Liquid discharge head

Abstract

A liquid discharge head includes: a plurality of discharge modules having a discharge driving element and a discharge heater electrically connected to the discharge driving element; a plurality of circulation modules having a circulation driving element and a circulation heater electrically connected to the circulation driving element, the circulation modules being arranged in pairs with the discharge modules, and the number of the circulation modules being the same as the number of the discharge modules; a latch circuit for latching a data signal including selection information for selecting each of the plurality of discharge modules and the plurality of loop modules; and a control unit for selectively controlling the first group of loop modules or the second group of loop modules based on a count value of an edge of the latch signal generating the latch timing.

Description

Technical Field

[0001] This disclosure relates to a liquid discharge head that discharges liquid while circulating it. Background Technology

[0002] A circulating liquid discharge device is known for circulating a liquid (also known as ink), wherein the ink is circulated in a circulation flow channel communicating with a discharge orifice by means of a circulation drive element provided in addition to a discharge drive element for discharging the ink. A Japanese translation of PCT International Application Publication No. 2020-507497 (hereinafter referred to as Patent Document 1) discloses a technique for selectively driving either a discharge drive element or a circulation drive element. Summary of the Invention

[0003] This disclosure discloses advantageous features for driving a cyclic drive element with an optimal number of drives in a discharge element substrate including a discharge drive element and a cyclic drive element, while reducing the amount of data transmitted and avoiding concentrated power consumption of some cyclic drive elements.

[0004] According to some embodiments of this disclosure, a liquid discharge head includes: a plurality of discharge modules having discharge drive elements and discharge heaters electrically connected to the discharge drive elements; a plurality of circulation modules having circulation drive elements and circulation heaters electrically connected to the circulation drive elements, the circulation modules being arranged in pairs with the discharge modules, and the number of circulation modules being the same as the number of discharge modules; a latching circuit for latching a data signal including selection information for selecting each of the plurality of discharge modules and the plurality of circulation modules; and a control unit for selectively controlling a first group of circulation modules or a second group of circulation modules among the plurality of circulation modules based on a count value of an edge of the latching signal, the latching signal generating a latching timing that causes the latching circuit to latch the data signal, the second group of circulation modules being arranged in a placement area different from the first group of circulation modules.

[0005] The features of this disclosure will become clear from the following description of embodiments with reference to the accompanying drawings. The following description of the embodiments is provided as an example. Attached Figure Description

[0006] Figure 1A This is a schematic perspective view of a liquid discharge device having a main ink tank as a liquid reservoir located outside the liquid discharge head 1.

[0007] Figure 1B This is a schematic perspective view of a liquid discharge device having a secondary ink reservoir located directly above the liquid discharge head.

[0008] Figure 2A yes Figure 1A and1B An exploded perspective view of the liquid discharge head in the image.

[0009] Figure 2B This is a schematic diagram illustrating a scenario where a liquid discharge chip is provided for four colors.

[0010] Figure 2C This is a schematic diagram illustrating a scenario where a liquid discharge chip is provided for two colors.

[0011] Figure 2D This is a schematic diagram illustrating a scenario where a liquid is dispensed from a chip for a given color.

[0012] Figure 3A This is a plan view of the individual discharge unit as seen from the direction in which the droplet exits through the discharge orifice.

[0013] Figure 3B It is along Figure 3A The cross-sectional view taken from line IIIb-IIIb in the diagram.

[0014] Figure 3C It is along Figure 3A A cross-sectional view taken from line IIIb-IIIb, showing the structure of the substrate and Figure 3B The difference is shown.

[0015] Figure 3D It is a schematic diagram showing ink flowing into the pressure chamber when the first energy generating element is driven.

[0016] Figure 4A It is along Figure 3A The cross-sectional view of the individual discharge unit taken by line IIIb-IIIb is used to illustrate the generation and growth process of bubbles generated by the membrane boiling of ink heated by the second energy generation element.

[0017] Figure 4B It is along Figure 3A The cross-sectional view of the individual discharge unit taken by line IIIb-IIIb is used to illustrate the contraction process of bubbles generated by the film boiling of ink heated by the second energy generating element.

[0018] Figure 4C It is along Figure 3A The cross-sectional view of the individual discharge unit taken by line IIIb-IIIb is used to illustrate the process after the bubbles generated by the film boiling of the ink heated by the second energy generating element disappear.

[0019] Figure 5A This is a diagram showing the state where the circulation of ink is temporarily stopped.

[0020] Figure 5B It is shown in Figure 5AThe state shown in the diagram is followed by the state after the ink circulation flow is generated by driving the second energy generating element.

[0021] Figure 5C It is shown in Figure 5B The diagram shows a state where the ink circulation is temporarily stopped after the state shown.

[0022] Figure 5D It is shown in Figure 5C The state shown in the diagram is followed by the state after the ink circulation flow is generated by driving the second energy generating element.

[0023] Figure 6A This is a diagram showing the state where the circulation of ink is temporarily stopped.

[0024] Figure 6B It is shown in Figure 6A The state shown in the diagram is followed by the state after the ink circulation flow is generated by driving the second energy generating element.

[0025] Figure 6C It is shown in Figure 6B The diagram shows a state where the ink circulation is temporarily stopped after the state shown.

[0026] Figure 6D It is shown in Figure 6C The state shown in the diagram is followed by the state after the ink circulation flow is generated by driving the second energy generating element.

[0027] Figure 7 It is shown Figure 2A A diagram illustrating an example circuit structure of the liquid discharge chip's discharge element substrate.

[0028] Figure 8A It is a functional block diagram of the circuit structure for controlling the data supply circuit.

[0029] Figure 8B This is a diagram of the circuit structure of the cyclic control circuit.

[0030] Figure 9 It is a timing diagram showing the relationship between the latch signals, latch counter signals, and decoder signals of the latch counter circuit and the decoder circuit.

[0031] Figure 10 This is a plan view of the substrate for the ejected components in the first case.

[0032] Figure 11 This is a plan view of the substrate for the ejected components in the second scenario.

[0033] Figure 12 This is a plan view of the substrate for the ejected components in the third case. Detailed Implementation

[0034] In the following description, various exemplary embodiments, features, and aspects of this disclosure will be described with reference to the accompanying drawings. Note that the embodiments described below are not intended to limit this disclosure, and not all combinations of features of the embodiments described below are necessary for the solutions of this disclosure. Note that the same components are denoted by the same reference numerals.

[0035] (Overview)

[0036] A circulating liquid discharge device for circulating ink is known. This liquid discharge device has a liquid discharge head. The ink is circulated to expel air bubbles from the flow channel of the liquid discharge head and to prevent the ink near the discharge orifice from thickening. Regarding ink circulation, a method using pressure difference (hereinafter also referred to as the "differential pressure method") is well known, for example. In the differential pressure method, the pressure on the side supplying ink to the discharge orifice (also called the inner side) is set higher than the pressure on the side collecting ink (also called the outer side) using a pressure adjusting mechanism or the like. By setting the pressure difference in this way, ink can flow from the inner side to the outer side. Here, to circulate the ink, it is necessary to feed the ink flowing to the outer side back to the inner side. For this purpose, a pump is used. Note that some liquid discharge devices have a pump located outside the liquid discharge head and circulate the ink between the liquid discharge head and the main unit of the liquid discharge device. Another type of liquid discharge device has a pump located inside the liquid discharge head and circulates the ink within the liquid discharge head. However, the differential pressure circulation method uses a pressure adjusting mechanism, a pump, and other mechanisms. Therefore, the main unit of the discharge device and the liquid discharge head tend to be large in size.

[0037] Therefore, in addition to the differential pressure method, there is also an ink circulation method as described below. That is, in addition to the discharge drive element for discharging ink, a circulation drive element is also provided in the circulation flow channel communicating with the discharge hole. A mechanism having this structure and driving the circulation drive element to circulate ink in the circulation flow channel is known.

[0038] Furthermore, a circuit configuration is disclosed for selectively driving each of a plurality of discharge drive elements and a plurality of circulation drive elements disposed on a discharge element substrate included in a liquid discharge head. Using this circuit configuration, an address is assigned to each of the plurality of discharge drive elements and the plurality of circulation drive elements, thereby achieving the function of selectively driving each of the plurality of discharge drive elements and the plurality of circulation drive elements. Therefore, as the number of discharge drive elements and circulation drive elements increases, the amount of data transmitted for the data signals specifying each address increases. As the amount of transmitted data increases, the number of circuits for resolving problems such as crosstalk between data signals increases, therefore it is preferable to reduce the amount of transmitted data. To reduce the amount of transmitted data, a configuration can be considered whereby selection information for circulation drive elements is converted in the discharge element substrate according to selection information for discharge drive elements, and each circulation drive element is selected.

[0039] For example, when using a heater as an energy generating element, if the discharge heater on select signal is "1", it can be selected as a discharge drive element for the discharge heater. If using a heater as an energy generating element, if the discharge heater on select signal is "0", it can be selected as a circulation drive element for the circulation heater. This configuration reduces the amount of data transmitted.

[0040] However, even with this configuration, each of the discharge drive element and the circulation drive element is selected via a data signal with the same drive frequency. First, the optimal timing for discharging ink is different from the optimal timing for circulating ink. For example, if the drive frequency of the discharge drive element >> the drive frequency of the circulation drive element, controlling only the circulation drive element or the discharge drive element will result in the circulation drive element's drive frequency being higher than actually needed. Therefore, it may not be possible to reduce power consumption.

[0041] Furthermore, using the above configuration, even if the number of drives of the discharge drive element is greater than the number of drives of the cyclic drive element, the cyclic drive element will inevitably turn on when the discharge drive element is turned off. Therefore, from the perspective of reducing power consumption, a mechanism is needed that can appropriately set the number of drives of the cyclic drive element.

[0042] Furthermore, in driving the cyclic drive elements, a large number of cyclic drive elements may be activated simultaneously, potentially leading to concentrated power consumption. If concentrated power consumption occurs in some cyclic drive elements, the load on the power supply of the liquid discharge device in the inkjet recording apparatus increases. Therefore, a mechanism is needed that can appropriately set the number of cyclic drive elements activated simultaneously.

