Liquid ejection head and liquid ejection method

Abstract

To provide a liquid ejection head and a liquid ejection method capable of driving with data amount being optimized.SOLUTION: There is provided a liquid ejection method using a liquid ejection head comprising: individual ejection units each having an ejection port, a pressure chamber, a first thermal energy generating element provided in the pressure chamber, an individual flow path communicating with the pressure chamber, and a second thermal energy generating element provided in the individual flow path; and a common flow path for supplying liquid to the individual flow paths of a plurality of individual ejection units. The liquid ejection method is characterized in that the first thermal energy generating element and the second thermal energy generating element are controlled so that: the second thermal energy generating element is not driven when the first thermal energy generating element is driven; and the second thermal energy generating element is driven upon receiving a drive signal instructing the second thermal energy generating element to be driven when the first thermal energy generating element is not driven.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection method using the liquid ejection head. [Background technology]

[0002] Circulation-type liquid ejection devices are known that circulate ink in a liquid ejection head (hereinafter also referred to as the "head") to expel air bubbles from the flow path and prevent ink from thickening near the ejection ports. A well-known method of circulating ink is a method using a pressure difference (hereinafter also referred to as the "differential pressure method"). This method uses a pressure adjustment mechanism or the like to increase the pressure on the side that supplies ink to the ejection ports (the "inside") compared to the side that recovers ink (the "outside"), thereby causing ink to flow from the "inside" to the "outside." To circulate the ink, the ink that has flowed to the "outside" must be returned to the "inside," which requires a pump as a mechanism. Some liquid ejection devices circulate the liquid between the liquid ejection head and the main body by installing a pump outside the head, such as the recording device main body, while others circulate the liquid within the liquid ejection head by installing a pump inside the liquid ejection head. However, such a differential pressure method requires mechanisms such as a pressure adjustment mechanism and a pump, which can lead to an increase in the size of the recording device main body and the head.

[0003] Therefore, ink circulation methods other than the differential pressure method have been investigated. Specifically, a circulation flow path that communicates with the ejection port is provided, and an energy generating element (hereinafter also referred to as a "flow energy generating element") that is separate from the energy generating element for ejecting ink (hereinafter also referred to as an "ejection energy generating element") is arranged in the circulation flow path, and the ink is circulated in the circulation path by driving the flow energy generating element.

[0004] Patent Document 1 discloses a configuration in which a circulation flow path is provided that extends so as to intersect with an array of ejection ports in which a plurality of ejection ports are arranged, and a flow energy generating element is provided in the circulation path. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-104312 Summary of the Invention [Problem to be solved by the invention]

[0006] However, Patent Document 1 does not go so far as to describe what kind of drive data is used to drive the ejection energy generating elements and flow energy generating elements, which are electrothermal conversion elements. While it is generally conceivable to provide drive data for each energy generating element, the amount of data increases depending on the number of energy elements. Therefore, an object of the present invention is to provide a liquid ejection head and a liquid ejection device that can be driven with an optimized amount of data in an ink circulation system that uses both ejection energy generating elements and flow energy generating elements, as in Patent Document 1. [Means for solving the problem]

[0007] In order to solve the above problems, the liquid ejection method of the present invention is characterized by comprising: an individual ejection unit having an ejection port for ejecting liquid, a pressure chamber communicating with the ejection port, a first thermal energy generating element provided in the pressure chamber and generating energy for ejecting liquid from the ejection port, an individual flow path communicating with the pressure chamber, and a second thermal energy generating element provided in the individual flow path; and a common flow path for supplying liquid to the individual flow paths of a plurality of the individual ejection units, wherein the first thermal energy generating element and the second thermal energy generating element are configured to be driven and controlled under the following conditions: (conditions) When the first heat energy generating element is driven, the second heat energy generating element is not driven, When the first thermal energy generating element is not driven, the second thermal energy generating element is driven when a drive signal instructing the second thermal energy generating element to be driven is received.

[0008] Furthermore, in order to solve the above-mentioned problems, a liquid ejection head of the present invention comprises an ejection port for ejecting liquid, a pressure chamber communicating with the ejection port, a first thermal energy generating element provided in the pressure chamber and generating energy for ejecting liquid from the ejection port, an individual flow path communicating with the pressure chamber, a second thermal energy generating element provided in the individual flow path, and a drive circuit for controlling the drive of the first thermal energy generating element and the second thermal energy generating element, wherein the drive circuit comprises a first switch configured to be able to switch the first thermal energy generating element and the second thermal energy generating element mutually exclusively so that only one of them is in a driveable state, and a second switch configured to be able to switch the second thermal energy generating element between a driveable state and a non-driveable state, The present invention is characterized by having the following. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a liquid ejection head and a liquid ejection method that can be driven with an optimized amount of data. [Brief explanation of the drawings]

[0010] [Figure 1] Overall view of a device using a liquid ejection head [Figure 2] Overall view of a liquid ejection head and an overall view of a liquid ejection chip [Figure 3] Schematic diagram of the vicinity of the ejection port of the liquid ejection head [Figure 4] Schematic diagram of the vicinity of the ejection port of the liquid ejection head [Figure 5] Schematic diagram of the vicinity of the ejection port of the liquid ejection head [Figure 6] Schematic diagram of the vicinity of the ejection port of the liquid ejection head [Figure 7]Schematic diagram of the vicinity of the ejection port of the liquid ejection head according to the first embodiment. [Figure 8] Circuit configuration diagram for comparison [Figure 9] Circuit configuration diagram in the first embodiment [Figure 10] Schematic diagram of the vicinity of the ejection port of the liquid ejection head according to the second embodiment. [Figure 11] 10 is a schematic diagram of the vicinity of the ejection port of the liquid ejection head according to the third embodiment; [Figure 12] 10 is a schematic diagram of the vicinity of the ejection port of the liquid ejection head according to the fourth embodiment; [Figure 13] 13 is a schematic diagram of the vicinity of the ejection port of the liquid ejection head according to the fifth embodiment; [Figure 14] 13 is a schematic diagram of the vicinity of the ejection port of the liquid ejection head according to the sixth embodiment; [Figure 15] FIG. 10 is a diagram showing drive timings for energy generating elements in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the present disclosure, and not all combinations of features described in the present embodiments are necessarily essential to the solutions of the present disclosure. Note that identical components are designated by the same reference numerals. In the following description, the basic configuration of the present disclosure will first be described, followed by a description of the features of the present disclosure.

