Recording element substrate

Abstract

A recording element substrate is disclosed. A recording element substrate includes: an array of resistive heating element regions, a first row of resistive heating elements in parallel with a second row of resistive heating elements; a first row of drive elements in parallel with a second row of drive elements positioned in parallel with the resistive heating element regions; a first wiring layer connecting one of the first and second rows of drive elements further from the resistive heating element regions with one of the first and second rows of resistive heating elements closer to the drive element regions; and a second wiring layer connecting one of the first and second rows of drive elements closer to the resistive heating element regions with one of the first and second rows of resistive heating elements further from the drive element regions.

Description

Technical Field

[0001] This disclosure relates to a technique for arranging driving elements on a recording element substrate. Background Technology

[0002] Conventionally, circulating liquid ejection devices that circulate ink in a liquid ejection head are known. Japanese Patent Publication No. 2020-104493 (hereinafter referred to as Document 1) discloses a configuration in which an ejection energy generating element for ejecting ink and a circulation energy generating element for circulating the ink are provided. Furthermore, a drive element is used to drive each of the ejection energy generating element and the circulation energy generating element.

[0003] Document 1 discloses a configuration in which rows of jet energy generating elements and rows of circulating energy generating elements are arranged in parallel. Therefore, although a driving element is provided on the recording element substrate for each of the jet energy generating elements and the circulating energy generating elements, there are cases where the driving elements cannot be properly arranged on the recording element substrate. Summary of the Invention

[0004] According to one aspect of this disclosure, a recording element substrate includes: a resistance heating element region comprising a first row of resistance heating elements and a second row of resistance heating elements, the first row of resistance heating elements comprising a plurality of first resistance heating elements arranged in a row, and the second row of resistance heating elements comprising a plurality of second resistance heating elements arranged in a row, the second row of resistance heating elements being parallel to the first row of resistance heating elements; and a driving element region comprising a first row of driving elements and a second row of driving elements, the first row of driving elements comprising a plurality of first driving elements for driving the plurality of first resistance heating elements, the plurality of first driving elements being arranged in a row, and the second row of driving elements comprising a plurality of second driving elements arranged in a row. The second drive element row is parallel to the first drive element row, and the drive element region is positioned parallel to the resistance heating element region; a first wiring layer connects the first drive element row and the second drive element row that are farther from the resistance heating element region to the first drive element row and the second drive element row that are closer to the drive element region; and a second wiring layer connects the first drive element row and the second drive element row that are closer to the resistance heating element region to the first drive element row and the second drive element row that are farther from the drive element region, wherein the first wiring layer is formed in a layer different from the second wiring layer.

[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 embodiments is by way of example. Attached Figure Description

