Liquid ejection head and liquid ejection device

Abstract

The amount of data required to drive the liquid ejection head is reduced. [Solution] The liquid ejection head comprises a flow path forming portion having an ejection port from which liquid is ejected, a pressure chamber communicating with the ejection port, and an individual flow path communicating with the pressure chamber, a first energy generating element provided at a position corresponding to the pressure chamber in the flow path forming portion and generating energy for ejecting liquid from the ejection port, a second energy generating element provided at a position corresponding to the individual flow path in the flow path forming portion and generating energy for liquid to flow through the individual flow path, and a selection drive circuit 200 that determines whether to drive the second energy generating element depending on whether to drive the first energy generating element.

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection apparatus equipped with the liquid ejection head. [Background technology]

[0002] A circulation-type liquid ejection device is known that circulates ink to expel air bubbles in the flow path of the liquid ejection head and to suppress thickening of ink near the ejection orifices. As a circulation mechanism for circulating ink, there is a configuration in which a circulation flow path communicating with the ejection orifices is provided in the liquid ejection head, and an energy generating element is provided to generate energy to circulate the ink.

[0003] Patent Document 1 discloses a configuration including an ejection element for ejecting liquid from an ejection port, a pump element for circulating the liquid in a circulation flow path, and a drive circuit for independently driving the ejection element and the pump element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2013-544678 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above configuration, each ejection element and pump element is addressed separately, and separate drive data is required to drive each element. Therefore, as the number of ejection elements and pump elements increases, the amount of data handled also increases.

[0006] The present invention has been made in view of the above-mentioned problems, and has as its object to reduce the amount of data required to drive a liquid ejection head. [Means for solving the problem]

[0007] In order to achieve the above object, the liquid ejection head of the present invention comprises: a flow path forming portion having an ejection port from which a liquid is ejected, a pressure chamber communicating with the ejection port, and an individual flow path communicating with the pressure chamber; a first energy generating element provided at a position corresponding to the pressure chamber of the flow path forming portion, the first energy generating element generating energy for ejecting liquid from the ejection port; a second energy generating element provided at a position corresponding to the individual flow path of the flow path forming portion, the second energy generating element generating energy for causing liquid to flow through the individual flow path; a selection drive circuit that determines whether to drive the second energy generating element depending on whether to drive the first energy generating element; The present invention is characterized by comprising: [Effects of the Invention]

[0008] According to the present invention, the amount of data required to drive the liquid ejection head can be reduced. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a schematic configuration of a liquid ejection device according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing a control system of the liquid ejection device according to the first embodiment. [Figure 3] FIG. 1 is an explanatory diagram of a liquid ejection head according to a first embodiment. [Figure 4] FIG. 10 is an explanatory diagram of a straight-type flow channel configuration. [Figure 5] FIG. 2 is an explanatory diagram of the principle of generation of a circulating flow of ink. [Figure 6] FIG. 10 is an explanatory diagram of the concentrated state of ink in a straight individual flow path. [Figure 7] FIG. 10 is an explanatory diagram of the ink concentration state in a U-shaped individual flow path. [Figure 8] FIG. 1 is an explanatory diagram of a U-shaped flow channel configuration. [Figure 9]FIG. 10 is a block diagram illustrating the configuration of a selection drive circuit according to a comparative configuration. [Figure 10] FIG. 2 is a block diagram illustrating the configuration of a selection drive circuit according to the first embodiment. [Figure 11] FIG. 10 is a schematic diagram of the vicinity of an ejection port of a liquid ejection head according to a second embodiment. [Figure 12] FIG. 10 is a diagram showing an example of the wiring arrangement of a selection drive circuit. [Figure 13] FIG. 10 is a schematic diagram of the vicinity of an ejection port of a liquid ejection head according to a third embodiment. [Figure 14] FIG. 10 is a schematic diagram of the vicinity of an ejection port of a liquid ejection head according to a fourth embodiment. [Figure 15] FIG. 11 is a schematic diagram of the vicinity of an ejection port of a liquid ejection head according to a fifth embodiment. [Figure 16] FIG. 13 is a schematic diagram of the vicinity of an ejection port of a liquid ejection head according to a sixth embodiment. [Figure 17] FIG. 13 is a schematic diagram of the vicinity of an ejection port of a liquid ejection head according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes in detail the embodiments of the present invention with reference to the drawings. The dimensions, materials, shapes, and relative positions of the components described in the embodiments may be changed as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, the scope of the present invention is not limited to the following embodiments.

[0011] The present invention relates to a recording element unit provided in a liquid ejection head that performs recording by ejecting liquid onto a recording medium. The present invention is preferably applicable to, for example, a recording element unit of an inkjet head provided in an inkjet printer that uses an inkjet recording method to perform recording by foaming a liquid such as ink using thermal energy. However, the recording element unit of the present invention is not limited to this, and can be applied to recording element units of various liquid ejection heads that eject liquid using thermal energy.

[0012] Hereinafter, a liquid ejection head and a liquid ejection device including the liquid ejection head according to an embodiment of the present invention will be described with reference to the drawings. In each of the following embodiments, a specific configuration of a liquid ejection head that ejects ink will be described, but the present invention is not limited thereto. The liquid ejection head of the present invention can be applied to devices such as printers, copiers, facsimiles with communication systems, and word processors with printer units, as well as industrial recording devices combined with various processing devices. For example, it can also be used in applications such as biochip production and electronic circuit printing.

[0013] First Embodiment A liquid ejection apparatus 50 according to a first embodiment of the present invention will be described below. The liquid ejection apparatus 50 is an inkjet recording apparatus that uses an inkjet recording method, and includes a liquid ejection head 1 that can eject ink as a liquid.

[0014] (Liquid discharge device) The schematic configuration of a liquid ejection device 50 according to the first embodiment will be described. Figures 1(a) and 1(b) are perspective views showing an example of the configuration of a recording unit of the liquid ejection device 50. The liquid ejection device 50 is a serial type liquid ejection device that records an image by ejecting liquid onto a recording medium P using a liquid ejection head 1 that scans in a direction intersecting the transport direction of the recording medium P.

[0015] The application of the present invention is not limited to serial-type liquid ejection devices. For example, the present invention can also be applied to a page-wide type liquid ejection device that uses a line head (page-wide type head) that is long in the page width direction of the recording medium to eject liquid onto the recording medium being transported in the transport direction to record an image.

[0016] The liquid ejection head 1 is capable of ejecting four types of ink: black (K), cyan (C), magenta (M), and yellow (Y), and is capable of recording full-color images using these inks. The inks that can be ejected from the liquid ejection head are not limited to the four types of ink mentioned above. The present disclosure is also applicable to liquid ejection heads for ejecting other types of ink. In other words, there are no limitations on the types and number of inks that can be ejected from the liquid ejection head.

[0017] In the following explanation, the scanning direction (movement direction) of the liquid ejection head 1 is referred to as the X direction, the transport direction of the recording medium P in the recording unit as the Y direction, and the vertical direction as the Z direction. The X direction, Y direction, and Z direction intersect with each other (in this example, they are perpendicular). Furthermore, the scanning direction (movement direction) of the liquid ejection head 1 may be referred to as the main scanning direction, and the transport direction of the recording medium P as the sub-scanning direction.

[0018] In a serial type liquid ejection device 50, the liquid ejection head 1 is mounted on a carriage 60. The carriage 60 moves back and forth in the main scanning direction (X direction) along a guide shaft 51. The recording medium P is transported in the sub-scanning direction (Y direction) that intersects (in this example, is perpendicular to) the main scanning direction by transport rollers 55, 56, 57, and 58 that constitute a transport unit (transport means).

[0019] Fig. 1(a) is a perspective view showing an example of a configuration in which a main ink tank 2 serving as a liquid storage unit is provided in the device body (outside the liquid ejection head 1) of a liquid ejection device 50, and a sub-ink tank 54 is provided in the liquid ejection head 1. The liquid (ink) stored in the ink tank 2 is supplied to the sub-ink tank 54 on the liquid ejection head 1 side via an ink supply tube (liquid communication path) 59 or the like by the driving force of an external pump 71. In other words, in the example shown in Fig. 1(a), the device body of the liquid ejection device 50 and the liquid ejection head 1 are each provided with a liquid storage unit for storing ink.

[0020] Fig. 1(b) is a perspective view showing an example of a configuration in which there is no main ink tank 2, and an ink tank 54 is provided directly above the liquid ejection head 1. In this case, the liquid ejection head 1 may be provided integrally with the ink tank 54 and configured to be removable and attachable to the carriage 60. Alternatively, the liquid ejection head 1 may be provided integrally with the carriage 60, and only the ink tank 54 may be removable and attachable. The following description will be given using the configuration in Fig. 1(a) as a representative example.

[0021] The liquid ejection head 1 is configured to include individual ejection units, which will be described later. The specific configuration will be described later, but the individual ejection unit is a recording element unit in which ejection ports for ejecting liquid, pressure chambers communicating with the ejection ports, and individual flow paths communicating with the pressure chambers are formed. The individual ejection unit also includes a first energy generating element (ejection energy generating element) that generates energy for ejecting liquid from the ejection ports, and a second energy generating element (flow energy generating element) that generates energy for causing the liquid to flow through the individual flow paths. The first energy generating element is provided at a position corresponding to the pressure chamber, and the second energy generating element is provided at a position corresponding to the individual flow paths. The liquid ejection head 1 has a plurality of individual ejection units, each of which has a supply flow path for supplying liquid to the individual flow paths in the individual ejection unit.

[0022] When using the liquid ejection head 1, the evaporation of volatile components such as water at the ejection ports and the resulting concentration of solids near the ejection ports can sometimes cause the ejection of the liquid to become unstable, and various measures have been taken to prevent this. For example, the liquid ejection device 50 can be provided with a cap member (not shown) at a position offset in the X direction from the conveyance path of the recording medium P, which can cover the ejection port surface of the liquid ejection head 1 on which the ejection ports are formed. The cap member covers the ejection port surface of the liquid ejection head 1 when the recording operation is not being performed, and prevents the ejection ports from drying out. It is used for prevention and protection purposes.