[0012] <Liquid discharge device> First, a schematic configuration of a liquid ejection device 50 according to this embodiment will be described. FIG. 1 is an enlarged view of a liquid ejection head 1 and its surroundings of the liquid ejection device 50, and FIGS. 1(a) and 1(b) are perspective views schematically illustrating a liquid ejection device using a liquid ejection head. The liquid ejection device 50 shown in FIG. 1 is a serial-type liquid ejection device that records an image by ejecting liquid onto a recording medium P using a liquid ejection head that scans in a direction intersecting the transport direction of the recording medium P. The present invention is not limited to serial-type liquid ejection devices, but can also be applied to page-wide-type liquid ejection devices that use a line head (page-wide-type head) that is long in the page width direction of the recording medium to eject liquid onto a recording medium transported in the transport direction. The liquid ejection head according to this embodiment is capable of ejecting four types of ink: black (K), cyan (C), magenta (M), and yellow (Y), and full-color images can be recorded using these inks. The inks that can be ejected from the liquid ejection head are not limited to the four types mentioned above. The present disclosure can also be applied to liquid ejection heads for ejecting other types of ink. In other words, the types and numbers of inks ejected from the liquid ejection head are not limited.

[0013] 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 is transported in a sub-scanning direction (Y direction) that intersects (in this example, orthogonal to) the main scanning direction by transport rollers (transport means) 55, 56, 57, and 58. Note that in each figure referred to below, the Z direction indicates the vertical direction, and intersects (in this example, orthogonal to) the XY plane defined by the X and Y directions.

[0014] FIG. 1(a) shows a configuration in which a main ink tank 2 serving as a liquid storage unit is provided outside the liquid ejection head. The liquid (ink) stored in the ink tank 2 is supplied to a 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 21. On the other hand, FIG. 1(b) shows a configuration in which an ink tank 54 is provided directly above the liquid ejection head 1 (without a main ink tank 2 serving as a liquid storage unit outside the liquid ejection head). In this case, the liquid ejection head 1 may be provided integrally with the ink tank 54 and configured to be removable / attachable to / from a carriage 60, or the liquid ejection head 1 may be provided integrally with the carriage 60 and only the ink tank 54 may be removable / attachable. The following explanation will use the configuration in FIG. 1(a) as a representative example.

[0015] The liquid ejection head 1 is configured to include individual ejection units, which will be described later (see FIG. 2). The specific configuration will be described later, but each individual ejection unit is provided with an ejection port for ejecting liquid, a pressure chamber communicating with the ejection port, a first energy generating element (ejection energy generating element) that is provided in the pressure chamber and generates energy for ejecting liquid from the ejection port, an individual flow path that communicates with the pressure chamber, and a second energy generating element (flow energy generating element) that is provided in the individual flow path. The liquid ejection head 1 has a plurality of individual ejection units, and each individual ejection unit has a supply flow path for supplying liquid to the individual flow path in the individual ejection unit.

[0016] When using a liquid ejection head, the evaporation of volatile components such as water from the ejection orifices and the resulting concentration of solids near the ejection orifices can sometimes cause unstable liquid ejection. Various methods have been developed to prevent this. For example, a liquid ejection device can be provided with a cap member (not shown) located in the X direction away from the recording medium transport path, which can cover the ejection orifice surface of the liquid ejection head. The cap member is used to cover the ejection orifice surface of the liquid ejection head to prevent the orifices from drying out and protect them when not performing printing operations. An ink suction mechanism (not shown) can also be provided, in which case the cap member is used to suction ink from the orifices. This ink suction operation refreshes the ink near the orifices, maintaining the quality of the resulting image. Other known methods include performing a preliminary ejection (pre-ejection) when not performing printing to discard concentrated ink, and performing a preliminary ejection of ink (paper preliminary ejection / intra-page preliminary ejection) on the recording medium during printing operations at a location and amount that is inconspicuous in terms of image quality. Although these methods contribute greatly to improving image quality, they require some ink to be discarded in order to refresh the ejection ports, and therefore it is necessary to reduce the amount of wasted ink as much as possible.

[0017] To address this issue, a second energy generating element (flow energy generating element) is installed in each individual flow path to circulate the ink within the flow path, which can suppress the amount of waste ink while also preventing the nozzles from drying out and the ink from concentrating near the nozzles. More specifically, this can minimize the number of preliminary ejections and suction recovery operations. Furthermore, minimizing the number of preliminary ejections and other operations can also lead to improvements in throughput and yield.

[0018] The second energy generating element (flow energy generating element) does not need 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 effects can be obtained compared to when it is not provided.

[0019] 1(a) 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.

[0020] <Basic configuration of liquid ejection head> Fig. 2(a) is an exploded perspective view of the liquid ejection head of this embodiment. As shown in Fig. 2, the liquid ejection head is configured to include a sub-ink tank 54 that temporarily stores ink in the head, and a liquid ejection chip 3 that ejects ink supplied from the sub-ink tank 54 onto a recording medium P. The liquid ejection head of this embodiment is fixedly supported on the carriage of the liquid ejection device by positioning means and electrical contacts (not shown) that are provided on the carriage. The liquid ejection head ejects ink while moving together with the carriage in the main scanning direction (X direction) shown in Fig. 1, and performs recording on the recording medium P.

[0021] An ink supply tube 59 is provided to the external pump 21 connected to the ink tank 2, which serves as an ink supply source (see FIG. 1( a)). A liquid connector (not shown) is provided at the end of this ink supply tube. 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 the head housing of the liquid ejection head 1. This forms an ink supply path from the ink tank 2 to the liquid ejection head 1 via the external pump 21. In this embodiment, four types of ink are used, so four sets of ink tanks 2, external pumps 21, ink supply tubes 59, and sub-ink tanks 54 are provided, one for each ink, and four independent ink supply paths are formed corresponding to each ink. In this way, the liquid ejection device of this embodiment is provided with an ink supply system to which ink is supplied from the ink tank 2 provided outside the liquid ejection head 1. Note that the liquid ejection device of this embodiment is not provided with an ink recovery system that recovers ink in the liquid ejection head back to the ink tank. Therefore, the liquid ejection head is provided with a liquid connector insertion port for connecting the ink supply tube of the ink tank, but is not provided with a connector insertion port for connecting a tube for recovering ink from the liquid ejection head to the ink tank. Note that a liquid connector insertion port is provided for each ink.