[0006] Figure 1A This is a perspective view schematically showing an ink tank, which serves as a reservoir, located outside the liquid jet head; Figure 1B This is a perspective view schematically showing a liquid jetting device with an ink sub-tank positioned directly above the liquid jetting head; Figure 2A This is an exploded perspective view of the liquid injection head 1 in Figure 1; Figure 2B This is a diagram illustrating the case where four colors can be sprayed using a single liquid spraying chip; Figure 2C This is a diagram illustrating the case where two colors can be sprayed using a single liquid spraying chip; Figure 2D This is a diagram illustrating the case where a single liquid jet chip can spray only one type of color. Figure 3A This is a plan view of a single jet unit as seen from the direction in which the droplet is ejected from the nozzle; Figure 3B It is along Figure 3A A cross-sectional view taken from section IIIB-IIIB; Figure 3C It is along Figure 3A The cross-sectional view taken from IIIB-IIIB shows the arrangement of components on the substrate. Figure 3B The configurations are different; Figure 3D This is a diagram illustrating the inflow of ink when the first jet heater or the second jet heater is activated; Figure 4A It is truncated along IIIB-IIIB. Figure 3A A cross-sectional view of a separate jetting unit, used to illustrate the generation and growth process of bubbles generated by the film boiling of the ink when the ink is heated by the second jetting heater; Figure 4B It is truncated along IIIB-IIIB. Figure 3A A cross-sectional view of a separate jetting unit, used to illustrate the contraction process of bubbles generated by film boiling of the ink when the ink is heated by the second jetting heater; Figure 4C It is truncated along IIIB-IIIB. Figure 3A A cross-sectional view of a separate jetting unit is used to illustrate the defoaming process of bubbles generated by film boiling of the ink when the ink is heated by the second jetting heater. Figure 5A It is a diagram showing a state where the flow of circulating ink has temporarily stopped; Figure 5B It shows that immediately following Figure 5A The diagram shows the state after the second jet heater is driven to generate a circulating ink flow following the initial state. Figure 5C It is shown in Figure 5B A diagram illustrating the state after which the circulating ink flow temporarily stops; Figure 5D It shows that immediately following Figure 5C The diagram shows the state after the second jet heater is driven to generate a circulating ink flow following the initial state. Figure 6A It is a diagram showing a state where the flow of circulating ink has temporarily stopped; Figure 6B It shows that immediately following Figure 6A The diagram shows the state after the second jet heater is driven to generate a circulating ink flow following the initial state. Figure 6C It is shown in Figure 6B A diagram illustrating the state after which the circulating ink flow temporarily stops; Figure 6D It shows that immediately following Figure 6C The diagram shows the state after the second jet heater is driven to generate a circulating ink flow following the initial state. Figure 7A This is a plan view seen from the direction in which the droplets are ejected from the nozzle; Figure 7B It is along Figure 7A The cross-sectional view taken from VIIB-VIIB in the diagram; Figure 7C yes Figure 7A An enlarged schematic diagram of a single flow channel in the process; Figure 8A This is a plan view seen from the direction in which the droplets are ejected from the nozzle; Figure 8B It is along Figure 8A The cross-sectional view taken from VIIIB-VIIIB in the diagram; Figure 8C It is along Figure 8A The cross-sectional view taken from VIIIB-VIIIB shows the arrangement of components on the substrate 18. Figure 8B The configurations are different; Figure 9A This is a plan view seen from the direction in which the droplets are ejected from the nozzle; Figure 9B It is along Figure 9A A cross-sectional view taken from IXB-IXB in the diagram; Figure 9C It is along Figure 9A The cross-sectional view taken from IXB-IXB shows the arrangement of components on the substrate. Figure 9B The configurations are different; Figure 10 This is a diagram illustrating an example of the circuit configuration of a recording element substrate according to this embodiment; Figure 11A It is a functional block diagram of the circuit configuration for controlling the data supply circuit; Figure 11B It is shown Figure 11A A diagram illustrating an example of the circuit configuration of the second injection group selection circuit; Figure 12 This is a diagram illustrating an example of the arrangement of the heater and drive element according to the first case of this embodiment; Figure 13 yes Figure 12 A partial enlarged view of an example of the arrangement of the heater and drive element in the first case; Figure 14 It shows along Figure 13 A diagram showing the cross-sectional structure intercepted by the XIIIB-XIIIB line; Figure 15 This is a diagram showing a comparative example of the arrangement of the heater and drive element; Figure 16 This is an example of the arrangement of the heater and drive element according to the second case of this embodiment; Figure 17A This is a plan view seen from the direction in which the droplets are ejected from the nozzle; and Figure 17B It is along Figure 17A A cross-sectional view taken from the XVIIB-XBIIB line. Detailed Implementation

[0007] Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the present disclosure, and not all combinations of features described in the following embodiments are required for the solutions of the present disclosure. Note that the same constituent elements will be given the same reference numerals.

[0008] (Overview) Conventionally, inkjet recorders, for example, are known as liquid ejection heads that eject ink (also called liquids). An inkjet recorder head includes an ejection nozzle for ejecting ink. Volatile components in the ink may evaporate from this nozzle. Therefore, the evaporation of volatile components in the ink may thicken the ink in the nozzle. This thickening of the ink changes the ink ejection rate. If the ink ejection rate changes, it is also assumed that the ink landing accuracy will not be as expected. In other words, a decrease in ink landing accuracy may lead to ejection failure. In particular, when the pause time in inkjet operation is long, the increase in ink viscosity may be significant. If the increase in ink viscosity is significant, it is also assumed that solids in the ink adhere to the interior of the nozzle. Under this assumption, the flow resistance of the ink increases. Therefore, inkjet failure may be more likely to occur.

[0009] One known countermeasure to the liquid thickening phenomenon described above is to direct fresh liquid towards the ejection nozzle. To facilitate liquid flow, methods exist that, for example, use a pump or similar device located on the main body side in addition to the ejection components. Using this pump, a pressure difference can be generated in the liquid within the inkjet head. This pressure difference allows the liquid to circulate. Alternatively, methods exist that incorporate a circulation element within the ejection components themselves. If a resistance heating element is used as the circulation element, it can cause the liquid to bubble. This bubbling can also circulate the liquid.

[0010] Incidentally, a technique is disclosed that uses an ejector heater for ink ejection operation and a circulation heater for ink circulation operation to allow desired liquid to be ejected from the ejector after a prolonged period of no liquid ejection from the ejector. In this technique, multiple ejector heaters (also referred to as first resistance heating elements) and multiple circulation heaters (also referred to as second resistance heating elements) are each arranged in rows, and these rows are arranged in parallel.

