Liquid dispensing head

Abstract

To reduce the amount of data transferred in a discharge element substrate equipped with a discharge drive element and a circulation drive element, while avoiding power concentration on some of the circulation drive elements, and enabling the circulation drive elements to be driven with an optimal number of drives. [Solution] The liquid discharge head 1 includes a plurality of discharge modules, each having a discharge drive element and a discharge heater electrically connected to the discharge drive element; a plurality of circulation modules, arranged in the same number of pairs as the discharge modules, each having a circulation drive element and a circulation heater electrically connected to the circulation drive element; a latch circuit that latches a data signal containing selection information for selecting each of the plurality of discharge modules and the plurality of circulation modules; and a control means that selects and controls a first set of circulation modules and a second set of circulation modules, which have a different arrangement area from the first set of circulation modules, based on the count value of the edges of the latch signal that generates the latch timing of the data signal by the latch circuit.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head that ejects liquid while circulating the liquid.

Background Art

[0002] Conventionally, among circulation-type liquid ejection devices that circulate liquid (also referred to as ink), ink in a circulation flow path communicating with a discharge port is circulated by a circulation driving element different from a discharge driving element that discharges the ink by a circulation driving element known. Further, Patent Document 1 discloses a technique for selectively driving a discharge driving element and a circulation driving element.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the technique of Patent Document 1 has an aspect in which it is not possible to avoid power concentration on a part of each circulation driving element and drive the circulation driving element at an optimal number of driving times while reducing the amount of transfer data in a discharge element substrate including a discharge driving element and a circulation driving element.

Means for Solving the Problems

[0005] An aspect of the present disclosure aims to reduce the amount of transfer data in a discharge element substrate including a discharge driving element and a circulation driving element, avoid power concentration on a part of each circulation driving element, and drive the circulation driving element at an optimal number of driving times.

[0006] Aspects of the present disclosure are liquid discharge heads comprising: a plurality of discharge modules each having a discharge drive element and a discharge heater electrically connected to the discharge drive element; a plurality of circulation modules arranged in the same number of pairs as the discharge modules, each having a circulation drive element and a circulation heater electrically connected to the circulation drive element; a latch circuit for latching a data signal containing selection information for selecting each of the plurality of discharge modules and the plurality of circulation modules; and control means for selecting a first set of circulation modules and a second set of circulation modules having a different arrangement area from the first set of circulation modules, based on the count value of the edges of the latch signal that generates the latch timing of the data signal by the latch circuit. [Effects of the Invention]

[0007] According to this disclosure, it is possible to reduce the amount of data transferred in a discharge element substrate equipped with a discharge drive element and a circulation drive element, avoid power concentration on a portion of each circulation drive element, and drive the circulation drive element with an optimal number of drives. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of the overall configuration of a liquid dispensing device. [Figure 2] This figure shows an example of the basic configuration of a liquid dispensing head. [Figure 3] This is a schematic diagram illustrating the vicinity of the discharge port of an individual discharge unit, which includes a straight-type individual flow path. [Figure 4] This diagram explains the principle behind the generation of ink circulation. [Figure 5] This diagram illustrates how ink concentration is reduced due to the circulation of ink in straight, individual channels. [Figure 6] This diagram illustrates how ink concentration is reduced due to the circulation of ink in U-shaped individual channels. [Figure 7] This figure shows an example of the circuit configuration of the discharge element substrate of the liquid discharge chip shown in Figure 2. [Figure 8] This figure shows an example of the circuit configuration of the control data supply circuit in Figure 7. [Figure 9] Figure 7 is a timing chart showing the relationship between the latch signal, latch counter signal, and decoder signal in the latch counter circuit and decoder circuit. [Figure 10] This is a plan view of the ejection element substrate for the first case. [Figure 11] This is a plan view of the discharge element substrate for the second case. [Figure 12] This is a plan view of the ejection element substrate for the third case. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Note that the following embodiments are not limiting to the scope of this disclosure, and not all combinations of features described in the following embodiments are essential to the solutions of this disclosure. The same reference numerals are used for identical components.

[0010] (overview) Conventionally, circulating liquid dispensing devices that circulate ink are known. This liquid dispensing device has a liquid dispensing head. The ink is circulated for the purpose of discharging air bubbles in the flow path of the liquid dispensing head and suppressing the viscosity of the ink near the outlet. For example, a method using a pressure difference (hereinafter also referred to as the "differential pressure method") is a well known method for circulating ink. In the differential pressure method, by using a pressure adjustment mechanism, the pressure on the side supplying ink to the outlet (also referred to as the in side) is set higher than that on the side from which the ink is recovered (also referred to as the out side). By setting such a pressure difference, ink can flow from the in side to the out side. Here, in order to circulate the ink, it is necessary to return the ink that has flowed to the out side to the in side. For this reason, a pump is required as a mechanism. In some cases, the pump is installed outside the head of the liquid dispensing device body to circulate the ink between the liquid dispensing head and the dispensing device body. Alternatively, in some cases, the pump is installed inside the liquid dispensing head to circulate the ink within the liquid dispensing head. However, such differential pressure circulation methods require mechanisms such as a pressure adjustment mechanism and a pump. Therefore, the dispensing device itself and the liquid dispensing head tend to be larger.

[0011] Therefore, as an alternative method to the differential pressure method for circulating ink, the following method exists: In some cases, a circulation drive element separate from the ejection drive element for ejecting ink is placed in the circulation channel that communicates with the ejection port. Mechanisms are known in which the ink in the circulation channel is circulated by driving the circulation drive element with such an arrangement.

[0012] Also disclosed is a circuit configuration for selectively driving each of a plurality of ejection driving elements and a plurality of circulation driving elements provided on an ejection element substrate included in a liquid ejection head. In such a circuit configuration, each of the plurality of ejection driving elements and the plurality of circulation driving elements is selectively driven by assigning an address to each of them. Therefore, as the number of the plurality of ejection driving elements and the plurality of circulation driving elements increases, the transfer data amount of the data signal for specifying an address individually increases. As the transfer data amount increases, for example, the circuits for dealing with problems such as crosstalk of the data signal increase, so it is preferable not to increase the transfer data amount. Therefore, in order to reduce the transfer data amount, a configuration is conceivable in which the selection information of the circulation driving elements is converted in the ejection element substrate according to the selection information of the ejection driving elements, and each circulation driving element is selected.

[0013] For example, when a heater is used as the energy generating element, when the ejection heater on selection signal is "1", the ejection driving element that functions as an ejection heater is selected. Further, when a heater is used as the energy generating element, a configuration is conceivable in which when the ejection heater on selection signal is "0", the circulation driving element that functions as a circulation heater is selected. With such a configuration, reduction of the transfer data amount is possible.

[0014] However, even with such a configuration, each of the ejection driving element and the circulation driving element is selected by a data signal having the same driving frequency. Originally, the optimal timing is different between the timing of ejecting ink and the timing of circulating ink. For example, when the driving frequency of the ejection driving element >> the driving frequency of the circulation driving element, if the circulation driving element and the ejection driving element are mutually exclusive controlled, the circulation driving element is driven more than necessary. Therefore, there may be a case where the power consumption cannot be reduced.

[0015] Alternatively, when the number of driving times of the ejection driving element >> the number of driving times of the circulation driving element, in the above configuration, when the ejection driving element is off, the circulation driving element inevitably turns on. Therefore, a mechanism capable of appropriately setting the number of driving times of the circulation driving element is required from the viewpoint of reducing power consumption.

[0016] Furthermore, when driving the circulation driving element, power concentration may occur due to overlapping on-timing in a large number of circulation driving elements. When power concentration occurs in some of the circulation driving elements among each circulation driving element, the power load of the liquid ejection device, which is an inkjet recording device, will increase. Therefore, a mechanism capable of appropriately setting the number of circulation driving elements that turn on simultaneously is required.

[0017] Therefore, in the present disclosure, at least, a latch signal that counts an input data signal for specifying an ejection module having an ejection driving element is counted. The circulation driving element is controlled to a drivable state until the cumulative count value obtained by counting the latch signal exceeds a first threshold value and the difference count value obtained by counting the latch signal starting from the cumulative count value exceeds a second threshold value. According to such processing, the total time for driving the circulation driving element can be reduced, so that power consumption can be reduced.

[0018] In addition, in the present disclosure, based on the count value of the edge of the latch signal, among a plurality of circulation modules, a first circulation module set and a second circulation module whose arrangement area is different from that of the first circulation module set are selectively controlled. The latch signal is a signal that generates a data signal latch timing including selection information for selecting each of the plurality of ejection modules and the plurality of circulation modules. With such a configuration, the amount of transferred data can be reduced. Also, since the first circulation module set and the second circulation module whose arrangement area is different from that of the first circulation module set are selectively controlled, it is possible to avoid power concentration caused by driving the circulation driving element and reduce power consumption.

[0019] <Liquid discharge device 50> Figure 1 shows an example of the overall configuration of the liquid dispensing device 50. Figure 1(a) is a schematic perspective view showing the liquid dispensing device 50 in which a main ink tank 2 is provided as a liquid storage unit outside the liquid dispensing head 1. Figure 1(b) is a schematic perspective view showing the liquid dispensing device 50 in which an ink sub-tank 54 is provided directly above the liquid dispensing head 1. First, the common parts of Figure 1(a) and Figure 1(b) will be explained.