[0043] In other words, according to the inventors' research, it was found that using a discharge element substrate that includes a discharge drive element and a cycle drive element according to the prior art, it is impossible to drive the cycle drive element with the optimal number of drives while reducing the amount of data transmitted and avoiding concentrated power consumption of some cycle drive elements.

[0044] In view of this, according to this disclosure, at least the latch signals used to latch input data signals, which are used to specify a discharge module having a discharge drive element, are counted. The cyclic drive element is controlled to be driveable until a cumulative count value obtained by counting the latch signals exceeds a first threshold and a differential count value obtained by counting the latch signals starting from the cumulative count value exceeds a second threshold. This process can reduce the total time the cyclic drive element is driven, thus reducing power consumption.

[0045] Furthermore, according to this disclosure, based on the count value of the edge of the latch signal, a first group of loop modules or a second group of loop modules among a plurality of loop modules are selectively controlled, and the second group of loop modules is arranged in a different placement area than the first group of loop modules. Each latch signal is a signal that generates a data signal latch timing, which includes selection information for selecting each of the plurality of discharge modules and the plurality of loop modules. Using this configuration, the amount of data transmitted can be reduced. Furthermore, since the first group of loop modules or the second group of loop modules arranged in a different placement area than the first group of loop modules are selectively controlled, concentrated power consumption caused by the driving of the loop drive element can be avoided, and power consumption can be reduced.

[0046] <Liquid Discharge Device 50>

[0047] Figure 1A and 1B This is a diagram showing an example of the overall construction of the liquid discharge device 50. Figure 1A This is a schematic perspective view of a liquid discharge device 50, which has a main ink tank 2 as a liquid reservoir located outside the liquid discharge head 1. Figure 1B This is a schematic perspective view of a liquid dispensing device 50, which has a secondary ink reservoir 54 located directly above the liquid dispensing head 1. First, it will be described... Figure 1A and Figure 1B The CCP has some of these parts.

[0048] The liquid ejection device 50 includes a liquid ejection head 1 and transport rollers 55, 56, 57, and 58. The liquid ejection head 1 can scan in a direction X orthogonal to the transport direction Y of the medium P to be ejected. The liquid ejection head 1 is mounted on a carrier 60. The carrier 60 moves back and forth along a guide shaft 51 in the main scanning direction (also referred to as direction X). The transport rollers 55, 56, 57, and 58 transport the medium P to be ejected in a secondary scanning direction (also referred to as the transport direction Y) that intersects (in this embodiment, is orthogonal) the main scanning direction. That is, the liquid ejection device 50 constitutes a tandem inkjet ejection device, which forms an image by ejecting liquid from the liquid ejection head 1 onto the medium P to be ejected being transported in the transport direction Y while moving the liquid ejection head 1 in direction X. Note that the application of this disclosure is not limited to tandem inkjet ejection devices. This disclosure can also be applied to page-width inkjet ejection devices, which form images by using a lead (page-width head) extending in the page-width direction of the ejected medium P to eject liquid onto the medium P being transported in the transport direction Y. Note that in Figure 1A and Figure 1B In this context, direction Z is the vertical direction. That is, direction Z is the direction that intersects (or is orthogonal to) the XY plane defined by direction X and transport direction Y.

[0049] The liquid ejector head 1 can eject four types of ink: black (K), cyan (C), magenta (M), and yellow (Y). The liquid ejector head 1 can use these four types of ink to form a full-color image. Note that the ink ejected from the liquid ejector head 1 is not limited to the four types mentioned above. For example, this disclosure can also be applied to a liquid ejector head 1 that ejects another type of ink (such as spot color ink). That is, the type and quantity of ink ejected from the liquid ejector head 1 are not limited.

[0050] Next, we will describe Figure 1A and Figure 1B The differences between them. Figure 1A In this configuration, the secondary ink tank 54 is mounted on the liquid discharge head 1. Four ink supply pipes (liquid communication channels) 59 are attached to the secondary ink tank 54. The liquid discharge 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 secondary ink tank 54 through the four ink supply pipes 59 under the driving force of the external pump 70. On the other hand, in Figure 1B In the middle, the auxiliary ink tank 54 is located directly above the liquid discharge head 1. Figure 1B and Figure 1A The difference is that the main ink tank 2 is not located outside the liquid outlet 1, therefore the four ink supply pipes 59 are not attached, and an external pump 70 is not provided. Note that in Figure 1A and Figure 1BIn this configuration, the liquid discharge head 1 can be provided integrally with the secondary ink tank 54 and can be configured such that the liquid discharge head 1 is removably attached to the bracket 60. Alternatively, the secondary ink tank 54 can also be provided integrally with the bracket 60, and only the secondary ink tank 54 can be removably attached to the bracket 60. (See reference...) Figure 1A The construction in the following is described.

[0051] <Basic Structure of Liquid Discharge Head 1>

[0052] Figures 2A to 2D It is shown Figure 1A and Figure 1B A diagram illustrating the basic construction of the liquid discharge head 1. Figure 2A yes Figure 1A and Figure 1B Exploded perspective view of liquid discharge head 1 in the middle. Figure 2B , Figure 2C and Figure 2D It is shown Figure 2A A diagram illustrating an example of the liquid discharge chip 3 is shown. The liquid discharge head 1 includes a housing portion 53, a secondary ink reservoir 54, and the liquid discharge head 3. In the liquid discharge head 1, the secondary ink reservoir 54 temporarily stores ink. The secondary ink reservoir 54 is housed within the housing portion 53. As described in detail later, the liquid discharge chip 3 is located at the bottom of the housing portion 53. The liquid discharge chip 3 discharges ink supplied from the secondary ink reservoir 54 onto the medium P to be discharged.

[0053] Although not shown in the figure, a liquid connector insertion port is provided in the wall of housing portion 53. Figure 1A A liquid connector at the tip of the ink supply tube 59 is inserted into the liquid connector insertion port and connected to it in a fluid-tight manner. This configuration forms an ink supply channel from the ink tank 2 via the external pump 70 to the liquid discharge head 1. In this embodiment, four types of ink are used. Therefore, for each of these four types of ink, a set of ink tank 2, external pump 70, ink supply tube 59, and auxiliary ink tank 54 are provided. Thus, four ink supply channels corresponding to the respective inks are independently formed. In this embodiment, the liquid discharge device 50 has an ink supply system that supplies ink from the ink tank 2 located outside the liquid discharge head 1.

[0054] A first support member 4 and a second support member 7 are provided between the housing portion 53 and the liquid discharge chip 3. An electrical wiring member 5 is provided below the liquid discharge chip 3. Specifically, the first support member 4 has an ink supply port and an ink collection port. The second support member 7 has an opening. The liquid discharge chip 3 is engaged and fixed to the first support member 4. The first support member 4 is engaged and fixed to the second support member 7. The second support member 7 holds the electrical wiring member 5 in such a way that the electrical wiring member 5 is electrically connected to the liquid discharge chip 3. The electrical wiring member 5 applies an electrical signal to the liquid discharge chip 3 for discharging ink or for circulating ink.

[0055] Note that in this embodiment, the liquid discharge device 50 does not include any ink collection system for collecting ink from the liquid discharge head 1 into the ink tank 2. Therefore, the ink tank 2 does not have a connector insertion port for connecting a tube for collecting ink, but the liquid discharge head 1 has a liquid connector insertion port for connecting a liquid connector for the ink supply tube 59.

[0056] Figure 2B This diagram illustrates the case where a liquid discharge chip 3 is provided for four colors. That is, Figure 2B This illustrates a liquid ejection chip 3 capable of ejecting four colors of ink. The liquid ejection chip 3 includes multiple ejection holes and pads for electrical implementation. The four colors are, for example, black, cyan, magenta, and yellow, and each color is assigned to a separate column. Each column extends in the transport direction Y and is spaced apart from each other in the direction X. Each column includes multiple ejection holes. The multiple ejection holes are arranged at regular intervals in the Y direction. The ejection holes in each column can be arranged in rows in the Y direction instead of being spaced apart from each other in the X direction. Alternatively, only black can be assigned to two columns, and the other three colors can be assigned to three columns, for a total of five columns and four colors. Note that in... Figure 2A In the example configuration shown, the liquid discharge chip 3 is a single chip providing four colors. That is, Figure 2A The liquid discharge chip 3 in the middle is Figure 2B The liquid discharge chip 3 shown is illustrated.

[0057] Figure 2C This diagram illustrates a scenario where a liquid discharge chip 3 is provided for two colors. In this case, two chips are used. That is, Figure 2C This illustrates a scenario where one liquid discharge chip 3 can discharge two colors of ink. Regarding the installation of the liquid discharge chip 3 in the liquid discharge head 1, two liquid discharge chips 3 capable of discharging two colors of ink can be installed in one liquid discharge head 1, or as follows... Figure 2D As shown, two liquid discharge heads 1 can be prepared, each liquid discharge head 1 having a liquid discharge chip 3 capable of discharging ink of a certain color.

[0058] Figure 2D This diagram illustrates a scenario where a liquid discharge chip 3 is provided for a single color. In this case, four chips are used. That is, Figure 2D This illustrates a scenario where one liquid discharge chip 3 can discharge ink of one color. Regarding the installation of the liquid discharge chip 3 in the liquid discharge head 1, four liquid discharge chips 3 capable of discharging ink of one color can be installed in one liquid discharge head 1, or four liquid discharge heads 1 can be prepared, each liquid discharge head 1 having one liquid discharge chip 3 capable of discharging ink of one color.

[0059] like Figure 2C and Figure 2D As shown in the illustration, when multiple liquid discharge chips 3 are mounted on a single liquid discharge head 1, the liquid discharge chips 3 can have different chip lengths. Furthermore, the number of colors of the liquid discharge chips 3 is not particularly limited, and various color combinations are possible. For example, although... Figure 2A An example is shown where the number of colors of the liquid discharge chip 3 is four, but the number of colors of the liquid discharge chip 3 can also be greater than four.