[0023] Furthermore, an ink suction mechanism (not shown) can be provided in the liquid ejection device 50. When an ink suction mechanism is provided, the cap member is used to suck ink from the ejection ports. By performing this ink suction operation, the ink near the ejection ports can be refreshed, and the quality of the resulting image can be maintained.

[0024] It is also possible to discard concentrated ink by performing a process known as preliminary ejection (preliminary ejection) when no printing operation is being performed. Furthermore, even during printing, it is possible to preliminarily eject an inconspicuous amount of ink onto a position on the printing medium that is not noticeable in terms of image quality (paper preliminary ejection / intra-page preliminary ejection). While these methods contribute greatly to improving image quality, they also waste some ink to refresh the ejection orifices, so it is necessary to reduce the amount of wasted ink as much as possible.

[0025] To address this issue, by providing a second energy generating element (flow energy generating element) in each individual flow path and circulating the ink within the flow path, it is possible to suppress the drying of the ejection ports and the concentration of ink near the ejection ports while reducing the amount of waste ink. More specifically, it is possible to minimize the number of preliminary ejections and suction recovery operations. Furthermore, reducing the number of preliminary ejections and other operations also leads to improvements in throughput and yield.

[0026] The second energy generating element (flow energy generating element) does not necessarily have to be provided in all of the individual discharge units of the liquid discharge head. If it is provided in some of the individual discharge units, the above-mentioned effect can be obtained compared to when no second energy generating element is provided.

[0027] Furthermore, the liquid ejection head 1 may be configured so that all of the locations corresponding to the four types of ink are provided with second energy generating elements, or so that only the locations corresponding to one type of ink are provided with second energy generating elements. In other words, the liquid ejection head may be configured so that only at least one type of ink is circulated, rather than all four types of ink.

[0028] 2 is a block diagram showing a control system of the liquid ejection device 50. The CPU 800 is a control unit that controls the operation of each unit of the liquid ejection device 50 based on programs such as processing procedures stored in the ROM 301. The RAM 302 is used as a work area when the CPU 800 executes processing. The CPU 800 receives image data from a host device 400 external to the liquid ejection device 50, for example, and controls the head driver 1A based on the image data to control the driving of the ejection elements provided in the liquid ejection head 1.

[0029] The CPU 800 also controls drivers of various actuators provided in the liquid ejection device 50. For example, the CPU 800 controls a motor driver 303A of a carriage motor 303 for moving the carriage 60, a motor driver 304A of a conveyance motor 304 for conveying the recording medium P, a pump driver 71A of an external pump 71, etc. Note that while FIG. 2 shows a form in which processing is performed after receiving image data from the host device 400, processing may also be performed in the liquid ejection device 50 without relying on data from the host device 400.

[0030] (liquid ejection head) An example of the configuration of the liquid ejection head 1 will now be described. Figures 3(a) to 3(d) are explanatory diagrams of the liquid ejection head 1 according to the first embodiment. Figure 3(a) is an exploded perspective view of the liquid ejection head 1.

[0031] The liquid ejection head 1 has four sub ink tanks 5 that temporarily store ink in the head. 4, and a liquid ejection tip 3 for ejecting ink supplied from a sub-ink tank 54 onto a recording medium P.

[0032] The liquid ejection head 1 further includes a first support member 4, a second support member 7, and an electric wiring member (electric wiring tape) 5. The liquid ejection chip 3 is connected to one surface of the first support member 4, and an ink tank 54 is connected to the other surface. A flow path is formed in the first support member 4, penetrating from one surface to the other opposite surface, and the first support member 4 sends ink supplied from the ink tank 54 to the liquid ejection chip 3 while supporting the liquid ejection chip 3.

[0033] The second support member 7 is connected to the connection surface of the first support member 4 that connects to the liquid ejection chip 3. The second support member 7 has an opening formed therein through which the liquid ejection chip 3 can be inserted, and is connected to the first support member 4 so that the liquid ejection chip 3 is positioned within the opening. The second support member 7 also supports the electrical wiring member 5.

[0034] The electrical wiring member 5 is electrically connected to the liquid ejection chip 3 and sends to the liquid ejection chip 3 an ejection signal for ejecting ink, which is sent from the main body of the liquid ejection device 50 or the like.

[0035] The liquid ejection head 1 in the first embodiment is fixedly supported on a carriage 60 by positioning means and electrical contacts (not shown) provided on the carriage 60 of the liquid ejection device 50. The liquid ejection head 1 ejects ink while moving together with the carriage 60 in the main scanning direction (X direction) to perform recording on the recording medium P.

[0036] An ink supply tube 59 is provided to an external pump 71 connected to a main ink tank 2, which serves as an ink supply source. A liquid connector (not shown) is provided at the end of the ink supply tube 59. When the liquid ejection head 1 is mounted on the liquid ejection device 50, the liquid connector provided at the end of the ink supply tube 59 is liquid-tightly connected to a liquid connector insertion port, which is a liquid inlet port provided in a head housing of the liquid ejection head 1. This forms an ink supply path from the ink tank 2 via the external pump 71 to the liquid ejection head 1. In the first embodiment, four types of ink are used, so a total of four sets of ink tanks 2, external pumps 71, ink supply tubes 59, and sub-ink tanks 54 are provided, one for each ink. The liquid ejection device 50 is then formed with four independent ink supply paths, one for each ink.

[0037] In this way, the liquid ejection device 50 is provided with an ink supply system to which ink is supplied from the ink tank 2 provided outside the liquid ejection head 1. The liquid ejection device 50 is not provided with an ink recovery system to recover ink inside the liquid ejection head 1 to the ink tank 2. Therefore, the liquid ejection head 1 is provided with a liquid connector insertion port for connecting the ink supply tube 59 of the ink tank 2, but is not provided with a connector insertion port for connecting a tube for recovering ink from the liquid ejection head 1 to the ink tank 2. A liquid connector insertion port is provided for each ink.

[0038] Figures 3(b), (c), and (d) are diagrams showing examples of the configuration of the liquid ejection chips 3 that make up the liquid ejection head 1. Figure 3(b) shows an example of a configuration where one chip is used for four colors of ink. Figure 3(c) shows an example of a configuration where one chip is used for two colors of ink. Figure 3(d) shows an example of a configuration where one chip is used for one color of ink. Each liquid ejection chip 3 is provided with an ejection port 11 and pads used for electrical mounting. Figure 3(a) shows the chip configuration of Figure 3(b).

[0039] FIG. 3(b) shows an example in which one liquid ejection chip 3 is provided for each of four colors of ink, and the liquid ejection head 1 is provided with one liquid ejection chip 3. The four colors are, for example, black, cyan, magenta, and yellow. The liquid ejection chip 3 has a plurality of ejection ports 11 evenly spaced in the Y direction. An array of ejection openings arranged side by side at intervals is provided for each color. In this example, two arrays of ejection openings arranged offset in the X direction are provided for each color. Note that instead of two arrays of ejection openings for each color, only one array of ejection openings may be provided. Also, two arrays of ejection openings may be provided for black, for a total of five arrays for four colors.

[0040] 3(c) shows an example in which one liquid ejection chip 3 is provided for each of two colors of ink, and the liquid ejection head 1 is equipped with two liquid ejection chips 3. When mounting two chips on the liquid ejection head 1, two chips may be mounted on one liquid ejection head 1, or two heads may be prepared, each with one chip mounted on one liquid ejection head 1.

[0041] Fig. 3(d) shows an example in which one liquid ejection chip 3 is provided for each color of ink, and the liquid ejection head 1 is provided with four liquid ejection chips 3. In this example, as in the example of Fig. 3(c), four chips may be mounted on one liquid ejection head, or four liquid ejection heads, each mounted with one chip, may be prepared.

[0042] Also, when the chip is divided into multiple parts, as shown in Figure 3(c) and (d), not all of them need to be the same chip length. Also, various combinations of other colors for the chip are possible, and the same applies when the total number of colors is more than four.

[0043] (liquid ejection chip) The configuration of the liquid ejection chip 3, particularly the components of the circulation unit, will be described in more detail. First, two basic configurations, "straight type" and "U-shaped type," will be described as examples of the configuration of individual flow paths in the liquid ejection chip 3. Each individual flow path is a flow path in which a first energy generating element (ejection energy generating element) and a second energy generating element (flow energy generating element) are arranged in correspondence with each other, and which sends ink to the ejection port 11.

[0044] [Straight type] In this specification, a "straight-type" individual flow path means an individual flow path that has a straight shape extending in a direction intersecting with the ejection port array so that both ends of the individual flow path are located on either side of the ejection port array. In other words, in the individual flow path of the individual ejection unit, the first energy generating element and the second energy generating element are arranged side by side in a direction intersecting with the ejection port array.

[0045] 4(a) to 4(d) are explanatory diagrams of a straight-type flow path configuration. FIG. 4(a) is an explanatory diagram of the configuration near the ejection orifice 11 of the liquid ejection chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid ejection chip 3 is viewed in the Z direction. The Z direction is approximately parallel to the direction in which liquid is ejected from the ejection orifice 11. FIG. 4(b) is a cross-sectional view taken along line AA in FIG. 4(a). FIG. 4(c) is a cross-sectional view taken along line AA in FIG. 4(a) showing a configuration example different from the example shown in FIG. 4(b). FIG. 4(d) is a diagram explaining the flow of ink when the first energy generating element 14 is driven. In FIG. 4(a), the first energy generating element 14 and the second energy generating element 24 are shown with hatching similar to that in FIG. 4(b) to show the positional relationship of the main components, and the ejection orifice 11 is shown with a solid line.

[0046] The liquid ejection chip 3 has a substrate 18 in which ejection ports 11 are formed, and an orifice plate 19 connected to the substrate 18 and having a flow path formed therein, and is a flow path forming portion in which a flow path through which ink flows is formed. Ink supplied from an ink tank 54 passes through the flow path formed in the substrate 18 and is ejected from the ejection ports 11. An ink meniscus is formed at the ejection port 11, forming an ejection port interface as an interface between the ink and the atmosphere.