[0020] The liquid ejection device 50 comprises a liquid ejection head 1 and transport rollers 55, 56, 57, and 58. The liquid ejection head 1 is scannable in a direction X intersecting the transport direction Y of the ejection medium P. The liquid ejection head 1 is mounted on a carriage 60. The carriage 60 reciprocates along a guide axis 51 in the main scanning direction (also referred to as direction X). The transport rollers 55, 56, 57, and 58 transport the ejection medium P in a sub-scanning direction (also referred to as transport direction Y) that intersects (orthogonal in this embodiment) the main scanning direction. That is, the liquid ejection device 50 constitutes a serial-type inkjet ejection device that ejects an image by scanning the liquid ejection head 1 in direction X and ejecting liquid from the liquid ejection head 1 onto the ejection medium P being transported in the transport direction Y. Note that the application of this disclosure is not limited to serial-type inkjet ejection devices. This disclosure is also applicable to page-wide inkjet ejection devices that use a line head (page-wide head) that is long in the page width direction of the ejection medium P, and eject images by ejecting liquid onto the ejection medium P being transported in the transport direction Y. In Figures 1(a) and 1(b), direction Z indicates the vertical direction. That is, direction Z is the direction that intersects (orthogonal in this embodiment) the XY plane specified by direction X and transport direction Y.

[0021] The liquid ejection head 1 is capable of ejecting four types of ink: black (K), cyan (C), magenta (M), and yellow (Y). The liquid ejection head 1 can eject a full-color image using these four types of ink. However, the inks that can be ejected from the liquid ejection head 1 are not limited to the above four types. For example, this disclosure is also applicable to a liquid ejection head 1 for ejecting other types of ink, such as spot color inks. In other words, the type and number of inks ejected from the liquid ejection head 1 are not limited.

[0022] Next, we will explain the differences between Figure 1(a) and Figure 1(b). In Figure 1(a), an ink sub-tank 54 is mounted on the liquid ejection head 1. Four ink supply tubes (liquid passages) 59 are attached to the ink sub-tank 54. The liquid ejection device 50 also includes a main ink tank 2 and an external pump 70. The main ink tank 2 stores ink. The ink stored in the main ink tank 2 is supplied to the ink sub-tank 54 via the four ink supply tubes 59 by the driving force of the external pump 70. On the other hand, in Figure 1(b), the ink sub-tank 54 is located directly above the liquid ejection head 1. In Figure 1(b), the difference from Figure 1(a) is that the main ink tank 2 is not located outside the liquid ejection head 1, so the four ink supply tubes 59 are not attached, and the external pump 70 is not provided. In both Figure 1(a) and Figure 1(b), the liquid discharge head 1 may be integrally provided with the ink sub-tank 54 and configured to be removable from or attachable to the carriage 60. Alternatively, the ink sub-tank 54 may be integrally provided with the carriage 60, and only the ink sub-tank 54 may be configured to be removable from or attachable. In the following description, the configuration shown in Figure 1(a) will be used.

[0023] <Basic configuration of liquid dispensing head 1> Figure 2 shows an example of the basic configuration of the liquid ejection head 1 shown in Figure 1. Figure 2(a) is an exploded perspective view of the liquid ejection head 1 shown in Figure 1. Figures 2(b), 2(c), and 2(d) show an example of the liquid ejection tip 3 shown in Figure 2(a). The liquid ejection head 1 comprises a storage section 53, an ink sub-tank 54, and a liquid ejection tip 3. The ink sub-tank 54 temporarily stores ink in the liquid ejection head 1. The ink sub-tank 54 is housed in the storage section 53. As will be described in detail later, the liquid ejection tip 3 is provided at the bottom of the storage section 53. The liquid ejection tip 3 ejects the ink supplied from the ink sub-tank 54 onto the ejection medium P.

[0024] Although not shown in the diagram, a liquid connector insertion port is provided on the wall of the housing section 53. A liquid connector, provided at the tip of the ink supply tube 59 shown in Figure 1(a), is inserted into this liquid connector insertion port to create a liquid-tight connection. This configuration forms an ink supply path from the ink tank 2 through the external pump 70 to the liquid discharge head 1. In this embodiment, four types of ink are used. Therefore, four sets of ink tanks 2, external pumps 70, ink supply tubes 59, and ink sub-tanks 54 are provided, corresponding to each ink. Consequently, four ink supply paths corresponding to each ink are formed independently. Thus, in this embodiment, the liquid discharge device 50 includes an ink supply system in which ink is supplied from an ink tank 2 located outside the liquid discharge head 1.

[0025] A first support member 4 and a second support member 7 are provided between the storage section 53 and the liquid ejection tip 3. An electrical wiring member 5 is provided below the liquid ejection tip 3. Specifically, the first support member 4 is provided with an ink supply port and an ink recovery port. The second support member 7 is provided with an opening. The liquid ejection tip 3 is adhesively fixed to the first support member 4. The first support member 4 is adhesively fixed to the second support member 7. The second support member 7 holds the electrical wiring member 5 so that it is electrically connected to the liquid ejection tip 3. The electrical wiring member 5 applies electrical signals to the liquid ejection tip 3 to eject ink and electrical signals to circulate ink.

[0026] In this embodiment, the liquid ejection device 50 does not include an ink recovery system for recovering the ink in the liquid ejection head 1 into the ink tank 2. Therefore, although the liquid ejection head 1 is provided with a liquid connector insertion port for connecting the liquid connector of the ink supply tube 59, it is not provided with a connector insertion port for connecting a tube that recovers ink to the ink tank 2.

[0027] Figure 2(b) shows a case where the liquid ejection chip 3 is composed of one chip for every four colors. That is, Figure 2(b) shows a case where one liquid ejection chip 3 can eject four colors. The liquid ejection chip 3 comprises multiple ejection ports and pads used for electrical mounting. The four colors are, for example, black, cyan, magenta, and yellow, and each color is separated into a row. Each row is configured along the transport direction Y and spaced apart along the direction X. Each row contains multiple ejection ports. The multiple ejection ports are spaced equally along the Y direction. The ejection ports of each row may be arranged in a single row along the Y direction instead of spaced apart along the X direction. Alternatively, black may be arranged in two rows, the other three colors in three rows, and the four colors in a total of five rows. Note that the liquid ejection chip 3 in Figure 2(a) shows an example of a configuration with one chip for every four colors. That is, the liquid ejection chip 3 in Figure 2(a) represents the case in Figure 2(b).

[0028] Figure 2(c) shows a case where the liquid ejection chip 3 is composed of one chip for every two colors. In this case, two chips are used. That is, Figure 2(c) shows a case where one liquid ejection chip 3 can eject two colors. When mounting the liquid ejection chip 3 to the liquid ejection head 1, one liquid ejection head 1 may be equipped with two liquid ejection chips 3 capable of ejecting two colors, or two liquid ejection heads 1 may be equipped with one liquid ejection chip 3 capable of ejecting one color each.

[0029] Figure 2(d) shows a case where the liquid ejection chip 3 consists of one chip per color. In this case, four chips are used. That is, Figure 2(d) shows a case where one liquid ejection chip 3 can eject one color. When mounting the liquid ejection chips 3 to the liquid ejection head 1, four liquid ejection chips 3 may be mounted on one liquid ejection head 1, or four liquid ejection heads 1, each equipped with one liquid ejection chip 3 capable of ejecting one color, may be prepared.

[0030] Furthermore, as shown in Figures 2(c) and 2(d), in cases where multiple liquid ejection chips 3 are mounted on a single liquid ejection head 1, the chip lengths of each liquid ejection chip 3 do not necessarily have to be the same. Also, the number of colors of the liquid ejection chip 3 is not particularly limited, and various combinations of colors are possible. For example, Figure 2(a) shows an example where the liquid ejection chip 3 has four colors, but the number of colors of the liquid ejection chip 3 may be more than four.

[0031] <Individual channel; straight type> The liquid discharge head 1 comprises a plurality of individual discharge units, each containing an individual flow path. The liquid discharge head 1 also includes a supply flow path for supplying liquid to the individual flow path of each individual discharge unit. Figure 3 is a schematic diagram illustrating the vicinity of the discharge port 11 of an individual discharge unit, which includes a straight individual flow path 23. Figure 3(a) is a plan view taken from the direction in which liquid droplets are discharged from the discharge port 11 of the individual discharge unit. Figure 3(b) is a cross-sectional view taken along the line IIIb-IIIb in Figure 3(a). Figure 3(c) is a cross-sectional view taken along the line IIIb-IIIb in Figure 3(a), but with a different configuration within the substrate 18 compared to Figure 3(b).

[0032] Each individual discharge unit comprises a discharge port 11, a pressure chamber 12, a first energy generating element 14 (also referred to as the discharge energy generating element 14), and a second energy generating element 24 (also referred to as the circulation energy generating element 24).

[0033] The pressure chamber 12 is formed in the space between the substrate 18 and the orifice plate 19, partitioned by a partition wall 21, corresponding to each discharge port 11. The pressure chamber 12 can be filled with ink (also referred to as liquid). The discharge port 11 is an opening formed in a part of the orifice plate 19. A meniscus of ink flowed through the pressure chamber 12 forms at the discharge port 11, creating a discharge port interface as the interface between the ink and the atmosphere. The discharge port 11 discharges liquid.

[0034] Individual flow paths 23 extend in a second direction that intersects (orthogonal in this embodiment) the direction in which the discharge ports 11 are lined up (first direction). The individual flow paths 23 include a pressure chamber 12, an inlet (upstream) side connecting flow path 13, and an outlet (downstream) side connecting flow path. The inlet side connecting flow path 13 communicates with one end of the pressure chamber 12. The outlet side connecting flow path communicates with the other end of the pressure chamber 12.

[0035] A first supply opening 22 is provided at one end of the individual channel 23. The first supply opening 22 is an opening through which liquid passes from a common channel (not shown) to the upstream side of the individual channel 23 within the substrate 18. A second supply opening 32 is provided at the other end of the individual channel 23. The second supply opening 32 is an opening through which liquid passes from a common channel (not shown) to the downstream side of the individual channel 23 within the substrate 18. Liquid is supplied to the individual channel 23 through the first supply opening 22 and the second supply opening 32.

