Liquid ejecting head, liquid ejecting apparatus, and method of manufacturing liquid ejecting head

Abstract

The invention relates to a liquid ejecting head, a liquid ejecting apparatus, and a method of manufacturing the liquid ejecting head. In the liquid ejecting head, a circulation flow path has an inlet through which a liquid flows into a pressure chamber and an outlet through which the liquid flows out of the pressure chamber, the pressure chamber is arranged between the inlet and the outlet, and the circulation flow path extends such that the inlet, the pressure chamber, and the outlet are arranged in this order, the second energy generating element is disposed closer to the inlet side than the first energy generating element, and a communication passage allowing the outflow-side common flow path and the inflow-side common flow path to communicate with each other has an outflow-side opening in the outflow-side common flow path and includes an outflow-side communication passage. The outflow-side communication passage is formed on a side surface inclined such that a width in the second direction increases further away from the outflow-side opening in the first direction.

Description

Technical Field

[0001] This disclosure relates to liquid jet heads and liquid jetting devices. Background Technology

[0002] A circulating liquid jetting device is known that circulates ink to expel air bubbles from the flow path of the liquid jetting head and suppress the increase in ink viscosity near the jetting nozzle. As a method of ink circulation, a differential pressure system utilizing a pressure difference exists. In this system, by using a pressure regulating mechanism, the pressure on the inside of the ink supply to the jetting nozzle is made higher than the pressure on the outside of the ink recovery area, thereby causing the ink to flow from the inside to the outside. In this case, for effective ink circulation, it is efficient to return the ink that has flowed to the outside to the inside, and a pump can be used as the mechanism for this purpose. Note that the pump can be located outside the head of the recording device body to circulate liquid between the liquid jetting head and the body, or it can be located inside the liquid jetting head to circulate liquid within the head. However, this differential pressure circulation method requires mechanisms such as pressure regulating mechanisms and pumps, thus easily leading to a larger size for the recording device body and head.

[0003] Therefore, methods for circulating ink other than differential pressure systems have been studied. More specifically, in addition to a first energy generating element that generates energy for ink ejection, a second energy generating element that generates energy for liquid flow is arranged in a single-use flow path communicating with the ejection nozzle. Mechanisms for circulating ink by driving the second energy generating element and causing ink to flow in the single-use flow path are known. Japanese Patent Application Publication 2020-104312 discloses a structure in which a flow path extending in a direction intersecting with an ejection nozzle array having a plurality of ejection nozzles is provided, and the flow path includes a first energy generating element and a second energy generating element.

[0004] Here, in the liquid ejection head disclosed in Japanese Patent Application Publication No. 2020-104312, there is room for improvement in the ejection characteristics and circulation characteristics of ink as a recording liquid in the chip structure that includes elements for generating ejection energy and elements for generating flow energy. Summary of the Invention

[0005] This disclosure aims to provide a technique for improving the jetting and circulation characteristics of a liquid in a liquid jet head, which includes an energy-generating element for jetting liquid and an energy-generating element for causing liquid flow.

[0006] To address these issues, a liquid jet head according to some embodiments of this disclosure includes the following features: a liquid jet section configured to have a pressure chamber, a jet port for jetting liquid from the pressure chamber, and a first energy generating element for generating energy to jettison liquid disposed inside the pressure chamber from the jet port; a circulation flow path configured to have an inlet for allowing liquid supplied to the pressure chamber to flow in and an outlet for allowing liquid recovered from the pressure chamber to flow out, the circulation flow path having the pressure chamber disposed between the inlet and the outlet; a second energy generating element configured to be disposed in the circulation flow path closer to the inlet than the first energy generating element; and a common flow path configured to include an outflow-side common flow path, an inflow-side common flow path, and a connecting passage, the outflow-side common flow path being... A common flow path is formed on the outside of the outlet and the common flow path on the inlet side. A connecting passage allows the common flow path on the outlet side and the common flow path on the inlet side to communicate with each other. The nozzle is open in a first direction. The inlet is located on one side of the pressure chamber in a second direction that intersects the first direction. The outlet is located on the other side of the pressure chamber in the second direction. The circulation path extends in the second direction such that the inlet, the pressure chamber, and the outlet are arranged in this order in the second direction. The connecting passage has an outlet side opening that is open in the first direction in the common flow path on the outlet side and includes an outlet side connecting passage formed on a side surface that is inclined such that the width in the second direction increases the further away from the outlet side opening in the first direction.

[0007] The features of this disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following description of the embodiments is given by way of example. Attached Figure Description

[0008] Figure 1A This is a perspective view showing the construction of a liquid jetting device with a main ink tank disposed outside the liquid jetting head according to Example 1.

[0009] Figure 1B This is a perspective view showing the structure of a liquid jetting device that includes an ink tank in the liquid jetting head.

[0010] Figure 2A This is an exploded perspective view of the liquid jet head according to Example 1.

[0011] Figure 2B This diagram illustrates a liquid jet chip with a series of nozzles for four colors of ink, and how a single liquid jet chip can be used to jet the four colors of ink.

[0012] Figure 2C This diagram illustrates a structure in which two ink nozzles of different colors are provided in a liquid jet chip, and four ink colors can be jetted using two liquid jet chips.

[0013] Figure 2D This diagram illustrates a structure in which a single color ink nozzle is provided in a liquid jet chip, and four liquid jet chips can be used to jet four different colors of ink.

[0014] Figure 3A This is a diagram showing the structure near the nozzle of a liquid jet head constructed according to Example 1, and a diagram showing the main components of the liquid jet head when viewed along the Z direction.

[0015] Figure 3B It is along Figure 3A The sectional view taken by line AA in the figure.

[0016] Figure 3C It is the segment along line AA that has the same... Figure 3B The diagram shows cross-sectional views of liquid jet heads with different configurations.

[0017] Figure 3D It is along Figure 3A The diagram shows a cross-sectional view taken by line AA, and is a diagram illustrating the ink flow when ink is ejected from the nozzle.

[0018] Figure 4A This is a diagram showing how bubbles are generated in the linear ink circulation structure according to Example 1 by driving a second energy generating element (circulation heater).

[0019] Figure 4B This is a diagram illustrating the ink flow during the bubble contraction process in the linear ink circulation structure according to Example 1.

[0020] Figure 4C This is a diagram showing the ink flow after bubble elimination in the linear ink circulation configuration according to Example 1.

[0021] Figure 5A This is a diagram showing the state in which the recording operation of the liquid jetting device used in the linear ink circulation structure according to Example 1 is temporarily stopped.

[0022] Figure 5B It is shown in Figure 5A The diagram shows the state obtained after the second energy generating element has just generated the circulating flow.

[0023] Figure 5C It is shown in Figure 5B A diagram showing the state when recording operations are temporarily suspended again.

[0024] Figure 5D It is shown in Figure 5C The diagram shows the state obtained after the second energy generating element has just generated the circulating flow.

[0025] Figure 6A This diagram illustrates the state when the recording operation of the liquid jetting device is temporarily stopped in the U-shaped ink circulation structure of the comparative example.

[0026] Figure 6B It is shown in Figure 6A The diagram shows the state obtained after the second energy generating element has just generated the circulating flow.

[0027] Figure 6C It is shown in Figure 6B A diagram showing the state when recording operations are temporarily suspended again.

[0028] Figure 6D It is shown in Figure 6C The diagram shows the state obtained after the second energy generating element has just generated the circulating flow.

[0029] Figure 7A This is a diagram showing the structure near the injection port of the liquid jet head in the U-shaped ink circulation structure of the comparative example.

[0030] Figure 7B It is along Figure 7A The sectional view taken by line AA in the figure.

[0031] Figure 7C It is shown Figure 7A A diagram of the area near the flow path in the middle section.

[0032] Figure 8 This is a diagram illustrating the control structure of the liquid injection device according to Example 1.

[0033] Figure 9A It is a plan view of the liquid jet head according to Example 1, viewed along the direction from which the liquid droplets are ejected from the nozzle.

[0034] Figure 9B It is along Figure 9A The sectional view is taken in the direction of arrow A.

[0035] Figure 10A This is a plan view of the liquid jet head according to Example 2, viewed along the direction from which the liquid droplets are ejected from the nozzle.

[0036] Figure 10B It is along Figure 10A The cross-sectional view taken in the direction of arrow B shown in the figure.

[0037] Figure 11A This is a cross-sectional view of the liquid jet head, which is a variation of Example 1 based on Example 2.

[0038] Figure 11B This is a cross-sectional view of the liquid jet head according to a variation of Example 2.

[0039] Figure 12A This is a diagram showing the initial state of the substrate of the liquid jet head in the manufacturing process of the liquid jet head according to Example 2.

[0040] Figure 12B This diagram illustrates the state in which multiple holes are formed by performing multiple laser processing on the rear surface side of the substrate during the manufacturing process of the liquid jet head according to Example 2.

[0041] Figure 12C This diagram illustrates the state in which a laser-processed substrate is immersed in an etching solution and anisotropically etched, starting from multiple holes, to form recesses in the manufacturing process of the liquid jet head according to Example 2.

[0042] Figure 12D This diagram illustrates the state in which the recess is machined to communicate with the surface side of the substrate during the manufacturing process of the liquid jet head according to Example 2.

[0043] Figure 12E This is a diagram showing the state in which the film is attached to the rear surface side of the substrate during the manufacturing process of the liquid jet head according to Example 2.

[0044] Figure 12F This diagram illustrates the state in which a dry etched surface resist pattern is formed on the surface side of a substrate and an etching process is performed during the manufacturing process of the liquid jet head according to Example 2.