[0047] Between the substrate 18 and the orifice plate 19, pressure chambers 12 are formed, each separated by a partition wall 21 and corresponding to each ejection port 11, and individual flow paths 23 for causing ink to flow through these pressure chambers 12. In the configuration example shown in Fig. 4(a), the pressure chambers 12 and the individual flow paths 23 are formed corresponding to each of the plurality of ejection ports 11. Fig. 4(a) shows the individual flow paths 23 formed in a straight line from a position corresponding to the first energy generating element 14 to a position corresponding to the second energy generating element 24. In this example, the extension direction of the individual flow paths 23 (X direction) is perpendicular to the direction in which the ejection ports 11 are lined up in a row (Y direction).

[0048] The liquid ejection chip 3 is formed with a first opening 22 communicating with one end of the individual flow path 23 and a second opening 32 communicating with the other end of the individual flow path 23. In the first embodiment, one first opening 22 and one second opening 32 are provided for each individual flow path 23. That is, in the X direction, the first opening 22 is located on one side of the individual flow path 23, and the second opening 32 is located on the other side. The liquid ejection chip 3 also has a common flow path 25 communicating with the multiple first openings 22 and the multiple second openings 32.

[0049] 4(a), a plurality of independent openings such as the first opening 22 and the second opening 32 are provided as openings for supplying liquid from the common flow path 25 to the individual flow paths 23, but the present invention is not limited to this configuration. For example, as shown in Fig. 8(a) described later, a configuration in which a supply groove is provided as one large opening may also be used.

[0050] The substrate 18 is provided with a first energy generating element 14 that generates energy for ejecting ink in the pressure chamber. The first energy generating element 14 is provided at a position that overlaps with the ejection port 11 and the pressure chamber 12 of the individual flow path 23 when viewed in the Z direction. The first energy generating element 14, together with the ejection port 11 and the pressure chamber 12, is located closer to the second opening 32 than the first opening 22. By driving the first energy generating element 14 to generate heat and cause the ink in the pressure chamber 12 to bubble, the resulting bubble-generating energy can be used to eject ink from the ejection port 11.

[0051] In the first embodiment, an electrothermal converting element is used as the first energy generating element 14. However, the first energy generating element 14 is not limited to an electrothermal converting element, and a piezoelectric element or the like can also be used.

[0052] The substrate 18 is further provided with second energy generating elements 24 that generate energy to generate a circulating flow 27, which is a flow of ink in the individual flow paths. The second energy generating elements 24 are located closer to the first opening 22 than the second opening 32. As shown by the arrows in FIG. 4(a), the circulating flow 27 is directed from the second energy generating elements 24 toward the first energy generating elements 14 and is substantially parallel to the X direction.

[0053] In the first embodiment, the second energy generating element 24 is an electrothermal converting element.

[0054] The individual flow paths 23 extend in a second direction (X direction) that intersects (in this example, is perpendicular to) the first direction (Y direction) in which the ejection ports 11 are lined up in rows. The individual flow paths 23 include a pressure chamber 12, an inlet (upstream) connection flow path 13 that communicates with one end of the pressure chamber 12, and an outlet (downstream) connection flow path 26 that communicates with the other end of the pressure chamber 12. In the following description, the terms inlet (inlet), outlet (outlet), upstream, and downstream of the individual flow paths 23 refer to their positional relationship in the flow of ink during circulation when the second energy generating element 24 is driven.

[0055] The individual flow paths 23 communicate at one upstream end and the other downstream end with a first opening 22 and a second opening 32 that penetrate the substrate 18. Therefore, the connecting flow paths 13 are arranged in a direction perpendicular to the ejection port array. The second energy generating element 24 is located on the second energy generating element side. In other words, when viewed in the Z direction, the second energy generating element 24 is provided at a position overlapping with the connection flow path 13 of the individual flow path 23. The two ends of the individual flow path 23 are located on opposite sides of the ejection port row in the X direction.

[0056] The ink flows in the individual flow paths 23 are broadly classified into two types: (1) a first ink flow for driving the first energy generating element 14 and refilling after ejection, and (2) a second ink flow for driving the second energy generating element 24 and forming a circulating flow 27.

[0057] When the first energy generating element 14 is driven and ink (liquid) is ejected from the ejection port 11, ink is supplied from the first opening 22 and the second opening 32 as the ink is ejected. That is, ink flows into the pressure chamber 12 from both openings (the first opening 22 and the second opening 32) via the individual flow paths 23. In FIG. 4(d), arrows indicate the flow of ink when the first energy generating element 14 is driven and ink droplets (liquid droplets) are ejected from the ejection port 11. This flow is the first ink flow. At this time, the first opening 22 and the second opening 32 each function as a supply opening for supplying ink to the individual flow paths 23.

[0058] When the second energy generating element 24 is driven to form the circulation flow 27, ink flows into the individual flow path 23 through the first opening 22 on the connecting flow path 13 side, and ink flows out to the outside through the second opening 32 on the connecting flow path 26 side. In this example, the ink that flows out from the second opening 32 is returned to the first opening 22 and circulated, thereby forming the circulation flow 27 inside the individual flow path 23. At this time, the first opening 22 functions as a supply opening for supplying ink to the individual flow path 23, and the second opening 32 functions as a recovery opening for recovering the ink that has flowed out from the individual flow path 23.

[0059] 4(b) shows a configuration in which the first opening 22 and the second opening 32 are shared within the chip and communicate with the same common flow path 25, but the configuration is not limited to this. For example, as shown in FIG. 4(c), the first opening 22 and the second opening 32 may be connected to separate flow paths and shared outside the recording head.

[0060] Filters 31 for removing foreign matter from the ink may be provided in the ink circulation paths inside and outside the liquid ejection head 1. In the example shown in Fig. 4(a), the filters 31 are disposed outside the individual flow paths 23, on the inlet and outlet sides of the individual flow paths 23. Alternatively, the filters 31 may be disposed between the first energy generating element 14 and the second energy generating element 24 in the individual flow paths 23. In this case, the filters 31 do not need to be disposed on the upstream side (second energy generating element side) outside the individual flow paths 23.

[0061] [U-shape] In this specification, a "U-shaped" individual flow path means a flow path that is U-shaped when viewed in the Z direction. That is, in the individual flow path, the first energy generating element and the second energy generating element are arranged along the ejection port row. The individual flow path is configured so that both ends are located on one side of the ejection port row. In the following description of the U-shaped individual flow path, elements similar to those of the straight-type individual flow path shown in Figures 4(a) to 4(d) will be assigned the same reference numerals and will not be described again.

[0062] 8(a) to 8(d) are explanatory diagrams of a U-shaped flow path configuration. FIG. 8(a) is an explanatory diagram of the configuration in the vicinity of the discharge port 11 of the liquid discharge chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid discharge chip 3 is viewed in the Z direction. FIG. 8(b) is a BB cross-sectional view of FIG. 8(a). FIG. 8(c) is an enlarged schematic diagram of the individual flow path section in FIG. 8(a). In FIG. 8(a), the first energy generating element 14 and the second energy generating element 24 are hatched in the same manner as in FIG. 8(b) to show the positional relationship of the main components. 1, and the outlet 11 is shown in solid lines.

[0063] 8(a), two ejection port arrays are shown, each configured with a plurality of ejection ports 11 aligned in the Y direction. Individual flow paths 23 including pressure chambers 12 are formed corresponding to each of the plurality of ejection ports 11. In addition, a supply groove 42 is formed in the substrate 18 between the two ejection port arrays, with the Y direction as its longitudinal direction and opening in the Z direction.

[0064] The first energy generating elements 14 and the second energy generating elements 24 are both located near the supply groove 42 and are provided at positions overlapping with the individual flow paths 23 when viewed in the Z direction. The first energy generating elements 14 and the second energy generating elements 24 are arranged side by side in a first direction (Y direction) in which the ejection ports 11 are arranged in a row. Looking at the entire liquid ejection chip, a plurality of first energy generating elements 14 and a plurality of second energy generating elements 24 are arranged alternately in the first direction. The individual flow paths 23 are formed in a bent U-shape so that the end of the flow path corresponding to the first energy generating element 14 and the end of the flow path corresponding to the second energy generating element 24 are connected.

[0065] The individual flow paths 23 include a pressure chamber 12, an inlet (upstream) connecting flow path 13 that communicates with one end of the pressure chamber 12, and an outlet (downstream) connecting flow path 26 that communicates with the other end of the pressure chamber 12. The connecting flow path 13 is a flow path that overlaps with the second energy generating element 24 when viewed in the Z direction. The individual flow paths 23 communicate with a supply groove 42 that penetrates the substrate 18 at both the upstream connecting flow path 13 and the downstream connecting flow path 26. Both ends of the individual flow paths 23 open toward the supply groove 42 in the X direction, and are positioned adjacent to one side of the supply groove 42 in the Y direction.

[0066] The ink flows in the U-shaped individual flow paths 23 are classified into two types, (1) a first ink flow and (2) a second ink flow, similar to the straight type.

[0067] When the first energy generating element 14 is driven and liquid is ejected from the ejection port 11, ink is supplied from the supply groove 42 along with the ejection, and ink flows into the pressure chamber 12 from both the connection flow path 13 and the connection flow path 26. This flow is the first ink flow.

[0068] When the second energy generating element 24 is driven to form the circulating flow 27, the liquid flows into the individual flow path 23 from the connecting flow path 13 on the inlet (upstream) side and flows out to the connecting flow path 26 on the outlet (downstream) side. In this example, the liquid flows into and out of the common supply groove 42, forming the circulating flow 27 indicated by the arrows in Figures 4(a) and (b) in the individual flow path 23. This flow is the second ink flow.

[0069] 8(a), a supply groove 42 is provided as an opening for supplying liquid to the individual flow paths 23, but the present invention is not limited to this configuration. For example, instead of the supply groove 42, a plurality of openings aligned in the first direction (Y direction) as shown in FIG. 4(a) may be provided. When the supply groove 42 is replaced with a plurality of openings, the openings are configured to be shared within the chip, similar to FIG. 4(b).