[0022] Figures 2(b), (c), and (d) are overall views of the liquid ejection chips that make up a liquid ejection head. Figure 2(b) shows a configuration of one chip for four colors, Figure 2(c) shows a configuration of one chip for two colors, and Figure 2(d) shows a configuration of one chip for one color. Each liquid ejection chip is provided with ejection ports and pads used for electrical mounting. Figure 2(a) shows the chip configuration of Figure 2(b).

[0023] FIG. 2(b) shows a first embodiment in which one chip is configured for four colors. The four colors are, for example, black, cyan, magenta, and yellow, and each color has its own column, which is aligned in the Y direction. The ejection openings in each column are adjacent to each other but offset in the X direction, and are equally spaced along the Y direction. However, the ejection openings in each column may be aligned in a single column along the Y direction without being offset in the X direction. Alternatively, black may be arranged in two columns, for a total of five columns for the four colors.

[0024] 2(c) shows a second embodiment in which two chips are used, one chip for each of two colors. When mounting two chips on a liquid ejection head, two chips may be mounted on one liquid ejection head, or two heads may be prepared in which one chip is mounted on one liquid ejection head.

[0025] Fig. 2(d) shows a third embodiment in which four chips are used, one for each color. As in Fig. 2(c), four chips may be mounted on one liquid ejection head, or four liquid ejection heads may be prepared, each with one chip mounted thereon.

[0026] Also, when the chip is divided into multiple parts, as shown in Figure 2(c)(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.

[0027] <Components of the circulation unit> (Straight type) Fig. 3 is a schematic diagram illustrating the vicinity of the ejection ports of a straight-type liquid ejection head. In this specification, the term "straight-type" refers to a straight shape in which individual flow paths in which first energy generating elements (ejection energy generating elements) and second energy generating elements (flow energy generating elements) are arranged extend in a direction intersecting the ejection port array (in the case of Fig. 3, a direction perpendicular to the ejection port array) so that both ends of the individual flow paths are located on either side of the ejection port array. In other words, in the individual flow paths of the individual ejection units, the first energy generating elements and the second energy generating elements are arranged in a direction intersecting the ejection port array.

[0028] Fig. 3(a) is a plan view seen from the direction in which droplets are ejected from the ejection port. Fig. 3(b) is a cross-sectional view taken along line A-A' in Fig. 3(a). Fig. 3(c) is another cross-sectional view taken along line A-A' in Fig. 3(a). Fig. 3(d) is a diagram illustrating ink flow when the first energy generating element is driven.

[0029] 3(a) to 3(c), pressure chambers 12 are formed between a substrate 18 and an orifice plate 19, each separated by a partition wall 21 and corresponding to a respective ejection port 11, and individual flow paths 23 are formed for causing ink to flow through the pressure chambers 12. An ink meniscus is formed at the ejection port 11, forming an ejection port interface as an interface between the ink and the atmosphere.

[0030] The substrate 18 is provided with a first energy generating element 14, which is an electrothermal conversion element that generates energy for ejecting ink in the pressure chamber. The first energy generating element 14, together with the ejection port 11 and the pressure chamber 12, is located closer to the second supply opening 32 than to the first supply 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 bubbling energy can be used to eject ink from the ejection port 11.

[0031] The substrate 18 is also provided with a second energy generating element 24, which is an electrothermal conversion element that generates energy to cause the ink in the individual flow paths to circulate in a circulating flow 27 indicated by the arrows.

[0032] Furthermore, the substrate 18 is provided with an opening for supplying liquid from the common flow path to the individual flow paths. This opening may be configured to have multiple openings (independent supply openings) as shown in Fig. 3(a), or may be a supply groove as a single large opening as shown in Fig. 7(a) described below. The second energy generating element 24 is located closer to the first supply opening 22 than the second outlet opening 32.

[0033] The individual flow paths 23 extend in a second direction that intersects (in this example, perpendicular to) the direction (first direction) in which the ejection ports are aligned in a row. The individual flow paths 23 include a pressure chamber 12, an inlet (upstream) side connecting flow path 13 in FIG. 3(b) that communicates with one end of the pressure chamber 12, and an outlet (downstream) side flow path in FIG. 3(b) that communicates with the other end of the pressure chamber 12. The individual flow paths 23 communicate at one upstream end and the other downstream end with a first supply opening 22 and a second supply opening 32 that penetrate the substrate 18, respectively. Therefore, the connecting flow path 13 is located closer to the second energy generating element than the ejection port row. Both ends of the individual flow paths 23 are located on opposite sides of the ejection port row.

[0034] The ink flows in the individual flow paths are broadly classified into two types: (1) a first ink flow for driving the first energy element 14 and refilling after ejection, and (2) a second ink flow for driving the second energy element 24 and forming a circulating flow.

[0035] When the first energy element 14 is driven and liquid is ejected from the ejection port 11, ink is supplied from the first supply opening 22 and the second supply opening 32 during ejection, as shown in Figure 3(d), and ink flows into the pressure chamber from both supply openings.

[0036] When the second energy element 24 is driven to form a circulating flow, ink flows into the individual flow paths 23 through the first supply opening 22, which is on the connecting flow path side, and flows out to the outside through the second supply opening 32, which is not on the connecting flow path side. In this example, ink flowing out from the second supply opening 32 is returned to the first supply opening 22 and circulated, thereby forming a circulating flow 27, indicated by the arrow, in the individual flow paths 23. Note that FIG. 3(b) shows a configuration in which the first supply opening 22 and the second supply opening 32 are shared within the chip. Also, FIG. 3(c) shows a configuration in which the first supply opening 22 and the second supply opening 32 are connected to individual flow paths and shared outside the printhead; either configuration is acceptable.

[0037] Filters 31 for removing foreign matter from the ink may be provided in the ink circulation paths inside and outside the recording head 20. In FIG. 3, the filters are arranged on the inlet and outlet sides, which are outside the individual paths. Also, filters may be arranged between the first energy generating element and the second energy generating element in the individual paths. In this case, it is not necessary to arrange a filter on the upstream side (the second energy generating element side), which is outside the individual paths.