[0045] Figure 12G This illustrates the manufacturing process of the liquid injection head according to Example 2, where... Figure 12F The diagram shows a state in which the hole created in the dry etching process is connected to a pre-existing common flow path on the outflow side and forms a common flow path on the inflow side.

[0046] Figure 12H This diagram shows the state where the film on the back surface of the substrate has been peeled off and the process is complete.

[0047] Figure 13 This is a block diagram illustrating the control configuration of the liquid injection device according to Example 1. Detailed Implementation

[0048] In the following, various exemplary embodiments, features, and aspects of this disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the subject matter of this disclosure, and not all combinations of features described in the embodiments are necessary for the solutions according to this disclosure. Identical components are denoted by the same reference numerals. In the following description, the basic structure according to this disclosure is first described, followed by the characteristic components according to this disclosure.

[0049] Example 1

[0050] A liquid jetting apparatus 50 according to Example 1 of this disclosure will now be described. The liquid jetting apparatus 50 is an inkjet recording apparatus using an inkjet recording method and includes a liquid jetting head 1 capable of jetting ink as a liquid.

[0051] Liquid jetting equipment

[0052] Figure 1A and Figure 1B This is a perspective view showing the construction of the liquid jetting device 50 according to Example 1. Figure 1A and Figure 1B The liquid ejection device 50 shown is a liquid ejection device (serial liquid ejection device) that performs image recording by ejecting liquid onto the recording medium P using a liquid ejection head 1 that scans in a direction intersecting the transport direction of the recording medium P. This disclosure is not limited to serial liquid ejection devices, but can also be applied to page-width liquid ejection devices that perform image recording by ejecting liquid onto a recording medium transported in the transport direction using a linear head (page-width head) that is longer in the page-width direction of the recording medium. The liquid ejection head 1 according to Example 1 can eject four types of ink, including black (K), cyan (C), magenta (M), and yellow (Y), and these inks can be used to record panchromatic images. The inks that can be ejected from the liquid ejection head 1 are not limited to the four types of inks mentioned above. This disclosure can also be applied to liquid ejection heads capable of ejecting other types of ink, and there are no particular limitations on the type and quantity of ink ejected from the liquid ejection head.

[0053] In the liquid jetting apparatus 50, the liquid jetting head 1 is mounted in a carriage 60. The carriage 60 reciprocates along a guide shaft 51 in the main scanning direction (X direction). The recording medium P is conveyed by transport rollers 55, 56, 57, and 58, which serve as transport units, in a sub-scanning direction (Y direction) that intersects the main scanning direction. In Example 1, the main scanning direction and the sub-scanning direction are orthogonal to each other. In each of the figures referred to below, the Z direction represents the vertical direction and intersects the XY plane defined by the X and Y directions. In Example 1, the Z direction intersects the XY plane.

[0054] Figure 1A The diagram shows a structure in which the main ink tank 2, serving as a liquid storage unit, is located outside the liquid ejector head 1. Driven by an external pump 40, ink stored in the main ink tank 2 is supplied to the auxiliary ink tank 54 on the liquid ejector head 1 via an ink supply pipe 59, etc. On the other hand, Figure 1BA configuration is shown where the main ink tank 2 is not external to the liquid ejector head 1, and the ink tank 54 is included within the liquid ejector head 1. This configuration can be one where the liquid ejector head 1 and the ink tank 54 are integrally formed and can be attached / removed relative to the carriage 60. Alternatively, a configuration can be adopted where the liquid ejector head 1 and the carriage 60 are integrally formed, and only the ink tank 54 is attachable and removable. An external pump 40 for supplying ink to the ink tank 54 is a supply unit for supplying ink to the liquid ejector head 1. Figure 1A Example 1 illustrates the construction shown.

[0055] The liquid injection head 1 is configured to include a single-purpose injection unit as described below. Although a specific configuration is described below, the single-purpose injection unit is a recording element unit having an injection port for injecting liquid and a single-purpose flow path communicating with the injection port. A pressure chamber is formed at a position in the single-purpose flow path corresponding to the injection port, and a first energy generating element (ejection energy generating element) is provided in the pressure chamber to generate energy for injecting liquid from the injection port. A second energy generating element (flow energy generating element) is provided at a position in the single-purpose flow path different from the position of the first energy generating element to generate energy for causing liquid to flow. The liquid injection head 1 includes a plurality of single-purpose injection units and has a supply flow path for supplying liquid to the single-purpose flow path in each single-purpose injection unit.

[0056] There are instances where liquid jetting becomes unstable due to the evaporation of volatile components (such as moisture) from the nozzle of the liquid jetting head 1, leading to the concentration of solid components near the nozzle. Various countermeasures have been considered to prevent this. For example, in the liquid jetting apparatus 50, a cap member (not shown) can be provided at a position offset in the X direction from the transport path of the recording medium P, covering the nozzle surface of the liquid jetting head 1. When recording operations are not performed, the cap member covers the nozzle surface of the liquid jetting head 1 and serves to prevent the nozzle from drying out and to protect the nozzle.

[0057] In addition, an ink suction mechanism (not shown) can be provided. When an ink suction mechanism is provided, the cap member is used for ink suction operations such as drawing ink from the ejector nozzle. By performing the ink suction operation, the ink near the ejector nozzle can be updated and the image quality of the resulting image can be maintained.

[0058] Furthermore, when not recording, thickened ink can be discarded by performing a jetting process known as preliminary jetting (pre-jetting). During recording, this preliminary jetting can also be performed with an inconspicuous amount of ink in an inconspicuous location on the recording medium (paper preliminary jetting / in-page preliminary jetting) to improve image quality. While these methods greatly contribute to improved image quality, the amount of waste ink needs to be reduced because some ink is wasted to refresh the jet nozzles.

[0059] Related to this requirement, by incorporating a second energy-generating element (flow energy-generating element) into a single-use flow path and circulating the ink through the flow path, it is possible to suppress waste ink volume while also suppressing nozzle drying and ink thickening near the nozzle. More specifically, the number of initial ejection or suction recovery operations can be reduced. Furthermore, by reducing the number of initial ejection operations, throughput and production volume can be increased.

[0060] The second energy generating element does not necessarily have to be installed in all single-use injection units of the liquid jet head. When the second energy generating element is installed in some single-use injection units, the aforementioned effects can be achieved more effectively compared to not having a second energy generating element.

[0061] The liquid jet head 1 may also have a configuration in which a second energy generating element is provided for all portions corresponding to each of the four types of ink, or for only portions corresponding to one type of ink. The liquid jet head 1 may be configured to circulate only at least one type of ink, rather than all four types.

[0062] Liquid injection head

[0063] The construction of the liquid injection head 1 according to Example 1 will now be described. Figures 2A to 2D This is a diagram showing the construction of the liquid injection head 1 according to Example 1. Figure 2A This is an exploded perspective view of liquid injection head 1.

[0064] The liquid ejector head 1 includes four sub-ink tanks 54 for temporarily storing ink and a liquid ejection chip 3 for ejecting ink supplied from the sub-ink tanks 54 onto the recording medium P.

[0065] The liquid jet head 1 also includes a first support member 4, a second support member 7, and an electrical wiring member 5 (electrical wiring strip). The liquid jet chip 3 is connected to one surface of the first support member 4, and the sub-ink tank 54 is connected to the other surface. The first support member 4 has a flow path extending from one surface to the other, and while supporting the liquid jet chip 3, the first support member 4 transfers ink supplied from the sub-ink tank 54 to the liquid jet chip 3.

[0066] The second support member 7 is connected to the surface of the first support member 4 that is connected to the liquid jet chip 3. The second support member 7 has an opening through which the liquid jet chip 3 can pass, and the second support member 7 is connected to the first support member 4 when the liquid jet chip 3 is positioned inside the opening. The second support member 7 also supports the electrical wiring member 5.

[0067] The electrical wiring component 5 is electrically connected to the liquid jet chip 3 and sends the jetting signal for ink jetting received from the main body of the liquid jetting device 50 to the liquid jet chip 3.

[0068] According to Example 1, the liquid ejector head 1 is fixed to and supported by the carriage 60 of the liquid ejection device 50 via an alignment unit and electrical contacts (not shown) provided on the carriage 60. The liquid ejector head 1 performs recording on the recording medium P by ejecting ink while moving together with the carriage 60 in the main scanning direction (X direction).

[0069] Ink supply tube 59 is provided on the external pump 40 connected to the main ink tank 2, which serves as the ink supply source (see reference). Figure 1A A liquid connector (not shown) is provided at the end of the ink supply pipe 59. When the liquid jet head 1 is mounted on the liquid jetting device 50, the liquid connector at the end of the ink supply pipe 59 is liquid-tightly connected to the liquid connector insertion port, which serves as a liquid inlet, located in the housing of the liquid jet head 1. As a result, an ink supply path is formed from the ink tank 2 to the liquid jet head 1 via the external pump 40. In Example 1, since four types of ink are used, a total of four sets of ink tanks 2, external pumps 40, ink supply pipes 59, and auxiliary ink tanks 54 are provided, each corresponding to one of the inks. Four ink supply channels corresponding to each ink are formed independently.

[0070] As described above, the liquid jetting device 50 is provided with an ink supply system for supplying ink from the ink tank 2 outside the liquid jetting head 1. Note that the liquid jetting device 50 does not include an ink recovery system for recovering ink from the liquid jetting head 1 back into the ink tank 2. Therefore, although a liquid connector insertion port is provided for connecting the ink supply tube 59 to the ink tank 2, the liquid jetting head 1 does not have a connector insertion port for connecting the tube for recovering ink from the liquid jetting head 1 back into the ink tank 2. The liquid connector insertion port is provided corresponding to each ink.

