Liquid dispensing head

Abstract

This invention provides a technology to optimize the amount of drive data in an ink circulation type liquid ejection head that uses both an ejection energy generating element and a fluid energy generating element. [Solution] A liquid dispensing head having a discharge port, a pressure chamber, a first energy generating element that discharges liquid from the discharge port, an individual flow path communicating with the pressure chamber, an individual dispensing unit having a second energy generating element provided in the individual flow path, and a common flow path that supplies liquid to the individual flow paths of the individual dispensing units, wherein the second energy generating element is not driven when the first energy generating element is driven, and when the first energy generating element is not driven, the second energy generating element is driven only when a drive instruction signal for the second energy generating element is received.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head.

Background Art

[0002] A circulation type liquid ejection device that circulates ink is known for the purpose of discharging bubbles in a flow path and suppressing thickening of ink near a discharge port in a liquid ejection head (hereinafter also referred to as a "head"). As a method of circulating ink, a method using a pressure difference (hereinafter also referred to as a "differential pressure method") is well known. In this method, by using a pressure adjustment mechanism or the like to make the pressure on the side where ink is supplied (inlet side) to the discharge port higher than the side where ink is recovered (outlet side), ink is caused to flow from the inlet side to the outlet side. At this time, in order to circulate the ink, it is necessary to return the ink flowing to the outlet side to the inlet side, and a pump is required as a mechanism for this. There are some that circulate liquid between the liquid ejection head and the main body by providing a pump outside the head such as the recording device main body, and there are also some that circulate liquid inside the liquid ejection head by providing a pump inside the liquid ejection head. However, in such a circulation method of the differential pressure type, mechanisms such as a pressure adjustment mechanism and a pump are required, and the recording device main body and the head tend to be enlarged.

[0003] Therefore, ink circulation methods other than the differential pressure method have been studied. Specifically, a circulation flow path communicating with the discharge port is provided, and an energy generating element different from the energy generating element for discharging ink (hereinafter also referred to as a "discharge energy generating element") in the circulation flow path (hereinafter also referred to as a "flow energy generating element") is arranged, and a mechanism for circulating ink in the circulation path by driving this flow energy generating element is known.

[0004] Patent Document 1 discloses a configuration in which a circulation flow path extending so as to intersect a discharge port row in which a plurality of discharge ports are arranged is provided, and a flow energy generating element is provided in the circulation path.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-104312 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, Patent Document 1 does not describe how to drive the discharge energy generation element and the fluid energy generation element using drive data. Generally, it is conceivable to provide drive data to each energy generation element, but the amount of data will increase depending on the number of energy generation elements.

[0007] This invention has been made in view of the above-mentioned problems. The present invention aims to provide a technology for optimizing the amount of drive data in an ink circulation type liquid ejection head that uses both an ejection energy generating element and a fluid energy generating element. [Means for solving the problem]

[0008] This invention employs the following configuration: A nozzle for dispensing liquid, A pressure chamber communicating with the aforementioned discharge port, A device provided in the pressure chamber that generates energy for discharging liquid from the outlet. The first energy generating element, Individual flow channels communicating with the aforementioned pressure chamber, A second energy generating element provided in the individual flow path and An individual dispensing unit having, A common channel for supplying liquid to the individual channels of the multiple individual discharge units, A liquid dispensing head having, When the first energy generating element is driven, the second energy generating element is not driven. If the first energy generating element is not driven, the second energy generating element is driven only when a drive signal instructing the second energy generating element to be driven is received. This is a liquid dispensing head characterized by the following features. [Effects of the Invention]

[0009] According to the present invention, a technique for optimizing the amount of drive data in an ink circulation type liquid ejection head that uses both an ejection energy generating element and a fluid energy generating element can be provided. [Brief explanation of the drawing]

[0010] [Figure 1] Overall diagram of the device using a liquid dispensing head [Figure 2] Overall diagram of the liquid discharge head and overall diagram of the liquid discharge tip [Figure 3] Schematic diagram of the area near the discharge port of the liquid discharge head. [Figure 4] Schematic diagram of the area near the discharge port of the liquid discharge head. [Figure 5] Schematic diagram of the area near the discharge port of the liquid discharge head. [Figure 6] Schematic diagram of the area near the discharge port of the liquid discharge head. [Figure 7] Schematic diagram of the vicinity of the discharge port of the liquid discharge head in the first embodiment. [Figure 8] Circuit diagram in comparative configuration [Figure 9] First circuit diagram in the first embodiment [Figure 10] Second circuit diagram in the first embodiment [Figure 11] Third circuit diagram in the first embodiment [Figure 12] Schematic diagram of the vicinity of the discharge port of the liquid discharge head in the second embodiment. [Figure 13] Schematic diagram of the vicinity of the discharge port of the liquid discharge head in the third embodiment. [Figure 14]Schematic diagram of the vicinity of the liquid ejection port of the liquid ejection head in the fourth embodiment [Figure 15] Schematic diagram of the vicinity of the liquid ejection port of the liquid ejection head in the fifth embodiment [Figure 16] Schematic diagram of the vicinity of the liquid ejection port of the liquid ejection head in the sixth embodiment

Embodiments for Carrying Out the Invention

[0011] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the present disclosure, and not all combinations of the features described in the present embodiments are essential for the solution means of the present disclosure. The same reference numerals are assigned to the same components. In the following description, first, the basic configuration of the present disclosure will be described, and then the characteristic parts of the present disclosure will be described.

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

[0013] In the serial type liquid dispensing device 50, the liquid dispensing head 1 is mounted on a carriage 60. The carriage 60 reciprocates along the guide axis 51 in the main scanning direction (X direction). The recording medium is transported by transport rollers (transport means) 55, 56, 57, and 58 in the sub-scanning direction (Y direction) which intersects (in this example, is orthogonal) with the main scanning direction. In the figures referenced below, the Z direction represents the vertical direction and intersects (in this example, is orthogonal) with the XY plane defined by the X and Y directions.

[0014] Figure 1(a) shows a configuration in which a main ink tank 2 is provided outside the liquid ejection head as a liquid storage unit. 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 passage) 59, etc., by the driving force of an external pump 28. On the other hand, Figure 1(b) shows a configuration in which the ink tank 54 is provided directly above the liquid ejection head 1 (without a main ink tank 2 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 be detachable / attachable to the carriage 60, or the liquid ejection head 1 may be provided integrally with the carriage 60 and only the ink tank 54 may be detachable / attachable. The following explanation will use the configuration in Figure 1(a) as a representative example.