[0038] (U-shaped) Here, the vicinity of the ejection orifices of a U-shaped liquid ejection head will be described using FIG. 7 of the first embodiment described later. In this specification, "U-shaped" refers to a shape in which the flow path in which the first energy generating elements (ejection energy generating elements) and the second energy generating elements (flow energy generating elements) are arranged is U-shaped. That is, in the individual flow paths, the first energy generating elements and the second energy generating elements are arranged along the ejection orifice array. In addition, the individual flow paths are configured so that both ends thereof are located on one side of the ejection orifice array. FIG. 7(a) is a plan view seen from the direction in which droplets are ejected from the ejection orifices. FIG. 7(b) is an AB cross-sectional view of FIG. 7(a). FIG. 7(c) is an enlarged schematic view explaining the names of elements in the individual flow path section in FIG. 7(a).

[0039] In FIG. 7, both the first energy generating element 14 and the second energy generating element 24 are located near the supply groove 42. The individual flow paths 23 are formed in a U-shape by alternately arranging the first energy generating elements and the second energy generating elements in a direction (first direction) in which the ejection ports are aligned in a row. The individual flow paths 23 include a pressure chamber 12, an inlet (upstream) connecting flow path 13 in FIG. 7(b) that communicates with one end of the pressure chamber 12, and an outlet (downstream) flow path in FIG. 7(b) that communicates with the other end of the pressure chamber 12. The individual flow paths 23 communicate with a supply groove 42 that penetrates the substrate 18 on both its upstream and downstream sides. Both ends of the individual flow paths 23 are located adjacent to one side of the supply groove 42.

[0040] The ink flows in the individual flow paths are classified into two types, (1) the first ink flow and (2) the second ink flow, just like in the straight type.

[0041] When the first energy element 14 is driven and liquid is ejected from the ejection port 11, ink is supplied from the supply groove 42 in association with the ejection, and ink flows into the pressure chamber from both the connecting flow channel side and the opposite side.

[0042] When the second energy element 24 is driven to form a circulating flow, the flow enters the individual flow channels 23 from the inlet (upstream) side, which is the connecting flow channel side, and flows out to the outlet (downstream) side. In this example, both flow into and out of a common supply groove 42, forming a circulating flow 27 indicated by the arrows in the individual flow channels 23. Note that although this embodiment is shown as a supply groove 42, it may be replaced with a row of supply openings aligned in the first direction as shown in FIG. 3. If replaced with a supply opening, the supply opening will have a common configuration within the chip, similar to FIG. 3(b).

[0043] (Pump principle) FIG. 4 illustrates the principle of the generation of a circulating flow of ink when a second energy generating element (circulation heater) 24, which is an electrothermal conversion element, is used. FIGS. 4(a), 4(b), and 4(c) are cross-sectional views similar to FIG. 3(b), respectively illustrating the generation, growth, contraction, and post-death processes of a bubble B caused by film boiling of ink when ink is heated by the circulation heater 24. In FIG. 4(a), the circulation heater 24 is located closer to the first supply opening 22 than the second supply opening 32. Therefore, the flow resistance R1 between the circulation heater 24 and the first supply opening 22 is smaller than the flow resistance R2 between the circulation heater 24 and the second supply opening 32. FIG. 4(a) also includes an equivalent circuit that expresses these flow resistances R1 and R2 as electrical resistances. Due to the difference between the flow resistances R1 and R2, the bubble B generated by film boiling of ink grows toward the supply channel 14 side with the smaller flow resistance R1, as shown in FIG. 4(a). Therefore, in the individual flow path 13, the flow Fa of ink toward the supply flow path 14 is larger than the flow Fb of ink toward the outflow flow path 15.

[0044] FIG. 4(b) is an explanatory diagram of the flow of ink during the contraction of bubble B. As bubble B contracts, ink flows in to compensate for the contracted volume. As shown in FIG. 4(b), the flow Fc of ink flowing in from the first supply opening 22 on the side with small flow resistance R1 is larger than the flow Fd of ink flowing in from the second supply opening 32 on the side with large flow resistance R2. Furthermore, the vanishing position of bubble B shifts from above the circulation heater 24 toward the second supply opening 32.

[0045] 4(c) is an explanatory diagram showing the process after the collapse of bubble B. Due to the relationship Fc>Fd that occurred in FIG. 4(b), a circulating flow F of ink is generated from the first supply opening 22 to the second supply opening 32.

[0046] The size 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, assuming that the second energy generating element 24 is a circulation heater 24, which is an electrothermal conversion element, it is preferable that the second energy generating element 24 be located closer to one of the two ends of the individual flow path 23 than the first energy generating element. More specifically, the flow resistance ratio R1 / R2 is preferably set 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. It is important for the circulating flow F to increase the ink flow Fa toward the supply flow path 14 (shown in FIGS. 4(a) and 4(b)) and increase the ink flow Fc flowing in from the first supply opening 22. Therefore, it is effective to reduce the flow resistance R1. It is also important to minimize the ink flow Fb toward the outlet flow path 15 and reduce the ink flow Fd flowing in from the second supply 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. Also, if the bubbles B are large, that is, the bubble volume is large, this leads to an increase in the excluded volume of the fluid generated in the individual flow paths 23, and therefore the circulating flow F becomes larger. As a means for increasing the bubble volume, -Increased size of circulation heater 17 - Widen the width and height of the flow path 13 to reduce flow resistance -Reducing ink viscosity -Increased head temperature Double pulse drive pulse Examples include:

[0047] 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 supply opening 32 side, and fresh ink flows into the ejection port 11 from the first supply opening 22 side through the connecting flow path 13. In this way, by making it difficult for the concentrated ink to accumulate in the ejection port 11, the influence of the concentrated ink can be suppressed and the initial ink ejection state can be maintained.