[0071] Figure 2B , Figure 2C and Figure 2D This is a diagram showing an example of the construction of a liquid jetting chip 3 constituting a liquid jetting head 1. Each liquid jetting chip 3 is provided with a jetting port 11 and a pad 15 for electrical mounting. Figure 2A Therefore Figure 2B This is shown in the form of a chip structure.

[0072] The liquid ejector head 1 can eject ink of four colors. These four colors are, for example, black, cyan, magenta, and yellow. In the liquid ejector chip 3, an ejector array 28 is formed for each color of ink. An ejector array 28 consists of a first column 25 and a second column 26, each consisting of a plurality of ejector nozzles 11 arranged at equal intervals along the Y direction, and the first column 25 and the second column 26 are arranged in the X direction. The ejector nozzles 11 included in the first column 25 and the ejector nozzles 11 included in the second column 26 are offset from each other in the Y direction. Although a configuration of the ejector array 28 consisting of a plurality of ejector nozzles 11 arranged in two columns is shown, a configuration of the ejector array 28 consisting of a plurality of ejector nozzles 11 arranged in one column is also possible.

[0073] Figure 2B The diagram illustrates a configuration where four ink nozzle rows 28 are arranged in a liquid jet chip 3, and one liquid jet chip 3 can jet four ink colors. Alternatively, a configuration can be adopted where two nozzle rows 28 are arranged only for black, and a total of five nozzle rows 28 are arranged for the four colors.

[0074] Figure 2C The diagram shows a configuration where two ink nozzles of different colors are disposed within a single liquid ejection chip 3, and two liquid ejection chips 3 can eject four colors of ink. Alternatively, two liquid ejection chips 3 can be installed in a single liquid ejection head 1, or two liquid ejection heads 1 can each be equipped with one liquid ejection chip 3.

[0075] Figure 2D The diagram shows a liquid jet chip 3 with a nozzle for one color of ink, and four liquid jet chips 3 capable of jetting four colors of ink. As a configuration with four liquid jet chips 3 installed, four liquid jet chips 3 can be installed in one liquid jet head 1, and four liquid jet heads 1, each with one liquid jet chip 3 installed, can be prepared.

[0076] In addition, such as Figure 2C and Figure 2D As shown, when the liquid jet chip 3 is divided into multiple chips, not all chips need to have the same chip length. Furthermore, various other color combinations of the chips are also possible, even when the total number of colors is greater than four.

[0077] Linear ink circulation structure

[0078] Figures 3A-3D to Figures 5A-5D This is a diagram illustrating the construction of a linear ink cycle according to Example 1. Figures 3A-3D to Figures 5A-5DThis is a simplified diagram used to illustrate the generation mechanism and effect of the circulating flow in a linear ink circulation structure. Therefore, Figures 3A-3D to Figures 5A-5D The liquid injection head 1 shown has the same structure as the liquid injection head 1 according to Example 1 (see below). Figure 9A and Figure 9B as well as Figure 10A and Figure 10B The descriptions differ in some aspects. However, in the liquid injection head 1 according to Example 1, reference... Figures 3A-3D to Figures 5A-5D The described mechanism for ink circulation and its effects are similar. Additionally, see the following references... Figures 3A-3D to Figures 5A-5D In the description, unless otherwise stated, the contents applicable to the liquid injection head 1 according to Example 1 will be incorporated as part of the description of Example 1.

[0079] Figure 3A This is a diagram showing the structure near the injection port 11 of the liquid injection head 1, and a diagram showing the main components of the liquid injection head 1 when viewed in the Z direction. Figure 3B It is along Figure 3A The sectional view taken by line AA in the figure. Figure 3C It is along Figure 3A The cross-sectional view is taken by line AA in the middle, and is with the Figure 3B The diagram shows a cross-sectional view of a liquid jet head 1 with different configurations. Figure 3D It is along Figure 3A The diagram shows a cross-sectional view taken by line AA, and is a diagram illustrating the ink flow when ink is ejected from the nozzle.

[0080] The liquid jet head 1 has a substrate 18 and an orifice plate 19 stacked on top of each other, and a jet array 63 consisting of a plurality of jet nozzles 11 arranged along the Y direction is formed in the orifice plate 19. The ink meniscus unfolds on the jet nozzles 11 and forms a jet nozzle interface as an interface between ink and atmosphere.

[0081] Between the substrate 18 and the perforated plate 19, a plurality of single-purpose flow paths 23 are formed. These single-purpose flow paths are separated by a partition wall 21, communicate with a plurality of injection ports 11, and extend in the X direction. The single-purpose flow paths 23 extend linearly in the X direction, which is orthogonal to the Y direction in which the plurality of injection ports 11 are arranged in the injection port row 63.

[0082] Furthermore, a first flow path 61 connected to one end of a plurality of single-use flow paths 23 and a second flow path 62 connected to the other end of a plurality of single-use flow paths 23 are formed. The first flow path 61 and the second flow path 62 extend in the Y direction and are located on opposite sides of each other in the X direction, with the jet nozzle row 63 between them.

[0083] In the single-use flow path 23, a pressure chamber 12 is formed at a position corresponding to the injection port 11. The pressure chamber 12 is connected to the first flow path 61 via the connecting flow path 13, and to the second flow path 62 via the connecting flow path 10. In other words, the single-use flow path 23 includes the pressure chamber 12, the connecting flow path 10, and the connecting flow path 13.

[0084] In the substrate 18, a first energy generating element 14 (ejection energy generating element) is provided at a position corresponding to the ejection port 11 to generate energy for ejecting ink inside the ejection pressure chamber 12. Here, an electrothermal conversion element is used as the first energy generating element 14. By driving the first energy generating element 14 to generate heat and cause bubbles to form in the ink inside the pressure chamber 12, ink can be ejected from the ejection port 11 using foaming energy. The first energy generating element 14 is not limited to an electrothermal conversion element, and a piezoelectric element or the like can also be used.

[0085] Furthermore, a second energy generating element 24 (flow energy generating element) is provided in the substrate 18 to generate energy to produce a circulating flow 27 (flow) in the ink inside the single-use flow path 23, as indicated by the arrow. Here, an electrothermal conversion element is used as the second energy generating element 24. In the X direction, the second energy generating element 24 is located at a position different from that of the first energy generating element 14.

[0086] In the first flow path 61, a plurality of first openings 22 for allowing ink to flow into / out of the common flow path 29 are arranged along the Y direction. In the second flow path 62, a plurality of second openings 32 for allowing ink to flow into / out of the common flow path 29 are arranged along the Y direction. The first openings 22 and the second openings 32 penetrate the substrate 18 in the stacking direction.

[0087] The first energy generating element 14, the nozzle 11, and the pressure chamber 12 are closer to the second opening 32 than the first opening 22. The second energy generating element 24 is closer to the first opening 22 than the second opening 32. The single-use flow path 23 communicates with the first opening 22 at one end (-X direction side) in the X direction and with the second opening 32 at the other end (+X direction side). The flow path 13 in the X direction is located on the side of the second energy generating element 24 of the nozzle array 63. The two ends of the single-use flow path 23 in the X direction are located on opposite sides, with the nozzle array 63 located between them.

[0088] There are two main types of ink flow in the single-use flow path 23. That is, (1) a first type of ink flow to replenish the ink jet driven by the first energy generating element 14, and (2) a second type of ink flow as a circulating flow 27 generated by driving the second energy generating element 24.

[0089] When the first energy generating element 14 is driven and ink is ejected from the ejection port 11, such as Figure 3D As shown, an ink flow 27 is generated that flows into the pressure chamber 12 of the single-use flow path 23 from both the first opening 22 and the second opening 32. Correspondingly, ink is supplied to the single-use flow path 23 from both the first opening 22 and the second opening 32.

[0090] When the second energy generating element 24 is driven and a circulating flow 27 is formed, ink flows into the single-use flow path 23 from the inlet 37 on the side of the connecting flow path 13 (the side of the first opening 22), and flows out from the outlet 38 on the side of the connecting flow path 10 (the side of the second opening 32). The ink that has flowed out from the second opening 32 returns to the first opening 22 via the common flow path 29. Correspondingly, a circulating flow 27, as indicated by the arrow, is generated inside the single-use flow path 23.

[0091] exist Figure 3B In the configuration shown, the first opening 22 and the second opening 32 are connected to a common flow path 29 inside the chip of the liquid injection head 1. Figure 3C In the illustrated configuration, the first opening 22 and the second opening 32 are connected to separate flow paths 291 and 292 inside the chip of the liquid jet head 1, and to a common flow path outside the chip of the liquid jet head 1. This disclosure is applicable to any of these configurations.

[0092] A filter for removing foreign matter from inside the ink can be installed in the ink circulation path both inside and outside the liquid jet head 1. Figures 3A to 3D In the example shown, filter 31 is disposed near one end (the second energy generating element 24 side) and the other end (the first energy generating element 14 side) in the X direction of the single-use flow path 23. Alternatively, the filter can be arranged in the single-use flow path 23 between the first energy generating element 14 and the second energy generating element 24. In this case, the filter may not be disposed near the end of the single-use flow path 23 in the X direction (the second energy generating element 24 side).

[0093] In the liquid jet head 1, a first energy generating element 14 and a second energy generating element 24 are arranged in a single-use flow path 23 extending linearly in the X direction. By driving the second energy generating element 24, a circulating flow 27 of ink can be generated in the single-use flow path 23. The two ends of the single-use flow path 23 are located on opposite sides of each other in the X direction relative to the jet nozzle array 63. Therefore, the inlet 37 (upstream end) and outlet 38 (downstream end) of the circulating flow 27 are connected to the first flow path 61 and the second flow path 62, which are different from each other, and are separate from each other. This ink circulation configuration is called a linear type.