[0036] A first energy generating element 14 is formed on the substrate 18 closer to the second supply opening 32 than to the first supply opening 22. The first energy generating element 14 is an element that generates energy to discharge the liquid in the pressure chamber 12 from the discharge port 11. Specifically, the first energy generating element 14 is driven to generate heat, causing the liquid (also called ink) in the pressure chamber 12 to foam, and the foaming energy is used to discharge the ink from the discharge port 11. In this embodiment, an electrothermal conversion element is used for the first energy generating element 14, but it is not particularly limited. For example, a piezoelectric element may be used for the first energy generating element 14.

[0037] A second energy generating element 24 is formed on the substrate 18 closer to the first supply opening 22 than to the second supply opening 32. The second energy generating element 24 is an element that generates energy to create a circulating flow of ink in the individual flow channels 23 in the direction indicated by the arrow 27. In this embodiment, an electrothermal conversion element is used for the second energy generating element 24, but it is not particularly limited. For example, a piezoelectric element may be used for the second energy generating element 24.

[0038] Here, we will explain the straight type. The straight type means that the shape of the individual channel 23 is configured such that both ends of the individual channel 23 are located on either side of the discharge port 11, and the direction passing through both ends of the individual channel 23 extends in a direction that intersects with the direction along the row of discharge ports 11 (in the example in Figure 3, it is a perpendicular direction). In other words, the individual channel 23 has the first energy generating element 14 and the second energy generating element 24 arranged in a direction that intersects with the direction along the row of discharge ports 11.

[0039] Furthermore, an inlet-side connecting channel 13 is formed on the second energy generating element 24 side. The inlet-side connecting channel 13 consists of a portion of the individual channel 23 on the second energy generating element 24 side and the first supply opening 22. On the other hand, an outflow channel is formed on the first energy generating element 14 side. The outflow channel consists of another portion of the individual channel 23 on the first energy generating element 14 side and the second supply opening 32.

[0040] Next, the flow of ink through the individual channels 23 will be explained. The flow of ink through the individual channels 23 can be classified into two types. The first ink flow is the flow that the liquid ejection device 50 uses to drive the first energy generating element 14 and eject ink from the ejection port 11, and then refill the ink. The second ink flow is the flow that the liquid ejection device 50 uses to drive the second energy generating element 24 and generate a circulating flow in the direction of arrow 27.

[0041] <First ink flow> Figure 3(d) shows how the liquid dispensing device 50 drives the first energy generating element 14 and ink is dispensed from the dispensing port 11. Figure 3(d) is a diagram illustrating the ink flow when the first energy generating element 14 is driven. In one example in Figure 3(d), as ink is dispensed from the dispensing port 11, ink is supplied from the first supply opening 22 and the second supply opening 32, respectively. Therefore, ink flows into the pressure chamber 12 from both the first supply opening 22 and the second supply opening 32.

[0042] <Second ink flow> On the other hand, when the second energy generating element 24 is driven to create a circulating flow, ink flows into the individual flow path 23 via the first supply opening 22, and ink flows out of the individual flow path 23 via the second supply opening 32. In this embodiment, the liquid ejection device 50 circulates the ink that has flowed out from the second supply opening 32 back to the first supply opening 22, thereby creating a circulating flow of ink in the individual flow path 23 in the direction indicated by the arrow 27. Figure 3(c) shows an example in which the first supply opening 22 and the second supply opening 32 are shared within the liquid ejection tip 3. Figure 3(d) shows an example in which the first supply opening 22 and the second supply opening 32 are each provided as individual flow paths, and each individual flow path is shared outside the liquid ejection head 1.

[0043] Further explanation of ink circulation is provided. Ink contains volatile components such as water and solid components. When using the liquid ejection head 1, the ejection of ink from the ejection port 11 may become unstable due to the evaporation of volatile components of the ink from the ejection port 11 and the concentration of solid components of the ink near the ejection port 11 as a result of the evaporation of volatile components. Therefore, various measures have been taken to prevent the ejection of ink from the ejection port 11 from becoming unstable.

[0044] For example, a cap member (not shown) may be provided at a position off-center in the X direction from the transport path of the discharged medium P. The shape of this cap member is formed to cover the discharge port surface of the liquid discharge head 1 where the discharge port 11 is located. When the liquid discharge head 1 is not performing a recording operation on the discharged medium P, the cap member can cover the discharge port surface of the liquid discharge head 1 where the discharge port 11 is located, thereby preventing the discharge port 11 from drying out and protecting it.

[0045] Furthermore, an ink suction mechanism (not shown) may be provided. In cases where a cap member and an ink suction mechanism are provided, the cap member is used in conjunction with the ink suction operation from the discharge port 11. The ink suction operation refreshes the ink near the discharge port 11, thereby maintaining the image quality of the resulting image.

[0046] Furthermore, when the liquid ejection head 1 is not performing a recording operation on the ejection medium P, concentrated ink can be discarded by performing an ejection operation called pre-ejection (also referred to as pre-ejection). It is also known that when the liquid ejection head 1 is performing a recording operation on the ejection medium P, an ejection operation called pre-ejection (also referred to as surface pre-ejection or in-page pre-ejection) is performed. Surface pre-ejection or in-page pre-ejection is an ejection operation in which an inconspicuous amount of ink is ejected at an inconspicuous location on the ejection medium P. These ejection operations greatly contribute to improving image quality, but some ink is discarded in order to refresh the ejection port 11. Therefore, it is preferable to reduce the amount of waste ink as much as possible.

[0047] Therefore, by providing a second energy generating element 24 on the substrate 18 that heats the ink in the individual flow channels 23, it becomes possible to generate a circulating flow of ink. This circulating flow of ink suppresses the amount of waste ink while also suppressing drying of the discharge port 11 and concentration of ink near the discharge port 11. From another perspective, it is possible to minimize the number of times ink is pre-discharged and ink is aspirated. Furthermore, by minimizing the number of times ink is pre-discharged, it becomes possible to improve the overall throughput and yield of the liquid dispensing device 50. The above effects can be achieved by providing the second energy generating element 24 in at least some of the individual flow channels 23 among the multiple individual flow channels 23 included in the liquid dispensing head 1.

[0048] Furthermore, the liquid ejection head 1 in Figure 1(a) may be configured such that the second energy generating element 24 is provided at all locations corresponding to the four types of ink, or it may be configured such that the second energy generating element 24 is provided only at the location corresponding to one type of ink. In other words, the liquid ejection head 1 may be configured to circulate only at least one type of ink out of the multiple types of ink.

[0049] Furthermore, a filter 31, as shown in Figure 3(a), may be provided in the ink circulation channel to remove foreign matter contained in the ink. The filter 31 is a projection made by extending a part of the orifice plate 19 toward the substrate 18. In the example shown in Figures 3(a) to 3(d), the filter 31 is provided at one end and the other end of the individual channel 23. In the ink circulation channel, one end of the individual channel 23 corresponds to the ink inflow side, and the other end of the individual channel 23 corresponds to the ink outflow side. The filter 31 may also be provided within the individual channel 23 at a position between the first energy generating element 14 and the second energy generating element 24. If the filter 31 is provided within the individual channel 23 at a position between the first energy generating element 14 and the second energy generating element 24, the filter 31 does not need to be provided at both the one end and the other end of the individual channel 23. Next, the principle of generating the ink circulation flow will be explained using Figure 4.

[0050] <Principle of generating ink circulation> Figure 4 is a diagram illustrating the principle of ink circulation flow generation. In Figure 4, the filter 31 is omitted from the illustration for ease of explanation. Figure 4(a) is a cross-sectional view of the individual ejection unit of Figure 3(a) taken between IIIb and IIIb, illustrating the generation and growth process of bubbles B generated by the boiling of the ink film after the ink is heated by the second energy generating element 24. Figure 4(b) is a cross-sectional view of the individual ejection unit of Figure 3(a) taken between IIIb and IIIb, illustrating the contraction process of bubbles B generated by the boiling of the ink film after the ink is heated by the second energy generating element 24. Figure 4(c) is a cross-sectional view of the individual ejection unit of Figure 3(a) taken between IIIb and IIIb, illustrating the post-defoaming process of bubbles B generated by the boiling of the ink film after the ink is heated by the second energy generating element 24. Next, the generation and growth process, contraction process, and post-defoaming process of bubbles B will be explained.

[0051] <Formation and growth process of bubble B> As shown in Figure 4(a), the second energy generating element 24 is positioned closer to the first supply opening 22 than to the second supply opening 32. Therefore, the flow resistance R1 generated in the flow path between the second energy generating element 24 and the first supply opening 22 due to the ink circulation is smaller than the flow resistance R2 generated in the flow path between the second energy generating element 24 and the second supply opening 32. Consequently, the bubbles B generated by the boiling of the ink film grow biased towards the flow path with the relatively smaller flow resistance R1, as shown in Figure 4(a), due to the difference between flow resistance R1 and flow resistance R2. Therefore, the ink flow vector Fa toward the flow path on the side where flow resistance R1 is generated is larger than the ink flow vector Fb toward the flow path on the side where flow resistance R2 is generated. Note that the circuit including flow resistances R1 and R2 is an equivalent circuit that represents the flow resistance generated in the flow path including the individual flow path 23 due to the ink circulation flow, likened to electrical resistance.

[0052] <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 of bubble B. At that time, as shown in Figure 4(b), the flow vector Fc of the ink flowing in from the first supply opening 22 on the flow resistance R1 side is greater than the flow vector Fd of the ink flowing in from the second supply opening 32 on the flow resistance R2 side. In addition, the defoaming position of bubble B shifts from above the second energy generating element 24 to a flow path closer to the second supply opening 32.