[0048] The circulating flow F is a transient flow that occurs during the growth and contraction process of the bubble B when it is generated. Therefore, after the bubble B collapses, the inertial flow attenuates over time and stops after a certain period of time. Therefore, to steadily generate the circulating flow F for a certain period of time, the heating element of the circulation heater 24 must be repeatedly driven. The driving cycle of the circulation heater 24 is not particularly limited as long as it can discharge the concentrated ink from the ejection port 11. However, because the circulating flow F is a transient flow that occurs during the growth and contraction process of the bubble B when it is generated, taking into account the 10 μs cycle from bubble generation to collapse, driving the circulation heater 24 at a high driving frequency, such as 100 kHz, reduces its effectiveness. Therefore, it is preferable to drive the circulation heater 17 at a frequency of, for example, 100 Hz to several tens of kHz. The higher the driving frequency, the more the circulating flow F is maintained, thereby increasing the effectiveness of discharging the concentrated ink. However, at the same time, it is necessary to consider the increase in ink temperature due to heat generated by driving the circulation heater 24. Therefore, the circulation heater 24 must be driven at an appropriate frequency.

[0049] (recirculation concentration) Figures 5 and 6 are diagrams for explaining the elimination of concentration due to the circulating flow of ink caused by the second energy generating element. Figure 5 shows a straight configuration in which the inlet and outlet of the circulating flow in the individual flow paths are separate, while Figure 6 shows a U-shaped configuration in which the inlet and outlet of the circulating flow in the individual flow paths are adjacent. Note that areas where the ink has concentrated are shown in a dark color, and the degree of concentration is expressed by the shade of color.

[0050] First, in Figure 5, Figure 5(a) shows the state after a temporary pause. During a temporary pause, volatile components evaporate from the ejection orifice, causing ink to concentrate near the orifice. Figure 5(b) shows the state immediately after a circulating flow is subsequently generated by the second energy generating element. The circulating flow eliminates the concentration near the orifice. The ink that has concentrated near the orifice is discharged from the outlet, and concentration is eliminated throughout the individual flow paths. Figure 5(c) shows the state after another temporary pause. As in Figure 5(a), ink concentration again progresses near the orifice. From there, Figure 5(d) shows the state immediately after a circulating flow is generated by the second energy generating element. As in Figure 5(b), concentration near the orifice is again eliminated, and concentration is eliminated throughout the individual flow paths. As described above, in a straight-type inkjet printer in which the inlet and outlet of the individual flow paths are separated, the concentration state is reset each time the temporary pause and circulation operation are repeated.

[0051] Meanwhile, in Figure 6, Figure 6(a) shows the state after a temporary pause. During this pause, ink concentration progresses near the ejection orifices, as in Figure 5(a). Figure 6(b) shows the state immediately after a circulatory flow is subsequently generated by the second energy generating element. Here, because the inlet and outlet of the individual flow path are adjacent, concentrated ink near the ejection orifices is discharged from the outlet, but re-enters from the inlet. This results in the entire individual flow path being replaced with slightly concentrated ink rather than fresh ink (hereafter referred to as recirculation concentration). Figure 6(c) shows the state after a further pause. In this case, in addition to the state shown in Figure 6(b), ink concentration again progresses near the ejection orifices, as explained in Figure 6(a). Figure 6(d) shows the state immediately after a circulatory flow is further generated by the second energy generating element. In this case, as explained in Figure 6(b), the entire individual flow path is replaced with even more concentrated ink than in Figure 6(b) due to the effects of recirculation concentration. As described above, in a U-shaped configuration where the inlet and outlet of the individual flow path are adjacent, the concentration state is not reset each time a temporary pause and circulation operation are repeated, and concentration gradually progresses throughout the individual flow paths, causing the concentration state to worsen. Furthermore, even if the circulation operation is not repeated, if the area near the discharge port has become highly concentrated due to a long pause, for example, the concentration state is unlikely to improve even with the first circulation operation. This is because the improvement in the concentration state due to recirculation concentration is small.

[0052] Therefore, between a straight type where the inlet and outlet of the individual flow paths are separate and a U-shaped type where the inlet and outlet of the individual flow paths are adjacent, there is a difference in the state of concentration elimination that occurs with temporary pauses and circulation operations due to differences in the influence of the discharged concentrated ink.With a straight type, the concentrated state is easily eliminated including the entire individual flow path, so there is little risk of reduced ejection stability due to concentrated ink.On the other hand, with a U-shaped type, it is difficult to eliminate the concentrated state including the entire individual flow path through recirculation concentration, so ejection is likely to become unstable depending on the concentration of the entire individual flow path.

[0053] (ink) As shown 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, it is possible to suppress the effects of concentrated ink that has thickened due to evaporation at the ejection port. In other words, since the ink ejection state can be maintained in a good condition, the effects of changes in ejection speed and the like can be further reduced, making it easier to stabilize ejection.

[0054] On the other hand, depending on the application of the liquid ejection head and the liquid ejection device equipped with the head, inks with different types of colorants and solid content are expected to be used. In other words, maintaining a high level of ejection stability regardless of the ink used is desirable for liquid ejection head performance. For example, to address issues that can arise from water in the ink, such as curling (warping) and cockling (wavy wrinkles) on plain paper, inks with reduced water content can be used. Inks with low water content have a high concentration of solids, such as organic solvents, pigments, and resins, and are prone to a rapid increase in viscosity as the water evaporates, leading to a decrease in ink ejection stability. For such inks, the method of generating a circulating flow within a pressure chamber, as described in the present invention, is very effective because it can suppress the increase in ink viscosity. Generally, inks with a high solid content are defined as those with a solid content of 10 wt% or more. In other words, the present invention is preferably applied to inks with a solid content of 10 wt% (mass%) or more.

[0055] Furthermore, the head operating temperature can be controlled by placing heaters over the entire chip and controlling them to maintain a constant temperature. Since ink viscosity changes depending on the temperature, the ink viscosity at the head operating temperature affects ejection stability.

[0056] When a circulating flow is formed using the second energy generating element, 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 of several hundred microseconds depends on the drive frequency of the circulating heater. This is because the circulating heater produces a transient circulating flow that decays over time and stops after a certain period of time. When 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 element, the average flow velocity can be several mm / s to 100 mm / s.

[0057] When using ink with a high pigment concentration, for example, ink with a viscosity of 3 cP to 6 cP at the head operating temperature, the ink tends to thicken at the nozzle opening depending on the non-ejection time (rest time). This can easily cause changes in ejection speed and lead to a decrease in ejection stability. Therefore, it is necessary to circulate the ink while the rest time is short, and it is necessary to eliminate concentration by performing regular or transient ink circulation at high frequency. When a circulation heater is used as the second energy generating element, transient ink circulation occurs, so performing circulation at high frequency can contribute to eliminating concentration at the nozzle opening.