[0094] The process of generating a circulating flow

[0095] Figures 4A to 4CThis diagram illustrates the process of generating a circulating flow of ink by driving the second energy generating element 24. Figure 4A , Figure 4B and Figure 4C Is with Figure 3B A similar cross-sectional view is shown, illustrating the process by which ink is heated by the second energy generating element 24 and bubbles are generated, grow, shrink, and removed due to the boiling of the ink film.

[0096] Figure 4A This is a view showing the generation of bubble B by driving the second energy generating element 24 (circulating heater). The second energy generating element 24 is closer to the first opening 22 than the second opening 32. Therefore, the flow resistance R1 between the second energy generating element 24 and the first opening 22 is less than the flow resistance R2 between the second energy generating element 24 and the second opening 32. Figure 4A The equivalent circuit for representing such flow resistances R1 and R2 as resistors is shown in the diagram. For example... Figure 4A As shown, due to the difference between the flow resistances R1 and R2, bubbles B generated by film boiling of the ink film tend to grow towards the first flow path 61, which has a lower flow resistance R1. Therefore, within the single-use flow path 23, the ink flow Fa towards the first flow path 61 becomes greater than the ink flow Fb towards the second flow path 62.

[0097] Figure 4B This diagram illustrates the ink flow during the contraction of bubble B. As bubble B contracts, ink flows in to compensate for the volume corresponding to the contraction. At this time, as... Figure 4B As shown, the ink flow Fc flowing into the first opening 22 from the side with low flow resistance R1 is greater than the ink flow Fd flowing into the second opening 32 from the side with high flow resistance R2. Furthermore, the elimination position of bubble B shifts from the second energy generating element 24 towards the second opening 32.

[0098] Figure 4C This is a diagram showing the ink flow after bubble B is eliminated. Based on... Figure 4B The relationship Fc>Fd generated in the process produces a circulating flow F of ink from the first opening 22 toward the second opening 32.

[0099] The magnitude of this circulating flow F is influenced by the ratio of flow resistances R1 and R2, as well as the size of bubble B. For example, when an electrothermal conversion element (heater) is used as the second energy generating element 24, the second energy generating element 24 can be located closer to one end of the single-use flow path 23 than the first energy generating element 14. More specifically, the flow resistance ratio R1 / R2 can be set within a range of at least 0.05 and no greater than 0.40. By setting the flow resistance ratio R1 / R2 within this range, the circulating flow F can be maximized.

[0100] By increasing Figure 4Aand Figure 4B The circulating flow F can be increased by increasing the ink flow Fa towards the first flow path 61 and increasing the ink flow Fc flowing in from the first opening 22. Therefore, reducing the flow resistance R1 is effective. Furthermore, the circulating flow F can be increased by decreasing the ink flow Fb towards the second flow path 62 and decreasing the ink flow Fd flowing in from the second opening 32. Therefore, increasing the flow resistance R2 is effective. As described above, the circulating flow F can be increased by decreasing the flow resistance R1 and increasing the flow resistance R2, i.e., by decreasing the flow resistance ratio R1 / R2. Here, although the adjustment of the flow resistance ratios R1 and R2 is not limited to a specific method, they can be adjusted, for example, by changing the position of the second energy generating element 24 in the single-use flow path 23. In other words, for example, there is a method in which the magnitudes of the flow resistances R1 and R2 are changed by changing the flow path distance between the second energy generating element 24 and the first opening 22, and the flow path distance between the second energy generating element 24 and the second opening 32. Alternatively, the flow path cross-section on both sides of the second energy generating element 24 can be changed, or both the flow path distance and the flow path cross-section can be changed. For example, the flow resistances R1 and R2 can be changed by arranging structures that prevent flow along the flow path.

[0101] Furthermore, as the accumulation of bubble B increases, the volume of ink discharged from the single-use flow path 23 due to foaming increases, thus increasing the circulating flow F. Methods for increasing the volume of bubble B include increasing the size of the second energy generating element 24, reducing the flow resistance R1 by increasing the width and height of the connecting flow path 13, reducing the ink viscosity, increasing the temperature of the liquid jet head 1, and configuring the drive pulse as a dual pulse.

[0102] Since a portion of the circulating ink flow F enters the ejector 11, the concentrated ink in the ejector 11 is sent to the second opening 32 side, and fresh ink flows into the ejector 11 from the first opening 22 side via the connecting flow path 13. By thereby preventing the concentrated ink from easily remaining inside the ejector 11, the influence of the concentrated ink can be suppressed and the initial ink ejection state can be maintained.

[0103] The circulating flow F is a transitional flow that accompanies the growth and contraction processes of the generated bubbles B. Therefore, the inertial flow of bubble B weakens over time after bubble elimination and stops after a certain period. By repeatedly driving the second energy generating element 24, the circulating flow F can be stably generated for a certain period. The driving cycle of the second energy generating element 24 is not particularly limited, as long as the concentrated ink in the ejector nozzle 11 can be discharged. However, since the time from bubble B generation to bubble elimination is approximately 10 microseconds (μs), driving at a high driving frequency such as 100 kHz would reduce the effect. Therefore, for example, the second energy generating element 24 can be driven at a cycle of approximately 100 Hz to tens of kHz. The higher the driving frequency, the more stably the circulating flow F is maintained, and the greater the effect of discharging the concentrated ink. On the other hand, it is effective to consider the increase in ink temperature caused by the heat generated accompanying the driving of the second energy generating element 24. For this purpose, the number of times the second energy generating element 24 is driven can be appropriately controlled.

[0104] Although an example of using an electrothermal conversion element as the second energy generating element 24 has been shown in the description given above, a piezoelectric element can also be used as the second energy generating element 24. In the case of a piezoelectric element, depending on its driving method, the direction of the circulating flow can be opposite to the direction described above.

[0105] U-shaped ink circulation structure

[0106] The U-shaped ink circulation structure is described as a comparative example of the linear ink circulation structure. Figures 7A to 7C This is a diagram showing a liquid injection head for a comparative example. Figure 7A This is a diagram showing the structure near the nozzle 11 of the liquid injection head in the comparative example, and a diagram showing the main components of the liquid injection head 1 when viewed in the Z direction. Figure 7B It is along Figure 7A The sectional view taken by line AA in the figure. Figure 7C It is shown Figure 7A The diagram near the single-use flow path in the middle.

[0107] The comparative example liquid jet head has a stacked substrate 18 and an orifice plate 19, and a jet nozzle array 63 consisting of a plurality of jet nozzles 11 arranged along the Y direction is formed in the orifice plate 19. A first energy generating element 14 and a second energy generating element 24 are arranged alternately in parallel with the jet nozzle array 63.

[0108] Between the substrate 18 and the perforated plate 19, a plurality of single-purpose flow paths 23 are formed, separated by a partition wall 21, communicating with a plurality of injection ports 11, and formed in a U-shape. Each single-purpose flow path 23 has a first portion 33 and a second portion 34 extending in the X direction, and a third portion 35 extending in the Y direction and connecting one end of the first portion 33 and the second portion 34 in the X direction. The other end of the first portion 33 and the second portion 34 in the X direction communicates with a flow path 64, and the flow path 64 communicates with a common flow path 43. The two ends of the single-purpose flow path 23 are adjacent to each other in the Y direction and communicate with the flow path 64 on the same side (one side) in the X direction. The common flow path 43 is configured to penetrate the substrate 18.

[0109] The second energy generating element 24 is disposed in the first part 33, and the pressure chamber 12 and the first energy generating element 14 are disposed in the second part 34. The single-use flow path 23 is a flow path formed by a U-shaped bend to connect the first energy generating element 14 and the second energy generating element 24 arranged along the Y direction.

[0110] In the single-use flow path 23, a pressure chamber 12 is formed at a position corresponding to the injection port 11. The pressure chamber 12 is connected to the flow path 64 via the connecting flow path 10 and via the connecting flow path 13. In other words, the single-use flow path 23 includes the pressure chamber 12, the connecting flow path 10, and the connecting flow path 13. The connecting flow path 13 is formed in a portion of the first part 33, the third part 35, and the second part 34, and the connecting flow path 10 is formed in a portion of the second part 34. A first energy generating element 14 is located near the connection between the connecting flow path 10 and the flow path 64, and a second energy generating element 24 is located near the connection between the connecting flow path 13 and the flow path 64.

[0111] As the ink flow in the single-use flow path 23, there are: (1) a first ink flow to supplement the ink ejected by driving the first energy generating element 14; and (2) a second ink flow as a circulating flow 27 generated by driving the second energy generating element 24.

[0112] When ink is ejected from the ejection port 11 by driving the first energy generating element 14, in order to supply the ink that is ejected along with the common flow path 43, the ink flows into the pressure chamber 12 from both the side of the connecting flow path 10 and the side of the connecting flow path 13.

[0113] When a circulating flow 27 is formed by driving the second energy generating element 24, ink flows into the single-use flow path 23 from the inlet 39 on the side of the connecting flow path 13, and flows out to the side of the connecting flow path 10 from the outlet 36. Based on the circulating flow 27 generated within the single-use flow path 23 (indicated by the arrow), ink flows in / out relative to the shared common flow path 43. Alternatively, methods such as... Figures 3A to 3DThe configuration shown is for communication with a common flow path (not shown) via a plurality of openings arranged in flow path 64 and along the Y direction. In this case, as... Figure 3B As shown, multiple openings are connected to a common flow path inside the chip.

[0114] In the comparative example liquid jet head, within a U-shaped single-use flow path 23, a first energy generating element 14 and a second energy generating element 24 are arranged along the Y direction and configured to align with the jet nozzle array 63. By driving the second energy generating element 24, a circulating flow 27 of ink can be generated within the single-use flow path 23. The two ends of the single-use flow path 23 are located on the same side (one side) in the X direction relative to the jet nozzle array 63. Therefore, the inlet 39 (upstream end) and outlet 36 (downstream end) of the circulating flow 27 are connected to a common flow path 64. This ink circulation configuration is referred to as U-shaped.