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

[0016] When using a liquid ejection head, the ejection of liquid can become unstable due to evaporation of volatile components such as water from the ejection port, and the resulting concentration of solids near the ejection port. Various measures have been taken to prevent this. For example, a liquid ejection device may be provided with a cap member (not shown) that can cover the ejection port surface of the liquid ejection head, located off-center in the X direction from the transport path of the recording medium. The cap member is used to cover the ejection port surface of the liquid ejection head when recording is not in progress, preventing drying and protecting the ejection port. Furthermore, an ink suction mechanism (not shown) may also be provided, in which case the cap member is used for ink suction from the ejection port. This ink suction refreshes the ink near the ejection port, maintaining the quality of the resulting image. In addition, methods are known to perform pre-ejection (pre-discharge) when recording is not in progress to discard concentrated ink, or to pre-eject ink (paper surface pre-discharge / in-page pre-discharge) in a position and amount on the recording medium that is not visually noticeable during recording. While these methods significantly improve image quality, they involve discarding some ink to refresh the ink nozzle, so minimizing the amount of waste ink is essential.

[0017] To address these challenges, a second energy generating element (fluid energy generating element) is installed in each individual flow path to circulate the ink within the flow path. This suppresses the amount of waste ink while also preventing drying at the discharge port and ink concentration near the discharge port. More specifically, the number of pre-discharge and suction recovery cycles can be minimized. Furthermore, minimizing the number of pre-discharge cycles leads to improvements in throughput and yield.

[0018] The second energy generating element (fluid energy generating element) does not need to be installed in all individual dispensing units of the liquid dispensing head. The above-mentioned effects can be obtained by installing it in some individual dispensing units compared to not installing it.

[0019] Furthermore, the liquid ejection head shown in Figure 1(a) may be configured such that all parts corresponding to the four types of ink are equipped with the second energy generating element, or it may be configured such that only the parts corresponding to one type of ink are equipped with the second energy generating element. In other words, the liquid ejection head may not circulate all four types of ink, but may be configured to circulate at least one type of ink.

[0020] <Basic configuration of a liquid dispensing head> Figure 2(a) is an exploded perspective view of the liquid ejection head of this embodiment. As shown in Figure 2, the liquid ejection head comprises a sub-ink tank 54 for temporarily storing ink in the head and a liquid ejection tip 3 for ejecting the ink supplied from the sub-ink tank 54 onto the recording medium P. In this embodiment, the liquid ejection head is fixedly supported on the carriage by positioning means (not shown) and electrical contacts provided on the carriage of the liquid ejection device. The liquid ejection head ejects ink while moving together with the carriage in the main scanning direction (X direction) shown in Figure 1, and records onto the recording medium P.

[0021] An external pump 28, connected to an ink tank 2 which serves as the ink supply source, is equipped with an ink supply tube 59 (see Figure 1(a)). A liquid connector (not shown) is provided at the tip of this ink supply tube. When the liquid ejection head 1 is mounted on the liquid ejection device 50, the liquid connector at the tip of the ink supply tube 59 is liquid-tightly connected to the liquid connector insertion port, which is the liquid inlet provided on the head housing of the liquid ejection head 1. This forms an ink supply path from the ink tank 2 through the external pump 28 to the liquid ejection head 1. In this embodiment, since four types of ink are used, four sets of ink tanks 2, external pumps 28, ink supply tubes 59, and sub-ink tanks 54 are provided, corresponding to each ink, and four independent ink supply paths corresponding to each ink are formed. Thus, the liquid ejection device of this embodiment is equipped with an ink supply system that supplies ink from an ink tank 2 located outside the liquid ejection head 1. Note that the liquid ejection device of this embodiment is not equipped with an ink recovery system that recovers the ink in the liquid ejection head into the ink tank. Therefore, while the liquid ejection head is equipped with a liquid connector port for connecting the ink supply tube of the ink tank, it is not equipped with a connector port for connecting a tube to collect the ink from the liquid ejection head back into the ink tank. Note that a separate liquid connector port is provided for each ink cartridge.

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

[0023] Figure 2(b) shows a first embodiment in which one chip is configured for each of the four colors. The four colors are, for example, black, cyan, magenta, and yellow, and each color is configured for a separate row. The nozzles are arranged in the Y direction. The nozzles in each row are offset in the X direction from adjacent nozzles and are spaced equally along the Y direction. However, the nozzles in each row may also be arranged in a single row along the Y direction without offset in the X direction. Alternatively, black may be arranged in two rows, resulting in a total of five rows for the four colors.

[0024] Figure 2(c) shows a second embodiment in which one chip is configured for each of the two colors, and two chips are used. When mounting the two chips to the liquid dispensing head, the two chips may be mounted on one liquid dispensing head, or two heads may be prepared, each with one chip mounted on it. Figure 2(d) shows a third embodiment in which one chip is configured for each color, and four chips are used. Similar to Figure 2(c), four chips may be mounted on a single liquid dispensing head, or four liquid dispensing heads, each with one chip mounted, may be prepared.

[0025] Furthermore, as shown in Figures 2(c) and 2(d), if the chip is divided into multiple parts, they do not all need to have the same chip length. Also, various combinations of other colors are possible for the chip, and the same applies when the total number of colors exceeds four.

[0026] <Components of the circulation unit> (Straight type) Figure 3 is a schematic diagram illustrating the vicinity of the discharge port of a straight-type liquid discharge head. In this specification, "straight-type" means that the individual flow path in which the first energy generating element (discharge energy generating element) and the second energy generating element (flow energy generating element) are arranged is straight in shape, extending in a direction that intersects the row of discharge ports (in the case of Figure 3, a direction perpendicular to the row of discharge ports), with both ends of the flow path located on either side of the row of discharge ports. In other words, in the individual flow path of the individual discharge unit, the first energy generating element and the second energy generating element are arranged in a direction that intersects the row of discharge ports.

[0027] Figure 3(a) is a plan view from the direction in which the liquid droplet is ejected from the nozzle. Figure 3(b) is a cross-sectional view taken along line A-A' in Figure 3(a). Figure 3(c) is another cross-sectional view taken along line A-A' in Figure 3(a). Figure 3(d) is a diagram illustrating the ink flow when the first energy generating element is driven.

[0028] In Figures 3(a) to 3(c), a pressure chamber 12 corresponding to each discharge port 11 is formed between the substrate 18 and the orifice plate 19, separated by a partition wall 21, and individual flow paths 23 for flowing ink through these pressure chambers 12. An ink meniscus is present at the discharge port 11, forming a discharge port interface that serves as the interface between the ink and the atmosphere.

[0029] The substrate 18 is equipped with a first energy generating element 14 that generates energy for ejecting ink from the pressure chamber. In this example, an electrothermal conversion element is used. The first energy generating element 14, along 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 foam the ink in the pressure chamber 12, the foaming energy can be used to eject ink from the ejection port 11. The first energy generating element is not limited to an electrothermal conversion element as in this example; a piezoelectric element or the like can be used.

[0030] Furthermore, the substrate 18 is equipped with a second energy generating element 24 that generates energy to create a circulating flow 27 in the individual channels, as indicated by the arrows. In this example, an electrothermal conversion element is used. Therefore, the second energy generating element 24 is also referred to as a circulating heater 24.

[0031] Furthermore, the substrate 18 is provided with openings for supplying liquid from the common channel to the individual channels. This opening may be configured to have multiple openings (independent supply openings), as shown in Figure 3(a), or it may be a single large supply groove, as shown in Figure 7(a), which will be described later. The second energy generating element 24 is located closer to the first supply opening 22 than to the second supply opening 32.