[0058] 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 at the ejection port increases in viscosity 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, the recovery procedure creates a circulation flow, contributing to the elimination of condensation at the ejection port without generating waste ink. Depending on the pause time, it is possible to prevent the generation of waste ink by recovery procedures using only circulation operations. Alternatively, recovery procedures using circulation operations can be combined with suction operations to remove air bubbles in the head, separate from the elimination of condensation, to minimize waste ink generation.

[0059] 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 to reduce the effects of concentrated ink. Therefore, even when a circulation heater is used as the second energy generating element, the lower the effects of recirculation concentration, the better the circulation effect can be obtained. In other words, a straight-type configuration is more effective than a U-type configuration.

[0060] (First embodiment) Fig. 7 is a schematic diagram illustrating in detail the vicinity of the ejection ports of a liquid ejection head that ejects liquid such as ink in the first embodiment. Fig. 7(a) is a plan view seen from the direction in which droplets are ejected from the ejection ports. Fig. 7(b) is an AB cross-sectional view of Fig. 7(a). Fig. 7(c) is an enlarged schematic diagram illustrating the names of elements in the individual flow path section in Fig. 7(a). Fig. 8 is a block diagram illustrating the selective drive circuit configuration on a substrate in a comparative configuration, and Fig. 9 is a block diagram illustrating the selective drive circuit configuration on a substrate in this embodiment.

[0061] 7(a) and 7(b), an ejection port 11 for ejecting liquid is formed in an orifice plate 19. A first energy generating element 14 is formed directly below the ejection port 11 in a substrate 18. A second energy generating element 24 is similarly formed on the substrate 18 together with the first energy generating element 14 to form a circulating flow 27 in an individual flow path 23. Liquid is supplied to the individual flow path 23 including the ejection port 11 from a supply groove 42. At this time, both ends of the individual flow path are adjacent in the first direction, which is the direction in which the ejection ports are arranged.

[0062] Here, the flow path shape shown in Figure 7(a) is referred to as a U-shape, and both ends of the individual flow path are adjacent in the first direction, which is the direction in which the ejection ports are arranged. The names of each element, which are also used in Figures 8 and 9, will be explained. As shown in Figure 7(c), 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 is designated as Ai (i = 1, 2, 3, ..., n) and the second energy generating element is designated as Bi (i = 1, 2, 3, ..., n). In this case, it is indicated that, for example, A1 and B1 are in the same individual flow path.

[0063] (Driving method of the comparative configuration) In the comparative configuration, a selection drive circuit 200 as shown in FIG. 8 is formed on a substrate 18. A voltage source (+V) and a controller 110 are provided outside the substrate and connected to the selection drive circuit 200 on the substrate. An on-off drive circuit (on-off switch) 210 is included, which drives the first energy generating elements (A1 to A8) or the second energy generating elements (B1 to B8) on or off in response to control signals at each address (N1 to N16 in this configuration) received from the control data supply circuit 100. That is, the first and second energy generating elements are independently controlled by switches configured to be switchable between a drivable state and a non-drivable state. Here, the control data supply circuit controls the drive pulse for driving the first energy generating element or the second energy generating element and the time interval for applying the drive pulse to each element.

[0064] In the comparative configuration, the first energy generating element and the second energy generating element are linked to separate addresses, and separate drive circuits are required. Therefore, separate drive data must be provided for the first energy generating element and the second energy generating element. Therefore, the amount of data increases in proportion to the total number of elements, including the first energy generating element and the second energy generating element.

[0065] (Driving method of the embodiment: toggle driving) In this embodiment, a selection drive circuit 200 as shown in FIG. 9 is formed on a substrate 18. A voltage source and a controller 110 are provided outside the substrate and connected to the selection drive circuit 200 on the substrate. The circuit includes an on-on drive circuit (first switch for on-on switching) 230 that turns on and drives either the first energy generating elements (A1 to A16) or the second energy generating elements (B1 to B16) in response to a control signal at each address (N1 to N16 in this embodiment) received from the control data supply circuit 100. That is, the circuit includes a switch configured to mutually exclusively switch the first energy generating element and the second energy generating element so that only one of them is drivable. This switch ensures that when the first energy generating element is drivable, the second energy generating element is always in an indriveable state. Conversely, when the second energy generating element is drivable, the first energy generating element is always in an indriveable state. Here, the control data supply circuit 100 controls the drive pulse for driving the first energy generating element or the second energy generating element and the time (interval) for applying the drive pulse to each element.

[0066] Even when the second energy generating element side is selected by the on-on drive circuit 230, the drive is further controlled by the on-off drive circuit (second switch for switching on and off) 240 of the second energy generating element in accordance with the drive enable / disable signal 300 of the second energy generating element. That is, the second energy generating element is further controlled by a switch configured to be switchable between a drive enable / disable state and a drive disable state. Therefore, when the first energy generating element is in a drive disable state, the second energy generating element is in a drive enable state, but is actually driven only when it receives a drive signal (drive enable / disable signal) instructing it to be driven. If there is no drive enable / disable signal, the second energy generating element is not driven even if the second energy generating element side is selected by the on-on drive circuit 230. That is, in this case, neither the first energy generating element nor the second energy generating element is driven.

[0067] To summarize the above, in this embodiment, the drive circuit for controlling the drive of the first energy generating element and the second energy generating element has a first switch configured to be able to switch the first energy generating element and the second energy generating element mutually exclusively so that only one of them is in a driveable state, and a second switch configured to be able to switch the second energy generating element between a driveable state and an indriveable state, and is characterized in that by using this drive circuit, the first energy generating element and the second energy generating element are configured to be drive-controlled under the following conditions. Condition: When the first energy generating element is driven, the second energy generating element is not driven, and when the first energy generating element is not driven, the second energy generating element is driven when a drive signal instructing the second energy generating element to be driven is received.

[0068] Furthermore, it is preferable that the on-off drive circuit (second switch) is provided closer to the second energy generating element than the on-on drive circuit (first switch) and electrically downstream of the second energy generating element. It is also preferable that a common drive signal is used to drive and control a plurality of second energy generating elements.