[0060] <Individual Flow Channel: Straight-through Type>

[0061] The liquid discharge head 1 includes multiple individual discharge units, each containing a flow channel. The liquid discharge head 1 also includes a supply flow channel for supplying liquid to the individual flow channels of each individual discharge unit. Figures 3A to 3D This is a schematic diagram of the discharge port 11 of the individual discharge head, which includes a straight-through individual flow channel 23, and its surrounding area. Figure 3A This is a plan view of the individual discharge unit as seen from the direction in which the droplet is discharged from the discharge hole 11. Figure 3B It is along Figure 3A The cross-sectional view taken from line IIIb-IIIb in the diagram. Figure 3C It is along Figure 3A A cross-sectional view taken from line IIIb-IIIb in the diagram. Figure 3A The structure and Figure 3B The construction shown is different.

[0062] The individual discharge unit includes a discharge port 11, a pressure chamber 12, a first energy generating element 14 (also called discharge energy generating element 14) and a second energy generating element 24 (also called circulating energy generating element 24).

[0063] Pressure chamber 12 is formed for each discharge port 11 by separating the space between substrate 18 and perforated plate 19 by partition plate 21. Pressure chamber 12 can be filled with ink (also referred to as liquid). Discharge port 11 is an opening formed in a portion of perforated plate 19. In discharge port 11, the meniscus of ink flowing through pressure chamber 12 is stretched to form discharge port interface, serving as an interface between ink and atmosphere. Discharge port 11 discharges liquid.

[0064] Individual flow channels 23 extend in a second direction that intersects (or is orthogonal in this embodiment) the direction in which the discharge ports 11 are arranged in rows (a first direction). Individual flow channels 23 include a pressure chamber 12, an inlet-side (upstream-side) connecting flow channel 13, and an outlet-side (downstream-side) connecting flow channel. The inlet-side connecting flow channel 13 communicates with one end of the pressure chamber 12. The outlet-side connecting flow channel communicates with the other end of the pressure chamber 12.

[0065] A first supply opening 22 is provided at one end of the individual flow channel 23. The first supply opening 22 is an opening that extends from the common flow channel (not shown) through the substrate 18 to the upstream side of the individual flow channel 23. A second supply opening 32 is provided at the other end of the individual flow channel 23. The second supply opening 32 is an opening that extends from the common flow channel (not shown) through the substrate 18 to the downstream side of the individual flow channel 23. Liquid is supplied to the individual flow channel 23 through the first supply opening 22 and the second supply opening 32.

[0066] In the substrate 18, the first energy generating element 14 is positioned closer to the second supply opening 32 than the first supply opening 22. The first energy generating element 14 is an element that generates energy to expel liquid from the pressure chamber 12 through the discharge port 11. Specifically, the first energy generating element 14 is driven to generate heat to cause the liquid (also referred to as ink) in the pressure chamber 12 to bubble, and the ink can be discharged from the discharge port 11 by the bubbling energy. Although the first energy generating element 14 used in this embodiment is an electrothermal conversion element, the first energy generating element 14 is not particularly limited. For example, a piezoelectric element can be used as the first energy generating element 14.

[0067] In the substrate 18, the second energy generating element 24 is positioned closer to the first supply opening 22 than the second supply opening 32. The second energy generating element 24 is an element that generates energy to produce a circulating flow of ink in the individual flow channel 23 in the direction indicated by arrow 27. Although the second energy generating element 24 used in this embodiment is an electrothermal conversion element, the second energy generating element 24 is not particularly limited. For example, a piezoelectric element can be used as the second energy generating element 24.

[0068] Here, a straight-through type will be described. A straight-through type means that the opposite ends of the individual flow channel 23 are located on opposite sides of the discharge port 11, and the individual flow channel 23 is shaped such that the opposite ends of the individual flow channel 23 are arranged in a direction that intersects (orthogonally in the example of Figure 3) the row direction of the discharge port 11. In other words, the individual flow channel 23 is arranged in such a way that the first energy generating element 14 and the second energy generating element 24 are arranged in a direction that intersects the row direction of the discharge port 11.

[0069] Furthermore, an inlet-side connecting flow channel 13 is formed on the side of the second energy generating element 24. The inlet-side connecting flow channel 13 is formed by the portion of the individual flow channel 23 closer to the second energy generating element 24 and the first supply opening 22. On the other hand, an outlet flow channel is formed on the side of the first energy generating element 14. The outlet flow channel is formed by the other portion of the individual flow channel 23 closer to the first energy generating element 14 and the second supply opening 32.

[0070] Next, the ink flow in the individual flow channel 23 will be described. The ink flow in the individual flow channel 23 is classified into two types. The first ink flow is the replenishment flow after the liquid discharge device 50 drives the first energy generating element 14 to discharge ink from the discharge port 11. The second ink flow is the circulating flow generated by the liquid discharge device 50 driving the second energy generating element 24 in the direction indicated by arrow 27.

[0071] <The First Ink Stream>

[0072] Figure 3D This illustrates how the liquid discharge device 50 drives the first energy generating element 14 to discharge ink from the discharge port 11. Figure 3D This diagram illustrates ink flowing into the pressure chamber 12 when the first energy generating element 14 is driven. Figure 3D In the example shown, when ink is discharged from the discharge port 11, ink is supplied through each of the first supply opening 22 and the second supply opening 32. Therefore, ink flows into the pressure chamber 12 through both the first supply opening 22 and the second supply opening 32.

[0073] <Second Ink Stream>

[0074] On the other hand, when the second energy generating element 24 is driven to generate a circulating flow, ink flows into the individual flow channel 23 through the first supply opening 22 and flows out of the individual flow channel 23 through the second supply opening 32. In this embodiment, the liquid discharge device 50 generates a circulating flow of ink in the individual flow channel 23 in the direction indicated by arrow 27 by feeding the ink flowing out via the second supply opening 32 back to the first supply opening 22. Figure 3CAn example is shown where the first supply opening 22 and the second supply opening 32 are provided as separate flow channels and merged outside the liquid discharge head 1. Figure 3D An example is shown where the first supply opening 22 and the second supply opening 32 are combined in the liquid discharge chip 3.

[0075] The circulating flow of the ink will be described further. The ink contains volatile components (such as water) and solid components. During the use of the liquid discharge head 1, the discharge of the ink through the discharge hole 11 may become unstable, for example, due to the evaporation of volatile components through the discharge hole 11 or due to the concentration of solid components near the discharge hole 11 caused by the evaporation of volatile components. Various measures are taken to prevent the discharge of ink through the discharge hole 11 from becoming unstable.

[0076] For example, a cap member (not shown) may be provided at a location offset in the X direction from the delivery channel of the discharged medium P. This cap member is shaped to cover the discharge port surface of the liquid discharge head 1, which is provided with the discharge port 11. When the liquid discharge head 1 is not performing a recording operation on the discharged medium P, the cap member can prevent the discharge port 11 from drying out or protect the discharge port 11 by covering the discharge port surface of the liquid discharge head 1.

[0077] In addition, an ink intake mechanism (not shown) may be provided. When a cap member and an ink intake mechanism are provided, the cap member works in conjunction with the ink intake operation performed through the discharge hole 11. The ink intake operation refreshes the ink near the discharge hole 11, thus maintaining the quality of the formed image.

[0078] Furthermore, when the liquid ejector head 1 is not performing a recording operation on the ejected medium P, concentrated ink can be discarded by performing an ejection operation called preliminary ejection (also known as preliminary spray). It is also known that when the liquid ejector head 1 is performing a recording operation on the ejected medium P, an ejection operation called preliminary ejection (also known as on-paper preliminary ejection or in-page preliminary ejection) is performed. On-paper preliminary ejection or in-page preliminary ejection is an ejection operation that ejects a small amount of ink from the ejected medium P at a location inconspicuous in terms of image quality. These ejection operations contribute significantly to the improvement of image quality. However, some ink is discarded in order to refresh the ejection orifice 11. It is preferable to minimize the amount of ink discarded.

[0079] In this regard, a second energy generating element 24 for heating the ink in the individual flow channels 23 is provided in the substrate 18 to generate a circulating flow of ink. By generating a circulating flow of ink, the amount of discarded ink can be reduced, and drying of the discharge hole 11 and concentration of ink near the discharge hole 11 can be prevented. From another perspective, the number of initial ink discharges and the number of ink intakes can be minimized. Furthermore, since the number of initial ink discharges is minimized, the overall throughput and output of the liquid discharge device 50 can be increased. Note that if the second energy generating element 24 is provided for at least some of the multiple individual flow channels 23 included in the liquid discharge head 1, the second energy generating element 24 can produce the above-mentioned effects.

[0080] also, Figure 1A The liquid discharge head 1 can be configured with a second energy generating element 24 located at all positions for four types of ink, or it can be configured with a second energy generating element 24 located only at a position for one type of ink. That is, the liquid discharge head 1 can be configured to circulate at least one of multiple types of ink.

[0081] Note that to remove foreign matter from the ink, you can set the ink circulation channel... Figure 3A The filter 31 shown is a protrusion formed by a portion of the perforated plate 19 protruding toward the substrate 18. Figures 3A to 3D In the example shown, filter 31 is located at one end of individual flow channel 23 and at the other end of individual flow channel 23. In the ink circulation channel, one end of individual flow channel 23 corresponds to the ink inflow side, while the other end of individual flow channel 23 corresponds to the ink outflow side. Filter 31 can be located between the first energy generating element 14 and the second energy generating element 24 in individual flow channel 23. When filter 31 is located between the first energy generating element 14 and the second energy generating element 24 in individual flow channel 23, filters 31 at one end of individual flow channel 23 and at the other end of individual flow channel 23 are not required. Next, reference will be made to... Figures 4A to 4C Describe the principle behind the generation of the circulating flow of ink.