[0032] The individual channel 23 extends in a second direction that intersects (in this example, perpendicular to) the direction in which the discharge ports are arranged in a row (first direction). The individual channel 23 includes the pressure chamber 12, an inlet (upstream) side connecting channel 13 in Figure 3(b) that communicates with one end of the pressure chamber 12, and an outlet (downstream) side channel in Figure 3(b) that communicates with the other end of the pressure chamber 12. At one upstream end and the other downstream end of the individual channel 23, the individual channel 23 communicates with a first supply opening 22 and a second supply opening 32 that penetrate the substrate 18, respectively. Therefore, the connecting channel 13 is located on the second energy generating element side of the discharge port row. Both ends of the individual channel 23 are located on opposite sides of the discharge port row. The first supply opening 22 and the second supply opening 32 are supplied with liquid from the common channel 38.

[0033] The ink flow in the individual channels can be broadly classified into two types: (1) a first ink flow that drives the first energy generating element 14 and refills after ejection, and (2) a second ink flow that drives the second energy generating element 24 and forms a circulating flow.

[0034] When the first energy generating element 14 is driven and liquid is discharged from the discharge port 11, ink is supplied from the first supply opening 22 and the second supply opening 32 as shown in Figure 3(d), and ink flows into the pressure chamber from both supply openings.

[0035] When the second energy generating element 24 is driven to form a circulating flow, ink flows into the individual channel 23 through the first supply opening 22, which is on the connecting channel side, and flows out to the outside through the second supply opening 32, which is not on the connecting channel side. In this example, the ink that has flowed 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 within the individual channel 23. Figure 3(b) shows a configuration in which the first supply opening 22 and the second supply opening 32 are common within the chip. Alternatively, Figure 3(c) shows a configuration in which the first supply opening 22 and the second supply opening 32 are connected to individual channels and are common outside the recording head; either configuration is acceptable.

[0036] The ink circulation channels inside and outside the recording head 20 may be equipped with filters 31 to remove foreign matter from the ink. In Figure 3, the filters are located on the inflow and outflow sides, which are outside the individual channels. Alternatively, a filter may be placed between the first energy generating element and the second energy generating element in the individual channels. In that case, it is not necessary to place a filter on the upstream side (second energy generating element side), which is outside the individual channels.

[0037] (U-shaped) Here, the vicinity of the discharge port of the U-shaped liquid discharge head will be explained using Figure 7 of the first embodiment described later. In this specification, "U-shaped" means a shape in which the flow path in which the first energy generating element (discharge energy generating element) and the second energy generating element (flow energy generating element) are arranged is U-shaped. That is, in the individual flow path, the first energy generating element and the second energy generating element are arranged along the row of discharge ports. Furthermore, the individual flow path is configured such that both ends are located on one side with respect to the row of discharge ports. Figure 7(a) is a plan view as seen from the direction in which liquid droplets are discharged from the discharge port. Figure 7(b) is a cross-sectional view of AB in Figure 7(a). Figure 7(c) is an enlarged schematic diagram illustrating the element names in the individual flow path section in Figure 7(a).

[0038] In Figure 7, the first energy generating element 14 and the second energy generating element 24 are both It is located near the supply groove 42. The individual channel 23 is formed in a U-shape, with the first and second energy generating elements arranged alternately in the direction in which the discharge ports are lined up (first direction) and bent to connect them. The individual channel 23 includes a pressure chamber 12, an inlet (upstream) side connecting channel 13 in Figure 7(b) that communicates with one end of the pressure chamber 12, and an outlet (downstream) side channel in Figure 7(b) that communicates with the other end of the pressure chamber 12. The individual channel 23 communicates with the supply groove 42 that penetrates the substrate 18 on both its upstream and downstream sides. Both ends of the individual channel 23 are located adjacent to each other on one side of the supply groove 42.

[0039] The ink flow in each individual channel is classified into two types, similar to the straight type: (1) the first ink flow and (2) the second ink flow.

[0040] When the first energy generating element 14 is driven and liquid is discharged from the discharge port 11, ink flows into the pressure chamber from both the connecting channel side and the opposite side in order to supply ink from the supply groove 42 accompanying the discharge.

[0041] When the second energy generating element 24 is driven to form a circulating flow, the individual channel 23 receives water from the inlet (upstream) side, which is the connecting channel side, and flows out to the outlet (downstream) side. In this example, both flow into and out of the common supply groove 42, forming a circulating flow 27 within the individual channel 23, as indicated by the arrows. In this embodiment, it is shown as a supply groove 42, but it may be replaced with a row of supply openings arranged in the first direction as shown in Figure 3. If replaced with supply openings, the supply openings will have a common configuration within the chip, similar to Figure 3(b).

[0042] (Pump principle) Figure 4 is a diagram illustrating the principle of ink circulation flow generation when using a second energy generating element (circulation heater) 24, which is an electrothermal conversion element. Figures 4(a), 4(b), and 4(c) are cross-sectional views similar to Figure 3(b), showing the generation and growth process, contraction process, and post-defoaming process of bubbles B due to film boiling of the ink, as the ink is heated by the circulation heater 24. In Figure 4(a), the circulation heater 24 is located closer to the first supply opening 22 than to 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. Figure 4(a) incorporates an equivalent circuit in which these flow resistances R1 and R2 are represented as electrical resistances. Due to the difference in flow resistances R1 and R2, the bubbles B generated by film boiling of the ink grow towards the first supply opening 22 side, where the flow resistance R1 is smaller, as shown in Figure 4(a). Therefore, within the individual flow path 13, the ink flow Fa toward the first supply opening 22 is greater than the ink flow Fb toward the outflow flow path 15.

[0043] Figure 4(b) is an explanatory diagram of the ink flow during the contraction process of bubble B. During the contraction process of bubble B, ink flows in to compensate for the volume lost due to the contraction. At that time, as shown in Figure 4(b), the ink flow Fc flowing in from the first supply opening 22 on the side with the small flow resistance R1 is greater than the ink flow Fd flowing in from the second supply opening 32 on the side with the large flow resistance R2. Also, the defoaming position of bubble B will be shifted from above the circulation heater 24 towards the second supply opening 32.

[0044] Figure 4(c) is an explanatory diagram showing the post-defoaming process of bubble B. From the relationship Fc > Fd that occurred in Figure 4(b), a circulating flow F of ink is generated from the first supply opening 22 to the second supply opening 32.