[0069] Figure 15 shows the drive timing for each energy generating element for the circuit for each energy generating element shown in Figure 9. For simplicity, the diagram shows two pairs of first and second energy generating elements, but the same applies to multiple pairs. As shown in Figure 15(a), when a common drive enable / disable signal 300 is not received, only the first energy generating element is selected and driven, and the second energy generating element is not selected and driven. On the other hand, as shown in Figures 15(b) and 15(c), when a common drive enable / disable signal 300 is received, the second energy generating element is selected and driven when the first energy generating element is not selected. In this case, the first energy generating element and the second energy generating element in the same individual flow path are driven exclusively. By providing the common drive enable / disable signal 300 in this way, a drive timing is generated to drive the second energy generating element, thereby forming a circulating flow. By periodically providing the common drive enable / disable signal 300, a circulating flow is periodically formed in response, thereby continuously achieving the circulation effect.

[0070] In FIG. 15(b), the first energy generating elements are not selected, and in that case, the second energy generating elements are selected and driven. When all the first energy generating elements are not driven in this manner, this corresponds to a case where a common drive enable / disable signal 300 is provided, for example, between scans or between pages in a printing operation. In FIG. 15(c), the first energy generating elements are selected and driven as in FIG. 15(a), but when the first energy generating elements are not selected in response to the common drive enable / disable signal 300, the second energy generating elements are selected and driven. When the first energy generating elements are driven sporadically in this manner, this corresponds to a case where a common drive enable / disable signal 300 is provided when printing characters or images, for example, during scanning in a printing operation.

[0071] Although the drive pulse for the energy generating element is shown as a single pulse here, a drive pulse consisting of two or more pulses may also be used. Furthermore, the drive pulses given to the first energy generating element and the second energy generating element may be the same or different drive pulses may be used.

[0072] For comparison, the following describes countermeasures for thickened ink in a liquid ejection head that does not form a circulating flow. 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, the preliminary ejection operation and suction operation are performed in the head standby area before the head leaves the cap that protects the head and heads off to the printing operation. Alternatively, the 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 performed at different times 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.

[0073] In this embodiment, the number of preliminary ejection and suction operations can be reduced by performing circulation operations by driving the second energy generating elements. In this case, the timing of circulation operations in the head standby area or non-printing areas during reciprocating movement is similarly different from the timing of printing operations. Therefore, in this embodiment, the drive of the second energy generating elements can be easily controlled using the drive enable / disable signal 300 for the second energy generating elements. Furthermore, for ink that is prone to thickening, priority must be given to the ejection operation during circulation operations in the printing area of ​​reciprocating movement, with timing close to the printing operation. On the other hand, by providing multiple timings for the circulation operation or setting a fixed period for the timing of the circulation operation, it is not necessary to drive the circulation operation and the printing operation simultaneously. Therefore, in this embodiment, when the first energy generating element is selected, the first energy generating element is driven, allowing the circulation operation to be appropriately controlled without affecting the printing operation.

[0074] As described above, the second energy generating element is driven and controlled according to the drive data and drive enable / disable signal for the first energy generating element. This eliminates the need to provide drive data for the second energy generating element, which has the advantage of reducing the amount of drive data required.

[0075] Furthermore, even when there are multiple second energy generating elements, it is possible to control their driving based on a common driving enable / disable signal. In this embodiment, the first energy generating elements Ai and the second energy generating elements Bi are controlled as one group, totaling 32 elements (16 pairs) up to n=16, but the total number of elements in one group can also be various numbers such as 16 (8 pairs), 24 (12 pairs), etc.

[0076] In this embodiment, the drive enable / disable signal 300 is provided on the substrate 18 to control the drive of the second energy generating element, but the drive of the second energy generating element may also be controlled by providing it on a liquid ejection head outside the substrate or on a liquid ejection device outside the liquid ejection head.

[0077] (Second embodiment) Figure 10 is a schematic diagram illustrating in detail the vicinity of the ejection ports of a liquid ejection head that ejects liquid such as ink in the second embodiment. Figure 10(a) is a plan view seen from the direction in which droplets are ejected from the ejection ports. Figures 10(b) and 10(c) are two examples of AB cross-sectional views of Figure 10(a).

[0078] Here, FIGS. 10(b) and (c) show two examples because the shape of the back side of the substrate changes depending on the type of etching method used for the substrate, but the cross section may have either shape.

[0079] The present embodiment differs from the first embodiment in that the inlet and outlet of each individual flow path are separated into a straight configuration. In this embodiment, both ends of each individual flow path are separated and arranged at opposite positions in a second direction perpendicular to a first direction in which the ejection ports are arranged.

[0080] The advantage of this configuration is that the inflow and outflow of the circulation flow are separated into opposite directions, so that ink that has become concentrated at the ejection port due to circulation does not re-flow into the individual flow paths, thereby suppressing the effects of concentration.

[0081] (Third embodiment) Fig. 11 is a schematic diagram illustrating in detail the vicinity of the ejection orifices of a liquid ejection head that ejects liquid such as ink in the third embodiment. Fig. 11(a) is a plan view seen from the direction in which droplets are ejected from the ejection orifices. Figs. 11(b) and (c) are two examples of AB cross-sectional views of Fig. 11(a), which are similar to Figs. 10(b) and (c).

[0082] This embodiment differs from the second embodiment in that three supply opening arrays are provided, resulting in a double array of ejection openings, with each ejection opening array located closer to the central supply opening array. In other words, ejection opening arrays are formed on both sides of the direction in which the multiple supply openings are arranged.

[0083] The advantage of this configuration is that by increasing the number of supply openings by one, from two to three, the number of ejection opening rows can be doubled from one to two. As shown in the figure, it is also possible to arrange the two ejection opening rows with a different pitch. In addition, a configuration is possible in which no wiring area is required between the openings in the central supply opening row, allowing for a high degree of freedom in the size and resolution of the openings in the central supply opening row. This makes it easier to speed up refilling of the nozzles and achieve high productivity.

[0084] In this embodiment, the three supply opening rows are positioned at the same location in the direction between the nozzle rows, but they may be shifted in each row in accordance with the nozzle position and the wiring layout between the openings. This also applies to the following embodiments.

