreover, the head for ejecting liquid contains: a matrix of holes for pushing, in which there are many holes for pushing; a first duct that communicates with one side of the pressure chamber; a second duct that communicates with the other side of the pressure chamber; a matrix of supply ducts, in which a plurality of supply ducts supplying liquid to the first duct are arranged in a direction of arranging a plurality of ejection openings, wherein the plurality of supply ducts extend in a direction intersecting a surface containing an ejection energy generating element; an array of collection ducts in which a plurality of collection ducts collecting liquid in the second duct are arranged in a direction of receiving a plurality of ejection openings, wherein the plurality of ducts for collection extend in a direction of intersection; a common supply duct that extends in the direction of the plurality of ejection openings and communicates with the plurality of supply ducts, and a common collection duct that extends in the direction of the plurality of ejection openings and communicates with the plurality of collection ducts. 20. The head for ejecting a liquid according to p. 19, in which a plurality of ejection hole arrays are arranged in a direction crossing the direction of the plurality of ejection holes, and wherein the matrix of ducts for supply and the matrix of ducts for collection are alternately arranged in a direction that intersects the direction of placement of the plurality of ejection openings. 21. The head for ejecting a liquid according to claim 19 or 20, in which fluid in the pressure chamber circulates outside the pressure chamber.

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