[0070] (Pump principle) Next, the principle of generating a circulating flow of ink by driving the second energy generating element 24, which is an electrothermal conversion element, will be explained. The principle of generating a circulating flow will be explained using the straight-type individual flow path 23 shown in Figs. 4(a) and (b) as an example. Figs. 5(a) to (c) are explanatory diagrams of the principle of generating a circulating flow of ink, showing a cross section taken along line AA in Fig. 4(a). Figs. 5(a) to (c) respectively show the generation and growth process, contraction process, and post-death process of bubbles B caused by film boiling of ink when ink is heated by the second energy generating element 24, which serves as a circulation heater. It has been done.

[0071] FIG. 5(a) illustrates the generation and growth process of bubble B. The second energy generating element 24 is located closer to the first opening 22 than to the second opening 32. Therefore, the flow resistance R1 between the second energy generating element 24 and the first opening 22 is smaller than the flow resistance R2 between the second energy generating element 24 and the second opening 32. FIG. 5(a) also includes an equivalent circuit that expresses the flow resistances R1 and R2 as electrical resistances. Due to the difference between the flow resistances R1 and R2, bubble B generated by ink film boiling grows toward the first opening 22, which is the supply flow path with the smaller flow resistance R1, as shown in FIG. 5(a). Therefore, within the individual flow paths 23, the ink flow Fa toward the first opening 22 is larger than the ink flow Fb toward the second opening 32.

[0072] FIG. 5(b) is a diagram showing the contraction process of bubble B. As bubble B contracts, ink flows in to compensate for the contracted volume. As shown in FIG. 5(b), the flow Fc of ink flowing in from the first opening 22 on the side with small flow resistance R1 is larger than the flow Fd of ink flowing in from the second opening 32 on the side with large flow resistance R2. Furthermore, the vanishing position of bubble B shifts from above the second energy generating element 24 (circulation heater) toward the second opening 32.

[0073] Fig. 5(c) is a diagram showing the process after the collapse of bubble B. Due to the relationship Fc>Fd in the ink flow generated during the contraction process of bubble B in Fig. 5(b), a circulating flow F of ink is generated from the first opening 22 to the second opening 32. In this way, a circulating flow F is generated from the first opening 22 side to the second opening 32 side, that is, from the second energy generating element 24 side to the first energy generating element 14 side.

[0074] The magnitude of the circulating flow F is affected by the ratio of flow resistances R1 and R2 and the size of the bubbles B. For example, consider a case where a circulation heater, which is an electrothermal conversion element, is used as the second energy generating element 24. In this case, in order to increase the circulating flow F, it is preferable that the second energy generating element 24 is located closer to one of the two ends of the individual flow path 23 than the first energy generating element 14. In other words, it is preferable that the distance from the second energy generating element 24 to one end of the individual flow path 23 is shorter than the distance from the first energy generating element 14 to the other end of the individual flow path 23. More specifically, it is preferable to set the flow resistance ratio R1 / R2 in the range of 0.05 to 0.40. By setting the flow resistance ratio R1 / R2 in this range, the circulating flow F can be maximized.

[0075] It is important for the circulation flow F to increase the ink flow Fa toward the first opening 22 shown in Figures 5(a) and (b) and to increase the ink flow Fc flowing in from the first opening 22. Therefore, it is effective to reduce the flow resistance R1. It is also important to make the ink flow Fb toward the outflow channel 15 as small as possible and to reduce the ink flow Fd flowing in from the second opening 32. Therefore, it is effective to increase the flow resistance R2. From the above, it is important to reduce the flow resistance R1 and increase the flow resistance R2, that is, to reduce the flow resistance ratio R1 / R2. Furthermore, a large bubble B, that is, a large bubble volume, leads to an increase in the excluded volume of the fluid generated in the individual channel 23, and therefore the circulation flow F becomes larger. As a means for increasing the bubble volume, - Enlargement of the size of the second energy generating element 24 (circulation heater) ·Increase the width and height of the individual flow paths 23 to reduce flow resistance -Reducing ink viscosity -Increased head temperature Double pulse drive pulse Examples include:

[0076] When part of the ink circulation flow F enters the ejection port 11, the concentrated ink in the ejection port 11 is sent to the second opening 32 side, and fresh ink flows into the ejection port 11 from the first opening 22 side through the connecting flow path 13. In this way, by making it difficult for the concentrated ink to remain in the ejection port 11, the influence of the concentrated ink can be suppressed and the initial ink ejection state can be maintained.

[0077] The circulating flow F is a transient flow that accompanies the growth and contraction processes of the bubble B when it is generated. Therefore, the inertial flow after the bubble B disappears attenuates over time and stops after a certain period of time. Therefore, in order to steadily generate the circulating flow F for a certain period of time, it is necessary to repeatedly drive the second energy generating element 24, which is a circulation heater.

[0078] The drive cycle of the second energy generating element 24 is not particularly limited as long as it can discharge the concentrated ink from the ejection port 11. However, because the second energy generating element 24 is a transient flow accompanying the growth and contraction processes of the generated bubble B, the effectiveness of the drive cycle is reduced when the second energy generating element 24 is driven at a high drive frequency, such as 100 kHz, taking into account the 10 μs cycle that is the time it takes for the bubble to disappear. Therefore, it is preferable to drive the second energy generating element 24 at a cycle of, for example, 100 Hz to several tens of kHz. The higher the drive frequency, the more the circulating flow F is maintained, thereby increasing the effectiveness of discharging the concentrated ink. However, it is also necessary to consider the temperature rise of the ink due to heat generated by the drive of the second energy generating element 24. Therefore, the number of times the second energy generating element 24 is driven must be appropriate.

[0079] (recirculation concentration) Next, the elimination of ink concentration in the individual flow paths 23 due to ink circulation will be described in more detail. Figures 6(a) to 6(d) are explanatory diagrams of the ink concentration state in a straight-type individual flow path 23 in which the inlet and outlet for the circulating flow are separate. Figures 7(a) to 7(d) are explanatory diagrams of the ink concentration state in a U-shaped individual flow path 23 in which the inlet and outlet for the circulating flow are adjacent. In Figures 6(a) to 6(d) and 7(a) to 7(d), areas where ink is concentrated are shown in dark colors, and the degree of concentration is expressed by the shade.

[0080] 6(a) shows a state in which the circulating flow 27 of ink is temporarily stopped in the straight-type individual flow path 23. When the circulating flow 27 is temporarily stopped and the ink does not flow, the volatile components of the ink evaporate from the ejection port, and the ink becomes concentrated near the ejection port.

[0081] 6(b) shows the state immediately after the second energy generating element 24 is driven from the state shown in FIG. 6(a) to generate the circulating flow 27. The circulating flow 27 eliminates the concentration near the ejection orifice. The ink that has concentrated near the ejection orifice is discharged from the outlet of the individual flow path 23, and the concentration is eliminated throughout the individual flow paths.

[0082] Figure 6(c) shows a state in which the ink circulation flow 27 has been further temporarily stopped from the state shown in Figure 6(b). By temporarily stopping the ink circulation flow 27, the ink concentration in the vicinity of the ejection orifice progresses again, resulting in the same state as shown in Figure 6(a).

[0083] Fig. 6(d) shows the state immediately after the second energy generating element 24 is driven from the state shown in Fig. 6(c) to generate the circulating flow 27. The circulating flow 27 eliminates the concentration near the discharge port again, as in the state shown in Fig. 6(b), and also eliminates concentration throughout the individual flow paths. As described above, in a straight type where the inlet and outlet of the individual flow path 23 are separated, the concentrated state is reset each time the temporary pause and circulating operation are repeated.

[0084] 7(a) shows a state in which the circulating flow 27 of ink is temporarily stopped in the U-shaped individual flow path 23. When the circulating flow 27 is temporarily stopped and ink does not flow, ink is discharged from the ejection port portion. The volatile components of the ink evaporate, and the ink becomes more concentrated near the ejection orifices.

[0085] FIG. 7(b) shows the state immediately after the second energy generating element 24 is driven from the state shown in FIG. 7(a) to generate the circulating flow 27. In the U-shaped individual flow channels 23, the inlet and outlet are adjacent and close to each other. Therefore, ink that has become concentrated near the ejection port is discharged from the outlet of the individual flow channel 23, but then flows back in through the inlet. This results in the entire individual flow channel being replaced with slightly concentrated ink rather than fresh ink. In the following explanation, this phenomenon is referred to as recirculation concentration.

[0086] Figure 7(c) shows a state in which the ink circulation flow 27 has been further temporarily paused from the state shown in Figure 7(b). By temporarily pausing the ink circulation flow 27, the ink concentration in the vicinity of the ejection orifice progresses again. At this time, the ink in the individual flow paths 23 is more concentrated than in the state shown in Figure 7(a).

[0087] 7(d) shows the state immediately after the second energy generating element 24 is driven from the state shown in FIG. 7(c) to generate the circulating flow 27. At this time, due to the effect of recirculation concentration, the entire individual flow path is replaced with ink that is even more concentrated than in the state shown in FIG. 7(b).

[0088] As described above, in the U-shaped individual flow path 23 in which the inlet and outlet are adjacent, the concentration state is not reset each time a temporary pause and a circulation operation are repeated, and the concentration gradually progresses throughout the individual flow path, causing the concentration state to worsen. Furthermore, even if the circulation operation is not repeated, if the vicinity of the discharge port is highly concentrated due to a long pause time, etc., the concentration state is difficult to improve even with the first circulation operation. This is because the improvement in the concentration state due to recirculation concentration is small.

[0089] Therefore, between a straight type in which the inlet and outlet of the individual flow path 23 are separate and a U-shaped type in which the inlet and outlet of the individual flow path 23 are adjacent, there is a difference in the state of concentration elimination associated with temporary pauses and circulation operations due to differences in the influence of the discharged concentrated ink. In the straight type, the concentrated state is easily eliminated including the entire individual flow path, so the discharge stability is less likely to be reduced due to concentrated ink. On the other hand, in the U-shaped type, the concentrated state is difficult to eliminate including the entire individual flow path due to recirculation concentration, so discharge is likely to become unstable depending on the concentration of the entire individual flow path.