[0115] Recycle Concentration

[0116] Figures 5A to 5D This is a diagram showing the circulating flow and ink concentration in a linear ink circulation configuration. Figures 5A to 5D In this context, the degree of ink concentration is indicated by light and dark shades, with darker areas exhibiting higher concentration.

[0117] Figure 5A The diagram illustrates a situation where recording operations using the liquid jetting device 50 are temporarily suspended. When recording operations are temporarily suspended, the volatile components of the ink evaporate from the jetting nozzle 11, and ink concentration occurs near the jetting nozzle 11.

[0118] Figure 5B This illustrates the state immediately following the generation of the circulating flow 27 by the second energy generating element 24. The circulating flow 27 eliminates concentration near the nozzle 11. The ink concentrated near the nozzle 11 is discharged from the outlet 38, fresh ink flows in from the inlet 37, and concentration is eliminated throughout the single-use flow path 23.

[0119] Figure 5C This shows the state where recording is temporarily paused again after this point. Similar to... Figure 5A As shown, ink concentration occurs near the nozzle 11. Figure 5D This illustrates the state immediately following the regeneration of the circulating flow 27 by the second energy-generating element 24. Similar to... Figure 5B The state shown eliminates concentration near the nozzle 11 and also eliminates concentration throughout the single-use flow path 23.

[0120] In this way, in a linear ink circulation structure where the inlet 37 and outlet 38 of the single flow path 23 are separated, the concentrated state is also eliminated by repeatedly performing temporary stops and circulation operations.

[0121] Figures 6A to 6D This is a diagram illustrating the circulating flow and ink concentration in the U-shaped ink circulation structure of the comparative example.

[0122] Figure 6A The diagram illustrates a situation where recording operations using the liquid jetting device are temporarily suspended. When recording operations are temporarily suspended, ink concentration occurs near the jetting nozzle 11.

[0123] Figure 6B The diagram shows the state immediately after the circulation flow 27 has been generated by the second energy generating element 24. In the U-shaped ink circulation configuration, the inlet 39 and outlet 36 of the single-use flow path 23 are connected to and close to the common flow path 64. Therefore, although the ink concentrated near the nozzle 11 is discharged from the outlet 36 of the single-use flow path 23, ink can flow back into the single-use flow path 23 from the inlet 39. Accordingly, even when the circulation flow 27 is generated, the ink in the entire single-use flow path 23 is replaced by slightly concentrated ink rather than by fresh ink. This phenomenon is called recirculation concentration.

[0124] Figure 6C This shows the state where recording is temporarily suspended again after this point. From Figure 6B As shown in the diagram, the ink near nozzle 11 is further concentrated.

[0125] Figure 6D This illustrates the state immediately following the regeneration of the circulating flow 27 by the second energy generating element 24. (As shown) Figure 6B As explained in the text, due to the effect of recirculation and concentration, the ink in the entire single-use flow path 23 is compared to Figure 6B More concentrated ink replacement.

[0126] In this way, in the U-shaped ink circulation structure where the inlet 39 and outlet 36 of the single-use flow path 23 are adjacent to each other, the concentrated state is not eliminated even with repeated temporary stops and circulation operations, and concentration gradually occurs throughout the single-use flow path 23. Furthermore, even without repeated circulation operations, the ink becomes highly concentrated near the ejector nozzle 11 due to prolonged stops, etc. In this situation, the concentrated state is not easily improved even in the first circulation operation. This is because recirculation concentration is unlikely to effectively reduce the degree of concentration.

[0127] Therefore, there are differences in how to eliminate concentration when performing a cyclic operation after a temporary stop, depending on the difference in the effect of the discharged concentrated ink, between a straight-line structure where the inlet and outlet of the single-use flow path are separate from each other, and a U-shaped structure where the inlet and outlet of the single-use flow path are adjacent to each other. In the straight-line structure, it is easy to eliminate the concentration state throughout the single-use flow path, so the jetting stability is less likely to decrease due to concentrated ink. On the other hand, in the U-shaped structure, due to the concentration during recirculation, it is difficult to eliminate the concentration state throughout the single-use flow path, so the jetting is prone to instability depending on the concentration throughout the single-use flow path.

[0128] ink

[0129] By using an electrothermal conversion element (circulating heater) as a second energy generating element 24, an ink circulation flow is generated within the single-use flow path 23, thereby suppressing the influence of concentrated ink whose viscosity increases due to the evaporation of volatile components in the ejection nozzle 11. Accordingly, the ink ejection state can be well maintained, and changes in ejection speed, etc., can be reduced, thus stabilizing the ejection process.

[0130] Here, depending on the application of the liquid jet head 1 or the liquid jetting device 50, there will be different situations such as the type of pigment and the content of solid components in the ink to be used. For example, on ordinary paper, in order to suppress curling (warping) and wrinkling (wavy wrinkles) caused by water in the ink, it is conceivable to use ink with reduced water content. In ink with low water content, due to the high concentration of solid substances other than water (such as organic solvents, pigments, resins, etc.), the viscosity tends to increase rapidly with the evaporation of water, which can easily lead to a decrease in ink jetting stability. Generally, ink with a solid content of 10% by weight or more by mass (wt%) can be considered a high solid content ink.

[0131] In the liquid ejector head 1 according to Example 1, since a circulating flow 27 can be generated within the single-use flow path 23 having a pressure chamber 12, the increase in ink viscosity can be suppressed even when using ink containing a solid content of 10 wt% (mass %) or more. Therefore, this disclosure can be suitably applied to the liquid ejector head 1 and the liquid ejection device 50 using ink containing a solid content of 10 wt% (mass %) or more. The liquid ejector head 1 according to Example 1 maintains good ejection stability regardless of the type of ink.

[0132] Furthermore, regarding the operating temperature of the liquid ejector head 1, the liquid ejector head can be heated to a constant temperature by arranging heaters throughout the chip and controlling the heaters. Since the viscosity of the ink varies with temperature, the ink viscosity at the head operating temperature affects the ejection stability.

[0133] In the liquid jet head 1 according to Example 1, the velocity of the circulating flow 27 formed by the second energy generating element 24 in the single-use flow path 23 can be from tens of millimeters per second (mm / s) to 1000 mm / s as an instantaneous velocity. The average velocity over a time width of approximately several hundred microseconds depends on the driving frequency of the second energy generating element 24. This is because the circulating flow 27 generated by the second energy generating element 24 is a transitional flow that decays over time and stops after a predetermined time. When the driving frequency of the second energy generating element 24 is set to approximately 10 kHz to 20 kHz (the same level as the driving frequency (jet frequency) of the first energy generating element 14), the average velocity of the circulating flow 27 that can be formed is from a few mm / s to 100 mm / s.

[0134] When using ink with high pigment concentration, depending on the non-jetting time (pause time), the ink viscosity increases in the nozzle 11, the jetting speed changes, and jetting stability is easily reduced. For example, an ink with a concentration such that its viscosity at the head operating temperature is at least 3 centipoise (cP) and not more than 6 cP can be considered an ink with high pigment concentration. When using such ink, ink circulation can be performed with a short pause time. Therefore, by performing a stable ink circulation or a high-frequency transition ink circulation, concentration can be eliminated. In the liquid jet head 1 according to Example 1, by driving the second energy generating element 24, transition ink circulation can be induced in the single-use flow path 23. Therefore, in the liquid jet head 1 according to Example 1, by performing circulation operation at a high frequency, concentration in the nozzle 11 when using high-concentration ink can be eliminated.

[0135] When using ink with low pigment concentration, although the jetting speed changes depending on the non-jetting time (pause time), the effect is smaller compared to high-concentration inks. For example, an ink with a concentration such that its viscosity at the head operating temperature is 1 cP or more but less than 3 cP can be considered an ink with low pigment concentration. When the pause time is long, for example, the viscosity of the ink increases in the jet nozzle 11, for example, depending on the non-printing drive time (pause time). When restarting after a predetermined stop time without printing, the effects of thickened ink can be suppressed by performing suction operations, wiping operations, and recovery operations combined with them (such as initial jetting); however, such recovery operations involve waste ink.

[0136] In the liquid ejector head 1 according to Example 1, by driving the second energy generating element 24 to form a circulating flow 27 in the single-use flow path 23, concentration in the ejector nozzle 11 is eliminated, and the increase in ink viscosity can be suppressed. Therefore, depending on the stop time, waste ink generation can also be prevented by performing a recovery process that only performs the circulation operation. In addition, while performing recovery by performing the circulation operation, a recovery process to reduce waste ink can be performed by combining a suction operation (different from eliminating concentration) for removing air bubbles inside the head.

[0137] Regardless of ink concentration, to suppress the effects of concentrated ink, initial fresh ink can be supplied near the nozzle 11. When using a circulating heater as the second energy-generating element 24, the smaller the effect of recirculation concentration, the better the ink circulation effect can be obtained. Compared to a U-shaped ink circulation configuration, a linear ink circulation configuration better maintains jetting performance based on ink circulation.

[0138] Drive control

[0139] Figure 13 This is a block diagram illustrating the control structure of the liquid jetting device 50 according to Example 1. The central processing unit (CPU) 800 is a control unit for controlling the operation of various components of the liquid jetting device 50 based on programs (such as processing steps) stored in the read-only memory (ROM) 301. The random access memory (RAM) 302 serves as a work area, etc., when the CPU 800 performs processing. The CPU 800 receives image data from a host device 400 located outside the liquid jetting device 50 and controls the liquid jetting head 1 by controlling the head driver 1A based on the image data. The CPU 800 receives information about the detected temperature from the temperature sensor 53. The CPU 800 uses the head driver 1A to control the driving of the first energy generating element 14 and the second energy generating element 24 of the liquid jetting head 1. Specifically, the CPU 800 is a control unit for controlling the driving of the second energy generating element 24 based on the temperature detected by the temperature sensor 53.