[0053] <Post-defoaming process of bubble B> As explained using Figure 4(b), the relationship Fc > Fd holds. Therefore, a flow vector F of the circulating ink flow from the first supply opening 22 to the second supply opening 32 is generated. The magnitude of the flow vector F is affected by the ratio of flow resistances R1 and R2 and the size of the bubbles B. For example, consider the case where a second energy generating element 24 is used. In this case, it is preferable that the position of the second energy generating element 24 be closer to one of the ends of the individual flow channels 23 than the position of the first energy generating element 14. Specifically, it is preferable that the flow resistance ratio R1 / R2 be set in the range of 0.05 to 0.40. By setting the flow resistance ratio R1 / R2 in the range of 0.05 to 0.40, it is possible to make the flow vector F of the circulating ink flow a maximum value. By increasing the ink flow vector Fa and increasing the ink flow vector Fc, the flow vector F of the circulating ink flow increases, and the circulating ink flow increases. Therefore, it is preferable to decrease the flow resistance R1. Furthermore, it is preferable to make the ink flow vector Fb as small as possible and to make the ink flow vector Fd small. Therefore, it is preferable to increase the flow resistance R2. From these points, it is preferable to make the flow resistance R1 small and increase the flow resistance R2. That is, it is preferable to make the flow resistance ratio R1 / R2 small. Also, if the bubbles B are large, that is, if the volume of bubbles B is large, it will result in an increase in the volume of fluid to be removed in the individual flow channels 23, and thus an increase in the circulating flow. Factors that contribute to the increase in circulating flow include, for example, the following: Factors that contribute to the increase in circulating flow include increasing the size of the second energy generating element 24. Factors that contribute to the increase in circulating flow include widening the width and height of the flow channel on the first supply opening 22 side to relatively reduce the flow resistance R1. Factors that contribute to the increase in circulating flow include reducing the viscosity of the ink. Factors that contribute to the increase in circulating flow include increasing the temperature of the liquid discharge head 1. Factors that contribute to the increase in circulating flow include making the drive pulse a double pulse. Doubling the drive pulse means the following:First, a short pulse is applied to the second energy generating element 24, such that no bubbles are generated in the flow path, to warm the ink around the flow path on the second energy generating element 24. Subsequently, a main pulse is applied to the second energy generating element 24 to generate bubbles for circulating the ink, thereby growing larger bubbles. Specifically, the first pulse raises the ink temperature over as wide an area as possible around the heater to just before the boiling point, and the second pulse vaporizes a wide area of ​​ink all at once. This causes the bubbles to grow larger. In other words, the bubble volume increases by inputting two pulses.

[0054] Furthermore, some of the ink flowing through the circulating ink enters the discharge port 11. This sends the concentrated ink in the discharge port 11 to the flow path on the second supply opening 32 side, while fresh ink flows from the flow path on the first supply opening 22 side through the individual flow path 23 into the discharge port 11. In this way, concentrated ink is less likely to accumulate in the discharge port 11. Therefore, it is possible to maintain the initial ink discharge state while suppressing the effects of concentrated ink.

[0055] The ink circulation flow is a transient flow associated with the growth and contraction processes when bubbles B are generated. Therefore, after bubbles B are defoamed, the inertial ink circulation flow attenuates over time and stops after a certain period of time. Consequently, in order to generate a steady circulation flow over a certain period of time, it is preferable to repeatedly drive the second energy generating element 24. The driving cycle of the second energy generating element 24 is not particularly limited, as long as it is sufficient to discharge the concentrated ink remaining in the discharge port 11. However, the ink circulation flow is a transient flow associated with the growth and contraction processes when bubbles B are generated. Therefore, if the driving frequency is high, such as 100 kHz, considering the 10 μs cycle time from the generation to the defoaming of bubbles B, a decrease that hinders the promotion of ink circulation flow may occur. Consequently, it is preferable to drive the second energy generating element 24 with a driving cycle of, for example, 100 Hz to several tens of kHz.

[0056] Specifically, the higher the driving frequency of the second energy generating element 24, the more the ink circulation flow is maintained, and therefore the greater the effect of discharging concentrated ink caused by the amount of circulating ink. However, the higher the driving frequency of the second energy generating element 24, the greater the potential for the ink temperature to rise due to the heat generated by the second energy generating element 24 during operation. Therefore, it is preferable to appropriately control the number of times the second energy generating element 24 is driven. Next, the deconcentration of ink associated with the ink circulation flow will be explained using Figures 5 and 6.

[0057] <Ink concentration removal; straight type> Figure 5 illustrates the process of ink concentration reduction associated with the circulation of ink in the straight-type individual channel 23. Figure 5(a) shows the state in which the ink circulation is temporarily suspended. Figure 5(b) shows the state immediately after the ink circulation is generated by driving the second energy generating element 24, following the state in Figure 5(a). Figure 5(c) shows the state in which the ink circulation is temporarily suspended, following the state in Figure 5(b). Figure 5(d) shows the state immediately after the ink circulation is generated by driving the second energy generating element 24, following the state in Figure 5(c). As shown in Figures 5(a) to 5(d), the straight-type individual channel 23 has a configuration in which the inlet and outlet of the ink circulation are separated. Furthermore, the ink in the individual channel 23 is hatched with dots, and the degree of ink concentration is expressed by increasing the density of the dots in areas where the ink is concentrated.

[0058] As shown in Figure 5(a), when the ink circulation is temporarily paused, volatile components of the ink evaporate from the discharge port 11. Therefore, ink concentration progresses near the discharge port 11. Subsequently, when the second energy generating element 24 is activated, the ink circulation resumes. As a result, as shown in Figure 5(b), the ink concentration that progressed near the discharge port 11 is resolved. Subsequently, when the ink circulation is temporarily paused again, as shown in Figure 5(c), ink concentration progresses again near the discharge port 11, similar to Figure 5(a). Subsequently, when the second energy generating element 24 is activated, the ink circulation resumes. As a result, as shown in Figure 5(d), the ink concentration that progressed near the discharge port 11 is resolved, similar to Figure 5(b). Therefore, ink concentration is resolved throughout the entire individual channel 23. As described above, in the straight-type individual channel 23, the ink concentration state is reset each time the ink circulation is temporarily paused and restarted.

[0059] <Ink density reduction; U-shaped> Figure 6 illustrates the process of ink concentration reduction associated with the circulation of ink in the U-shaped individual channel 23. Figure 6(a) shows the state in which the ink circulation is temporarily suspended. Figure 6(b) shows the state immediately after the ink circulation is generated by driving the second energy generating element 24, following the state in Figure 6(a). Figure 6(c) shows the state in which the ink circulation is temporarily suspended, following the state in Figure 6(b). Figure 6(d) shows the state immediately after the ink circulation is generated by driving the second energy generating element 24, following the state in Figure 6(c). As shown in Figures 6(a) to 6(d), the U-shaped individual channel 23 has an inlet and outlet for the ink circulation adjacent to each other. In addition, the ink in the individual channel 23 is covered with dot-shaped hatching, and the degree of ink concentration is represented by increasing the density of the dot-shaped hatching in areas where the ink is concentrated.

[0060] As shown in Figure 6(a), when the ink circulation is temporarily paused, volatile components of the ink evaporate from the discharge port 11. Therefore, ink concentration progresses near the discharge port 11. Subsequently, when the second energy generating element 24 is activated, the ink circulation resumes. As a result, the state shown in Figure 6(b) is reached. The inlet of the individual channel 23 in Figure 6(a) is adjacent to the outlet of the individual channel 23 in Figure 6(a). Therefore, although the ink that has become concentrated near the discharge port 11 is discharged from the outlet of the individual channel 23, some of the discharged ink flows back in from the inlet of the individual channel 23. Thus, the entire individual channel 23 is not replaced with fresh ink, but rather with slightly concentrated ink (hereinafter, this phenomenon will be called recirculation concentration). Subsequently, when the ink circulation is temporarily paused, as shown in Figure 6(c), ink concentration progresses again near the discharge port 11 from the state in Figure 6(b), similar to Figure 6(a). Subsequently, when the second energy generating element 24 is activated, the ink circulation flow resumes. As a result, as shown in Figure 6(d), due to the effect of recirculation concentration, the entire individual channel 23 is replaced with even more concentrated ink than in Figure 6(b). As described above, in the U-shaped individual channel 23, each time the ink circulation flow is paused and then resumed, the ink concentration state is not reset, and the ink concentration gradually progresses throughout the entire individual channel 23. Therefore, the ink concentration state deteriorates. Furthermore, even without repeated pauses and restarts of the ink circulation flow, if the pause period of the ink circulation flow is long, the ink near the discharge port 11 becomes concentrated, and even the first restart of the ink circulation flow does not significantly improve the ink concentration state. This is because the effect of recirculation concentration on improving the ink concentration state is small.

[0061] Therefore, the effect of temporarily pausing and restarting the ink circulation flow on resolving the ink concentration state differs between the straight-type individual channel 23 and the U-shaped individual channel 23 due to the difference in the effect of the discharged concentrated ink. Specifically, in the case of the straight-type individual channel 23, the ink concentration state is easily resolved, including the entire individual channel 23. On the other hand, in the case of the U-shaped individual channel 23, the ink concentration state is not easily resolved, including the entire individual channel 23, by recirculation concentration. Therefore, in the case of the U-shaped individual channel 23, the ink discharge may become unstable depending on the concentration of the entire individual channel 23.

[0062] <ink> As explained above, although the degree of ink concentration reduction differs depending on the differences in the flow path configuration, including the individual flow paths 23, the following effects can be achieved by generating a circulating flow of ink within the individual flow paths 23 using the second energy generating element 24, which can function as a circulating heater. Specifically, the effect of concentrated ink thickened by the evaporation of volatile components of the ink at the discharge port 11 can be suppressed. Therefore, the ink discharge state can be maintained in good condition, and the effect of changes in ink discharge speed can be further reduced. Consequently, it becomes possible to stabilize ink discharge.

[0063] On the other hand, depending on the application of the liquid ejection head 1 and the liquid ejection device 50 equipped with the liquid ejection head 1, it is conceivable that inks with different types of colorants and solid content may be used. In other words, it is preferable that the liquid ejection head 1 maintains ink ejection stability regardless of the type of ink used.