[0090] (ink) As described above, although the degree of elimination of concentration differs depending on the flow path configuration, by generating an ink circulation flow in the individual flow paths using the second energy generating element 24, it is possible to suppress the effects of concentrated ink that has evaporated and thickened at the ejection port 11. In other words, by driving the second energy generating element 24, the ink ejection state can be maintained in a good condition, which reduces the effects of changes in ejection speed and makes it easier to stabilize ejection.

[0091] On the other hand, depending on the application of the liquid ejection head 1 and the liquid ejection device 50 incorporating the liquid ejection head 1, inks with different types of colorants and solid content may be used. In other words, maintaining a high level of ejection stability regardless of the ink used is desirable for the performance of the liquid ejection head 1. For example, using ink with a reduced water content can be considered to address issues that can arise from the water in the ink, such as curling (warping) and cockling (wavy wrinkles) on plain paper. Ink with a low water content has a high concentration of solids, such as organic solvents, pigments, and resins, other than water. This makes it prone to a rapid increase in viscosity as the water evaporates, leading to a decrease in ink ejection stability. For such inks, generating a circulating flow within the pressure chamber is effective because it can suppress the increase in ink viscosity. Generally, ink with a high solid content refers to an ink with a solid content of 10 wt% or more. In other words, the present invention is suitable for inks with a solid content of 10 wt% (mass%) or more.

[0092] Furthermore, the temperature at which the liquid ejection head 1 operates may be controlled by placing heaters over the entire liquid ejection chip 3 and controlling the temperature to maintain a constant temperature. Since ink viscosity changes depending on temperature, the ink viscosity at the head operating temperature affects ejection stability.

[0093] When a circulating flow is formed using the second energy generating elements 24, the instantaneous circulating flow velocity can be several tens of mm / s to 1,000 mm / s. The average flow velocity over a time span on the order of several hundreds of microseconds depends on the drive frequency of the circulation heater. This is because the circulation heater generates a transient circulating flow that decays over time and stops after a certain period of time. When the second energy generating elements 24 are driven at a frequency of approximately 10 to 20 kHz, which is the same as the drive frequency (discharge frequency) of the first energy generating elements 14, the average flow velocity can be several mm / s to 100 mm / s.

[0094] When using ink with a high pigment concentration, for example, ink with a viscosity of 3 cP or more and 6 cP or less at the head operating temperature, the ink tends to thicken at the ejection port depending on the non-ejection time (rest time). This tends to cause changes in ejection speed and reduce ejection stability. When using such ink, it is necessary to circulate the ink while the rest time is short, and it is necessary to eliminate concentration by performing regular ink circulation or transient ink circulation at high frequency. When a circulation heater is used as the second energy generating element 24, transient ink circulation occurs, so performing circulation operation at high frequency can contribute to eliminating concentration at the ejection port.

[0095] On the other hand, when using ink with a low pigment concentration—for example, ink with a viscosity of 1 cP or more but 2 cP or less at the head operating temperature—the ejection speed may change depending on the non-ejection time (pause time), but the effect is relatively small compared to that of high-concentration ink. On the other hand, if the pause time is long, for example, the ink viscosity at the ejection orifice increases depending on the non-printing operation time (stop time). Therefore, when restarting after a period of no printing and stopping, recovery procedures involving waste ink, such as suction, wiping, and preliminary ejection combined with these, are required. When a circulation heater is used as the second energy generating element 24, the recovery procedure can contribute to eliminating concentration at the ejection orifice without generating waste ink by forming a circulation flow 27. Depending on the pause time, it is possible to prevent waste ink generation by recovery procedures using only circulation operations. Alternatively, recovery procedures using circulation operations can be combined with a suction operation to remove air bubbles inside the liquid ejection head 1, separate from concentration elimination, to minimize waste ink generation.

[0096] Whether the ink is high-concentration or low-concentration, it is desirable to return the ink to its original, fresh state as much as possible in order to suppress the effects of concentrated ink. Therefore, even when a circulation heater is used as the second energy generating element 24, the lower the effects of recirculation concentration, the better the circulation effect can be obtained. In other words, the straight-type configuration is more effective at eliminating concentration by circulating ink using the individual flow paths 23 than the U-shaped configuration.

[0097] (Method of driving a liquid ejection head) Next, a method for driving the liquid ejection head 1 according to the first embodiment will be described in more detail. Below, the method for driving the liquid ejection head 1 according to the first embodiment will be described using as an example a case where the individual flow paths 23 in the first embodiment are U-shaped as shown in Figures 8(a) to 8(c).

[0098] Before describing the method for driving the liquid ejection head 1 according to the first embodiment, a method for driving the liquid ejection head 1 in a comparative configuration will be described below. In describing the comparative configuration, the same components as those in the first embodiment will be assigned the same reference numerals and will not be described again. FIG. 9 shows the comparative configuration. 10 is a block diagram illustrating the configuration of the selection drive circuit 200 on the substrate 18 of the liquid ejection head 1 according to the first embodiment.

[0099] In the liquid ejection head 1, each individual flow path 23 is provided with a first energy generating element 14 and a second energy generating element 24. To distinguish between the elements, the first energy generating element 14 is designated as Ai (i = 1, 2, 3, . . . n), and the second energy generating element 24 is designated as Bi (i = 1, 2, 3, . . . n). In this case, for example, A1 and B1 indicate that they are in the same individual flow path. Furthermore, when there is no need to particularly distinguish between the elements, they are simply referred to as the first energy generating element 14 and the second energy generating element 24. In FIG. 9, n = 8, and an example configuration is shown in which eight first energy generating elements 14 and eight second energy generating elements 24 are provided. In FIG. 10, n = 16, and an example configuration is shown in which 16 first energy generating elements 14 and sixteen second energy generating elements 24 are provided.

[0100] [Comparative configuration driving method] In the comparative configuration, a selection drive circuit 200 as shown in Fig. 9 is formed on a substrate 18. The selection drive circuit 200 is a circuit for driving the first energy generating elements 14 and the second energy generating elements 24 based on control signals sent by a CPU 800, which is a control unit. The liquid ejection head 1 also includes a control data supply circuit 100, a voltage source 120 (+V) and a controller 110 that are provided outside the substrate 18. The voltage source 120 and the control data supply circuit 100 are each connected to the selection drive circuit 200, and the controller 110 is connected to the control data supply circuit 100.

[0101] The selection drive circuit 200 includes an on-off drive circuit 210. The on-off drive circuit 210 is an on-off changeover switch that drives the first energy generating elements 14 (A1 to A8) and the second energy generating elements 24 (B1 to B8) on or off. The on-off drive circuit 210 drives each element on or off in response to a control signal at each address (N1 to N16 in this example) received from the control data supply circuit 100. That is, the first energy generating elements 14 and the second energy generating elements 24 are each independently controlled by a switch that is configured to be switchable between a drivable state and a non-drivable state.

[0102] The control data supply circuit 100 controls the drive pulse for driving the first energy generating element 14 or the second energy generating element 24 and the time interval for applying the drive pulse to each element.

[0103] In the comparative configuration, the first energy generating elements 14 and the second energy generating elements 24 are linked to different addresses, and therefore, separate drive circuits must be provided. Therefore, separate drive data must be provided for the first energy generating elements 14 and the second energy generating elements 24. Therefore, the amount of data increases in accordance with the total number of elements, including the first energy generating elements 14 and the second energy generating elements 24.

[0104] [Driving method of the first embodiment] In the first embodiment, a selection drive circuit 200 as shown in FIG. 10 is formed on a substrate 18. The selection drive circuit 200 includes an ON-OFF-ON drive circuit 220, and is driven based on a control signal from a CPU 800, which is a control unit. As described above, the selection drive circuit 200 according to the first embodiment differs from the comparative configuration in that it includes an ON-OFF-ON drive circuit 220 instead of the ON-OFF drive circuit 210 of the comparative configuration. In addition, the voltage source 120 and the control data supply circuit 100 are each connected to the selection drive circuit 200, and the controller 110 controls the control data supply circuit The control data supply circuit 100, the voltage source 120, and the controller 110 have the same configuration as the comparative configuration.

[0105] The ON-OFF-ON drive circuit 220 switches each element ON / OFF in response to a control signal at each address (N1 to N16 in this example) received from the control data supply circuit 100. In the first embodiment, the first energy generating element Ai and the second energy generating element Bi corresponding to the same individual flow path 23 are linked to the same address. Then, in the first embodiment, whether to drive the first energy generating element Ai or the second energy generating element Bi is determined based on the drive data of the first energy generating element Ai which is based on the print data. In the first embodiment, the first energy generating element Ai and the second energy generating element Bi are selectively controlled by the same time-division control.

[0106] The first energy generating element Ai and the second energy generating element Bi corresponding to the same individual flow path 23 do not need to be driven simultaneously; it is sufficient to drive either one of them. Therefore, in the first embodiment, the second energy generating element Bi is configured to be driven and controlled in accordance with the drive data (drive state) of the first energy generating element Ai. That is, the selection drive circuit 200 determines whether to drive the second energy generating element Bi depending on whether to drive the first energy generating element Ai.

[0107] As described above, in the first embodiment, a pair of a first energy generating element Ai and a second energy generating element Bi provided corresponding to the same individual flow path 23 is assigned the same address. The selection drive circuit 200 is configured to select and drive only one of the first energy generating element Ai and the second energy generating element Bi, i.e., not to drive the two elements simultaneously. In other words, the first energy generating element 14 and the second energy generating element 24 are selectively driven and controlled by the selection drive circuit 200. Therefore, the selection drive circuit 200 according to the first embodiment does not drive the second energy generating element Bi when the first energy generating element Ai is driven, and drives the second energy generating element Bi when the first energy generating element Ai is not driven.

[0108] The ON-OFF-ON drive circuit 220 may be configured to be able to determine not to drive either the first energy generating element Ai or the second energy generating element Bi (to turn both off). In other words, the selection drive circuit 200 according to the first embodiment may be configured to be able to determine whether to drive the first energy generating element Ai, the second energy generating element Bi, or neither, in response to a single control signal (drive data).