[0082] <The principle of ink circulation>

[0083] Figures 4A to 4C This is a diagram illustrating the principle behind the circulation of ink. For ease of description, Figures 4A to 4C The illustration of filter 31 is omitted. Figure 4A It is along Figure 3AThe cross-sectional view of the individual discharge unit taken by line IIIb-IIIb is used to illustrate the generation and growth process of bubble B generated by the membrane boiling of ink heated by the second energy generation element 24. Figure 4B It is along Figure 3A The cross-sectional view of the individual discharge unit taken by line IIIb-IIIb is used to illustrate the contraction process of bubble B generated by the membrane boiling of ink heated by the second energy generating element 24. Figure 4C It is along Figure 3A The cross-sectional view of the individual discharge unit, taken by line IIIb-IIIb, is used to illustrate the process after the disappearance of bubble B generated by the film boiling of ink heated by the second energy generating element 24. Next, the formation and growth process of bubble B, the contraction process of bubble B, and the process after the disappearance of bubble B will be described.

[0084] <The formation and growth process of bubble B>

[0085] like Figure 4A As shown, the second energy generating element 24 is positioned closer to the first supply opening 22 within the first supply opening 22 and the second supply opening 32. Due to the generated circulating flow of ink, the flow resistance R1 in the flow channel between the second energy generating element 24 and the first supply opening 22 is less than the flow resistance R2 in the flow channel between the second energy generating element 24 and the second supply opening 32. Because of the difference between the flow resistances R1 and R2, the bubbles B generated by the film boiling of the ink grow towards the flow channel with the smaller flow resistance R1, as shown... Figure 4A As shown in the diagram. Therefore, the flow vector Fa of ink toward the flow channel with flow resistance R1 is greater than the flow vector Fb of ink toward the flow channel with flow resistance R2. Note that the circuit including flow resistances R1 and R2 is an equivalent circuit that compares the flow resistance generated by the circulating flow of ink in the flow channel including individual flow channel 23 with the resistance.

[0086] <The contraction process of bubble B>

[0087] During the contraction of bubble B, ink flows to compensate for the decrease in the volume of the shrinking bubble B. In this process, as... Figure 4B As shown, the flow vector Fc of the ink flowing out from the first supply opening 22 on the flow channel side with flow resistance R1 is greater than the flow vector Fd of the ink flowing out from the second supply opening 32 on the flow channel side with flow resistance R2. Furthermore, the location where bubble B disappears shifts from the second energy generating element 24 towards the flow channel closer to the second supply opening 32.

[0088] <The process after bubble B disappears>

[0089] As referenced above Figure 4BAs described, there exists a relationship: Fc > Fd. Therefore, the flow vector F of the circulating ink flow from the first supply opening 22 towards the second supply opening 32 occurs. The magnitude of the flow vector F depends on the ratio between the flow resistances R1 and R2 and the size of the bubble B. For example, consider the case where a second energy generating element 24 is used. In this case, the location where the second energy generating element 24 is deployed is preferably closer to one of the opposite end portions of the individual flow channel 23 than the location where the first energy generating element 14 is deployed. Specifically, this location is preferably set in the range of a flow resistance ratio R1 / R2 of 0.05 to 0.40. By setting the location in the range of a flow resistance ratio R1 / R2 of 0.05 to 0.40, the flow vector F of the circulating ink flow can be maximized. By increasing the ink flow vectors Fa and Fc, the flow vector F of the circulating ink flow increases, and the circulating ink flow increases. Therefore, the flow resistance R1 is preferably reduced. Furthermore, the ink flow vector Fb is preferably minimized, and the ink flow vector Fd is preferably reduced. Therefore, the flow resistance R2 is preferably increased. In short, the flow resistance R1 is preferably reduced, and the flow resistance R2 is preferably increased. That is, the flow resistance ratio R1 / R2 is preferably reduced. Furthermore, if bubble B is large, i.e., bubble B has a large volume, it means that the volume of fluid discharged in the individual flow channel 23 increases, and therefore, the circulation flow also increases. For example, factors that contribute to increasing the circulation flow are as follows: One factor that contributes to increasing the circulation flow is increasing the size of the second energy generating element 24. Another factor that contributes to increasing the circulation flow is increasing the width or height of the flow channel on the side of the first supply opening 22 to relatively reduce the flow resistance R1. Another factor that contributes to increasing the circulation flow is reducing the viscosity of the ink. Another factor that contributes to increasing the circulation flow is increasing the temperature of the liquid discharge head 1. Another factor that contributes to increasing the circulation flow is doubling the drive pulse. Doubling the drive pulse means the following: First, a short pulse that does not create bubbles in the flow channel above the second energy generating element 24 is applied to the second energy generating element 24 to heat the ink in the flow channel near the second energy generating element 24. Then, a main pulse is applied to the second energy generating element 24 to create bubbles that circulate the ink, causing larger bubbles to grow. Specifically, the first pulse heats the ink to near its boiling point over as wide a range as possible around the heater, while the second pulse causes rapid vaporization of the ink over that wide range. In this way, the bubbles grow larger. That is, by inputting two pulses, the volume of the bubbles increases.

[0090] Furthermore, a portion of the circulating ink flow enters the discharge port 11. Consequently, any concentrated ink in the discharge port 11 is pushed towards the flow channel on the second supply opening 32 side, while fresh ink is fed into the discharge port 11 from the flow channel on the first supply opening 22 side through the individual flow channel 23. In this way, concentrated ink is less likely to remain in the discharge port 11. Therefore, the impact of concentrated ink can be reduced, and the initial ink discharge state can be maintained.

[0091] The ink circulation flow is instantaneous during the formation, growth, and contraction of bubble B. Therefore, after bubble B disappears, the inertial circulation flow of the ink decays over time and stops after a certain period. Therefore, to stably generate a circulation flow within a certain time frame, it is preferable to repeatedly drive the second energy generating element 24. Note that the driving cycle of the second energy generating element 24 is not particularly limited, as long as the concentrated ink retained in the discharge orifice 11 can be discharged. However, the ink circulation flow is instantaneous during the formation, growth, and contraction of bubble B. Therefore, when considering a cycle of 10 μs (microseconds) as the duration of bubble B from formation to disappearance and driving the second energy generating element 24 at a high driving frequency such as 100 kHz (kilohertz), it is possible that the promotion of ink circulation flow will be inhibited. Therefore, the second energy generating element 24 is preferably driven with a driving cycle of, for example, 100 Hz to tens of kHz.

[0092] Specifically, as the driving frequency of the second energy generating element 24 increases, the ink circulation flow is more likely to be maintained, thus enhancing the effect of discharging concentrated ink through ink circulation. However, as the driving frequency of the second energy generating element 24 increases, the ink temperature is expected to rise due to the heat generated by the second energy generating element 24 during driving. Therefore, it is preferable to appropriately control the number of times the second energy generating element 24 is driven. Next, reference will be made to... Figures 5A to 5D and Figures 6A to 6D The description describes how ink concentration is eliminated through the circulation of ink.

[0093] Eliminating Ink Concentration: Straight-through Type

[0094] Figures 5A to 5D This diagram illustrates how ink concentration is eliminated through the circulating flow of ink in a straight-through individual flow channel 23. Figure 5A This is a diagram showing the state where the circulation of ink is temporarily stopped. Figure 5B It is shown in Figure 5A The diagram shows the state immediately following the state after the ink circulation flow is generated by driving the second energy generating element 24. Figure 5C It is shown in Figure 5B The diagram shows a state where the ink circulation is temporarily stopped after the state shown.

[0095] Figure 5D It is shown in Figure 5C The diagram shows the state immediately following the state generated by driving the second energy generating element 24 to produce a circulating flow of ink. (See diagram for example.) Figures 5A to 5D As shown, the straight-through individual flow channel 23 is configured with separate inlets and outlets for the circulating flow of ink. Note that the ink in the individual flow channel 23 is indicated by dotted shading, and concentrated ink is indicated by denser dotted shading to indicate the degree of ink concentration.

[0096] like Figure 5A As shown, when the ink circulation is temporarily stopped, the volatile components of the ink evaporate through the discharge port 11. Therefore, ink concentration continues near the discharge port 11. Afterwards, when the second energy generating element 24 is activated, the ink circulation resumes. Thus, as... Figure 5B As shown, ink concentration occurring near the discharge port 11 is eliminated. Subsequently, when the ink circulation flow is temporarily stopped, as... Figure 5A As shown, ink concentration continues again near the discharge port 11, as... Figure 5C As shown in the diagram. Then, when the second energy generating element 24 is activated, the ink circulation resumes. Therefore, as... Figure 5B As shown, ink concentration occurring near the discharge port 11 is eliminated, as... Figure 5D As shown in the diagram. Therefore, ink concentration is eliminated throughout the entire individual flow channel 23. In the straight-through individual flow channel 23, as described above, the ink concentration state is cleared each time the ink circulation flow is temporarily stopped and restarted.

[0097] <Ink Concentration Elimination: U-Shape>

[0098] Figures 6A to 6D This diagram illustrates how ink concentration is eliminated through the circulating flow of ink in the U-shaped individual flow channel 23. Figure 6A This is a diagram showing the state where the circulation of ink is temporarily stopped. Figure 6B It is shown in Figure 6A The diagram shows the state immediately following the state after the ink circulation flow is generated by driving the second energy generating element 24. Figure 6C It is shown in Figure 6B The diagram shows a state where the ink circulation is temporarily stopped after the state shown. Figure 6D It is shown in Figure 6C The diagram shows a state immediately following the state generated by driving the second energy generating element 24 to produce a circulating flow of ink. (See diagram for example.) Figures 6A to 6DAs shown, the U-shaped individual flow channel 23 is configured with adjacent inlets and outlets for the water circulation flow of ink. Note that the ink in the individual flow channel 23 is indicated by dotted shading, and concentrated ink is indicated by denser dotted shading to indicate the degree of ink concentration.