[0140] The CPU 800 also controls the drivers of various actuators disposed in the liquid jetting device 50. For example, the CPU 800 controls the motor driver 303A of the carriage motor 303 for moving the carriage 60, the motor driver 304A of the transfer motor 304 for transferring the recording medium P, and the pump driver 21A of the external pump 40. Although Figure 13 The diagram illustrates a configuration for receiving image data from the host device 400, but processing can also be performed on the liquid jetting device 50 without using any data from the host device 400.

[0141] Figure 8This diagram illustrates the control configuration of the liquid injection head 1 according to Example 1. The substrate 18 of the liquid injection chip 3 is provided with a controller 100, a selective drive circuit 200, an on / off drive circuit 240, a first energy generating element 14 (An) (n = 1 to 16), and a second energy generating element 24 (Bn) (n = 1 to 16). The liquid injection chip 3 is connected to an external power supply 120 and an external circuit 110. The external circuit 110 includes... Figure 13 The head driver 1A is shown. The CPU 800 that controls the head driver 1A is a control unit (control section) that controls the drive of the first energy generating element 14 and the second energy generating element 24.

[0142] The selective drive circuit 200 includes an on / off drive circuit 230 for selecting the first energy generating element 14 and the second energy generating element 24. In response to a control signal received from the controller 100 at each address Nn (n = 1 to 16), the on / off drive circuit 230 turns on either the first energy generating element 14 or the second energy generating element 24 to be driven. The controller 100 controls the drive pulses used to drive the first energy generating element 14 or the second energy generating element 24 and the time interval for applying the drive pulses to each element.

[0143] The controller 100 uses the drive enable / disable signal 300 of the second energy generating element 24 to control the on / off drive circuit 240. This controls the drive of the second energy generating element 24 when it is selected in the on / off drive circuit 230.

[0144] In this way, the drive of the second energy generating element 24 is controlled by using the on / off drive circuit 230 and the on / off drive circuit 240.

[0145] When the drive enable / disable signal 300 is a signal used to prevent the second energy generating element 24 from being driven, the second energy generating element 24 will not be driven even if it is selected in the on / off drive circuit 230. In this case, neither the first energy generating element 14 nor the second energy generating element 24 will be driven. On the other hand, when the first energy generating element 14 is selected in the on / off drive circuit 230, the first energy generating element 14 will be driven.

[0146] When the drive enable / disable signal 300 is used to drive the second energy generating element 24, the second energy generating element 24 is driven when it is selected in the on / off drive circuit 230. When the first energy generating element 14 is selected, the first energy generating element 14 is driven.

[0147] Therefore, the second energy generating element 24 is controlled based on the drive data of the first energy generating element 14 and the drive enable / disable signal 300. As a result, since it is not necessary to prepare drive data for the second energy generating element 24, the amount of drive data can be reduced by half.

[0148] exist Figure 8 In the example shown, although a configuration is illustrated where 16 groups of first energy generating elements 14 and second energy generating elements 24 (a total of 32 elements) are controlled as a group, the configuration is not limited to this. For example, 8 groups (16 elements) or 12 groups (24 elements) of first energy generating elements 14 and second energy generating elements 24 can be controlled as a group. Furthermore, in the case of multiple second energy generating elements 24, a shared drive enable / disable signal 300 can also be used.

[0149] Features of Example 1

[0150] Figure 9A and Figure 9B This is a schematic diagram showing in detail the area near the nozzle of the liquid jet head that sprays liquid (such as ink) in Example 1. Figure 9A It is a plan view taken along the direction in which droplets are ejected from nozzle 11. Figure 9B It is along Figure 9A The sectional view taken in the direction of arrow A shown.

[0151] First, the layout configuration of each part of the liquid injection head 1 according to this example is described. Here, although the first, second, and third directions used to define the layout of each part of the liquid injection head 1 are the Z, X, and Y directions in this example, and these three directions are configured to be orthogonal to each other, the configuration is not limited to such a configuration. Within the scope of not affecting the function of the liquid injection head 1, for example, these directions may be configured to have small angles relative to the Z, X, and Y directions and intersect each other.

[0152] As a structure forming an ink ejection section (liquid ejection section), the liquid ejection head 1 according to this example has a pressure chamber 12, an ejection port 11, and a first energy generating element 14 that generates energy to eject ink disposed inside the pressure chamber from the ejection port 11. This ink ejection section is arranged in a single-use flow path 23 (circulation flow path) extending in a second direction (X direction) intersecting the first direction (Z direction) in which the ejection port 11 is opened. During the circulation of ink formed by the second energy generating element 24, the single-use flow path 23 has an inlet 37 at one end in the second direction for ink supplied to the pressure chamber 12 to flow in, and an outlet 38 at the other end for ink recovered from the pressure chamber 12 to flow out. Outside the inlet 37 of the single-use flow path 23, a first flow path 61 (inflow-side common flow path) communicating with the single-use flow path 23 via the inlet 37 is provided. Furthermore, outside the outlet 38 of the single-use flow path 23, a second flow path 62 (outflow-side common flow path) communicating with the single-use flow path 23 via the outlet 38 is provided.

[0153] The first flow path 61 and the second flow path 62 are configured to communicate with each other via a common flow path 29 (and a single flow path 23). The common flow path 29 (connecting passage) has a first opening 22 (inflow-side opening) in the first flow path 61 opening along a first direction (-Z direction) and an inflow-side common flow path 72 (inflow-side connecting passage) extending from the first opening 22 along the first direction (Z direction). Additionally, the common flow path 29 has a second opening 32 (outflow-side opening) in the second flow path 62 opening along the first direction (-Z direction) and an outflow-side common flow path 71 (outflow-side connecting passage) extending from the second opening 32 along the first direction (Z direction). The outflow-side common flow path 71 is formed on an inclined side surface 711, which is inclined such that its width in the second direction (X direction) increases the further away from the second opening 32 in the first direction. The inclined side surface 711 is inclined such that it extends beyond the position where the inflow-side common flow path 72 is arranged in the second direction. The inflow-side common flow path 72 is a flow path that extends in a straight line along the first direction, opens on the inclined side surface 711, and communicates with the outflow-side common flow path 71.

[0154] The multiple ink jetting sections, each consisting of a free pressure chamber 12, an ejector nozzle 11, and a first energy generating element 14, are arranged in a third direction (Y direction) intersecting both the first direction (Z direction) and the second direction (X direction). A single-use flow path 23 is arranged in each of the multiple ink jetting sections, and the multiple single-use flow paths are arranged corresponding to the multiple ink jetting sections. A first flow path 61 (shared inflow-side flow path) is configured as a shared inflow-side flow path communicating with the inlet 37 of the multiple single-use flow paths 23. A second flow path 62 (shared outflow-side flow path) is configured as a shared outflow-side flow path communicating with the outlet 38 of the multiple single-use flow paths 23.

[0155] The plurality of first openings 22 (inflow-side openings) of the common flow path 29 opening into the first flow path 61 are arranged in a third direction (Y direction), and their number is less than the number of ink jet sections (inlets 37). In other words, one of the plurality of first openings 22 serves as a common opening for some of the plurality of inlets 37.

[0156] The second opening 32 (outflow side opening) of the common flow path 29 opening into the second flow path 62 is a single opening communicating with each of the plurality of outlets 38. The second opening 32 is also arranged relative to each of the plurality of outlets 38 in a second direction (X direction) and has an opening shape extending along a third third direction (Y direction) such that the distance from each of the plurality of outlets 38 in the second direction is constant.

[0157] Next, the features of the liquid injection head 1 according to this example will be described. The liquid injection head 1 according to this example includes a first opening 22 and a second opening 32, and an injection port 11, a first energy generating element 14, and a second energy generating element 24 (circulating heating element) are arranged in a flow path between the first opening 22 and the second opening 32. Here, the first energy generating element 14 is arranged close to the second opening 32, and the second energy generating element 24 (circulating heating element) is arranged close to the first opening 22. In this arrangement, as described above, since the circulating flow becomes a flow from the second energy generating element 24 (circulating heating element) towards the first energy generating element 14, a flow is generated to flow out to the second opening 32.

[0158] Additionally, multiple first openings 22 are arranged to form a supply opening row. Second openings 32 are formed as a common supply opening. In this example, the first energy generating element 14 and the second energy generating element 24 are arranged at a pitch of 600 dots per inch (dpi), and the second openings 32 are arranged at a pitch of 150 dpi.

[0159] As a feature of this example, the first energy generating element 14 is arranged close to the second opening 32, which serves as a common supply opening. Furthermore, as a result of this configuration, the following effects exist. That is, two points are included: (1) suppressing changes in the jetting characteristics of the jetting heating element, which serves as the first energy generating element 14, and (2) suppressing the concentration of the ink flowing in from the second opening 32 accompanying the jetting.

[0160] Details are described below. Ink can be supplied to the interior of the injection port 11 in conjunction with the ejection of the first energy generating element 14. For ink supply, ink flows from the second opening 32 through the single-use flow path 23. When the distance from each single-use flow path 23 to the second opening 32 is different for each nozzle, the ejection characteristics are different for each nozzle, and the supplementary characteristics of nozzles farther away from the second opening 32 deteriorate. Therefore, the second opening 32, which is close to the ejection heating element of the first energy generating element 14, can be formed as a common supply opening. On the other hand, although the first opening 22 is divided into multiple single-use supply openings, the circulating heating element of the second energy generating element 24 only generates circulating flow, so its effect on ejection is small. Therefore, the first opening 22 also has little effect in the single-use supply openings. Therefore, by arranging the first energy generating element 14 close to the second opening 32, which is a common supply opening, the deterioration of the ejection characteristics of the ejection heating element can be suppressed.