[0045] The magnitude of this circulating flow F is influenced by the ratio of flow resistances R1 and R2 and the size of the bubbles B. For example, the second energy generating element 24 is a circulating heater which is an electrothermal conversion element. Assuming the use of 24, it is particularly preferable that the second energy generating element 24 be located closer to one end of the individual flow path 23 than the first energy generating element. More specifically, it is preferable to set the flow resistance ratio R1 / R2 to a range of 0.05 to 0.40. By setting the flow resistance ratio R1 / R2 to this range, the circulating flow F can be made to a maximum value. For the circulating flow F, it is important to increase the ink flow Fa toward the first supply opening 22 shown in Figures 4(a) and (b), and to 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 reduce the ink flow Fb toward the outflow flow path 15 as much as possible, and to 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. Furthermore, a larger bubble B, meaning a larger bubble volume, leads to an increase in the volume of fluid removed from the individual flow channels 23, resulting in a larger circulation flow F.

[0046] As a means of increasing the volume of bubbles, • Increased size of the circulating heater 24 • Increase the width and height of the flow path 13 to reduce flow resistance. • Reduced ink viscosity • Increased head temperature • Double pulse operation for drive pulses These are some examples.

[0047] A portion of the circulating ink flow F enters the discharge port 11, sending the concentrated ink in the discharge port 11 to the second supply opening 32, and allowing fresh ink to flow into the discharge port 11 from the first supply opening 22 through the connecting channel 13. In this way, by making it less likely for concentrated ink to remain in the discharge port 11, the effects of the concentrated ink can be suppressed and the initial ink discharge state can be maintained.

[0048] The circulating flow F is a transient flow associated with the growth and contraction processes when bubbles B are generated. Therefore, the inertial flow after bubbles B are defoamed decays over time and stops after a certain period. Consequently, in order to generate the circulating flow F steadily for a certain period of time, it is necessary to repeatedly drive the heating element of the circulating heater 24. The driving cycle of the circulating heater 24 is not particularly limited, as long as it is sufficient to discharge the concentrated ink from the discharge port 11. However, since it is a transient flow associated with the growth and contraction processes when bubbles B are generated, if the cycle is 10 μs, which is the time from bubble generation to defoaming, and the heater is driven at a high driving frequency such as 100 kHz, the effect will be reduced. Therefore, for example, it is preferable to drive the circulating heater 24 at a cycle of about 100 Hz to several tens of kHz, and the higher the driving frequency, the more the circulating flow F is maintained, thus increasing the effect of discharging the concentrated ink. However, on the other hand, it is necessary to consider the temperature rise of the ink due to the heat generated when the circulating heater 24 is driven. Therefore, it is necessary to drive the circulating heater 24 appropriately.

[0049] Furthermore, the second energy generating element responsible for circulation may be driven with a lower energy than the normal driving energy required for discharge. In other words, the circulation drive of the second energy generating element may be driven with weaker energy than the discharge drive of the first energy generating element. Even when the driving energy of the second energy generating element is reduced, this can be adjusted accordingly by changing the size and aspect ratio of the energy generating element.

[0050] (recirculation concentration) Figures 5 and 6 illustrate the process of ink concentration reduction associated with the circulation flow of the second energy generating element. Figure 5 shows the separate inlet and outlet of the circulation flow in the individual channel. The configuration is a t-shape, and Figure 6 shows a U-shaped configuration where the inlet and outlet of the circulating flow in the individual channel are adjacent. Areas where the ink is concentrated are shown in darker colors, and the degree of concentration is expressed by the shade of color.

[0051] First, in Figure 5, Figure 5(a) shows the state during a temporary pause. During the temporary pause, volatile components evaporate from the discharge port, and ink concentration progresses near the discharge port. Figure 5(b) shows the state immediately after the second energy generating element generates a circulating flow. The circulating flow eliminates the concentration near the discharge port. The ink concentrated near the discharge port is discharged from the outlet, and the concentration is eliminated throughout the entire individual flow path. Figure 5(c) shows the state after another temporary pause. Similar to Figure 5(a), ink concentration progresses again near the discharge port. Figure 5(d) shows the state immediately after the second energy generating element generates a circulating flow again. Similar to Figure 5(b), the concentration near the discharge port is eliminated again, and the concentration is eliminated throughout the entire individual flow path. As described above, in a straight type where the inlet and outlet of the individual flow path are separated, the concentration state is reset each time the temporary pause and circulating operation are repeated.

[0052] On the other hand, in Figure 6, Figure 6(a) shows a state of temporary pause. During temporary pause, ink concentration proceeds near the discharge port, similar to Figure 5(a). Figure 6(b) shows the state immediately after the second energy generating element generates a circulating flow. Here, because the inlet and outlet of the individual flow path are adjacent, the ink concentrated near the discharge port is discharged from the outlet, but flows back in from the inlet. As a result, the entire individual flow path is replaced with slightly concentrated ink instead of fresh ink (hereinafter referred to as recirculation concentration). Figure 6(c) shows a state of further temporary pause. In this case, in addition to the state in Figure 6(b), ink concentration proceeds again near the discharge port as explained in Figure 6(a). Figure 6(d) shows the state immediately after the second energy generating element generates a circulating flow. In this case, as explained in Figure 6(b), due to the effect of recirculation concentration, the entire individual flow path is replaced with even more concentrated ink than in Figure 6(b). As described above, in a U-shaped configuration where the inlet and outlet of individual flow paths are adjacent, the concentration state is not reset each time the pause and circulation operation are repeated. Instead, concentration gradually progresses throughout the entire individual flow path, worsening the concentration state. Furthermore, even without repeated circulation operation, if the area near the discharge port becomes highly concentrated due to a long pause time, the concentration state is unlikely to improve even with the first circulation operation. This is because the improvement in the concentration state through recirculation concentration is small.

[0053] Therefore, in the straight type, where the inlet and outlet of individual flow paths are separate, and the U-shaped type, where the inlet and outlet of individual flow paths are adjacent, there are differences in the deconcentration state due to the influence of the discharged concentrated ink, resulting in differences in temporary pauses and the deconcentration state during circulation. In the straight type, the concentrated state is easily deconcentrated throughout the entire individual flow path, so a decrease in discharge stability due to concentrated ink is less likely to occur. On the other hand, in the U-shaped type, the concentrated state is difficult to deconcentrate throughout the entire individual flow path due to recirculation concentration, so discharge tends to become unstable depending on the concentration of the entire individual flow path.

[0054] (ink) As shown above, although the degree of deconcentration differs depending on the difference in the flow path configuration, by using a second energy generating element to create an ink circulation flow within the individual flow path, the effect of concentrated ink that has thickened due to evaporation at the discharge port can be suppressed. In other words, the ink discharge state can be maintained in good condition, so the effects of changes in discharge speed and other factors can be further reduced, and discharge can be stabilized more easily.

[0055] On the other hand, depending on the application of the liquid ejection head and the liquid ejection device that houses the head, it is expected that inks with different types of colorants and solid content will be used. In other words, it is desirable for the liquid ejection head to be able to maintain a high level of ejection stability regardless of the type of ink used. 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 may be used. It is conceivable that this method could be used. Ink with a low water content has a high concentration of solid components other than water, such as organic solvents, pigments, and resins. As a result, a rapid increase in viscosity is likely to occur as the water evaporates, which can lead to a decrease in ink discharge stability. For such inks, the method of generating a circulating flow in 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 have a solid content of 10 wt%. That is, it is preferable to apply the present invention to inks with a solid content of 10 wt% (mass%) or more.