[0109] With this configuration, there is no need to provide drive circuits with separate addresses for the first energy generating elements Ai and the second energy generating elements Bi, and there is no need to provide drive data for the second energy generating elements Bi, so the amount of drive data can be reduced accordingly. Furthermore, if a configuration is used in which multiple openings are provided instead of the supply grooves 42, it becomes possible to concentrate the circuits on one side using wiring between the openings for the wiring to each element, thereby improving circuit efficiency.

[0110] As shown in Fig. 9, in the comparative configuration, a total of 16 elements up to n=8 as the first energy generating elements Ai and second energy generating elements Bi for 16 addresses N1 to N16 are controlled as one group. On the other hand, as shown in Fig. 10, in the first embodiment, a total of 32 elements up to n=16 as the first energy generating elements Ai and second energy generating elements Bi for the same number of addresses N1 to N16 are controlled as one group. Therefore, in the first embodiment, the total number of elements in one group is double that of the comparative configuration.

[0111] For comparison, the viscosity of the ink in a liquid ejection head that does not form a circulating flow was Countermeasures are described below. These countermeasures include a preliminary ejection operation that ejects ink from the ejection ports and a suction operation that sucks ink from the ejection ports. For example, in a serial-type liquid ejection device, a preliminary ejection operation or a suction operation is performed in a head standby location before the head leaves the cap that protects the head and heads off to the printing operation. Alternatively, a preliminary ejection operation is performed in a non-printing area away from the printing medium when the carriage moves back and forth during the printing operation. These are timings that differ from the printing operation. Furthermore, in the case of ink that is prone to thickening, a preliminary ejection operation may be performed in addition to the printing operation in the printing area during the back and forth movement, to an extent that does not affect the image on the printing medium.

[0112] In the first embodiment, the number of preliminary ejection operations and suction operations can be reduced by performing a circulation operation by driving the second energy generating elements 24. Similarly, when a circulation operation is performed in a head standby area or a non-printing area during reciprocating movement, it is performed at a timing different from the printing operation. Therefore, in the first embodiment, it is possible to drive both the first energy generating elements 14 and the second energy generating elements 24 with a single control signal (drive data) without providing dedicated drive data for the second energy generating elements 24.

[0113] Furthermore, in the case of ink that is prone to thickening, the circulation operation in the printing area of ​​the reciprocating movement must prioritize the ejection operation at a timing close to the printing operation. On the other hand, by providing multiple circulation operation timings or a fixed period of time, it is not necessary to drive the circulation operation and the printing operation simultaneously. Therefore, in the first embodiment, by driving the first energy generating element 14 when the first energy generating element side is selected, the circulation operation can be controlled appropriately without affecting the printing operation.

[0114] In the first embodiment, the first energy generating elements Ai and the second energy generating elements Bi are controlled as one group, with a total of 32 elements (16 pairs) up to n=16, but this is not limited to such a configuration. For example, the total number of elements in one group can be various numbers such as 16 (8 pairs), 24 (12 pairs), etc.

[0115] Furthermore, the second energy generating element 24 is not limited to an electrothermal converting element, and may be, for example, a piezoelectric element. When a piezoelectric element is used, the direction of the circulating flow may be reversed depending on the driving method, compared to the case of an electrothermal converting element.

[0116] Second Embodiment Next, a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in the flow path configuration of the liquid ejection head 1. Only the differences between the configuration of the second embodiment and the configuration of the first embodiment will be described below. Components in the second embodiment that are similar to the configuration of the first embodiment will be assigned the same reference numerals and will not be described again.

[0117] Figures 11(a) to 11(c) are explanatory diagrams of the flow path configuration of the liquid ejection head 1 according to the second embodiment. Figure 11(a) is an explanatory diagram of the configuration in the vicinity of the ejection port 11 of the liquid ejection chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid ejection chip 3 is viewed in the Z direction. Figure 11(b) is a CC cross-sectional view of Figure 11(a). Figure 11(c) is a diagram showing a configuration example different from the example shown in Figure 11(b), and is a CC cross-sectional view of Figure 11(a).

[0118] The shape of the back side of the substrate 18 (the side opposite to the side to which the orifice plate 19 is bonded) can be changed depending on the type of etching method used for the substrate 18. FIGS. 11(b) and 11(c) show examples in which etching is performed by different methods, and common flow paths 25 of different shapes are formed. The common flow path 25 may have a shape in which the outer wall extends parallel to the Z direction as shown in FIG. 11(b), or a shape in which the outer wall extends away from the discharge port 11 as shown in FIG. 11(c). Therefore, the partition walls may have a shape that widens the distance between the partition walls in the X direction.

[0119] The individual flow paths 23 according to the second embodiment differ from those of the first embodiment in that they are straight rather than U-shaped. That is, the ends of the individual flow paths 23 according to the second embodiment are arranged so that they are separated at positions on opposite sides of the ejection port row in a second direction (X direction) that intersects (in this example, is perpendicular to) the first direction (Y direction) in which the plurality of ejection ports 11 are arranged. The second embodiment also differs from the first embodiment in that a plurality of first openings 22 and a plurality of second openings 32 are provided instead of a supply groove 42 as flow paths for supplying ink to the individual flow paths 23.

[0120] An advantage of this configuration is that the inlet and outlet of the circulating flow are positioned apart so that they are separated on opposite sides of the nozzle row, so that ink that has concentrated at the nozzle section as it circulates does not re-flow into the individual flow paths, thereby suppressing the effects of concentration.

[0121] Furthermore, since multiple independent openings are provided, it is possible to arrange the wiring to each element so that it passes between the openings, and it is also possible to concentrate the circuit on one side, which has the advantage of making the circuit more efficient.

[0122] An exemplary arrangement of the wiring 201 of the selection drive circuit 200 connected to the first energy generating elements 14 and the second energy generating elements 24 will be described below. Figures 12(a) to 12(c) are diagrams showing an example of the arrangement of the wiring 201 of the selection drive circuit 200. The selection drive circuit 200 includes a plurality of wirings 201 to drive a plurality of first energy generating elements 14 and second energy generating elements 24.

[0123] 12(a) shows the arrangement of the wiring 201 of a liquid ejection chip 3 having the same configuration as that of the first embodiment (FIG. 8(a)). That is, the individual flow paths 23 of this configuration example are U-shaped, and supply grooves 42 are formed as openings for supplying liquid to the individual flow paths 23. Then, in the X direction, individual flow paths 23 corresponding to the ejection port arrays and ejection ports 11 are formed on both sides of the supply groove 42.

[0124] 12(a), the wiring 201 connected to the first energy generating element 14 and the second energy generating element 24 is arranged on the same side as the corresponding elements with respect to the supply groove 42. In other words, the selection drive circuits 200 are arranged on both sides of the supply groove 42 in the X direction.

[0125] 12(b) shows the arrangement of the wiring 201 of a liquid ejection chip 3 having the same configuration as that of the second embodiment (FIG. 11(a)). That is, the individual flow paths 23 of this configuration example are straight, extending in the X direction, and are provided with a first opening 22 for supplying liquid to the individual flow paths 23 and a second opening 32 for supplying and repairing liquid to the individual flow paths 23. In the X direction, the first opening 22 is located on one side of the individual flow paths 23, and the second opening 32 is located on the other side of the individual flow paths 23.

[0126] In the configuration example of FIG. 12(b), the wiring 201 connected to the first energy generating elements 14 and the second energy generating elements 24 are all arranged on the same side as the first openings 22 with respect to the individual flow paths 23. Each wiring 201 is arranged so as to pass between the first openings 22 adjacent to each other in the Y direction. In other words, the selection drive circuit 200 is arranged on that side with respect to the individual flow paths 23 in the X direction. By concentrating the selection drive circuits 200 on one side in this way, the efficiency of the circuit can be improved. Note that a configuration may also be adopted in which the wiring 201 is arranged on the other side as the second openings 32, and the selection drive circuit 200 is arranged on that other side with respect to the individual flow paths 23.

[0127] FIG. 12(c) shows an arrangement of the wiring 201 of a liquid ejection chip 3 having a configuration similar to that of the second embodiment (FIG. 11(a)), but different from the configuration shown in FIG. 12(b). In the configuration example of FIG. 12(c), the wiring 201 connected to the first energy generating elements 14 and the second energy generating elements 24 arranged in some sections are arranged on the same side of the individual flow paths 23 as the first openings 22. On the other hand, the wiring 201 connected to the first energy generating elements 14 and the second energy generating elements 24 arranged in other sections are arranged on the same side of the individual flow paths 23 as the second openings 32. In this manner, a configuration may be adopted in which one group of wiring 201 corresponding to a certain number of individual flow paths 23 is arranged alternately on one side and the other side of the individual flow paths 23. Whether the wiring 201 is arranged on one side of the individual flow paths 23 or on both sides may be determined appropriately in consideration of the configuration of the liquid ejection head 1 and the liquid ejection chip 3.

[0128] Third Embodiment Next, a third embodiment of the present invention will be described. The third embodiment differs from the first and second embodiments in the flow path configuration of the liquid ejection head 1. Only the differences between the configuration of the third embodiment and the configuration of the second embodiment will be described below. Elements in the configuration of the third embodiment that are similar to the configuration of the second embodiment will be assigned the same reference numerals and will not be described again.

[0129] Figures 13(a) to 13(c) are explanatory diagrams of the flow path configuration of the liquid ejection head 1 according to the third embodiment. Figure 13(a) is an explanatory diagram of the configuration in the vicinity of the ejection port 11 of the liquid ejection chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid ejection chip 3 is viewed in the Z direction. Figure 13(b) is a DD cross-sectional view of Figure 13(a). Figure 13(c) is a diagram showing a configuration example different from the example shown in Figure 13(b), and is a DD cross-sectional view of Figure 13(a).

[0130] The third embodiment differs from the second embodiment in the number of ejection port rows and aperture rows. While the second embodiment has one ejection port row and two aperture rows, the third embodiment has two ejection port rows and three aperture rows. The aperture rows and ejection port rows are arranged alternately in the X direction. An individual flow path 23 is formed corresponding to each ejection port 11, and each individual flow path 23 is sandwiched between the aperture rows in the X direction.