[0064] For example, in cases where the water content in the ink causes changes such as curling (also called warping) and cockling (also called wavy wrinkles) on ordinary paper, it may be considered to use ink with reduced water content. Also, ink with low water content has a higher concentration of solid components other than water, such as organic solvents, pigments, and resins. Therefore, as the water in the ink evaporates, the viscosity of the ink tends to increase rapidly. Consequently, ink with low water content is prone to causing a decrease in ink discharge stability. Therefore, when using ink with low water content, it is possible to suppress the increase in ink viscosity by creating a circulating flow of ink in a flow path configuration including individual flow paths 23 as in this embodiment. Generally, ink with a high solid content exhibits a solid content of 10 wt%. That is, this embodiment is preferably applied to ink with a solid content of 10 wt% (also called mass%) or more.

[0065] This section explains the relationship between the operating temperature of the liquid ejection head 1 and the viscosity of the ink. In some cases, the liquid ejection head 1 is used by driving and controlling the second energy generating element 24, which is arranged throughout the liquid ejection tip 3, until the temperature of the liquid ejection head 1 reaches a certain level. The viscosity of the ink changes depending on the ink temperature. Therefore, the viscosity of the ink at the operating temperature of the liquid ejection head 1 affects the ink ejection stability.

[0066] The relationship between the ink circulation velocity and the respective driving frequencies of the first energy generating element 14 and the second energy generating element 24 will be explained. When the second energy generating element 24, which can function as a circulation heater, generates an ink circulation flow, a circulation flow velocity of several tens of mm / s to 1000 mm / s is possible. The average flow velocity when viewed over a time width of several hundred microseconds depends on the driving frequency of the second energy generating element 24. This is because when the second energy generating element 24 generates an ink circulation flow, the ink circulation flow is a transient circulation flow that decays over time and stops after a certain period of time. On the other hand, the second energy generating element 24 can be driven at a frequency of about 10 to 20 kHz, which is similar to the driving frequency (also called the ejection frequency) of the first energy generating element 14, which can function as an ejection heater. In this case, the average flow velocity of the ink circulation flow can be several mm / s to 100 mm / s. Next, the relationship between pigment concentration and ink concentration deconcentration will be explained.

[0067] (Ink with a high pigment concentration) Let's explain the case of ink with a high pigment concentration. For example, when using ink with a concentration such that the viscosity of the ink at the operating temperature of the liquid ejection head 1 is 3 cP or more and 6 cP or less, the viscosity of the ink near the ejection port 11 tends to increase depending on the non-ejection time of the ink (also referred to as the pause time of the ink circulation flow). Therefore, changes in the ink ejection speed are likely to occur. This is likely to cause a decrease in ink ejection stability. To suppress the decrease in ink ejection stability, it is preferable to generate ink circulation and circulate the ink while the pause time of the ink circulation flow is short. Therefore, it is preferable to resolve the ink concentration by performing steady-state ink circulation or transient ink circulation at a high frequency. Therefore, transient ink circulation is possible by driving the second energy generating element 24. Therefore, by driving the second energy generating element 24 from the paused state of the ink circulation flow and restarting the ink circulation flow at a high frequency, it is possible to contribute to resolving the ink concentration near the ejection port 11.

[0068] (Ink with low pigment concentration) Let's explain the case of ink with a low pigment concentration. For example, if ink with a concentration such that the viscosity of the ink at the operating temperature of the liquid ejection head 1 is between 1 cP and 2 cP is used, the viscosity of the ink near the ejection port 11 may increase depending on the non-ejection time of the ink (also referred to as the pause time of the ink circulation flow). Therefore, a change in the ink ejection speed may occur, but the change in the ink ejection speed is relatively small compared to high-concentration ink. On the other hand, if the pause time of the ink circulation flow is long, for example, the viscosity of the ink near the ejection port 11 may increase depending on the non-printing drive time (also referred to as the stop time). Therefore, when restarting after stopping without printing for a certain period of time, it is preferable to perform recovery processing involving waste ink, such as ink suction operation, wiping operation, and preliminary ejection combining these. Therefore, by driving the second energy generating element 24, the recovery operation can be made to restart the ink circulation flow, which can contribute to eliminating the concentration of ink near the ejection port 11 without generating waste ink. Furthermore, depending on the downtime, it is possible to avoid generating waste ink by simply performing a recovery process that restarts the ink circulation by driving the second energy generating element 24. Alternatively, a recovery process that minimizes waste ink is possible by combining the recovery process of restarting the ink circulation with a suction operation to remove air bubbles B in the liquid ejection head 1, which is separate from the ink concentration removal process.

[0069] (A more suitable composition for eliminating ink concentration) As explained above, whether the ink is highly concentrated or low in concentration, it is preferable to return the ink to its initial fresh state as much as possible in order to suppress the effects of concentrated ink. For this reason, in the case of driving the second energy generating element 24, the lower the effect of recirculation concentration, the greater the circulation effect can be obtained. In other words, a straight-type individual flow path 23 configuration is more effective in obtaining a circulation effect than a U-type configuration. Next, the electrical circuit configuration for driving and controlling the first energy generating element 14 and the second energy generating element 24 according to this embodiment will be described with reference to Figures 8 and 9.

[0070] (Discharge element substrate α0) Figure 7 shows an example of the circuit configuration of the ejection element board α0 of the liquid ejection chip 3 in Figure 2. Figure 8 shows an example of the circuit configuration of the control data supply circuit α3 in Figure 7. Figure 8(a) is a functional block diagram of the circuit configuration of the control data supply circuit α3. Various signals are supplied to the ejection element board α0 from the main board β0. The main board β0 comprises a controller β1 and a power supply circuit β2. The controller β1 is mainly composed of ROM, RAM, and CPU, and controls the liquid ejection head 1 by supplying various electrical signals to the ejection element board α0. The controller β1 supplies the enable signal HE, latch signal LT, data signal DATA, and clock signal CLK to the ejection element board α0. Details of each signal will be described later. The power supply circuit β2 applies the power supply voltage VH to the ejection element board α0. The power supply circuit β2 and the ejection element board α0 are connected by GNDH. GNDH functions as the ground potential.

[0071] (Wiring Overview) The ejection element substrate α0 comprises a plurality of ejection modules α1, a plurality of circulation modules α2, and a control data supply circuit α3. The circulation modules α2 are arranged in pairs with the ejection modules α1. Therefore, the number of circulation modules α2 is the same as the number of ejection modules α1. Discharge group selection signal wiring α6 and shared time division selection signal wiring α8 are wired between the plurality of ejection modules α1 and the control data supply circuit α3. Circulation group selection signal wiring α7, shared time division selection signal wiring α8, and latch counter signal wiring γ2 are wired between the plurality of circulation modules α2 and the control data supply circuit α3.

[0072] In this embodiment, the multiple discharge modules α1 and the multiple circulation modules α2 are further classified into Block A and Block B. Block A is allocated a first number of discharge modules α1 and a first number of circulation modules α2 from the multiple discharge modules α1 and the multiple circulation modules α2. Block B is allocated a second number of discharge modules α1 and a second number of circulation modules α2 from the multiple discharge modules α1 and the multiple circulation modules α2. Block A and Block B are set in different arrangement areas. That is, Block A is allocated a first set of discharge modules from the multiple discharge modules α1 and a first set of circulation modules from the multiple circulation modules α2. The first set of discharge modules includes a first number of discharge modules α1. The first set of circulation modules includes a first number of circulation modules α2. Furthermore, block B is allocated a second set of discharge modules from among multiple discharge modules α1 and a second set of circulation modules from among multiple circulation modules α2. The second set of discharge modules contains a second number of discharge modules α1. The second set of circulation modules contains a second number of circulation modules α2. Therefore, the first set of discharge modules and the first set of circulation modules are placed in the same location, block A. The second set of discharge modules and the second set of circulation modules are placed in the same location, block B. Therefore, the first set of discharge modules and the second set of discharge modules are placed in different locations. The first set of circulation modules and the second set of circulation modules are placed in different locations.

[0073] As a circuit to select either Block A or Block B, a decoder circuit δ1 is provided in the latch counter signal wiring γ2. As will be described in detail later, decoder signal wiring δ2 and decoder signal wiring δ3 are wired to the output side of decoder circuit δ1. Decoder signal wiring δ2 is connected to the circulation module α2 of Block A. Decoder signal wiring δ3 is connected to the circulation module α2 of Block B.

[0074] (Discharge module α1) The ejection module α1 includes an ejection heater RhA, an ejection drive element MD1, and an ejection logic circuit AND1. The ejection heater RhA is composed of, for example, an electrothermal conversion element. A voltage from the power supply voltage VH is applied to the ejection heater RhA, and if the ejection drive element MD1 is in a conductive state, current flows through the ejection heater RhA. The ejection drive element MD1 is composed of, for example, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor). However, the ejection drive element MD1 may be composed of something other than a MOSFET. For example, the ejection drive element MD1 may be composed of a bipolar transistor. Alternatively, the ejection drive element MD1 may be composed of an IGBT (Insulated Gate Bipolar Transistor). The ejection logic circuit AND1 selectively drives the ejection drive element MD1. An enable signal HE, an ejection group selection signal, and a shared time division selection signal are input to the input side of the ejection logic circuit AND1. The enable signal HE is transmitted from controller β1. The enable signal HE controls the current pulse width of the discharge drive element MD1, that is, the duration for which the drain-source of the discharge drive element MD1 is conductive and current continues to flow between the drain and source of the discharge drive element MD1. The enable signal HE is a signal for adjusting the current pulse width so that more desired thermal energy can be generated, taking into account various manufacturing variations. Examples of various manufacturing variations include manufacturing variations in the resistance value of the discharge heater RhA mounted on the discharge element substrate α0, and manufacturing variations in the power supply circuit β2. Other examples of various manufacturing variations include the voltage drop in the power supply wiring when multiple heaters, such as the discharge heater RhA and the circulation heater RhB, are driven simultaneously. The heaters targeted for simultaneous drive here are the discharge heater RhA and the circulation heater RhB, which is located in a position not paired with the discharge heater RhA. The enable signal HE can be transmitted from the controller β1 via an external input terminal (not shown) provided on the ejection element substrate α0. The ejection group selection signal is supplied from the ejection group selection signal wiring α6. The shared time division selection signal is supplied from the shared time division selection signal wiring α8.The output side of the ejection logic circuit AND1 is connected to the gate of the ejection drive element MD1. Therefore, if all signals input from the input side of the ejection logic circuit AND1 are 1, a voltage is applied to the gate of the ejection drive element MD1, and the drain-source of the ejection drive element MD1 becomes conductive. When the drain-source of the ejection drive element MD1 is conductive, current flows through the ejection heater RhA, generating heat in the ejection heater RhA. This series of operations makes it possible for the ink to foam before being ejected and then ejected onto the ejection medium P. Although an example of the ejection heater RhA being composed of an electrothermal conversion element has been described, it is not limited to this. For example, the ejection heater RhA may be composed of a piezoelectric element.