[0099] like Figure 6A As shown, with the ink circulation temporarily stopped, the volatile components of the ink evaporate through the discharge port 11. Therefore, ink concentration continues near the discharge port 11. Subsequently, when the second energy generating element 24 is activated, the ink circulation is reselected. As a result, [the following occurs]. Figure 6B The state shown in the image. Figure 6A The entrance to the individual flow channel 23 and Figure 6A The outlet of the individual flow channel 23 is adjacent to the outlet. Therefore, although the ink concentrated near the discharge port 11 is discharged through the outlet of the individual flow channel 23, a portion of the discharged ink flows back into the individual flow channel 23 through the inlet. Thus, the ink in the individual flow channel 23 is not completely replaced by fresh ink; instead, a phenomenon occurs where the ink in the individual flow channel 23 is replaced by slightly concentrated ink (this phenomenon will be referred to as recirculation concentration). Later, when the ink circulation is temporarily stopped (e.g., when...), the ink flow is... Figure 6A (As shown), the ink is concentrated from Figure 6B The state shown continues again near the discharge port 11, as... Figure 6C As shown in the diagram. Then, when the second energy generating element 24 is activated, the ink circulation resumes. As a result, as... Figure 6D As shown, due to recirculation and concentration, the ink in the entire individual flow channel 23 is compared to Figure 6B The ink in the channel is replaced by a more concentrated ink. In the U-shaped individual flow channel 23, each time the ink circulation flow is temporarily stopped and restarted as described above, the concentrated state of the ink is not cleared, and the concentration of the ink throughout the entire individual flow channel 23 gradually continues. Therefore, the ink concentration state becomes worse. Note that not only when the temporary stop and restart of the ink circulation flow is not repeated, but also when the temporary stop of the ink circulation flow is prolonged, if the concentration of the ink near the discharge hole 11 continues, then even when the ink circulation flow is restarted for the first time, it is difficult to achieve the effect of improving the ink concentration state. This is because the effect of improving the ink concentration state is reduced due to recirculation concentration.

[0100] Therefore, due to the effect of the discharged concentrated ink, the straight-through individual flow channel 23 and the U-shaped individual flow channel 23 differ in their effectiveness in eliminating the concentrated state of the ink by temporarily stopping and restarting the ink circulation flow. Specifically, in the case of the straight-through individual flow channel 23, the concentrated state of the ink throughout the entire individual flow channel 23 is more likely to be eliminated. On the other hand, in the case of the U-shaped individual flow channel 23, due to the recirculation and concentration, the concentrated state of the ink throughout the entire individual flow channel 23 is unlikely to be eliminated. Therefore, in the case of the U-shaped individual flow channel 23, the ink discharge may become unstable depending on the degree of ink concentration throughout the entire individual flow channel 23.

[0101] <Ink>

[0102] As described above, although the degree of ink concentration reduction varies depending on the flow channel arrangement including the individual flow channel 23, the following effects can be achieved by generating a circulating flow of ink in the individual flow channel 23 using a second energy generating element 24 that can serve as a circulating heater. Specifically, the effects of concentrated ink, which increases viscosity due to the evaporation of volatile components through the discharge orifice 11, can be reduced. Therefore, excellent ink discharge conditions can be maintained, and the effects of variations in the ink discharge rate can be further reduced. Thus, ink discharge can be stabilized.

[0103] On the other hand, depending on the application of the liquid discharge head 1 or the liquid discharge device 50 equipped with the liquid discharge head 1, inks containing different pigments or having different solid content can be used. Regarding the performance of the liquid discharge head 1, regardless of the type of ink, it is preferable to maintain ink discharge stability.

[0104] For example, as a problem caused by moisture in the ink, deformations such as curling (called warping) or wrinkling (also called wavy creases) may occur on ordinary paper. In this case, ink with reduced moisture content can be used. Ink with reduced moisture content has a higher concentration of organic solvents, pigments, or solid components of the ink (such as resins) other than water. Therefore, as the moisture in the ink evaporates, the viscosity of the ink tends to increase rapidly. Therefore, ink with reduced moisture content is more likely to reduce ink discharge stability. In this regard, when using ink with reduced moisture content, the increase in ink viscosity can be reduced by generating a circulating flow of ink in the flow channel arrangement including individual flow channels 23, as in this embodiment. Generally, inks with high solid content contain 10 wt% solid components. Therefore, this embodiment is preferably applicable to inks containing 10 wt% (weight percentage, also called mass %) or more of solid components.

[0105] The relationship between the operating temperature of the liquid discharge head 1 and the viscosity of the ink will be described. The liquid discharge head 1 can be used by heating it until its temperature reaches a specific temperature by driving and controlling a second energy generating element 24 arranged across the liquid discharge chip 3. The viscosity of the ink varies with its temperature. Therefore, the viscosity of the ink at the operating temperature of the liquid discharge head 1 affects the ink discharge stability.

[0106] The relationship between the ink circulation rate and the driving frequency of each of the first energy generating element 14 and the second energy generating element 24 will be described. When the circulating flow of ink is generated using the second energy generating element 24, which can be used as a circulation heater, an instantaneous ink circulation rate of tens of mm / s to 1000 mm / s can be achieved. The average flow rate over a time span on the order of hundreds of μs depends on the driving frequency of the second energy generating element 24. This is because when the circulating flow of ink is generated using the second energy generating element 24, the ink circulation flow is instantaneous, which decays over time and stops after a certain period. However, the second energy generating element 24 can be driven at a frequency of approximately 10 to 20 kHz, which is approximately equal to the driving frequency (also called the discharge frequency) of the first energy generating element 14, which can be used as a discharge heater. In this case, the average flow rate of the circulating ink can be from a few mm / s to 100 mm / s. Next, the relationship between pigment concentration and the elimination of ink concentration will be described.

[0107] (Ink with high pigment concentration)

[0108] The case of inks with high pigment concentration will be described. For example, when using ink with a concentration such that the viscosity of the ink at the operating temperature of the liquid discharge head 1 is equal to or higher than 3 cP and equal to or lower than 6 cP, ink thickening may continue near the discharge orifice 11 according to the non-discharge period of the ink (referred to as the pause period of the ink circulation flow). Therefore, the ink discharge rate may change. Therefore, the ink discharge stability may decrease. In order to reduce the decrease in ink discharge stability, it is preferable to generate an ink circulation flow after the brief pause period of the ink circulation flow to circulate the ink. Therefore, it is preferable to eliminate ink concentration by steadily circulating the ink or by generating instantaneous ink circulation at a high frequency. In this regard, instantaneous ink circulation can be generated by driving the second energy generating element 24. By driving the second energy generating element 24 at a high frequency to perform the process of pausing the ink circulation flow and restarting the ink circulation flow, it is helpful to eliminate ink concentration near the discharge orifice 11.

[0109] (Ink with low pigment concentration)

[0110] The case of inks with low pigment concentration will be described. For example, when using ink with a concentration such that the viscosity of the ink at the operating temperature of the liquid discharge head 1 is equal to or higher than 1 cP and equal to or lower than 2 cP, the thickening of the ink can continue near the discharge orifice 11 according to the non-discharge period of the ink (referred to as the pause period of the ink circulation flow). Therefore, the ink discharge rate can be changed. However, the change in the ink discharge rate is relatively small compared to inks with high concentrations. However, if the pause period of the ink circulation flow is prolonged, for example, the thickening of the ink near the discharge orifice 11 can continue according to the non-printing / driving period (referred to as the stop time). Therefore, when the liquid discharge device is restarted after the stop period when the liquid discharge device is not used for printing, it is preferable to perform a recovery process involving waste ink, such as an ink intake operation, a wiping operation, or a preliminary discharge operation including a combination thereof. However, if the second energy generating element 24 is driven to restart the ink circulation flow, this operation can be used as a recovery operation and helps to eliminate the concentration of ink near the discharge orifice 11 without waste ink. Furthermore, depending on the duration of the interruption, the recovery operation can be achieved simply by driving the second energy generating element 24 to restart the ink circulation flow without wasting ink. Alternatively, a recovery operation with minimal wasted ink can be performed by combining the restart of the ink circulation flow for recovery with a suction operation for removing air bubbles B from the liquid discharge head 1 (which is different from the suction operation for eliminating ink concentration).

[0111] (A design better suited to eliminate ink concentrating)

[0112] As described above, regardless of whether the ink has a high or low concentration, it is preferable to restore the ink to its initial fresh state as much as possible to reduce the impact of concentrated ink. When driving the second energy generation element 24 for this purpose, a higher circulation effect can be achieved due to the reduced effect of recirculation concentration. That is, a higher circulation effect can be achieved in the straight-through individual flow channel 23 compared to the U-shaped individual flow channel 23. Next, reference will be made to... Figure 8A , Figure 8B and Figure 9 The circuit configuration for driving and controlling the first energy generating element 14 and the second energy generating element 24 according to this embodiment is described.

[0113] (Discharge of component substrate α0)

[0114] Figure 7 It is shown Figures 2A to 2D A diagram showing an example circuit configuration of the discharge element substrate α0 of the liquid discharge chip 3. Figure 8A and Figure 8B It is shown Figure 7 The diagram shows an example circuit construction of the control data supply circuit α3. Figure 8AThis is a functional block diagram of the circuit structure of the control data supply circuit α3. Various signals are supplied from the main substrate β0 to the discharge element substrate α0. The main substrate β0 includes a controller β1 and a power supply circuit β2. The controller β1 mainly includes a ROM, RAM, and CPU, and supplies various electrical signals to the discharge element substrate α0 to control the liquid discharge head 1. The controller β1 supplies the discharge element substrate α0 with an enable signal HE, a latch signal LT, a data signal DATA, and a clock signal CLK. These signals will be described in detail later. The power supply circuit β2 applies a power supply voltage VH to the discharge element substrate α0. The power supply circuit β2 and the discharge element substrate α0 are connected to each other at GNDH. GNDH is used as ground potential.

[0115] (Overview of cabling)

[0116] The discharge component substrate α0 includes multiple discharge modules α1, multiple circulation modules α2, and a control data supply circuit α3. Circulation modules α2 are arranged in pairs with discharge modules α1. Therefore, the number of circulation modules α2 is equal to the number of discharge modules α1. Between the multiple discharge modules α1 and the control data supply circuit α3, there are discharge group selection signal wiring α6 and common time-division selection signal wiring α8. Between the multiple circulation modules α2 and the control data supply circuit α3, there are circulation group selection signal wiring α7, common time-division selection signal wiring α8, and latch counter signal wiring γ2.