[0161] Furthermore, a circulating flow is generated by driving the circulating heating element, which serves as the second energy generating element 24, to eliminate concentrated ink inside the ejector 11. The concentrated ink flows out through the common second opening 32 on the downstream side to the common outflow path 71. Here, the common outflow path 71 is configured with an inclined shape and a large opening volume. For this purpose, the outflowed concentrated ink can be diluted. Therefore, even when ink is replenished along with the ejector heating element, the concentrated ink is diluted as ink flows in from the second opening 32, thus suppressing the effect of concentration.

[0162] Although the inclined shape of the common flow path 71 on the outflow side can be of various shapes depending on the etching method of the substrate 18, a similar effect to this example can be obtained for any shape. Figure 9B The configuration shown is an example of a configuration where the outflow-side common flow path 71 is formed by anisotropic etching of Si and the inflow-side common flow path 72 is formed by dry etching. As a detail of the manufacturing method (forming method) of the substrate 18, a method similar to the manufacturing method described in Example 2 below can be used.

[0163] Furthermore, as an advantage of constructing the first opening 22 as multiple openings, the portion of the substrate 18 without the first opening 22 has a beam structure and can be used as a portion for wiring to pass through. In other words, the layout for wiring to drive the jet heating element as the first energy generating element 14 and the circulating heating element as the second energy generating element 24 can be easily implemented.

[0164] Example 2

[0165] refer to Figure 10A and Figures 10B to 12A to Figure 12HExample 2 of this disclosure is described below. Here, in Example 2, the same reference numerals are used to denote the structures common to Example 1, and the differences between Example 2 and Example 1 are mainly described. In Example 2, matters not specifically described herein are similar to those according to Example 1.

[0166] Figure 10A and Figure 10B This is a detailed schematic diagram showing the area near the nozzle of the liquid injection head according to Example 2. Figure 10A It is a plan view taken along the direction in which droplets are ejected from nozzle 11. Figure 10B It is along Figure 10A The cross-sectional view taken in the direction of arrow B shown in the figure. Figure 11A It is a cross-sectional view of the liquid injection head according to the variant of Example 1 of Example 2, and it corresponds to the view along... Figure 10A The sectional view shown is a cross-sectional view taken in the direction of arrow B. Figure 11B This is a cross-sectional view of the liquid injection head according to a variant of Example 2, and it corresponds to the view along... Figure 10A The sectional view shown is a cross-sectional view taken in the direction of arrow B. Figures 12A to 12H This is an explanatory diagram of the process of manufacturing the liquid injection head according to Example 2.

[0167] First, the layout of each part of the liquid jet head according to this example is described. The liquid jet head according to this example has the following structure: for the structure of Example 1 consisting of an ink jet section, a single-use flow path 23, a first flow path 61 and a common flow path 72 on the inflow side, a mirror-symmetric structure having opposite orientations in the second direction is further arranged on the opposite side of the second opening 32.

[0168] More specifically, a second ink jetting section is provided in the second direction (X direction) opposite to the side where the multiple ink jetting sections (jet nozzle 11, pressure chamber 12, and first energy generating element 14) are arranged. The second ink jetting section (second liquid jetting section) consists of a jet nozzle 11b, a pressure chamber 12b, and a first energy generating element 14b, and the multiple second ink jetting sections are arranged in the third direction (Y direction). Multiple single-use flow paths 23b (second circulation flow paths) are provided corresponding to the multiple second ink jetting sections. Each single-use flow path 23b has an inlet 37b (second inlet) located on the other side of the pressure chamber 12b in the second direction (X direction) and an outlet 38b (second outlet) located on one side of the pressure chamber 12b in the second direction. The single-use flow path 23b extends in the second direction such that the outlet 38b, pressure chamber 12b, and inlet 37b are arranged in this order in the second direction (the direction from one side of the second direction to the other (-X direction)). A third flow path 61b (a second inflow-side common flow path) is formed on the outside of the inlet 37b. According to this example, the common flow path 29 has an inflow-side common flow path 72b (a second inflow-side connecting passage), which is configured to be mirror-symmetrical with respect to the second opening 32 as the inflow-side common flow path 72. The inflow-side common flow path 72b has a third opening 22b (a second inflow-side opening) that opens into the third flow path 61b in a first direction (Z direction), extends from the third opening 22b along the first direction, opens into the inclined side surface 711 of the outflow-side common flow path 71, and communicates with the outflow-side common flow path 71.

[0169] Next, the features of the liquid injection head according to this example are described. The liquid injection head according to this example includes a first opening 22, a second opening 32, and a third opening 22b. A second energy generating element 24 (circulating heating element), an injection port 11, and a first energy generating element 14 are arranged in a flow path between the first opening 22 and the second opening 32. Similarly, a second energy generating element 24b (circulating heating element), an injection port 11b, and a first energy generating element 14b are arranged in a flow path between the second opening 32 and the third opening 22b. Here, the first energy generating elements 14 and 14b are both arranged close to the second opening 32, and the second energy generating elements 24 and 24b (circulating heating elements) are arranged close to the supply ports of the first opening 22 and the third opening 22b. In this arrangement, as described above, since the circulating flow becomes a flow from the second energy generating elements 24 and 24b (circulating heating elements) toward the first energy generating elements 14 and 14b, a flow outward to the second opening 32 is generated.

[0170] Furthermore, multiple first openings 22 and third openings 22b are arranged to form supply opening columns. A second opening 32 is formed as a common supply opening. The first openings 22 and third openings 22b are arranged at a spacing of 300 dpi. In this example, the column of injection ports 11b has the following arrangement, wherein the position is offset upwards from the column of injection ports 11. Additionally, although the two columns of supply openings are located at the same position in the direction between injection port columns, they can be offset to match the position of the injection ports in each column.

[0171] As a feature of this example, the first energy generating element 14 is arranged close to the second opening 32, which serves as a common supply opening. As a result of this configuration, the following effects are achieved. That is, there are two points, including: (1) suppressing changes in the jetting characteristics of the jetting heating element, which serves as the first energy generating element 14, and (2) suppressing the concentration of the ink flowing in from the second opening 32 accompanying the jetting.

[0172] Details are described below. Ink can be supplied to the interior of the injection port 11 in conjunction with the ejection of the first energy generating element 14. For ink supply, ink flows from the second opening 32 through the single-use flow path 23. When the distance from each single-use flow path 23 to the second opening 32 is different for each nozzle, the ejection characteristics are different for each nozzle, and the supplementary characteristics of nozzles farther away from the second opening 32 deteriorate. For this reason, the second opening 32, which is close to the ejection heating element of the first energy generating element 14, can be formed as a common supply opening. On the other hand, although the first opening 22 and the third supply opening 42 are divided into multiple single-use supply openings, the circulating heating element of the second energy generating element 24 only generates circulating flow, so its impact on ejection is small. Therefore, the first opening 22 and the third supply opening 42 also have little impact in the single-use supply openings. Therefore, by arranging the first energy generating element 14 close to the second opening 32, which is a common supply opening, the deterioration of the ejection characteristics of the ejection heating element can be suppressed.

[0173] Furthermore, a circulating flow is generated by driving the circulating heating element, which serves as the second energy generating element 24, to eliminate concentrated ink inside the ejector 11. The concentrated ink flows out through the common second opening 32 on the downstream side to the common outflow path 71. Here, the common outflow path 71 is constructed with an inclined shape and a very large opening volume. Therefore, the concentrated ink that has flowed out can be diluted. Thus, even when ink is replenished along with the ejector heating element, the concentrated ink is diluted as ink flows in from the second opening 32, thereby suppressing the effect of concentration.

[0174] Although the inclined shape of the common flow path 71 on the outflow side can be of various shapes depending on the etching method of the substrate 18, a similar effect to this example can be obtained for any shape. Figure 10B The configuration shown is an example of a configuration where an outflow-side common flow path 71 is formed using anisotropic etching of Si, and inflow-side common flow paths 72 and 72b are formed to communicate with the outflow-side common flow path 71 formed by anisotropic etching using dry etching. For example, in the case of anisotropic etching of a type (#100) Si wafer, the inflow-side common flow path is patterned and processed at an angle of 54.7 degrees relative to the crystal axis direction.

[0175] Figure 11A A variation of Example 2, Example 1, is shown. In the liquid jet head of Variation 1, the common flow path 29 has an inflow-side downstream common flow path 82, an inflow-side upstream common flow path 83, an outflow-side common flow path 81, an inflow-side downstream common flow path 82b, and an inflow-side upstream common flow path 83b. The inflow-side downstream common flow path 82 has a first opening 22 and extends linearly in a first direction to the inflow-side upstream common flow path 83. The inflow-side upstream common flow path 83 is formed on an inclined side surface 831, which is inclined such that the farther away from the inflow-side downstream common flow path 82 in the first direction (i.e., the Z direction), the greater its width in the second direction (i.e., the X direction). The outflow-side common flow path 81 has a second opening 32 and is formed on an inclined side surface 811, which is inclined such that the farther away from the second opening 32 in the first direction (i.e., the Z direction), the greater its width in the second direction (i.e., the X direction). The downstream common flow path 82b on the inflow side has a third opening 22b and extends linearly to the upstream common flow path 83b on the inflow side in a first direction. The upstream common flow path 83b on the inflow side is formed on an inclined side surface 831b, which is inclined such that the width in the second direction (i.e., the X direction) increases with distance from the downstream common flow path 82b in the first direction (i.e., the Z direction). The upstream common flow path 83b on the inflow side, the outflow side common flow path 81b, and the upstream common flow path 83b on the inflow side are formed by anisotropic etching of Si. The downstream common flow path 82b on the inflow side is formed to be interconnected by performing dry etching on the upstream common flow path 83b and the upstream common flow path 83b formed by anisotropic etching.