[0056] Furthermore, regarding the operating temperature of the print head, it is sometimes used at a constant temperature achieved by placing and controlling heaters across the entire chip. Since ink viscosity changes with temperature, the ink viscosity at the print head operating temperature will affect the ejection stability.

[0057] When a circulating flow is formed by the second energy generating element, the instantaneous circulating flow velocity can reach several tens to 1000 mm / s. The average flow velocity over a time span of several hundred microseconds will depend on the drive frequency of the circulating heater. This is because, in the case of a circulating heater, the circulating flow is transient, decaying over time and stopping after a certain period. When driven at a frequency of around 10-20 kHz, similar to the drive frequency (discharge frequency) of the first energy generating element, the average flow velocity can reach several mm / s to 100 mm / s.

[0058] When using inks with high pigment concentrations, for example, inks with a viscosity of 3 cp to 6 cP at the head operating temperature, the ink tends to thicken at the nozzle depending on the non-discharge time (rest time). This can easily lead to changes in discharge speed and a decrease in discharge stability. Therefore, it is necessary to circulate the ink during short rest periods, and to eliminate concentration by performing steady-state or transient ink circulation at a high frequency. When a circulation heater is used as the second energy generating element, transient ink circulation occurs, and by performing circulation at a high frequency, it can contribute to eliminating concentration at the nozzle.

[0059] On the other hand, when using ink with a low pigment concentration, for example, ink with a viscosity of 1 cp to 2 cP at the head operating temperature, the ejection speed may change depending on the non-ejection time (downtime), but this effect is relatively small compared to high-concentration ink. However, if the downtime is long, for example, the ink viscosity will increase at the ejection port depending on the non-printing drive time (stop time). Therefore, when restarting after being stopped for a certain period of time without printing, it is necessary to perform recovery processing involving waste ink, such as suction, wiping, and preliminary ejection combined with these. If a circulating heater is used as the second energy generating element, a circulating flow can be formed and used for recovery processing, contributing to the deconcentration of ink at the ejection port without generating waste ink. Depending on the downtime, it may be possible to avoid generating waste ink with recovery processing using only circulating operation. Alternatively, it is possible to perform recovery processing that minimizes waste ink by combining circulating operation for recovery with suction operation for removing air bubbles inside the head, which is separate from deconcentration.

[0060] Whether using high-concentration or low-concentration ink, it is desirable to return the ink to its initial fresh state as much as possible to suppress the effects of concentrated ink. Therefore, even when using a circulation heater as a second energy generating element, the lower the effect of recirculation and concentration, the better the circulation effect can be obtained. In other words, a straight configuration is more effective than a U-shaped configuration.

[0061] (First Embodiment) Figure 7 is a schematic diagram illustrating in detail the vicinity of the discharge port of a liquid discharge head that discharges liquid such as ink in the first embodiment. Figure 7(a) shows the view from the direction in which the liquid droplet is discharged from the discharge port. This is a plan view. Figure 7(b) is a cross-sectional view of AB in Figure 7(a). Figure 7(c) is an enlarged schematic diagram illustrating the element names in the individual flow path section in Figure 7(a). Figure 8 is a block diagram illustrating the selective drive circuit configuration on the substrate in the comparative configuration, and Figure 9 is a block diagram illustrating the selective drive circuit configuration on the substrate in this embodiment.

[0062] In Figures 7(a) and 7(b), a discharge port 11 for discharging liquid is formed in the orifice plate 19. A first energy generating element 14 is formed directly below the discharge port 11 in the substrate 18. A second energy generating element 24 is similarly formed in the substrate 18 together with the first energy generating element 14 to form a circulating flow 27 in the individual channel 23. Liquid is supplied to the individual channel 23, including the discharge port 11, from the supply groove 42. At this time, both ends of the individual channel are adjacent in the first direction, which is the direction in which the discharge ports are aligned.

[0063] Here, in the system referred to as U-shaped based on the flow path shape shown in Figure 7(a), both ends of the individual flow paths are adjacent in the first direction, which is the direction in which the discharge ports are aligned. The names of each element used in Figures 8 and 9 will be explained. As shown in Figure 7(c), each individual flow path 23 is equipped with a first energy generating element 14 and a second energy generating element 24. To distinguish each element, the first energy generating element is denoted as Ai (i=1, 2, 3, ..., n) and the second energy generating element as Bi (i=1, 2, 3, ..., n). In this case, for example, A1 and B1 are located in the same individual flow path.

[0064] (Method of driving the comparative configuration) In the comparative configuration, a selective drive circuit 200, as shown in Figure 8, is formed on the substrate 18. A voltage source (+V) and a controller 110 acting as a control unit are provided outside the substrate and connected to the selective drive circuit 200 on the substrate. The selective drive circuit 200 includes an on-off drive circuit (on-off switch) 210.

[0065] The on-off drive circuit 210 responds to control signals at each address (N1 to N16 in this configuration) received from the control data supply circuit 100 to drive the first energy generating elements (A1 to A8) or the second energy generating elements (B1 to B8) either on or off. That is, the first and second energy generating elements are each independently controlled by switches configured to switch between a driveable state and a non-driveable state. The control data supply circuit 100 controls the drive pulses for driving the first or second energy generating elements and the time interval at which these drive pulses are applied to each element.

[0066] In the comparative configuration, the first and second energy generating elements are linked to separate addresses, and separate drive circuits are required for each. Therefore, separate drive data must be provided for both the first and second energy generating elements. Consequently, the amount of data increases in proportion to the total number of elements, including both the first and second energy generating elements.

[0067] (First driving method of the embodiment) In the first drive configuration of this embodiment, a selective drive circuit 200 as shown in Figure 9 is formed on the substrate 18. A voltage source (+V) and a controller 110 are provided outside the substrate and connected to the selective drive circuit 200 on the substrate. The selective drive circuit 200 includes an on-on drive circuit 230 (a first switch that switches between on and off).

[0068] The on-on drive circuit 230 responds to the control signals at each address (N1 to N16 in this embodiment) received from the control data supply circuit 100 by turning on either the first energy generating elements (A1 to A16) or the second energy generating elements (B1 to B16). To drive the first and second energy generating elements, the device has a switch configured to switch between them mutually so that only one of them can be driven at a time. With this switch, when the first energy generating element is drivable, the second energy generating element is always in a state where it cannot be driven, and conversely, when the second energy generating element is drivable, the first energy generating element is always in a state where it cannot be driven.

[0069] 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.

[0070] In the figure, the first energy generation element group 401 and the second energy generation element group 402 represent the first energy generation element 14 and the second energy generation element 24, respectively. Reference numerals 401A and 401B indicate different first energy generation element groups 401, respectively. Reference numerals 402A and 402B indicate different second energy generation element groups 402, respectively. Also, in the figure, for example, "14-A1" refers to the "first energy generation element A1," and "24-B1" refers to the "second energy generation element B1."