[0117] Note that in this embodiment, the plurality of discharge modules α1 and the plurality of circulation modules α2 are further divided into blocks A and B. A first number of discharge modules α1 and a first number of circulation modules α2 are assigned to block A. A second number of discharge modules α1 and a second number of circulation modules α2 are assigned to block B. Blocks A and B are located in different placement areas. That is, the first group of discharge modules in the plurality of discharge modules α1 and the first group of circulation modules in the plurality of circulation modules α2 are assigned to block A. The first group of discharge modules includes the first number of discharge modules α1. The first group of circulation modules includes the first number of circulation modules α2. The second group of discharge modules in the plurality of discharge modules α1 and the second group of circulation modules in the plurality of circulation modules α2 are assigned to block B. The second group of discharge modules includes the second number of discharge modules α1. The second group of circulation modules includes the second number of circulation modules α2. Therefore, the first group of discharge modules and the first group of circulation modules are arranged in the same placement area (block A). The second group of discharge modules and the second group of circulation modules are arranged in the same placement area (block B). Therefore, the first set of discharge modules and the second set of discharge modules are arranged in different placement areas. The first set of circulation modules and the second set of circulation modules are also arranged in different placement areas.

[0118] As a circuit for selecting either block A or block B, latch counter signal wiring γ2 includes decoder circuit δ1. As described later, decoder signal wiring δ2 and decoder signal wiring δ3 are provided on the output side of decoder circuit δ1. Decoder signal wiring δ2 is connected to loop module α2 in block A. Decoder signal wiring δ3 is connected to loop module α2 in block B.

[0119] (Discharge module α1)

[0120] The discharge module α1 includes a discharge heater RhA, a discharge drive element MD1, and a discharge logic circuit AND1. The discharge heater RhA is formed, for example, by an electrothermal conversion element. The discharge heater RhA is in a state where a power supply voltage VH is applied to it, and current flows through the discharge heater RhA when the discharge drive element MD1 is turned on. The discharge drive element MD1 is formed, for example, by a metal-oxide-semiconductor field-effect transistor (MOSFET). Note that the discharge drive element MD1 does not necessarily need to be formed by a MOSFET. For example, the discharge drive element MD1 can be formed by a bipolar transistor. Alternatively, the discharge drive element MD1 can be formed by an insulated-gate bipolar transistor (IGBT). The discharge logic circuit AND1 selectively drives the discharge drive element MD1. An enable signal HE, a discharge group selection signal, and a common time-division selection signal are input to the input side of the discharge logic circuit AND1. The enable signal HE is transmitted from the controller β1. The enable signal HE controls the current pulse width of the discharge drive element MD1, that is, the period during which the drain and source of the discharge drive element MD1 are connected and current flows between the drain and source of the discharge drive element MD1. The enable signal HE is used to adjust the current pulse width so that the desired amount of heat energy can be generated by taking into account various manufacturing variations. These various manufacturing variations include, for example, 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. These various manufacturing variations also include the voltage drop on the power supply side wiring when multiple heaters (such as the discharge heater RhA and the circulation heater RhB) are driven simultaneously. Note that the heaters driven simultaneously here are the discharge heater RhA and the circulation heater RhB, which is not arranged in pair with the discharge heater RhA. The enable signal HE can be transmitted from the controller β1 through an external input terminal (not shown) provided on the discharge element substrate α0. The discharge group selection signal is supplied on the discharge group selection signal wiring α6. The common time division selection signal is supplied on the common time division selection signal wiring α8. The output of the discharge logic circuit AND1 is connected to the gate of the discharge drive element MD1. Therefore, when all signals input to the input of the discharge logic circuit AND1 are 1, a voltage is applied to the gate of the discharge drive element MD1, and the drain and source of the discharge drive element MD1 are turned on. When the drain and source of the discharge drive element MD1 are turned on, current flows through the discharge heater RhA, causing the discharge heater RhA to heat up. Through this series of operations, the ink can be foamed and discharged onto the discharged medium P. Although an example of the discharge heater RhA being formed by an electrothermal conversion element has been described, this is not intended to be limiting. For example, the discharge heater RhA can be formed by a piezoelectric element.

[0121] (Loop module α2)

[0122] The loop module α2 includes a loop heater RhB, a loop drive element MD2, and a loop logic circuit AND2. The loop heater RhB is formed, for example, by an electrothermal conversion element. The loop heater RhB is in a state where a power supply voltage VH is applied to it, and current flows through the loop heater RhB when the loop drive element MD2 is turned on. The loop drive element MD2 is formed, for example, by a metal-oxide-semiconductor field-effect transistor (MOSFET). Note that the loop drive element MD2 does not necessarily need to be formed by a MOSFET. For example, the loop drive element MD2 can be formed by a bipolar transistor. Alternatively, the loop drive element MD2 can be formed by an insulated-gate bipolar transistor (IGBT). The loop logic circuit AND2 selectively drives the loop drive element MD2. An enable signal HE, a loop group selection signal, and a latch counter signal are input to the input side of the loop logic circuit AND2. The latch counter signal is obtained by counting the edges of the latch signal LT. The process of using the latch counter signal will be described in detail later. The enable signal HE is transmitted from the controller β1. The enable signal HE controls the current pulse width of the cyclic drive element MD2, that is, the period during which the drain and source of the cyclic drive element MD2 are turned on and current flows between the drain and source of the cyclic drive element MD2. The enable signal HE is used to adjust the current pulse width so that the desired amount of heat energy is generated by taking into account various manufacturing variations. For example, these various manufacturing variations include, for example, manufacturing variations in the resistance value of the cyclic heater RhB mounted on the discharge element substrate α0 and manufacturing variations in the power supply circuit β2. These various manufacturing variations also include the voltage drop on the power supply side wiring when multiple heaters (such as the cyclic heater RhB and the discharge heater RhA) are driven simultaneously. Note that 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 on the cyclic group selection signal line α7. The latch counter signal is supplied on the latch counter signal line γ2. The output side of the cyclic logic circuit AND2 is connected to the gate of the cyclic drive element MD2. Therefore, when all signals input to the input side of the loop logic circuit AND2 are 1, a voltage is applied to the gate of the loop drive element MD2, and the drain and source of the loop drive element MD2 are turned on. When the drain and source of the loop drive element MD2 are turned on, current flows through the loop heater RhB, causing the loop heater RhB to heat up. Through this series of operations, bubbles in the ink can grow and generate a circulating flow in the ink circulation channel. Although an example of the loop heater RhB being formed by an electrothermal conversion element has been described, this is not intended to be limiting. For example, the loop heater RhB can be formed by a piezoelectric element.

[0123] Note that regarding the aforementioned enable signal HE, to reduce the number of signal terminals, a single enable signal HE is shared between discharge and circulation. Therefore, it is impossible to separately control the current pulse width for discharge and circulation. Thus, based on the assumption that the discharge heater RhA and the circulation heater RhB are manufactured in the same semiconductor step of the semiconductor manufacturing process and ultimately have the same manufacturing variations (identical deviations from ideal resistance values), the current pulse width can be adjusted using a single enable signal HE. Alternatively, based on the assumption that the discharge heater RhA and the circulation heater RhB are made of the same material and ultimately have the same manufacturing variations (identical deviations from ideal resistance values), the current pulse width can be adjusted using a single enable signal HE.

[0124] Furthermore, the decoder signal is input to the input side of the loop logic circuit AND2 in block A via decoder signal wiring δ2. When all signals input to the input side of the loop logic circuit AND2 are 1, a voltage is applied to the gate of the loop drive element MD2. Therefore, the decoder signal input via decoder signal wiring δ2 is the signal that triggers the selection of the loop module α2 in block A.

[0125] Furthermore, the decoder signal is input to the input side of the loop logic circuit AND2 in block B via decoder signal wiring δ3. When all signals input to the input side of the loop logic circuit AND2 are 1, a voltage is applied to the gate of the loop drive element MD2. Therefore, the decoder signal input via decoder signal wiring δ3 is the signal that triggers the selection of the loop module α2 in block B.

[0126] Note that when only one of block A and block B exists, decoder signal wiring δ2, decoder signal wiring δ3, and decoder circuit δ1 are unnecessary. Alternatively, when multiple output modules α1 and multiple loop modules α2 are not divided into block A and block B, decoder signal wiring δ2, decoder signal wiring δ3, and decoder circuit δ1 are unnecessary.

[0127] (Control data supply circuit α3)

[0128] The control data supply circuit α3 includes shift registers α20a and α20b, latch circuits α21a and α21b, decoder circuit α22, and loop group control circuit α12. The control data supply circuit α3 also has external input terminals. Clock signal CLK, data signal DATA, and latch signal LT are supplied from controller β1 to the control data supply circuit α3 via the external input terminals. Clock signal CLK is used for serial data transmission of data signal DATA to shift registers α20a and α20b. Data signal DATA includes selection information regarding output module α1 and selection information regarding loop module α2. Latch signal LT acquires and holds information stored in each of shift registers α20a and α20b in each latch cycle. Decoder circuit α22 and loop group control circuit α12 will be described in detail later.

[0129] (Drive and control of the discharge heater RhA)

[0130] The driving and control of the discharge heaters RhA in the discharge heater array α9 will be described. The discharge heater array α9 is formed by m groups. Each group includes n discharge heaters RhA. The discharge heaters RhA are deployed directly below the ink discharge orifices. When a group is selected, the n discharge heaters RhA in that group are activated sequentially in a time-division manner. The driving and control of n (=16)×m (=40 groups) discharge heaters RhA arranged at a density of 600 dpi will be described.