[0176] Figure 11BA variant of Example 2 is shown. In the liquid jet head according to Variant Example 2, the common flow path 29 has an inflow-side common flow path 92, an outflow-side common flow path 91, and an inflow-side common flow path 92b. The inflow-side common flow path 92 has a first opening 22 and is formed on an inclined side surface 921, the inclined side surface being inclined such that the farther away from the first opening 22 in the first direction (i.e., the Z direction), the greater the width in the second direction (i.e., the X direction). The outflow-side common flow path 91 has a second opening 32 and is formed on an inclined side surface 911, the inclined side surface being inclined such that the farther away from the second opening 32 in the first direction (i.e., the Z direction), the greater the width in the second direction (i.e., the X direction). The inflow-side common flow path 92b has a third opening 22b and is formed on an inclined side surface 921b, the inclined side surface being inclined such that the farther away from the third opening 22b in the first direction (i.e., the Z direction), the greater the width in the second direction (i.e., the X direction). The inflow-side common flow path 92, the outflow-side common flow path 91, and the inflow-side common flow path 92b are all formed by anisotropic etching of Si.

[0177] Figures 12A to 12H It shows the manufacturing basis. Figure 10B The process flow diagram of the liquid injection head shown in Example 2 is a cross-sectional view. Figure 12A The initial state of the substrate 18 of the liquid injection head is shown (the state in which the common flow path 29 consisting of the outflow side common flow path 71 and the inflow side common flow paths 72 and 72b has not yet been formed). Figure 12B This illustrates a state in which multiple holes 181 are formed on the rear surface side of the substrate 18 (the surface opposite to the surface where the first energy generating element 14 and the second energy generating element 24 are formed) by performing multiple laser processing operations. Figure 12C The diagram shows a state in which anisotropic etching is performed starting from multiple holes 181 by immersing the laser-processed substrate 18 in an etching solution to form recesses 182. Figure 12D The recess 182 is shown to be processed to communicate with the front surface side of the substrate 18 (the surface side on which the first energy generating element 14 and the second energy generating element 24 are formed). Figure 12E The state in which the film 183 is attached to the rear surface side of the substrate 18 is shown. Figure 12F The diagram shows a state in which a dry etching surface resist pattern 184 is formed on the surface side of the substrate 18 and an etching process is performed. Figure 12G It shows how to pass Figure 12F The dry etching process shown creates holes that connect with a pre-existing outflow-side common flow path 71, forming inflow-side common flow paths 72 and 72b. After this, Figure 12H The image shows the state where the film 183 on the rear surface side of the substrate 18 has been peeled off and the processing is complete.

[0178] In each of the examples above, the various constructs can be combined.

[0179] According to this disclosure, the jetting and circulation characteristics of a liquid can be improved in a liquid jet head comprising a liquid, an energy generating element for jetting, and an energy generating element for causing the liquid to flow.

[0180] Although this disclosure has been described with reference to examples, it is to be understood that this disclosure is not limited to the disclosed examples. The scope of the appended claims should be given the broadest interpretation to cover all variations and equivalent structures and functions.

Claims

1. A liquid ejection head comprising: a liquid ejection section configured to have a pressure chamber, an ejection port for ejecting liquid from the pressure chamber, and a first energy generating element that generates energy for ejecting liquid provided inside the pressure chamber from the ejection port; a circulation flow path configured to have an inlet into which liquid supplied to the pressure chamber flows and an outlet from which liquid recovered from the pressure chamber flows, the circulation flow path having the pressure chamber disposed between the inlet and the outlet; a second energy generating element configured to be disposed closer to the inlet side than the first energy generating element in the circulation flow path; and a common flow path configured to include an outflow side common flow path formed on the outside of the outlet, an inflow side common flow path formed on the outside of the inlet, and a communication passage that allows the outflow side common flow path and the inflow side common flow path to communicate with each other, wherein the ejection port is opened in a first direction, wherein the inlet is located on one side of the pressure chamber in a second direction that intersects the first direction, wherein the outlet is located on the other side of the pressure chamber in the second direction, wherein the circulation flow path extends in the second direction such that the inlet, the pressure chamber, and the outlet are arranged in this order in the second direction, and wherein the communication passage has an outflow side opening that is opened in the first direction in the outflow side common flow path, and includes an outflow side communication passage formed on a side surface that is inclined such that the width in the second direction is greater the farther away from the outflow side opening in the first direction.

2. The liquid ejection head according to claim 1, the communication passage has an inflow side opening that is opened in the first direction in the inflow side common flow path, and includes an inflow side communication passage that extends in the first direction from the inflow side opening, is opened on the side surface of the outflow side communication passage, and communicates with the outflow side communication passage. wherein 3. The liquid ejection head according to claim 2, the inflow side communication passage extends linearly in the first direction. wherein 4. The liquid ejection head according to claim 2, the inflow side communication passage is formed on a side surface that is inclined such that the width in the second direction is greater the farther away from the inflow side opening in the first direction. wherein, 5. The liquid ejection head according to claim 2, a plurality of liquid ejection sections are arranged to be arranged in a third direction that intersects both the first direction and the second direction, wherein wherein a plurality of circulation flow paths are arranged corresponding to the plurality of liquid ejection sections, wherein the outflow side common flow path communicates with each of the outlets of the plurality of circulation flow paths, wherein the inflow side common flow path communicates with each of the inlets of the plurality of circulation flow paths, and wherein the outflow side opening is a single opening that communicates with each of the plurality of outlets, and the outflow side opening is also side by side with each of the plurality of outlets in the second direction and has a shape that extends in the third direction such that the distance to each of the plurality of outlets in the second direction is constant.

6. The liquid ejection head according to claim 5, a plurality of inflow side openings are arranged to be arranged in the third direction, and the number of the plurality of inflow side openings is smaller than the number of the plurality of liquid ejection sections. wherein, 7. The liquid ejection head according to claim 5, ​ wherein, The liquid ejection section is a first liquid ejection section, the circulation flow path is a first circulation flow path, the inlet is a first inlet, the outlet is a first outlet, the inflow-side common flow path is a first inflow-side common flow path, the inflow-side opening is a first inflow-side opening, and the inflow-side communication passage is a first inflow-side communication passage, The liquid ejection head further includes: a plurality of second liquid ejection sections arranged in a third direction with respect to the outflow-side opening on a side opposite to a side on which the plurality of first liquid ejection sections are arranged in the second direction; and a plurality of second circulation flow paths arranged corresponding to the plurality of second liquid ejection sections, the second circulation flow path having a second inlet on a side of a pressure chamber of the second liquid ejection section in the second direction and a second outlet on a side of the pressure chamber of the second liquid ejection section in the second direction, and the second circulation flow path extending in the second direction such that the second outlet, the pressure chamber of the second liquid ejection section, and the second inlet are arranged in this order in the second direction, wherein the communication passage includes: a second inflow-side common flow path formed on an outer side of the second inlet; and a second inflow-side communication passage having a second inflow-side opening opened in the first direction in the second inflow-side common flow path, the second inflow-side communication passage extending in the first direction from the second inflow-side opening, being opened on a side surface of the outflow-side communication passage, and communicating with the outflow-side communication passage.

8. The liquid ejection head according to claim 7, wherein the second inflow-side communication passage extending linearly in the first direction.

9. The liquid ejection head according to claim 7, wherein the second inflow-side communication passage being formed on a side surface inclined such that a width in the second direction becomes larger the farther away from the inflow-side opening in the first direction.

10. The liquid ejection head according to any one of claims 7 to 9, wherein the plurality of second inflow-side openings are arranged to be arranged in the third direction, and a number of the plurality of second inflow-side openings is smaller than a number of the plurality of second liquid ejection sections.

11. The liquid ejection head according to claim 1 or 2, wherein in the circulation flow path, a flow resistance R1 between the second energy generating element and the inlet and a flow resistance R2 between the second energy generating element and the outlet have a flow resistance ratio R1 / R2 of at least 0.05 and not more than 0.

40.

12. The liquid ejection head according to claim 11, wherein the second energy generating element is an electro-thermal conversion element.

13. The liquid ejection head according to claim 5, wherein the plurality of second energy generating elements corresponding to the plurality of liquid ejection sections are configured to be driven using a common control signal.

14. A liquid ejection apparatus including: the liquid ejection head according to claim 1; and a supply unit configured to supply a liquid to the liquid ejection head.

15. A manufacturing method for manufacturing the liquid ejection head according to claim 1, the manufacturing method including: forming the outflow-side communication passage using anisotropic etching.

16. A manufacturing method for manufacturing the liquid ejection head according to claim 3, the manufacturing method including: forming the outflow-side communication passage using anisotropic etching, and forming the inflow-side communication passage using dry etching.

17. A manufacturing method for manufacturing the liquid ejection head according to claim 4, the manufacturing method comprising: forming the outflow-side communication passage and the inflow-side communication passage using anisotropic etching.

18. A manufacturing method for manufacturing the liquid ejection head according to claim 8, the manufacturing method comprising: forming the second inflow-side communication passage using dry etching.

19. A manufacturing method for manufacturing the liquid ejection head according to claim 9, the manufacturing method comprising: forming the second inflow-side communication passage using anisotropic etching.

Images