[0075] (Circulation module α2) The circulating module α2 includes a circulating heater RhB, a circulating drive element MD2, and a circulating logic circuit AND2. The circulating heater RhB is composed of, for example, an electrothermal conversion element. A voltage from the power supply voltage VH is applied to the circulating heater RhB, and if the circulating drive element MD2 is in a conductive state, current flows through the circulating heater RhB. The circulating drive element MD2 is composed of, for example, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor). However, the circulating drive element MD2 may be composed of something other than a MOSFET. For example, the circulating drive element MD2 may be composed of a bipolar transistor. Alternatively, the circulating drive element MD2 may be composed of an IGBT (Insulated Gate Bipolar Transistor). The circulating logic circuit AND2 selectively drives the circulating drive element MD2. An enable signal HE, a circulating group selection signal, and a latch counter signal are input to the input side of the circulating logic circuit AND2. The latch counter signal is a signal obtained by countering the edges of the latch signal LT. Details of processing using the latch counter signal will be described later. The enable signal HE is transmitted from the controller β1. The enable signal HE controls the current pulse width of the circulating drive element MD2, that is, the time for which the drain-source of the circulating drive element MD2 is conductive and current continues to flow between the drain-source of the circulating drive element MD2. The enable signal HE is a signal for adjusting the current pulse width so that more desired thermal energy can be generated, taking into account various manufacturing variations. Examples of various manufacturing variations include manufacturing variations in the resistance value of the circulating heater RhB mounted on the discharge element substrate α0, and manufacturing variations in the power supply circuit β2. Other examples of various manufacturing variations include the voltage drop in the power supply wiring when multiple heaters, such as the circulating heater RhB and the discharge heater RhA, are driven simultaneously. The enable signal HE can be transmitted from the controller β1 via an external input terminal (not shown) provided on the discharge element substrate α0. The cyclic group selection signal is supplied from the cyclic group selection signal wiring α7. The latch counter signal is supplied from the latch counter signal wiring γ2.The output side of the circulating logic circuit AND2 is connected to the gate of the circulating drive element MD2. Therefore, if all signals input from the input side of the circulating logic circuit AND2 are 1, a voltage is applied to the gate of the circulating drive element MD2, and the drain-source of the circulating drive element MD2 becomes conductive. When the drain-source of the circulating drive element MD2 is conductive, current flows through the circulating heater RhB, generating heat in the circulating heater RhB. This series of operations allows ink bubbles to grow and a circulating flow to be generated in the ink circulation channel. Although an example of the circulating heater RhB being composed of an electrothermal conversion element has been described, it is not limited to this. For example, the circulating heater RhB may be composed of a piezoelectric element.

[0076] Furthermore, in order to reduce the number of signal terminals, the above-mentioned enable signal HE is shared by both the ejection and circulation heaters. Therefore, the current pulse width cannot be controlled individually for the ejection and circulation heaters. For this reason, the current pulse width may be adjusted using a single enable signal HE, assuming that the ejection heater RhA and the circulation heater RhB are manufactured using the same semiconductor process in the semiconductor manufacturing process and are finished with the same manufacturing variation (amount of resistance deviation from the ideal value). Alternatively, the current pulse width may be adjusted using a single enable signal HE, assuming that the ejection heater RhA and the circulation heater RhB are manufactured from the same material and are finished with the same manufacturing variation (amount of resistance deviation from the ideal value).

[0077] Furthermore, a decoder signal is input to the input side of the cyclic logic circuit AND2 in block A via the decoder signal wiring δ2. If all signals input from the input side of the cyclic logic circuit AND2 are 1, a voltage is applied to the gate of the cyclic drive element MD2. Therefore, the decoder signal input via the decoder signal wiring δ2 becomes the signal that determines the selection of the cyclic module α2 on the block A side.

[0078] Furthermore, a decoder signal is input to the input side of the cyclic logic circuit AND2 in block B via the decoder signal wiring δ3. If all signals input from the input side of the cyclic logic circuit AND2 are 1, a voltage is applied to the gate of the cyclic drive element MD2. Therefore, the decoder signal input via the decoder signal wiring δ3 becomes the signal that determines the selection of the cyclic module α2 on the block B side.

[0079] Furthermore, if only one of block A or block B is present, decoder signal wiring δ2, decoder signal wiring δ3, and decoder circuit δ1 are unnecessary. Alternatively, if multiple discharge modules α1 and multiple circulation modules α2 are not classified as either block A or block B, decoder signal wiring δ2, decoder signal wiring δ3, and decoder circuit δ1 are unnecessary.

[0080] (Control data supply circuit α3) The control data supply circuit α3 comprises shift registers α20a and α20b, latch circuits α21a and α21b, decoder circuit α22, and a circulating group control circuit α12. The control data supply circuit α3 is also provided with an external input terminal. The control data supply circuit α3 receives a clock signal CLK, a data signal DATA, and a latch signal LT from controller β1 via the external input terminal. The clock signal CLK is used when serially transferring the data signal DATA to shift registers α20a and α20b. The data signal DATA includes selection information for the output module α1 and selection information for the circulating module α2. The latch signal LT acquires and holds the information stored in shift registers α20a and α20b at each latch period. Details of the decoder circuit α22 and the circulating group control circuit α12 will be described later.

[0081] (Drive control of the discharge heater RhA) This section describes the drive control of ejector heaters RhA based on ejector heater array α9. The ejector heater array α9 consists of m groups. Each group contains n ejector heaters RhA. The ejector heaters RhA are positioned directly below the ink ejection port. When one group is selected, each of the n ejector heaters RhA within that group is operated sequentially in a time-division multiplexer. The ejector heater array is arranged in a 1-inch length at an array density of 600 dpi, and the drive control of (n=16) × (m=40 groups) of ejector heaters RhA is described.

[0082] (Time-division control within a single group) As described above, each ejection module α1 contains an ejection heater RhA. Furthermore, one group contains n ejection heaters RhA. Therefore, one group contains n ejection modules α1. Since we are assuming n=16, the 16 ejection modules α1 are time-division driven by a time-division selection signal. Time-division driving is a control method that divides the time of a certain ejection cycle into n=16 time units, and sequentially selects one ejection module α1 for each divided time unit. Here, within the same group, multiple ejection modules α1 cannot be selected simultaneously. All ejection modules α1 included in the same group are selected exactly once within one ejection cycle. In this type of time-division driving, only one of the shared time-division selection signal wires α8 is selected. Therefore, by including the decoder circuit α22 in the control data supply circuit α3, the amount of data transferred serially from the main board β0 can be further reduced.

[0083] (Decoder circuit α22; time-division control) The decoder circuit α22 is a circuit that expands the number of bits in the output data to 2 to the power of q, where q is the number of bits in the input data. Specifically, if 4 bits of input data are input to the decoder circuit α22, the decoder circuit α22 converts the 4 bits of input data into 2 to the power of 4 = 16 bits of output data. At this time, the output data of the decoder circuit α22 is output as information in which only 1 bit of the 16 bits is valid. This enables time-division multiplexing. Here, the shared time-division multiplexing selection signal wiring α8 output from the decoder circuit α22 is preferable to use all wiring as a transmission medium for the shared time-division multiplexing selection signal, unless there is a special application, in terms of input data utilization efficiency. The 4 bits of input data may be obtained, for example, from the bit configuration of the latch counter signal described later. This bit configuration is a 4-bit configuration, as shown in Table 1 described later. Also, as the amount of data in serial transfer increases, faster serial transfer is required. Therefore, it is preferable to reduce the amount of data as much as possible, as this will increase the cost and size of the signal transmission circuit, signal reception circuit and transmission line on the main board β0 and the ejection element board α0.

[0084] (Group selection control) To select and drive one of the m groups, an m-bit ejection group selection signal is output from the control data supply circuit α3. When selecting one of the m groups, it is possible to simultaneously select n ejection modules α1 included in that group. Information equivalent to the number of groups, m bits, is serially transferred from the main board β0. As described above, the ejection module α1 is selected and controlled so that current flows to the corresponding ejection heater RhA when the enable signal HE, the ejection group selection signal, and the shared time division selection signal are input to the ejection logic circuit AND1. In this embodiment, an example is described assuming n=16 and m=40, but it is not limited to these. For example, n=8 and m=80 may also be used. Alternatively, for example, a different nozzle length n=32 and m=40 may be used. However, since n is the time division number, it is preferable that n be a value expressed as a power of 2 (n=2, 4, 8, 16, 32...) in order to use the output signal of the decoder circuit α22 as the selection signal.

[0085] (Drive control of circulation module α2) This section describes the drive control of circulating heaters RhB based on the circulating heater array α10. The circulating heater array α10, like the discharge heater array α9, consists of m groups. Each group contains n circulating heaters RhB, similar to the discharge heater array α9. The circulating heaters RhB are arranged in close proximity to each other in pairs with the discharge heaters RhA. When one group is selected, each of the n circulating heaters RhB within that group is executed sequentially in a time-division multiplexer. This section describes the drive control of circulating heaters RhB for (n=16) × (m=40 groups).