[0071] The selection drive circuit 200 further includes an on-off drive circuit 240 (a second switch for switching between on and off) for the second energy generating element. The on-off drive circuit 240 controls the driving of the second energy generating element according to the driveability signal 300 for the second energy generating element, even when the second energy generating element is selected by the on-on drive circuit 230. That is, the second energy generating element is further controlled by a switch configured to switch between a driveable state and a non-driveable state.

[0072] Therefore, if the first energy generating element is in a state where it cannot be driven, the second energy generating element is in a state where it can be driven, but it will only actually be driven if it receives a drive signal (drive eligibility signal) instructing it to be driven. If there is no drive eligibility signal, the second energy generating element will not be driven even if the on-on drive circuit 230 selects the second energy generating element. In other words, in this case, neither the first nor the second energy generating element will be driven. Here, the first drive circuit in this embodiment is shown as a case in which a common drive eligibility signal is used for all of the multiple second energy generating elements.

[0073] In summary, in this embodiment, the drive circuit for controlling the driving of the first energy generating element and the second energy generating element comprises a first switch configured to be mutually exclusive in switching between the first energy generating element and the second energy generating element so that only one of them can be driven, and a second switch configured to be switchable between a drivable state and a non-drivable state for the second energy generating element, and is characterized in that by using this drive circuit, the first energy generating element and the second energy generating element are controlled to be driven under the following conditions.

[0074] Condition: When the first energy generating element is driven, the second energy generating element is not driven. 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.

[0075] Furthermore, it is preferable that the on-off drive circuit (second switch) is located closer to the second energy generating element and electrically downstream of the second energy generating element relative to the on-on drive circuit (first switch). It is preferable to control the drive of the raw elements using the common drive signal.

[0076] For comparison, the following describes countermeasures for thickened ink in liquid ejection heads that do not form a circulating flow. These countermeasures include pre-ejection, which ejects ink from the ejection port, and suction, which draws ink from the ejection port. For example, in a serial-type liquid ejection system, pre-ejection or suction is performed in the head standby area before the head leaves the protective cap and proceeds to the printing operation. Alternatively, pre-ejection is performed in the non-printing area away from the printing medium when the print carriage moves back and forth during the printing operation. These are at different timings than the printing operation. Furthermore, in the case of inks that are prone to thickening, pre-ejection may be performed in addition to the printing operation in the printing area during the back-and-forth movement, to the extent that it does not affect the image on the printing medium.

[0077] In this embodiment, the number of pre-discharge and suction operations can be reduced by performing a circulating operation by driving the second energy generating element. Even in this case, the circulating operation in the head standby area and the non-printing area during reciprocating movement is at a different timing than the printing operation. Therefore, in this embodiment, the driving of the second energy generating element can be easily controlled by the drive feasibility signal 300 for the second energy generating element. Furthermore, in the case of ink that is prone to thickening, in the circulating operation in the printing area during reciprocating movement, it is necessary to prioritize the discharge operation within a timing close to that of the printing operation. On the other hand, by providing multiple timings for the circulating operation or setting a certain period, it is not necessary to drive the circulating operation and the printing operation simultaneously. Therefore, in this embodiment, by driving the first energy generating element when the first energy generating element is selected, the circulating operation can be controlled as appropriate without affecting the printing operation.

[0078] As described above, the second energy generation element is controlled to operate according to the drive data and drive feasibility signal of the first energy generation element. This eliminates the need to provide drive data for the second energy generation element, thus reducing the amount of drive data required.

[0079] Furthermore, even when there are multiple second energy generating elements, it is possible to control the drive based on a common drive feasibility signal. In this embodiment, the first energy generating element Ai and the second energy generating element Bi are controlled as a group of 32 elements (16 sets) up to n=16, but the total number of elements in one group can be various numbers such as 16 (8 sets), 24 (12 sets), etc.

[0080] Furthermore, while an electrothermal conversion element or a piezoelectric element can be used as the second energy generating element, this embodiment describes the direction of the circulating flow in the case of an electrothermal conversion element. In the case of a piezoelectric element, the circulating flow may be opposite to that of this embodiment depending on the driving method.

[0081] In this embodiment, the drive capability signal 300 is provided on the substrate 18 to control the drive of the second energy generating element. However, the drive of the second energy generating element may also be controlled by providing a liquid discharge head outside the substrate or a liquid discharge device outside the liquid discharge head.

[0082] (Second driving method of the embodiment) Figure 10 is a block diagram illustrating the selective drive circuit configuration on the substrate in the second drive configuration of this embodiment. Here, multiple groups of individual ejection units are assumed. Each group of individual ejection units contains multiple individual ejection units. Instructions for the second energy generation element 24 by drive signals are given for each group of individual ejection units.

[0083] The difference between this embodiment and the first driving method is that the common drive feasibility signal 300 is the same as the first The key feature is that multiple drive-possibility signals 301 and 302 are provided. In this embodiment, multiple drive-possibility signals are provided for each array. Here, the first energy generation element group 401 and the second energy generation element group 402 refer to different rows. Note that this can be applied to two or more rows in the array. The first energy generation element group 401 and the second energy generation element group are each groups of energy generation elements included in multiple individual discharge units arranged in the array direction.

[0084] The advantages of this configuration include instantaneous power suppression and power averaging due to the distribution of the total number of driven second energy generating elements. In the first driving method, the second energy generating elements are controlled by a common drive / fail signal. When the common drive / fail signal is received, if not all of the first energy generating elements are driven, all of the second energy generating elements will be driven. In this way, if the first energy generating elements are hardly driven, the number of driven second energy generating elements increases accordingly, thus requiring more power.

[0085] In contrast, the second driving method allows for the suppression of the number of second energy generating elements driven by providing multiple drive / fail signals for each column. In particular, in the cyclic operation using the second energy generating element in the non-printing area, the first energy generating element is not driven and therefore requires power. Furthermore, because the timing is different from the printing operation, power is also allocated to other operations such as paper transport. Therefore, there are power limitations different from those in the printing area, and power suppression is required. Accordingly, by distributing the number of second energy generating elements driven by providing a drive / fail signal for each column, instantaneous power suppression and power averaging can be achieved.

[0086] Similarly, if a chip contains multiple colors, the same applies when the drive / fail signal is provided for each color rather than for each column. Also, if there are multiple inks of the same color, such as pigment and dye inks, the same applies when these are distinguished as separate colors and each has its own drive / fail signal. Providing a signal for each color reduces power consumption, similar to providing a signal for each column. Furthermore, in cases where only a specific color is used for printing, such as in black and white printing mode, power consumption can be reduced by providing a drive / fail signal only for that specific ink color.

[0087] Furthermore, when generating drive / fail signals for each column or color, multiple drive / fail signals can be supplied from outside the chip, or they can be divided and generated within the chip itself.

[0088] (Third driving method of the embodiment) Figure 10 is a block diagram illustrating the selective drive circuit configuration on the substrate in the third drive configuration of this embodiment. Here too, multiple groups of individual ejection units are assumed.