[0085] (Fourth embodiment) 12A and 12B are schematic diagrams illustrating in detail the vicinity of the ejection ports of a liquid ejection head that ejects liquid such as ink in a fourth embodiment. Fig. 12A is a plan view seen from the direction in which droplets are ejected from the ejection ports. Fig. 12B is an AB cross-sectional view of Fig. 12A.

[0086] This embodiment differs from the third embodiment in that there is an ejection port array near the supply opening arrays on both sides, and a second energy generating element is located near the central supply opening array, thereby reversing the direction of the circulating flow.

[0087] The advantage of this configuration is that ink concentrated near the ejection ports is branched off and discharged to the supply opening arrays on both sides, which reduces the effect of concentrated ink when it re-flows into the individual flow paths in response to ejection, etc. Also, because the ejection port arrays are spaced apart, the effect of interference caused by meniscus vibrations accompanying ejection from each ejection port is reduced.

[0088] (Fifth embodiment) 13A and 13B are schematic diagrams illustrating in detail the vicinity of the ejection ports of a liquid ejection head that ejects liquid such as ink in the fifth embodiment. Fig. 13A is a plan view seen from the direction in which droplets are ejected from the ejection ports. Fig. 13B is an AB cross-sectional view of Fig. 13A.

[0089] This embodiment differs from the third embodiment in that the second energy generating element is close to the first energy generating element, and the second energy generating element is closer to the central row of supply openings than to the supply openings on either side, thereby reversing the direction of the circulation flow.

[0090] The advantages of this configuration include the fact that, as with the third embodiment, there is a high degree of freedom in the size and resolution of the central supply opening row, which makes it easier to speed up refilling and achieve high productivity, and that, since ink concentrated near the ejection port is branched off and discharged to the supply opening rows on both sides, the impact of concentrated ink re-flowing into individual flow paths in response to ejection, etc., is suppressed.

[0091] (Sixth embodiment) Figure 14 is a schematic diagram illustrating in detail the vicinity of the ejection ports of a liquid ejection head that ejects liquid such as ink in the sixth embodiment. Figure 14(a) is a plan view seen from the direction in which droplets are ejected from the ejection ports. Figures 14(b) and 14(c) are cross-sectional views taken along lines A-A' and B-B' in Figure 14(a), respectively.

[0092] This embodiment differs from the first embodiment in that the rows of ejection ports on either side of the supply groove are arranged in a staggered pattern, and that a filter is also provided at the inlet of each individual flow path (near the second energy generating element). Even with this configuration, the effects of the present invention can be similarly obtained. [Explanation of symbols]

[0093] 11 Discharge port 12 Pressure Chamber 13 Connecting Channel 14 First energy generating element 18 PCB 19 Orifice plate 21 Bulkhead 22 first supply opening 24 Second energy generating element 27 Circulating flow 32 second supply opening 42 Supply groove

Claims

1. a discharge port for discharging a liquid; a pressure chamber communicating with the discharge port; a first thermal energy generating element provided in the pressure chamber and configured to generate energy for ejecting liquid from the ejection port; an individual flow channel communicating with the pressure chamber; a second thermal energy generating element provided in the individual flow path; an individual dispensing unit having a common flow path for supplying liquid to the individual flow paths of the plurality of individual discharge units; A liquid ejection method using a liquid ejection head having A liquid ejection method characterized in that the first thermal energy generating element and the second thermal energy generating element are controlled to be driven under the following conditions: (conditions) When the first thermal energy generating element is driven, the second thermal energy generating element is not driven, When the first thermal energy generating element is not driven, the second thermal energy generating element is driven when a drive signal instructing the second thermal energy generating element to be driven is received.

2. 2. The liquid ejection method according to claim 1, wherein the liquid ejection head comprises a drive control means for controlling the driving of the first thermal energy generating element and the second thermal energy generating element of the individual ejection unit.

3. The liquid ejection method according to claim 1 , wherein the plurality of ejection ports in the plurality of individual ejection units form an ejection port array.

4. The liquid ejection method according to claim 1 , wherein the individual flow paths of the individual ejection units are connected to the common flow path via an opening.

5. 4. The liquid ejection method according to claim 3, wherein the first thermal energy generating element and the second thermal energy generating element are arranged in the individual flow path of the individual ejection unit in a direction intersecting the ejection port array.

6. The liquid ejection method according to claim 5 , wherein the individual flow paths extend in a direction intersecting the ejection port array so that both ends of the individual flow paths are positioned on either side of the ejection port array.

7. 7. A liquid ejection method according to claim 6, wherein one ends of the plurality of individual flow paths are connected to the common flow path via a plurality of first openings arranged along the row of ejection ports, and the other ends of the plurality of individual flow paths are connected to the common flow path via a plurality of second openings arranged along the row of ejection ports.

8. 8. The liquid ejection method according to claim 7, wherein a first ejection port array and a second ejection port array are formed on both sides of the direction in which the plurality of second openings are arranged.

9. The liquid ejection method according to claim 8 , wherein the first thermal energy generating elements are arranged on the side of the individual flow paths closer to the second openings.

10. The liquid ejection method according to claim 8 , wherein the second thermal energy generating elements are arranged on the side of the individual flow paths closer to the second openings.

11. The liquid ejection method according to claim 3 , wherein the first thermal energy generating element and the second thermal energy generating element are arranged along the ejection port row in at least one of the plurality of individual flow paths.

12. The liquid ejection method according to claim 11, wherein both ends of the individual flow paths are positioned on one side of the ejection port array.

13. The liquid ejection method according to claim 1 , wherein the plurality of second thermal energy generating elements are driven and controlled using the common drive signal.

14. a discharge port for discharging a liquid; a pressure chamber communicating with the discharge port; a first thermal energy generating element provided in the pressure chamber and configured to generate energy for ejecting liquid from the ejection port; an individual flow channel communicating with the pressure chamber; a second thermal energy generating element provided in the individual flow path; a drive circuit for controlling the drive of the first thermal energy generating element and the second thermal energy generating element; A liquid ejection head having The drive circuit a first switch configured to be able to switch the first thermal energy generating element and the second thermal energy generating element mutually exclusively so that only one of them is in a driveable state; a second switch configured to be able to switch the second thermal energy generating element between an activatable state and an inactivatable state; A liquid ejection head comprising:

15. 15. The liquid ejection head according to claim 14, wherein the second switch is provided in the drive circuit closer to the second thermal energy generating element than the first switch.

Images