[0131] The substrate 18 is provided with first energy generating elements 14 and second energy generating elements 24 corresponding to each individual flow path 23. For each individual flow path 23, the outlet 11 and the first energy generating element 14 are located closer to the center than the second energy generating element 24. That is, in the individual flow path 23 located on the left side in FIG. 13(a), the first energy generating element 14 is located on the right side of the second energy generating element 24. Also, in the individual flow path 23 located on the right side in FIG. 13(a), the first energy generating element 14 is located on the left side of the second energy generating element 24. That is, when the second energy generating element 24 is driven, a circulating flow 27 is generated in the individual flow path 23 in a direction from the outside toward the center in the X direction.

[0132] Each of the three opening rows is composed of a plurality of openings 52 lined up in the Y direction. The three opening rows are configured so that the positions of the openings 52 in the Y direction are the same. When the circulating flow 27 is generated, ink flows into the individual flow paths 23 from the openings 52 on the outer sides in the X direction, and ink that flows out of the individual flow paths 23 is collected in the openings 52 on the center side in the X direction.

[0133] In the third embodiment, the ejection ports 11 constituting one ejection port array and the ejection ports 11 constituting the other ejection port array are arranged so as to be shifted in the Y direction.

[0134] The advantage of this configuration is that by increasing the number of aperture rows from two to three, the number of ejection port rows can be doubled from one to two. Furthermore, it is possible to displace one ejection port row from the other in the Y direction, providing a high degree of freedom in the arrangement of the ejection ports 11. Furthermore, since it is not necessary to provide a wiring area between the apertures in the central aperture row in the X direction, there is a high degree of freedom in the size and resolution of the apertures in the central aperture row. Another advantage of this is that it makes it easier to achieve high productivity by speeding up nozzle refilling.

[0135] In the third embodiment, the apertures constituting the three aperture rows are all arranged at the same position in the nozzle row direction (Y direction), but this configuration is not limited to this. For example, the apertures in each row may be arranged offset in accordance with the nozzle positions and the wiring routing between the apertures. This also applies to the following embodiments.

[0136] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described. The fourth embodiment differs from the third embodiment in the arrangement of the first energy generating element 14 and the second energy generating element 24. Only the differences between the configuration of the fourth embodiment and the configuration of the third embodiment will be described below. Elements in the fourth embodiment that are similar to those in the third embodiment will be given the same reference numerals and will not be described again.

[0137] Figures 14(a) and (b) are explanatory diagrams of the flow path configuration of the liquid ejection head 1 according to the fourth embodiment. Figure 14(a) is an explanatory diagram of the configuration in the vicinity of the ejection port 11 of the liquid ejection chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid ejection chip 3 is viewed in the Z direction. Figure 14(b) is an E-E cross-sectional view of Figure 14(a).

[0138] In the fourth embodiment, the positions of the first energy generating elements 14 and the second energy generating elements 24 are reversed from those in the third embodiment. That is, the second energy generating elements 24 are positioned closer to the center in the X direction than the first energy generating elements 14 and the outlets 11. Therefore, in the fourth embodiment, the direction of the circulating flow 27 generated when the second energy generating elements 24 are driven is from the center toward the outside in the X direction, which is opposite to the direction of the circulating flow 27 in the third embodiment.

[0139] The advantage of this configuration is that ink concentrated near the ejection ports is branched off and discharged to the opening rows on both sides, thereby suppressing the influence of concentrated ink when it re-flows into the individual flow paths in response to ejection, etc. Another advantage is that the multiple ejection port rows are spaced apart from each other, thereby suppressing the influence of interference caused by meniscus vibrations accompanying ejection from each ejection port 11.

[0140] Fifth Embodiment Next, a fifth embodiment of the present invention will be described. The fifth embodiment differs from the third embodiment in the arrangement of the first energy generating elements 14 and the second energy generating elements 24. Only the differences between the configuration of the fifth embodiment and the configuration of the third embodiment will be described below. Elements in the configuration of the fifth embodiment that are similar to those in the third embodiment will be assigned the same reference numerals and will not be described again.

[0141] Figures 15(a) and (b) are explanatory diagrams of the flow path configuration of the liquid ejection head 1 according to the fifth embodiment. Figure 15(a) is an explanatory diagram of the configuration in the vicinity of the ejection port 11 of the liquid ejection chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid ejection chip 3 is viewed in the Z direction. Figure 15(b) is an FF cross-sectional view of Figure 15(a).

[0142] The fifth embodiment differs from the third embodiment in that the second energy generating element 24 is closer to the first energy generating element 14. In the fifth embodiment, the second energy generating element 24 is disposed at a position closer to the central opening 52 in the X direction than the outer opening 52. With this configuration, the direction of the circulating flow 27 generated when the second energy generating element 24 is driven is from the central side to the outside in the X direction, which is opposite to the direction of the circulating flow 27 in the third embodiment.

[0143] The advantage of this configuration is that, as with the third embodiment, there is a high degree of freedom in the size and resolution of the central opening row, which makes it easy to achieve high productivity by speeding up refilling. Another advantage is that, because ink concentrated near the ejection ports is branched off and discharged to the opening rows on both sides, the influence of concentrated ink when it re-flows into the individual flow paths due to ejection, etc., is suppressed.

[0144] Sixth Embodiment Next, a sixth embodiment of the present invention will be described. The sixth embodiment differs from the first embodiment in the flow path configuration of the liquid ejection head 1. Only the differences between the sixth embodiment and the first embodiment will be described below. Elements in the sixth embodiment that are similar to those in the first embodiment will be given the same reference numerals, and descriptions thereof will be omitted.

[0145] Figures 16(a) and (b) are explanatory diagrams of the flow path configuration of the liquid ejection head 1 according to the sixth embodiment. Figure 16(a) is an explanatory diagram of the configuration in the vicinity of the ejection port 11 of the liquid ejection chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid ejection chip 3 is viewed in the Z direction. Figure 16(b) is a cross-sectional view taken along line GG in Figure 16(a). Figure 16(c) is a cross-sectional view taken along line HH in Figure 16(a).

[0146] In the sixth embodiment, similarly to the first embodiment, there are two rows of ejection ports on either side of the supply groove 42, and the individual flow paths 23 are U-shaped. The ejection ports 11 are arranged such that the ejection ports 11 constituting one of the ejection port rows and the ejection ports 11 constituting the other ejection port row are staggered in the Y direction.

[0147] In addition, in the first embodiment, the filter 31 was arranged only at the outlet of the individual flow path 23 (the end farther from the second energy generating element 24), but in the sixth embodiment, the filter 31 is also provided at the inlet of the individual flow path 23 (the end closer to the second energy generating element 24).

[0148] Even with this configuration, the same effects as in the first embodiment can be obtained.

[0149] Seventh Embodiment Next, a seventh embodiment of the present invention will be described. The seventh embodiment differs from the second embodiment in the flow path configuration of the liquid ejection head 1. Only the differences between the configuration of the seventh embodiment and the configuration of the second embodiment will be described below. Components in the seventh embodiment that are similar to the configuration of the second embodiment will be assigned the same reference numerals and will not be described again.

[0150] Figures 17(a) and (b) are explanatory diagrams of the flow path configuration of the liquid ejection head 1 according to the seventh embodiment. Figure 17(a) is an explanatory diagram of the configuration in the vicinity of the ejection port 11 of the liquid ejection chip 3, and is a schematic diagram showing the positional relationship of the main components when the liquid ejection chip 3 is viewed in the Z direction. Figure 17(b) is an FF cross-sectional view of Figure 17(a).

[0151] In the seventh embodiment, the individual flow paths 23 are straight and are formed so as to branch into two on the way from the inlet to the outlet of the circulating flow 27. The individual flow path 23 has one inlet located at one end side in the X direction and two outlets located at the other end side in the X direction, and two pressure chambers 12 (discharge ports 11) are connected to one individual flow path 23. In addition, two first energy generating elements 14 and one second energy generating element 24 are provided on the substrate 18 for one individual flow path 23.

[0152] The first energy generating elements 14 are provided corresponding to each of the bifurcated flow paths, and are positioned so as to overlap the ejection ports 11 and the individual flow paths 23 (pressure chambers 12) when viewed in the Z direction, and are disposed on the side closer to the second openings 32 in the X direction. The second energy generating elements 24 are provided in a portion that is not bifurcated, and are positioned so as to overlap the individual flow paths 23 when viewed in the Z direction, and are disposed on the side closer to the first openings 22 in the X direction. When the second energy generating elements 24 are driven, a circulation flow 27 is formed in the individual flow paths 23, in a direction from the first opening 22 side toward the second opening 32 side (to the right in FIG. 17(a)), and the ink in the individual flow paths 23 circulates.

[0153] An advantage of such a configuration is that the number of second energy generating elements 24 can be half of the number of first energy generating elements 14, thereby reducing the wiring between the openings.

[0154] Here, the configuration of the ON-OFF-ON drive circuit 220 is such that when neither of the two first energy generating elements 14 in the individual flow path are driven, the second energy generating element 24 is driven, and when both are driven, the second energy generating element 24 is not driven. However, when one of the first energy generating elements 14 is not driven (only one is driven), both a configuration in which the second energy generating element 24 is driven and a configuration in which it is not driven are conceivable.

[0155] The former is a configuration in which the second energy generating element 24 is driven when one of the first energy generating elements 14 is not driven. In this case, when one of the first energy generating elements 14 is not driven, the second energy generating element 24 is driven to form a circulating flow 27 at the discharge port portion. Therefore, even when only one specific one of the first energy generating elements 14 is driven for a long period of time, this is effective in that the circulating flow 27 of the second energy generating element 24 on the other side can also eliminate concentration at the discharge port portion.

[0156] The latter is a configuration in which the second energy generating element 24 is driven only when both of the first energy generating elements 14 are not driven. When at least one of the first energy generating elements 14 is driven, the second energy generating element 24 is not driven. This is therefore effective in that the driving of the second energy generating element 24 does not affect the ejection caused by the driving of the first energy generating element 14.