[0089] The difference between this embodiment and the first and second driving methods is that the drive-enabled / disabled signals 301 and 302 for each column are provided multiple times within the column as drive-enabled / disabled signals 301A~ and 302A~. In this embodiment, multiple drive-enabled / disabled signals are provided for each block within the column. This method of providing drive-enabled / disabled signals for multiple blocks can also be applied to multiple columns.

[0090] Advantages of this configuration include instantaneous power suppression and power averaging through the distribution of the total number of driven second energy generating elements. Similar to the second driving method, the number of driven second energy generating elements can be reduced, especially when the first energy generating elements are hardly driven or not driven in non-printed areas. Power can be further reduced because the drive / fail signal is per block rather than per column. Furthermore, if only a portion of a column is a non-printed area, the power of the second energy generating elements in that portion can be reduced. Example For example, in a serial-type liquid dispensing device, during the initial scan at the start of printing on the recording medium and the final scan at the end of printing, a portion of the column may be a non-printable area. If a cyclic operation using a second energy generating element is performed with each scan, the power consumption can be reduced accordingly. Also, in a page-wide type liquid dispensing device, the print width changes depending on the print size, so a portion of the column may be a non-printable area. In this case, printing is possible without performing a cyclic operation using a second energy generating element, thus reducing power consumption.

[0091] (Second embodiment) Figure 12 is a schematic diagram illustrating in detail the vicinity of the discharge port of a liquid discharge head that discharges liquid such as ink in the second embodiment. Figure 12(a) is a plan view taken from the direction in which the liquid droplet is discharged from the discharge port. Figures 12(b) and (c) are two examples of the AB cross-sectional view in Figure 12(a).

[0092] Figures 12(b) and (c) show two examples, illustrating how the shape of the back side of the substrate changes depending on the type of etching method used. However, either cross-sectional shape is acceptable.

[0093] The difference between this embodiment and the first embodiment is that it has a straight-type configuration in which the inlet and outlet of the individual flow path are separated. In this embodiment, both ends of the individual flow path are positioned opposite to the second direction, which is perpendicular to the first direction in which the discharge ports are aligned.

[0094] One advantage of this configuration is that, because the inflow and outflow of the circulating flow are separated in opposite directions, the ink concentrated at the discharge port does not re-enter into the individual flow channels as it circulates, thus suppressing the effects of concentration.

[0095] (Third embodiment) Figure 13 is a schematic diagram illustrating in detail the vicinity of the discharge port of a liquid discharge head that discharges liquid such as ink in the third embodiment. Figure 13(a) is a plan view as seen from the direction in which the liquid droplet is discharged from the discharge port. Figures 13(b) and (c) are two examples of the AB cross-sectional view in Figure 13(a), which is the same as Figures 12(b) and (c).

[0096] The difference between this embodiment and the second embodiment is that the number of discharge port rows is doubled by providing three supply opening rows, and each discharge port row is located on the side closer to the central supply opening row. That is, discharge port rows are formed on both sides of the arrangement direction in which the multiple supply openings are lined up. The discharge port row is an arrangement of discharge ports 11 included in a row of multiple individual discharge units. That is, two rows are arranged in parallel on the left and right sides along the central supply opening row. Here, the central opening row shared by the first and second rows is referred to as the second opening row in which the second openings are arranged. Also, the end opening rows provided for each of the first and second unit rows are referred to as the first opening row in which the first openings are arranged.

[0097] One advantage of this configuration is that the number of discharge rows can be doubled from one to two by increasing the number of supply openings from two to three. As shown in the figure, it is also possible to arrange the two rows of discharge rows with a staggered pitch. Furthermore, a configuration is possible that does not require a wiring area between the openings in the central supply opening row, and there is a high degree of flexibility in the size and resolution of the openings in the central supply opening row. This makes it easier to achieve high productivity by speeding up refilling for the nozzles.

[0098] 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 offset in each row to match the nozzle position and the wiring routing between the openings. The same applies to form.

[0099] (Fourth embodiment) Figure 14 is a schematic diagram illustrating in detail the vicinity of the discharge port of a liquid discharge head that discharges liquid such as ink in the fourth embodiment. Figure 14(a) is a plan view taken from the direction in which the liquid droplet is discharged from the discharge port. Figure 14(b) is a cross-sectional view of AB in Figure 14(a).

[0100] The difference between this embodiment and the third embodiment is that the direction of the circulating flow is reversed because there are discharge port rows on the sides closer to the supply opening rows and a second energy generating element on the side closer to the central supply opening row.

[0101] The advantages of this configuration include the fact that concentrated ink near the discharge port is branched and discharged into the supply opening rows on both sides, thereby suppressing the effect of concentrated ink when it re-flows into the individual flow channels in response to discharge, etc. In addition, because the discharge port rows are spaced apart, interference effects due to meniscus vibration associated with discharge from each discharge port are suppressed.

[0102] (Fifth embodiment) Figure 13 is a schematic diagram illustrating in detail the vicinity of the discharge port of a liquid discharge head that discharges liquid such as ink in the fifth embodiment. Figure 15(a) is a plan view taken from the direction in which the liquid droplet is discharged from the discharge port. Figure 15(b) is a cross-sectional view of AB in Figure 15(a).

[0103] The difference between this embodiment and the third embodiment is that the second energy generating element is close to the first energy generating element, and the direction of the circulating flow is reversed because the second energy generating element is closer to the central row of supply openings than to the supply openings on both sides.

[0104] The advantages of this configuration include, similar to the third embodiment, the high degree of freedom in the size and resolution of the central supply opening row, which allows for faster refilling and easier adaptation to high productivity. In addition, because the concentrated ink near the discharge port branches and is discharged to the supply opening rows on both sides, the influence of the concentrated ink when it re-flows into the individual flow paths in response to discharge, etc., is suppressed.

[0105] (Sixth embodiment) Figure 16 is a schematic diagram illustrating in detail the area near the nozzle of a liquid dispensing head that dispenses liquid such as ink in the sixth embodiment. Figure 16(a) is a plan view taken from the direction in which the liquid droplet is dispensed from the nozzle. Figures 16(b) and (c) are cross-sectional views taken along lines A-A' and B-B' in Figure 16(a), respectively.

[0106] The differences between this embodiment and the first embodiment are that the rows of discharge ports on either side of the supply groove are arranged in a staggered pattern, and filters are also provided at the inlet of each individual flow path (near the second energy generating element). The effects of the present invention can be obtained similarly even with this configuration.