[0086] (Time-division control within a single group) As described above, the circulating heater RhB is included in each circulating module α2. Furthermore, one group contains n circulating heaters RhB. Therefore, one group contains n circulating modules α2. Also, since we assume n=16, the 16 circulating modules α2 are time-division driven by a shared time-division selection signal with a time division ratio. In this embodiment, the time division ratio of the circulating module α2 is the same as the time division ratio of the discharge module α1, n=16.

[0087] (Group selection control) To select and drive one of the m groups, an m-bit cyclic group selection signal is output from the control data supply circuit α3. When selecting one of the m groups, it is possible to simultaneously select n cyclic modules α2 included in that group. Information equivalent to the number of groups, m bits, is serially transferred from the main board β0. As described above, the cyclic module α2 is selected and controlled so that current flows to the corresponding cyclic heater RhB when the enable signal HE, the cyclic group selection signal, and the shared time division selection signal are input to the cyclic logic circuit AND2. However, the cyclic group selection signal is transferred from the cyclic group control circuit α12 via the cyclic group selection signal wiring α7. The cyclic group control circuit α12 is included in the control data supply circuit α3.

[0088] (Circulation group control circuit α12) The circulating group control circuit α12 generates a circulating group selection signal according to the selection information of the discharge group selection signal. Figure 8(b) shows the circuit configuration of the circulating group control circuit α12. The circulating group control circuit α12 includes a NOT gate. The signal obtained from the discharge group selection signal wiring α6 is logically inverted by the NOT gate and processed as follows. That is, the result is output to the circulating group selection signal wiring α7 as a circulating group selection signal. Therefore, when the discharge module α1 is in a selected state, the circulating module α2 is in a deselected state. On the other hand, when the discharge module α1 is in a deselected state, the circulating module α2 is in a selected state. That is, the pair of discharge modules α1 and circulating module α2 are mutually exclusive in their selection, i.e., mutually exclusive control. Note that while time-division selection is not performed, neither the discharge module α1 nor the circulating module α2 is selected.

[0089] (Latch counter circuit γ1) The latch counter circuit γ1 outputs a latch counter signal after the count value obtained by counting the edges of the latch signal LT is set to a preset number of edges, A, and then until the next predetermined number of edges, B, is input. Figure 9 is a timing chart showing the relationship between the latch signal, latch counter signal, and decoder signal in the latch counter circuit γ1 and decoder circuit δ1 of Figure 7. As shown in Figure 9, the latch signal LT continues to be counted as time progresses, and the latch counter signal is in a High state from the time edge count A is input until a fixed number of edges, B, is input. At this time, the decoder circuit δ1 outputs a decoder signal via the decoder signal wiring δ2. This allows the cyclic module α2 of block A to be selected. For convenience, in Figure 9, the decoder signal at this time is shown as decoder signal δ2. Also, as shown in Figure 9, after the number of edges, B, is input, the latch signal LT continues to be counted as time progresses, and from the time edge count C (a preset number of edges) is input until edge count D is input, the following occurs: That is, the latch counter signal is in a High state. At this time, the decoder circuit δ1 outputs a decoder signal via the decoder signal wiring δ3. This allows the circulating module α2 of block B to be selected. For convenience, in Figure 9, the decoder signal at this time is shown as decoder signal δ3.

[0090] The latch counter circuit γ1 is composed of, for example, flip-flop circuits. The number of flip-flop circuits should be the number required for the number of latches to be counted. For example, if the number of latches to be counted is 1000, then 2 to the power of 10 is 1024, so at least 10 stages of flip-flop circuits are required.

[0091] In the example shown in Figure 9, edge counts A = 100,000 and B = 100 are set. Edge counts A and B vary depending on the properties of the ink used and the flow path shape. The edge counts C-(A+B)=100,000 and D=100 are set. The edge counts C and D vary depending on the properties of the ink used and the flow path shape. Specifically, the decoder circuit δ1 selects either the first circulation module set or the second circulation module set each time the count value reaches the preset edge count. The decoder circuit δ1 continues to select either the first circulation module set or the second circulation module set until a certain number of times have been counted after the count value reaches the preset edge count.

[0092] Furthermore, the number of edge strokes also varies depending on the heat output of the circulating heater RhB. For example, to prevent instability in the flow rate of the circulating ink, it is preferable that the number of edge strokes A be as large as possible and the number of edge strokes B be as small as possible. Similarly, it is preferable that the number of edge strokes C - (A + B) be as large as possible and the number of edge strokes D be as small as possible.

[0093] In the example shown in Figure 9, the latch counter signal rises in sync with the rising edge of the latch signal LT, but this is not the only possible configuration. For example, the latch counter signal may rise in sync with the falling edge of the latch signal LT.

[0094] Furthermore, if only one of Block A or Block B exists, or if multiple discharge modules α1 and multiple circulation modules α2 are not classified as Block A or Block B, the following approaches are also possible.

[0095] Specifically, the cumulative count value is used to count edge count A, and the cumulative count value is initialized each time edge count A is exceeded. On the other hand, the differential count value is used to count edge count B, with the cumulative count value as the starting point, and the differential count value is initialized each time edge count B is exceeded. Furthermore, this latch counter signal is used for selection control of the circulating heater RhB. Specifically, the shared time division selection signal, the circulating group selection signal, the latch counter signal, and the enable signal HE are input to the circulating logic circuit AND2. If all input signals are 1, that is, if the logic of all input signals is in a High state, current flows to the corresponding circulating heater RhB.

[0096] Next, assuming that multiple discharge modules α1 and multiple circulation modules α2 are classified into Block A and Block B, the correlation between latch signals, decoder signals, and circulation heater drive will be explained using Table 1. Table 1 shows an example using a 4-stage latch counter. That is, the bit configuration of the count value representing the latch counter output is a 4-bit configuration. It also shows that the circulation heater RhB of Block A is driven when the latch counter reaches 4 to 7 counts. It also shows that the circulation heater RhB of Block B is driven when the latch counter reaches 12 to 15 counts. This is an example where the decoder output instructing the drive of the circulation heater RhB is determined by the first and second bits of the latch counter output data. Specifically, if <first bit, second bit> is <0,1>, the circulation heater RhB of Block A is driven. If <first bit, second bit> is <1,1>, the circulation heater RhB of Block B is driven. If the first bit and second bit are anything else, the circulating heater RhB will not be driven. An example in Table 1 shows that the decoder output will be as follows.

[0097] [Table 1]

[0098] In this embodiment, the discharge module α1 and the circulation module α2 are each connected to a common power supply voltage VH (e.g., 24V) and a common ground potential GNDH. However, if it is desired to further mitigate fluctuations in discharge energy due to voltage drops when driving the discharge heater RhA and the circulation heater RhB, the following measures can be taken. Specifically, separate power supply voltage and ground potential supply wiring and external connection terminals may be provided for the discharge module α1 and the circulation module α2 within the discharge element board α0. In other words, they may be supplied individually from the power supply circuit β2 mounted on the main board β0.

[0099] Generally, since drive elements operate at a higher voltage than logic circuits, a substrate is used in which high-voltage drive elements and normal drive elements coexist. In this embodiment, the ejection drive element MD1 and the circulation drive element MD2 may be composed of high-voltage MOS transistors, specifically DMOS transistors (Double-diffused MOSFETs). The ejection logic circuit AND1, the circulation logic circuit AND2, the circulation group control circuit α12, and other logic circuits such as shift registers α20a, α20b, latch circuits α21a, α21b, and decoder circuit α22 may be composed of low-voltage MOS transistors.

[0100] (Circuit area) Next, we will explain the differences due to the circuit configuration. The drive current of the circulating heater RhB generates thermal energy to circulate the ink in the individual channels. When the drive current of the circulating heater RhB is smaller than the drive current of the ejection heater RhA that ejects to the ejection medium, the current driving capability of the DMOS transistor can be small. Therefore, since it is not necessary to make the area of ​​the circulating drive element MD2 larger than the area of ​​the ejection drive element MD1, a configuration in which the area of ​​the circulating drive element MD2 is smaller than the area of ​​the ejection drive element MD1 is more preferable.

[0101] (Example 1 of circuit layout) Figure 10 is a plan view of the ejection element substrate α30. In Figure 10, control data supply circuits α3 are arranged at two locations on the left and right ends of the ejection element substrate α30 along the X direction. Two systems of mechanisms for selective control are arranged from the control data supply circuits α3 to the ejection heater row α9 and the circulation heater row α10, respectively. In Figure 10, in the transport direction Y, three rows of ink supply port arrays α14 are arranged with spacing along the direction X. Between each ink supply port array α14, one row each of the ejection heater row α9 and the circulation heater row α10 is arranged along the transport direction Y. Of the three rows of ink supply port arrays α14, the left region of the left ink supply port array α14 and the right region of the right ink supply port array α14 are arranged as follows. Specifically, the following are arranged: discharge drive element MD1, circulation drive element MD2, discharge logic circuit AND1, circulation logic circuit AND2, discharge group selection signal wiring α6, circulation group selection signal wiring α7, and shared time division selection signal wiring α8. The latch signal generated by the latch counter circuit γ1 is input to the decoder circuit δ1 via the latch counter signal wiring γ2. The decoder circuit δ1 supplies the corresponding decoder signals via decoder signal wiring δ2, decoder signal wiring δ3, decoder signal wiring δ4, and decoder signal wiring δ5.

[0102] Multiple external connection terminals are arranged along the X direction at two locations, above and below the substrate edge in the transport direction Y, on the ejection element substrate α30. The arrangement of multiple external connection terminals constitutes an external connection terminal row. The external connection terminal row is arranged orthogonally with the ejection heater row α9 and the circulation heater row α10. Compared to the ejection element substrate α0, the ejection element substrate α30 has a control data supply circuit α3 arranged in the X direction. Therefore, compared to the ejection element substrate α0, the ejection element substrate α30 has a larger substrate dimension in the X direction, but it is possible to reduce the substrate dimension in the transport direction Y.