[0157] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) a flow path forming portion having an ejection port from which a liquid is ejected, a pressure chamber communicating with the ejection port, and an individual flow path communicating with the pressure chamber; a first energy generating element provided at a position corresponding to the pressure chamber of the flow path forming portion, the first energy generating element generating energy for ejecting liquid from the ejection port; a second energy generating element provided at a position corresponding to the individual flow path of the flow path forming portion, the second energy generating element generating energy for causing liquid to flow through the individual flow path; a selection drive circuit that determines whether to drive the second energy generating element depending on whether to drive the first energy generating element; A liquid ejection head comprising: (Configuration 2) a control unit that controls driving of the first energy generating element by transmitting a control signal that determines a driving state of the first energy generating element; The liquid ejection head described in configuration 1, characterized in that the selective drive circuit selects and drives only one of the first energy generating element and the second energy generating element based on the control signal that determines the drive state of the first energy generating element. (Configuration 3) The liquid ejection head described in configuration 2, characterized in that the selective drive circuit does not drive the second energy generating element when the first energy generating element is driven, and drives the second energy generating element when the first energy generating element is not driven. (Configuration 4) 4. The liquid ejection head according to any one of configurations 1 to 3, wherein the selective drive circuit selectively controls the first energy generating elements and the second energy generating elements by the same time-division control. (Configuration 5) The liquid ejection head according to any one of configurations 1 to 4, wherein the selection drive circuit is configured to be able to determine whether to drive only the first energy generating element, drive only the second energy generating element, or drive neither the first energy generating element nor the second energy generating element. (Configuration 6) A liquid ejection head described in any one of configurations 1 to 5, characterized in that the individual flow path is formed in a straight line from a position corresponding to the second energy generating element to a position corresponding to the first energy generating element. (Configuration 7) the flow path forming portion has a first opening for supplying liquid to the individual flow paths when the second energy generating element is driven, and a second opening for recovering liquid flowing out of the individual flow paths, A liquid ejection head as described in configuration 6, characterized in that, in the extension direction of the individual flow path, the first opening is arranged on one side of the individual flow path, and the second opening is arranged on the other side opposite the one side of the individual flow path. (Configuration 8) the flow path forming portion has a plurality of the individual flow paths aligned in a first direction, a plurality of the first openings aligned in the first direction, and a plurality of the second openings aligned in the first direction, 8. The liquid ejection head according to configuration 7, further comprising a plurality of the first energy generating elements and a plurality of the second energy generating elements corresponding to a plurality of the individual flow paths. (Configuration 9) the selection drive circuit includes a plurality of wirings connected to the first energy generating element and the second energy generating element; 9. The liquid ejection head according to configuration 8, wherein the plurality of wirings are arranged on the one side of the individual flow paths. (Configuration 10) the selection drive circuit includes a plurality of wirings connected to the first energy generating element and the second energy generating element; 9. The liquid ejection head according to configuration 8, wherein the plurality of wirings are arranged on the other side of the individual flow paths. (Configuration 11) the selection drive circuit includes a plurality of wirings connected to the first energy generating element and the second energy generating element; A liquid ejection head as described in configuration 8, characterized in that among the plurality of wirings, some of the wirings are arranged on one side of the individual flow paths, and some of the wirings are arranged on the other side of the individual flow paths. (Configuration 12) the selection drive circuit includes a plurality of wirings connected to the first energy generating element and the second energy generating element; 12. The liquid ejection head according to any one of configurations 8 to 11, wherein the wiring is arranged so as to pass between two of the first openings adjacent to each other in the first direction. (Configuration 13) A liquid ejection head described in any one of configurations 1 to 5, characterized in that the individual flow path is formed in a U-shape from a position corresponding to the second energy generating element to a position corresponding to the first energy generating element. (Configuration 14) 14. The liquid ejection head according to configuration 13, wherein one end and the other end of the individual flow path are adjacent to each other in the first direction. (Configuration 15) the flow path forming portion has a plurality of the individual flow paths and a supply groove for supplying liquid to the plurality of individual flow paths, the supply groove having a longitudinal direction in the first direction; A liquid ejection head as described in configuration 14, characterized in that the multiple individual flow paths are arranged side by side in the first direction on one side and the other side of the supply groove in a second direction intersecting the first direction. (Configuration 16) two of the pressure chambers and two of the first energy generating elements are provided in correspondence with each individual flow path; A liquid ejection device described in any one of configurations 1 to 5, characterized in that the individual flow path is formed by branching into two from a position corresponding to the second energy generating element to a position corresponding to the first energy generating element. (Configuration 17) 17. The liquid ejection head according to configuration 16, wherein the selective drive circuit drives the second energy generating element when neither of the two first energy generating elements is driven. (Configuration 18) 17. The liquid ejection head according to configuration 16, wherein the selective drive circuit drives the second energy generating element when only one of the two first energy generating elements is driven. (Configuration 19) 19. The liquid ejection head according to any one of configurations 1 to 18, wherein at least one of the first energy generating element and the second energy generating element is an electrothermal converting element. (Configuration 20) a conveying unit that conveys the recording medium; a liquid ejection head according to any one of the configurations 1 to 19, which ejects a liquid onto a recording medium transported by the transport unit; A liquid ejection device comprising: [Explanation of symbols]

[0158] 1...liquid ejection head, 3...liquid ejection chip (flow path forming portion), 11...ejection port, 12...pressure chamber, 14...first energy generating element, 23...individual flow path, 24...second energy generating element, 200...selection driving circuit

Claims

1. a flow path forming portion having an ejection port from which a liquid is ejected, a pressure chamber communicating with the ejection port, and an individual flow path communicating with the pressure chamber; a first energy generating element provided at a position corresponding to the pressure chamber of the flow path forming portion, the first energy generating element generating energy for ejecting liquid from the ejection port; a second energy generating element provided at a position corresponding to the individual flow path of the flow path forming portion, the second energy generating element generating energy for causing liquid to flow through the individual flow path; a selection drive circuit that determines whether to drive the second energy generating element depending on whether to drive the first energy generating element; A liquid ejection head comprising:

2. a control unit that controls driving of the first energy generating element by transmitting a control signal that determines a driving state of the first energy generating element, The liquid ejection head according to claim 1, characterized in that the selective drive circuit selects and drives only one of the first energy generating element and the second energy generating element based on the control signal that determines the drive state of the first energy generating element.

3. The liquid ejection head according to claim 2, wherein the selective drive circuit does not drive the second energy generating element when the first energy generating element is driven, and drives the second energy generating element when the first energy generating element is not driven.

4. 2. The liquid ejection head according to claim 1, wherein the selective drive circuit selectively controls the first energy generating elements and the second energy generating elements by the same time-division control.

5. The liquid ejection head according to claim 1, wherein the selective drive circuit is configured to be able to determine whether to drive only the first energy generating element, drive only the second energy generating element, or drive neither the first energy generating element nor the second energy generating element.

6. 2. The liquid ejection head according to claim 1, wherein the individual flow paths are formed linearly from a position corresponding to the second energy generating element to a position corresponding to the first energy generating element.

7. the flow path forming portion has a first opening for supplying liquid to the individual flow paths when the second energy generating element is driven, and a second opening for recovering liquid flowing out of the individual flow paths, The liquid ejection head according to claim 6, wherein the first opening is arranged on one side of the individual flow path in the extension direction of the individual flow path, and the second opening is arranged on the other side of the individual flow path opposite to the one side.

8. the flow path forming portion has a plurality of the individual flow paths aligned in a first direction, a plurality of the first openings aligned in the first direction, and a plurality of the second openings aligned in the first direction, 8. The liquid ejection head according to claim 7, further comprising a plurality of the first energy generating elements and a plurality of the second energy generating elements corresponding to a plurality of the individual flow paths.

9. the selection drive circuit includes a plurality of wirings connected to the first energy generating elements and the second energy generating elements; The liquid ejection head according to claim 8 , wherein the plurality of wirings are arranged on the one side of the individual flow paths.

10. the selection drive circuit includes a plurality of wirings connected to the first energy generating elements and the second energy generating elements; The liquid ejection head according to claim 8 , wherein the plurality of wirings are arranged on the other side of the individual flow paths.

11. the selection drive circuit includes a plurality of wirings connected to the first energy generating elements and the second energy generating elements; The liquid ejection head according to claim 8 , wherein, of the plurality of wirings, some of the wirings are arranged on the one side of the individual flow paths, and some of the wirings are arranged on the other side of the individual flow paths.

12. the selection drive circuit includes a plurality of wirings connected to the first energy generating elements and the second energy generating elements; 9. The liquid ejection head according to claim 8, wherein the wiring is arranged so as to pass between two of the first openings adjacent to each other in the first direction.

13. 2. The liquid ejection head according to claim 1, wherein the individual flow passages are formed in a U-shape from a position corresponding to the second energy generating element to a position corresponding to the first energy generating element.

14. 14. The liquid ejection head according to claim 13, wherein one end and the other end of the individual flow path are adjacent to each other in the first direction.

15. the flow path forming portion includes a plurality of the individual flow paths and a supply groove for supplying liquid to the plurality of individual flow paths, the supply groove having a longitudinal direction aligned with the first direction; The liquid ejection head according to claim 14, wherein the plurality of individual flow paths are arranged side by side in the first direction on one side and the other side of the supply groove in a second direction intersecting the first direction.

16. two pressure chambers and two first energy generating elements are provided in correspondence with each individual flow path; The liquid ejection device according to claim 1 , wherein the individual flow paths are bifurcated from a position corresponding to the second energy generating element to a position corresponding to the first energy generating element.

17. 17. The liquid ejection head according to claim 16, wherein the selective drive circuit drives the second energy generating element when neither of the two first energy generating elements is driven.

18. 17. The liquid ejection head according to claim 16, wherein the selective drive circuit drives the second energy generating element when only one of the two first energy generating elements is driven.

19. 2. The liquid ejection head according to claim 1, wherein at least one of the first energy generating element and the second energy generating element is an electrothermal converting element.

20. a conveying unit that conveys the recording medium; a liquid ejection head according to any one of claims 1 to 19, which ejects liquid onto a recording medium transported by the transport unit; A liquid ejection device comprising:

Images