[0107] [Configuration 1] A nozzle for dispensing liquid, A pressure chamber communicating with the aforementioned discharge port, A first energy generating element provided in the pressure chamber and generating energy for discharging liquid from the discharge port, Individual flow channels communicating with the aforementioned pressure chamber, A second energy generating element provided in the individual flow path and An individual dispensing unit having, A common channel for supplying liquid to the individual channels of the multiple individual discharge units. and, A liquid dispensing head having, When the first energy generating element is driven, the second energy generating element is not driven. If the first energy generating element is not driven, the second energy generating element is driven only when a drive signal instructing the second energy generating element to be driven is received. A liquid dispensing head characterized by the following features. [Configuration 2] When the aforementioned group of individual discharge units is divided into a group of individual discharge units, the drive control of the first energy generating element and the second energy generating element is performed for each group of individual discharge units. The drive signal that instructs the second energy generating element to be driven is a signal that is instructed for each of the individual discharge unit groups. Liquid dispensing head as described in Configuration 1. [Configuration 3] Each of the aforementioned groups of individual dispensing units is a row in which the multiple individual dispensing units are arranged in the direction of the arrangement. Liquid dispensing head as described in configuration 2. [Structure 4] Each of the aforementioned group of individual dispensing units includes a plurality of the aforementioned rows. Liquid dispensing head as described in configuration 3. [Composition 5] Each of the aforementioned multiple groups of individual dispensing units is a block containing multiple of the aforementioned individual dispensing units. Liquid dispensing head as described in configuration 2. [Composition 6] Each of the aforementioned group of individual dispensing units corresponds to an individual dispensing unit that dispenses a liquid of a different color. Liquid dispensing head as described in configuration 2. [Composition 7] The multiple discharge ports included in the multiple individual discharge units form a row of discharge ports. A liquid dispensing head as described in any one of items 1 to 6. [Structure 8] In the individual flow path of the individual discharge unit, the first energy generating element and the second energy generating element are arranged in a direction intersecting the row of discharge ports. Liquid dispensing head as described in configuration 7. [Composition 9] The individual flow channels extend in a direction intersecting the discharge port row such that both ends of the flow channel are positioned on either side of the discharge port row. Liquid dispensing head as described in configuration 8. [Configuration 10] The individual flow paths of the plurality of individual discharge units and the common flow path are connected via a first opening and a second opening. The first and second openings are arranged along the row of discharge ports to form the first and second rows of openings, respectively. A liquid dispensing head as described in any one of items 7 to 9. [Composition 11] Multiple groups of individual discharge units, each consisting of multiple individual discharge units arranged in parallel, are provided. The second row of openings is provided between the group of individual discharge units, and the group of individual It is shared by the discharge unit group, The first row of openings is provided for each of the multiple groups of individual discharge units. Liquid dispensing head as described in configuration 10. [Composition 12] In the individual flow channels, the first energy generating element is located on the side closer to the second opening. Liquid dispensing head as described in configuration 11. [Composition 13] In the individual flow channels, the second energy generating element is located on the side closer to the second opening. Liquid dispensing head as described in configuration 11. [Composition 14] In the individual flow path, the first energy generating element and the second energy generating element are arranged along the row of discharge ports. Liquid dispensing head as described in configuration 7. [Composition 15] The individual flow channels are configured such that both ends are located on one side relative to the row of discharge ports. Liquid dispensing head as described in configuration 14. [Composition 16] The second energy generating element performs a circulation drive to circulate the liquid in the individual flow path, and the first energy generating element performs a discharge drive to discharge the liquid from the discharge port. A liquid dispensing head as described in any one of items 1 to 15. [Composition 17] The aforementioned circulation drive is a drive with weaker energy than the aforementioned discharge drive. Liquid dispensing head as described in configuration 16. [Explanation of Symbols]

[0108] 11: Outlet, 12: Pressure chamber, 14: First energy generating element, 24: Second energy generating element, 110: Controller

Claims

1. A nozzle for dispensing liquid, A pressure chamber communicating with the aforementioned discharge port, A first energy generating element provided in the pressure chamber and generating energy for discharging liquid from the discharge port, Individual flow channels communicating with the aforementioned pressure chamber, A second energy generating element provided in the individual flow path and An individual dispensing unit having, A common channel for supplying liquid to the individual channels of the multiple individual discharge units, A liquid dispensing head having, When the first energy generating element is driven, the second energy generating element is not driven. If the first energy generating element is not driven, the second energy generating element is driven only when a drive signal instructing the second energy generating element to be driven is received. A liquid dispensing head characterized by the following features.

2. When the plurality of individual discharge units are divided into a plurality of groups of individual discharge units, the drive control of the first energy generating element and the second energy generating element is performed for each group of individual discharge units. The drive signal that instructs the second energy generating element to be driven is a signal that is instructed for each of the individual discharge unit groups. The liquid dispensing head according to claim 1.

3. Each of the aforementioned groups of individual dispensing units is a row in which the multiple individual dispensing units are arranged in the direction of the arrangement. The liquid dispensing head according to claim 2.

4. Each of the aforementioned group of individual dispensing units includes a plurality of the aforementioned rows. The liquid dispensing head according to claim 3.

5. Each of the aforementioned multiple groups of individual dispensing units is a block containing multiple of the aforementioned individual dispensing units. The liquid dispensing head according to claim 2.

6. Each of the aforementioned group of individual dispensing units corresponds to an individual dispensing unit that dispenses a liquid of a different color. The liquid dispensing head according to claim 2.

7. The multiple discharge ports included in the multiple individual discharge units form a row of discharge ports. A liquid dispensing head according to any one of claims 1 to 6.

8. In the individual flow path of the individual discharge unit, the first energy generating element and the second energy generating element are arranged in a direction that intersects with the row of discharge ports. The liquid dispensing head according to claim 7.

9. The individual flow channels extend in a direction intersecting the discharge port row such that both ends of the flow channel are positioned on either side of the discharge port row. The liquid dispensing head according to claim 8.

10. The individual flow paths of the plurality of individual discharge units and the common flow path are connected via a first opening and a second opening. The first and second openings are arranged along the row of discharge ports to form the first and second rows of openings, respectively. The liquid dispensing head according to claim 7.

11. Multiple groups of individual discharge units, each consisting of multiple individual discharge units arranged in parallel, are provided. The second row of openings is provided between the multiple groups of individual dispensing units and is shared by the multiple groups of individual dispensing units. The first row of openings is provided for each of the multiple groups of individual discharge units. The liquid dispensing head according to claim 10.

12. In the individual flow channels, the first energy generating element is positioned on the side closer to the second opening. The liquid dispensing head according to claim 11.

13. In the individual flow channels, the second energy generating element is positioned on the side closer to the second opening. The liquid dispensing head according to claim 11.

14. In the individual flow path, the first energy generating element and the second energy generating element are arranged along the row of discharge ports. The liquid dispensing head according to claim 7.

15. The individual flow channels are configured such that both ends are located on one side relative to the row of discharge ports. The liquid dispensing head according to claim 14.

16. The second energy generating element performs a circulation drive to circulate the liquid in the individual flow path, and the first energy generating element performs a discharge drive to discharge the liquid from the discharge port. A liquid dispensing head according to any one of claims 1 to 6.

17. The aforementioned circulation drive is a drive with weaker energy than the aforementioned discharge drive. The liquid dispensing head according to claim 16.

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