[0103] Furthermore, in Figure 10, if only one of block A or block B is present, the decoder circuit δ1 is unnecessary. Alternatively, if the multiple discharge modules α1 and multiple circulation modules α2 are not classified into block A and block B, the decoder circuit δ1 is unnecessary.

[0104] (Second example of circuit layout) Figure 11 is a plan view of the ejection element substrate α31. In Figure 11, the ejection element substrate α31 has its external connection terminals located on the left side in direction X. Compared to the ejection element substrate α30 in Figure 10, it is possible to reduce the substrate dimensions in the transport direction Y. Although not shown in the illustration, the wiring configuration of the ejection element substrate α31 is assumed to be one unit. In this assumption, if multiple ejection element substrates α31 are mounted along the arrangement direction of the ink supply port array α14, this configuration, in which the external connection terminals are not located on the extension of the ink supply port array α14, allows for a smaller distance between the ejection element substrates α31. That is, in the case of a liquid ejection head 1 in which multiple ejection element substrates α31, whose external connection terminals are not on the extension of the nozzle row, are mounted in the direction of the nozzle row, it is also possible to reduce the size of the liquid ejection head 1. Note that in Figure 11, the external connection terminal row is arranged parallel to the ejection heater row α9 and the circulation heater row α10.

[0105] (Third example of circuit layout) Figure 12 is a plan view of the ejection element substrate α32. In Figure 12, units including the control data supply circuit α3, ink supply port array α14, ejection heater row α9, circulation heater row α10, and ink supply port array α14 are arranged in line with direction X. This arrangement is designed to accommodate the case where different types of ink are supplied to the ink supply port array α14 on the ejection element substrate α32, and the distance between each ink supply port array α14 is increased for each unit. This configuration makes it possible to avoid mixing of inks of different types during ejection. In Figure 12, the external connection terminal row is arranged parallel to the ejection heater row α9 and the circulation heater row α10.

[0106] <Other Embodiments> Although various examples and embodiments of this disclosure have been described above, the spirit and scope of this disclosure are not limited to the specific descriptions herein. This disclosure is not limited to the embodiments described above, and various modifications may be made. Furthermore, this disclosure may combine some of the embodiments described above as appropriate.

[0107] (Variation 1) For example, in this embodiment, an example has been described in which the discharge drive element MD1 and the circulation drive element MD2 are composed of DMOS transistors, but the embodiment is not limited to this. For example, at least one of the discharge drive element MD1 and the circulation drive element MD2 may be composed of a SiC (Silicon Carbide) MOSFET.

[0108] This embodiment includes a configuration represented by the following liquid dispensing head.

[0109] <Configuration 1> A plurality of discharge modules, each having a discharge drive element and a discharge heater electrically connected to the discharge drive element, Multiple circulation modules are arranged in pairs in the same number as the discharge modules, each having a circulation drive element and a circulation heater electrically connected to the circulation drive element. A latch circuit that latches a data signal containing selection information for selecting each of the plurality of discharge modules and the plurality of circulation modules, A control means for selecting and controlling, from among the plurality of circulating modules, a first circulating module set and a second circulating module set having a different arrangement area from the first circulating module set, based on the count value of the edge of the latch signal that generates the latch timing of the data signal by the latch circuit, A liquid dispensing head characterized by having the following features.

[0110] <Configuration 2> The control means is A latch counter circuit whose count value is the number of edges obtained by counting the edges of the latch signal, Each time the count value reaches a preset number of edges, a decoder circuit selects either the first set of circulating modules or the second set of circulating modules. A liquid dispensing head according to configuration 1, characterized by comprising the above.

[0111] <Structure 3> The liquid discharge head according to configuration 2, characterized in that the decoder circuit continues to select either the first circulation module set or the second circulation module set until a certain number of times have been counted after the count value reaches the set number of edges.

[0112] <Structure 4> The liquid dispensing head according to configuration 3, characterized in that the number of set edges is greater than the number of fixed edges.

[0113] <Composition 5> A first set of discharge modules and a first set of circulation modules from among the plurality of discharge modules are arranged in the first block. The second set of discharge modules and the second set of circulation modules from among the plurality of discharge modules are arranged in the second block. The liquid discharge head according to configuration 1, further comprising a control data supply circuit that selects and controls each of the discharge modules and each of the circulation modules included in the first block and the second block, respectively, based on a shared time-division selection signal obtained from the bit configuration of the count value.

[0114] <Composition 6> The liquid discharge head according to configuration 5, characterized in that the control data supply circuit exclusively controls the discharge module and the circulation module based on the selection information and the shared time-division selection signal.

[0115] <Composition 7> The system further includes a discharge port for discharging the liquid filled into the pressure chamber by the aforementioned discharge heater, The liquid discharge head according to configuration 1, characterized in that the discharge port is provided at a position corresponding to the discharge heater and is not provided at a position corresponding to the circulation heater.

[0116] <Structure 8> The liquid discharge head according to configuration 7, characterized in that the circulation heater is arranged in a pair with the discharge heater in an individual flow path including the pressure chamber.

[0117] <Composition 9> The system further comprises a row of external connection terminals into which the aforementioned data signals are input, The liquid discharge head according to configuration 1, characterized in that the external connection terminal row is arranged orthogonally with the discharge heater row in which each of the discharge heaters is arranged and the circulation heater row in which each of the circulation heaters is arranged.

[0118] <Composition 10> The system further comprises a row of external connection terminals into which the aforementioned data signals are input, The liquid discharge head according to configuration 1, characterized in that the external connection terminal row is arranged in parallel with the discharge heater row in which each of the discharge heaters is arranged and the circulation heater row in which each of the circulation heaters is arranged.

[0119] <Composition 11> Each of the discharge drive elements is arranged along each of the discharge heaters. The liquid discharge head according to configuration 9 or 10, characterized in that each of the circulating drive elements is arranged along each of the circulating heaters.

[0120] <Composition 12> The liquid discharge head according to configuration 1, wherein the discharge heater and the circulation heater are connected to a common power supply voltage and a common ground potential.

[0121] <Composition 13> The liquid discharge head described in Configuration 1, wherein the discharge heater and the circulation heater are constructed using the same semiconductor process.

[0122] <Composition 14> The liquid discharge head described in configuration 1, wherein the discharge heater and the circulation heater are made of the same material. [Explanation of Symbols]

[0123] α1 Discharge Module α2 Circulation Module γ1 Latch Counter Circuit

Claims

1. A plurality of discharge modules, each having a discharge drive element and a discharge heater electrically connected to the discharge drive element, Multiple circulation modules are arranged in pairs in the same number as the discharge modules, each having a circulation drive element and a circulation heater electrically connected to the circulation drive element. A latch circuit that latches a data signal containing selection information for selecting each of the plurality of discharge modules and the plurality of circulation modules, A control means for selecting and controlling, from among the plurality of circulating modules, a first circulating module set and a second circulating module set having a different arrangement area from the first circulating module set, based on the count value of the edge of the latch signal that generates the latch timing of the data signal by the latch circuit, A liquid dispensing head characterized by having the following features.

2. The control means is A latch counter circuit whose count value is the number of edges obtained by counting the edges of the latch signal, Each time the count value reaches a preset number of edges, a decoder circuit selects either the first circulating module set or the second circulating module set. The liquid dispensing head according to claim 1, characterized by comprising:

3. The liquid discharge head according to claim 2, characterized in that the decoder circuit continues to select either the first circulation module set or the second circulation module set until a certain number of times have been counted after the count value reaches the set number of edges.

4. The liquid dispensing head according to claim 3, characterized in that the number of set edges is greater than the number of fixed edges.

5. The first set of discharge modules and the first set of circulation modules from among the plurality of discharge modules are arranged in the first block. The second set of discharge modules and the second set of circulation modules from among the plurality of discharge modules are arranged in the second block. The liquid discharge head according to claim 1, further comprising a control data supply circuit that selects and controls each of the discharge modules and each of the circulation modules included in the first block and the second block, respectively, based on a shared time-division selection signal obtained from the bit configuration of the count value.

6. The liquid dispensing head according to claim 5, characterized in that the control data supply circuit exclusively controls the dispensing module and the circulation module based on the selection information and the shared time division selection signal.

7. The system further includes a discharge port for discharging the liquid filled into the pressure chamber by the aforementioned discharge heater, The liquid discharge head according to claim 1, characterized in that the discharge port is provided at a position corresponding to the discharge heater and not at a position corresponding to the circulation heater.

8. The liquid discharge head according to claim 7, characterized in that the circulation heater is arranged in a pair with the discharge heater in an individual flow path including the pressure chamber.

9. The system further comprises a row of external connection terminals into which the aforementioned data signals are input, The liquid discharge head according to claim 1, characterized in that the external connection terminal row is arranged orthogonally with the discharge heater row in which each of the discharge heaters is arranged and the circulation heater row in which each of the circulation heaters is arranged.

10. The system further comprises a row of external connection terminals into which the aforementioned data signals are input, The liquid discharge head according to claim 1, characterized in that the external connection terminal row is arranged in parallel with the discharge heater row in which each of the discharge heaters is arranged and the circulation heater row in which each of the circulation heaters is arranged.

11. Each of the discharge drive elements is arranged along each of the discharge heaters. The liquid discharge head according to claim 9 or 10, characterized in that each of the circulating drive elements is arranged along each of the circulating heaters.

12. The liquid discharge head according to claim 1, wherein the discharge heater and the circulation heater are connected to a common power supply voltage and a common ground potential.

13. The liquid discharge head according to claim 1, wherein the discharge heater and the circulation heater are constructed using the same semiconductor process.

14. The liquid discharge head according to claim 1, wherein the discharge heater and the circulation heater are made of the same material.

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