[0131] (Time-division control within a group)

[0132] Each discharge module α1 includes a discharge heater RhA. A group includes n discharge heaters RhA. Therefore, a group includes n discharge modules α1. Assuming n = 16, the 16 discharge modules α1 are driven in a time-division manner by a time-division selection signal. Time-division driving is the control that divides a discharge cycle into n (= 16) time units and sequentially selects one of the discharge modules α1 in each time unit. Here, multiple discharge modules α1 are not selected simultaneously in the same group. Each discharge module α1 included in the same group can be selected once in a discharge cycle. In this time-division driving, only one line in the shared time-division selection signal wiring α8 is selected. Therefore, by including a decoder circuit α22 in the control data supply circuit α3, the amount of data serially transmitted from the main board β0 can be further reduced.

[0133] (Decoder circuit α22: Time-division control)

[0134] The decoder circuit α22 is a circuit that expands the number of bits of the output data from the number of bits q of the input data to 2 to the power of q. Specifically, when 4 bits of input data are input to the decoder circuit α22, the decoder circuit α22 converts the 4 bits of input data into 16 bits (16 is 2 to the power of 4) of output data. In this process, the output data of the decoder circuit α22 is output as information, where only 1 bit of the 16 bits is valid. This allows for time-division driving. Here, from the perspective of input data utilization, unless the common time-division selection signal wiring α8 is used for a special purpose, all wires of the common time-division selection signal wiring α8 used for the output of the decoder circuit α22 are preferably used as the transmission medium for the common time-division selection signal. Note, for example, that the 4 bits of input data can be derived from the bit configuration of the latch counter signal described later. The bit configuration is a 4-bit configuration, as shown in Table 1 below. Furthermore, as the amount of data transmitted serially increases, a higher serial transmission rate is required, thus increasing the cost and size of the signal transmission circuit, the signal receiving circuit, and the transmission lines of the main substrate β0 and the exhaust element substrate α0. Therefore, it is preferable to minimize the amount of data.

[0135] (Selective control of groups)

[0136] To selectively drive any one of the m groups, an m-bit discharge group selection signal is output from the control data supply circuit α3. When one of the m groups is selected, n discharge modules α1 included in that group can be selected simultaneously. The same m-bit information as the number of groups is serially transmitted from the main substrate β0. As described above, the enable signal HE, the discharge group selection signal, and the common time division selection signal are input to the discharge logic circuit AND1 of the discharge module α1, thereby selectively controlling the discharge module α1 so that current flows through the discharge heater RhA at the corresponding position. Although an example assuming n = 16 and m = 40 is described in this embodiment, this is not intended to be limiting. For example, n = 8 and m = 80 are also possible. Alternatively, for example, nozzle lengths n = 32 and m = 40, different from this embodiment, are also possible. However, since n is the number of time divisions, in order to use the output signal of the decoder circuit α22 as the selection signal, n is preferably a value expressed as a power of 2 (n = 2, 4, 8, 16, 32...).

[0137] (Drive and control of loop module α2)

[0138] The driving and control of the circulating heaters RhB in the circulating heater array α10 will be described. Similar to the exhaust heater array α9, the circulating heater array α10 consists of m groups. Also similar to the exhaust heater array α9, each group includes n circulating heaters RhB. The circulating heaters RhB are paired with and deployed close to the exhaust heaters RhA. When a group is selected, the n circulating heaters RhB in that group are activated sequentially in a time-division manner. The driving and control of n (=16)×m (=40 groups) circulating heaters RhB will be described.

[0139] (Time-division control within a group)

[0140] As described above, each circulation module α2 includes a circulation heater RhB. A group includes n circulation heaters RhB. Therefore, a group includes n circulation modules α2. Since n = 16 is assumed, the 16 circulation modules α2 are driven in a time-division manner by a time-division selection signal. In this embodiment, the number of time divisions used for circulation modules α2 is the same as the number of time divisions used for discharge modules α1 (n = 16).

[0141] (Selective control of groups)

[0142] To selectively drive any one of the m groups, an m-bit cyclic group selection signal is output from the control data supply circuit α3. When one of the m groups is selected, n cyclic modules α2 included in that group can be selected simultaneously. The same m bits of information as the number of groups are serially transmitted from the main board β0. As described above, the enable signal HE, the cyclic group selection signal, and the common time-division selection signal are input to the cyclic logic circuit AND2 of the cyclic module α2, thereby selectively controlling the cyclic module α2 so that current flows through the cyclic heater RhB at the corresponding location. However, the cyclic group selection signal is transmitted 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.

[0143] (Cyclic group control circuit α12)

[0144] The cyclic group control circuit α12 generates a cyclic group selection signal based on the selection information of the exit group selection signal. Figure 8BThis diagram illustrates the circuit configuration of the loop group control circuit α12. The loop group control circuit α12 includes a NOT circuit. The signal obtained by logically inverting the discharge group selection signal from the discharge group selection signal wiring α6 via the NOT circuit is processed as follows: That is, the result is output as the loop group selection signal to the loop group selection signal wiring α7. Therefore, when discharge module α1 is selected, loop module α2 is not selected. On the other hand, when discharge module α1 is not selected, loop module α2 is selected. That is, in a pair of discharge module α1 and loop module α2, one module is exclusively selected, or in other words, exclusively controlled. Note that in time-division control, when this pair is not selected, neither discharge module α1 nor loop module α2 is selected.

[0145] (Latch counter circuit γ1)

[0146] After receiving A edges as a predetermined number of edges (which is a pre-designed value obtained by counting the edges of the latch signal LT), the latch counter circuit γ1 outputs the latch counter signal while receiving a predetermined number B of subsequent edges. Figure 9 This is a timing diagram illustrating the relationship between the latch signals, latch counter signals, and decoder signals of the latch counter circuit γ1 and the decoder circuit δ1. (Example:) Figure 9 As shown, the latch signal LT continues to be counted over time, and after A input edges, the latch counter signal is high until B input edges representing a specific number of edges. Simultaneously, the decoder circuit δ1 outputs the decoder signal via decoder signal wiring δ2. In this way, the loop module α2 in block A can be selected. Note that in Figure 9 For convenience, this decoder signal is shown as decoder signal δ2. Furthermore, as... Figure 9 As shown, after B input edges, the latch signal LT continues to be counted over time, and after C input edges (the previously set set number of edges), the latch counter signal is high until D input edges. Simultaneously, the decoder circuit δ1 outputs the decoder signal via decoder signal wiring δ3. In this way, the loop module α2 in block B can be selected. Note that in Figure 9 For convenience, this decoder signal is shown as decoder signal δ3.

[0147] The latch counter circuit γ1 is formed, for example, by a flip-flop circuit. The desired number of flip-flop circuits can be provided for the number of latches to be counted. For example, when the number of latches to be counted is 1000, since 2 to the power of 10 is 1024, at least 10 levels of flip-flop circuits can be used.

[0148] Note that in Figure 9 In the example, edge count A is set to 100,000 and edge count B is set to 100. Edge counts A and B vary depending on the characteristics of the ink used or the shape of the flow channel. On the other hand, edge count C is set to satisfy the relationship: C - (A + B) = 100,000 and edge count D is set to 100. Edge counts C and D vary depending on the characteristics of the ink used or the shape of the flow channel. Whenever the count value reaches the previously set edge count, the decoder circuit δ1 selects either the first group of loop modules or the second group of loop modules. Furthermore, after the count value reaches the set edge count, the decoder circuit δ1 maintains the selected one of the first group of loop modules or the second group of loop modules until a specific edge count is reached.

[0149] The number of edges varies with the heat generated by the circulating heater RhB. For example, to prevent the flow rate of the circulating ink from becoming unstable, it is preferable to maximize the number of edges A and preferably minimize the number of edges B. Similarly, it is preferable to maximize the value of C-(A+B) with respect to the number of edges C and preferably minimize the number of edges D.

[0150] Although Figure 9 In the example, the latch counter signal rises on the rising edge of the latch signal LT, but this is not intended to limit it. For example, the latch counter signal could rise on the falling edge of the latch signal LT.

[0151] The process described below is also possible when only one of block A and block B exists, or when multiple discharge modules α1 and multiple circulation modules α2 are not divided into block A and block B.

[0152] That is, the number of edges A is counted using a cumulative count value, and the cumulative count value is initialized each time the number of edges A is exceeded. On the other hand, the number of edges B is counted using a differential count value starting from the cumulative count value, and the differential count value is initialized each time the number of edges B is exceeded. In addition, the latch counter signal is used for selective control of the circulating heater RhB. Specifically, the common 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. When all input signals are 1, that is, when the logic of all input signals is in a high-level state, current flows through the circulating heater RhB at the corresponding position.

[0153] Next, based on the assumption that multiple discharge modules α1 and multiple loop modules α2 are divided into blocks A and B, the correlation between latch signals, decoder signals, and the driving of the loop heater will be described with reference to Table 1. Table 1 shows an example using a four-stage latch counter. That is, the bit configuration of the count value indicating the latch counter output is a 4-bit configuration. Counts 4 to 7 from the latch counter circuit indicate that the loop heater RhB in block A should be driven. Counts 12 to 15 from the latch counter circuit indicate that the loop heater RhB in block B should be driven. In this example, the first and second bits of the latch counter output data determine the decoder output indicating the driving of the loop heater RhB. Specifically, when <first bit, second bit> is <0, 1>, the loop heater RhB in block A is driven. When <first bit, second bit> is <1, 1>, the loop heater RhB in block B is driven. When <first bit, second bit> is any combination other than the above, the loop heater RhB is not driven. The example shown in Table 1 illustrates such a decoder output.

[0154]

[0155]

[0156]

[0157] In this embodiment, a common power supply voltage VH (e.g., 24V) is connected as the power supply voltage for both the discharge module α1 and the circulation module α2, and a common GNDH is connected as ground potential. However, to reduce the variation in discharge energy caused by the voltage drop that occurs when the discharge heater RhA and the circulation heater RhB are driven, the following process is possible. That is, separate supply wiring and external connection terminals for the power supply voltage and ground potential can be provided for the discharge module α1 and the circulation module α2 in the discharge element substrate α0. Specifically, the unit voltage can be supplied to the discharge module α1 and the circulation module α2 separately from the power supply circuit β2 mounted in the main substrate β0.

[0158] Generally, driving elements are operated at voltages higher than those of logic circuits; therefore, a substrate comprising both high-voltage and ordinary driving elements is used. In this embodiment, the discharge driving element MD1 and the loop driving element MD2 can be formed from DMOS transistors (double-diffused MOSFETs) that are high-voltage MOS transistors. The discharge logic circuit AND1, the loop logic circuit AND2, the loop group control circuit α12, and other logic circuits (including shift registers α20a and α20b, latch circuits α21a and α21b, and decoder circuit α22) can be formed from low-voltage MOS transistors.

[0159] (Circuit area occupied)

[0160] Next, the differences due to circuit arrangement will be described. The drive current for the circulation heater RhB generates heat energy to circulate the ink in the individual flow channels. When the drive current for the circulation heater RhB is less than the drive current for the discharge heater RhA to discharge the ink onto the discharged medium, the current drive capability of the DMOS transistor can be low. Therefore, the area occupied by the discharge drive element MD1 does not need to be greater than the area occupied by the circulation drive element MD2, and thus the area occupied by the circulation drive element MD2 is preferably smaller than the area occupied by the discharge drive element MD1.

[0161] (First example of circuit layout)

[0162] Figure 10 This is a plan view of the component substrate α30. Figure 10 In this configuration, two control data supply circuits α3 are arranged in the X direction at the left and right ends of the discharge element substrate α30. The selectively driven mechanism is arranged in two systems, each system including the control data supply circuit α3, the discharge heater array α9, the circulating heater array α10, and the mechanism arranged between them. Figure 10 In this configuration, three ink supply port arrays α14 extending in the transport direction Y are arranged at intervals in the X direction. Between adjacent ink supply port arrays α14, a discharge heater array α9 and a circulation heater array α10 are arranged along the transport direction Y. In each of the regions to the left of the left ink supply port array α14 and to the right of the right ink supply port array α14, the following components are arranged: a discharge drive element MD1, a circulation drive element MD2, a discharge logic circuit AND1, a circulation logic circuit AND2, a discharge group selection signal wiring α6, a circulation group selection signal wiring α7, and a common 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 decoder signals to each component via decoder signal wiring δ2, decoder signal wiring δ3, decoder signal wiring δ4, or decoder signal wiring δ5.

[0163] Multiple external connection terminals are arranged along direction X at both ends of the discharge element substrate α30 in the transport direction Y. An external connection terminal array is formed by arranging these multiple external connection terminals. The external connection terminal array is arranged orthogonally to the discharge heater array α9 and the circulation heater array α10. Compared to the discharge element substrate α0, the control data supply circuit α3 in the discharge element substrate α30 is arranged in direction X. Therefore, although the discharge element substrate α30 has a larger substrate dimension in direction X compared to the discharge element substrate α0, its substrate dimension in the transport direction Y can be reduced.

[0164] Note that it is also in Figure 10 In the arrangement, decoder circuit δ1 is unnecessary when only one of block A and block B exists. Alternatively, decoder circuit δ1 is also unnecessary when multiple output modules α1 and multiple loop modules α2 are not divided into block A and block B.

[0165] (Second example of circuit layout)

[0166] Figure 11 This is a plan view of the component substrate α31. Figure 11 The discharge element substrate α31 has an external connection terminal on its left side in the X direction. Figure 10 Compared to the discharge element substrate α30 in the previous configuration, the substrate dimension in the transport direction Y can be reduced. Although not shown, it is assumed that the discharge element substrate α31 has a wiring arrangement of one unit. Based on this assumption, when multiple discharge element substrates α31 are arranged in the extension direction of the ink supply port array α14, the spacing between the discharge element substrates α31 can be reduced, wherein no external connection terminals are provided on the extension line of the ink supply port array α14. That is, when the liquid discharge head 1 includes multiple discharge head element substrates α31 arranged in the extension direction of the nozzle array, each discharge element substrate α31 has external connection terminals not provided on the extension line of the nozzle array, and the size of the liquid discharge head 1 can be reduced. Note that in Figure 11 In the middle, the external connection terminal array is arranged in parallel with the discharge head heater array α9 and the circulation heater array α10.

[0167] (Third example of circuit layout)

[0168] Figure 12 This is a plan view of the component substrate α32. Figure 12 In this arrangement, units including a control data supply circuit α3, an ink supply port array α14, an exhaust heater array α9, a circulation heater array α10, and an ink supply port array α14 are arranged side-by-side in the X direction. In this arrangement, assuming different types of ink are supplied to different ink supply port arrays α14 on the exhaust element substrate α32, the ink supply port array α14 of each unit is spaced apart from the ink supply port array α14 of another unit. This arrangement prevents the mixing of different types of ink during exhaust. Note that in... Figure 12 In the middle, the external connection terminal array is arranged in parallel with the discharge heater array α9 and the circulating heater array α10.

[0169] <Other Embodiments>

[0170] While various examples and embodiments 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 above embodiments and various modifications can be made. Furthermore, portions of the embodiments described above can be appropriately combined.

[0171] (Change 1)

[0172] For example, while this embodiment has been described with reference to an example in which the discharge drive element MD1 and the cycle drive element MD2 are formed by DMOS transistors, this is not intended to be limiting. For example, at least one of the discharge drive element MD1 and the cycle drive element MD2 may be formed by a silicon carbide (SiC) MOSFET.

[0173] Other embodiments

[0174] The embodiments of this disclosure can also be implemented by a computer that reads and executes computer-executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more fully referred to as a "non-transitory computer-readable storage medium") to perform the functions of one or more embodiments described above and / or includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing the functions of one or more embodiments described above, and by a method performed by a computer of the system or device, for example, reading and executing computer-executable instructions from a storage medium to perform the functions of one or more embodiments described above and / or controlling one or more circuits to perform the functions of one or more embodiments described above. The computer may include one or more processors (e.g., a central processing unit (CPU), a microprocessor unit (MPU), etc.) and may include a network of individual computers or individual processors to read and execute the computer-executable instructions. The computer-executable instructions may be provided to the computer, for example, from a network or a storage medium. The storage medium may include, for example, a hard disk, random access memory (RAM), read-only memory (ROM), storage devices for distributed computing systems, optical discs (such as CDs, DVDs, or Blu-ray discs). TM One or more of the following: flash memory devices, memory cards, etc.

[0175] Other embodiments

[0176] Embodiments of the present invention can also be implemented by providing software (including computer program products of computer programs) that performs the functions of the above embodiments to a system or device via a network or various storage media, and the computer (central processing unit (CPU) or microprocessor unit (MPU) of the system or device) reads and executes the computer program.

[0177] According to this disclosure, in a discharge element substrate including a discharge drive element and a cycle drive element, the cycle drive element can be driven with an optimal number of drives, while reducing the amount of data transmitted and avoiding concentrated power consumption of some cycle drive elements.

[0178] While this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A liquid discharge head, comprising: Multiple discharge modules, each having a discharge drive element and a discharge heater electrically connected to the discharge drive element; Multiple circulation modules, each having a circulation drive element and a circulation heater electrically connected to the circulation drive element, are arranged in pairs with discharge modules, and the number of circulation modules is the same as the number of discharge modules; A latching circuit is used to latch a data signal, the data signal including selection information for selecting each of the plurality of discharge modules and the plurality of circulation modules; as well as A control unit is used to selectively control a first group of loop modules or a second group of loop modules among the plurality of loop modules based on the count value of the edge of the latch signal, wherein the latch signal generates a latch timing that causes the latch circuit to latch the data signal, and the second group of loop modules is arranged in a different placement area than the first group of loop modules.

2. The liquid discharge head according to claim 1, wherein the control unit comprises: A latch counter circuit is used to count the number of edges of a latch signal and to set that number of edges as the count value. as well as The decoder circuit is used to select either the first or second loop module whenever the count value reaches a preset number of edges.

3. The liquid discharge head according to claim 2, wherein after the count value reaches a preset number of edges, the decoder circuit maintains one of the first group of loop modules and the second group of loop modules until a specific number of edges has been counted.

4. The liquid discharge head according to claim 3, wherein the preset number of edges is greater than the specific number of edges.

5. The liquid discharge head according to claim 1, wherein the first group of discharge modules and the first group of circulation modules 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 among the plurality of discharge modules are arranged in the second block, and The liquid discharge head also includes a control data supply circuit that selectively controls each discharge module and each circulation module included in the first block, or each discharge module and each circulation module included in the second block, based on a common time-division selection signal derived from the bit configuration of the count value.

6. The liquid discharge head according to claim 5, wherein the control data supply circuit exclusively controls the discharge module or the circulation module based on the selection information and the shared time-division selection signal.

7. The liquid discharge head according to claim 1, further comprising: The drain port is used to drain the liquid that has been filled into the pressure chamber by the drain heater. The discharge port is provided at the location corresponding to the discharge heater, and the discharge port is not provided at the location corresponding to the circulation heater.

8. The liquid discharge head according to claim 7, wherein the circulating heater and the discharge heater are paired and arranged in an individual flow channel including a pressure chamber.

9. The liquid discharge head according to claim 1, further comprising: An external connection terminal array, wherein multiple external connection terminals for inputting data signals are arranged in the external connection terminal array. The external connection terminal array is orthogonally arranged with the discharge heater array in which the discharge heater is arranged and the circulation heater array in which the circulation heater is arranged.

10. The liquid discharge head according to claim 1, further comprising: An external connection terminal array, wherein multiple external connection terminals for inputting data signals are arranged in the external connection terminal array. The external connection terminal array is arranged in parallel with the discharge heater array in which the discharge heater is arranged and the circulation heater array in which the circulation heater is arranged.

11. The liquid discharge head according to claim 9 or 10, wherein the discharge drive element is arranged along the discharge heater, and The circulating drive element is arranged along the circulating heater.

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

13. The liquid discharge head according to claim 1, wherein the discharge heater and the circulation heater are generated in 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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