[0011] To drive the jet heater and the circulation heater, it is assumed that a power supply, a driver (also called a drive element), and drain wiring for connecting the driver to the jet heater and the circulation heater are deployed. Considering other circuitry, the driver for the jet heater and the driver for the circulation heater can be placed on one side. In the above-described technique, multiple supply ports for supplying ink are arranged in a row. These multiple supply ports arranged in a row are for common use. Furthermore, as supply ports for supplying ink, a separate supply port can be provided for each segment unit based on the number of heaters such as the jet heater and the circulation heater. If separate supply ports are used, the driver and heater are positioned to clamp the separate supply ports. Therefore, it is sufficient to arrange the drain wiring to pass between the separate supply ports.

[0012] However, in recent years, the number of nozzles has been increasing to achieve higher resolution printing. With the increase in the number of nozzles, the amount of ink supplied also increases. It is conceivable to increase the size of the individual supply nozzles to accommodate the increased amount of ink supplied. However, the usable area on the recording element substrate is limited. Therefore, if the size of the individual supply nozzles is increased, the area between the individual supply nozzles becomes narrower. If the area between the individual supply nozzles becomes narrower, the area that the drain wiring can pass through can be reduced.

[0013] Furthermore, when a circulating heater is installed on a recording element substrate, the number of drain wires and drivers increases compared to a recording element substrate without a circulating heater. For example, assuming the same number of circulating heaters and jet heaters are deployed, the number of drain wires and drivers doubles. Under this assumption, the total number of drain wires increases. Therefore, in a layout where all drain wires, including the increased number of wires, pass through the area between independent supply ports, it may be impossible to ensure that the wire width of each drain wire meets expectations.

[0014] Furthermore, the aforementioned technology assumes that circulating heaters cannot be used. Under this assumption, all heaters mounted on the recording element substrate are jet heaters. If all heaters are jet heaters, the resistance values ​​of the drain wiring connecting the driver and the jet heaters can be made equal, thereby reducing the heat variation generated in each drain wiring. If this variation can be reduced, the jet heaters can be driven stably.

[0015] In this disclosure, the recording element substrate includes a resistance heating element region, a driving element region, a first wiring layer, and a second wiring layer. The resistance heating element region includes a first row of resistance heating elements and a second row of resistance heating elements. In the first row of resistance heating elements, a plurality of first resistance heating elements are arranged in a row. The second row of resistance heating elements is arranged parallel to the first row of resistance heating elements, and in the second row of resistance heating elements, a plurality of second resistance heating elements are arranged in a row. The driving element region is positioned parallel to the resistance heating element region. The driving element region includes a first row of driving elements and a second row of driving elements. In the first row of driving elements, a plurality of first driving elements for driving the plurality of first resistance heating elements are arranged in a row. The second row of driving elements is arranged parallel to the first row of driving elements, and in the second row of driving elements, a plurality of second driving elements are arranged in a row. The first wiring layer connects the row of driving elements farther from the resistance heating element region to the row of driving elements closer to the driving element region. The second wiring layer connects the row of first and second driving elements closer to the resistance heating element region to the row of first and second driving elements farther from the driving element region. The first wiring layer is formed in a different layer than the second wiring layer. This configuration makes it easier to uniformize the lengths of the wiring included in the first wiring layer and the wiring included in the second wiring layer. Therefore, it becomes easier to equalize the resistance values ​​of the wiring included in the first wiring layer and the wiring included in the second wiring layer. Therefore, the energy losses (hereinafter referred to as voltage drops) generated in the first and second wiring layers can be equalized. In other words, driving elements can be appropriately arranged on the recording element substrate.

[0016] Furthermore, this disclosure allows for the desired width of the drain wiring, ensuring the size of the driver and reducing the energy consumed by the drain wiring of the jet heater for efficient heater driving. In other words, the driving elements can be appropriately arranged on the recording element substrate.

[0017] Furthermore, according to this disclosure, the first wiring layer and the second wiring layer are formed in different layers. Therefore, arranging the drain wiring in two layers doubles the area through which the drain wiring can pass between independent supply ports. Additionally, the width of the drain wiring is set as intended, and the driver is arranged in two rows, thereby doubling the area where the driver can be placed. This ensures sufficient space for placing the driver. Therefore, the size of the driver can be set as intended.

[0018] The present disclosure will now be described in detail using the accompanying drawings.

[0019] <Liquid injection device 50> Figure 1AThis is a perspective view schematically showing an ink tank 2, which serves as a reservoir, mounted on the outside of the liquid jet head 1. Figure 1B This is a perspective view schematically showing a liquid jetting device 50 with an ink sub-tank 54 disposed directly above the liquid jetting head 1. First, the following will be described... Figure 1A and Figure 1B The common parts between them.

[0020] The liquid jetting device 50 includes a liquid jetting head 1 and feed rollers 55, 56, 57, and 58. The liquid jetting head 1 performs scanning in a direction X intersecting the feed direction Y of the target medium P. The liquid jetting head 1 is mounted on a carriage 60. The liquid jetting head 1 is fixedly supported by the carriage 60 using positioning components (not shown) and electrical contacts provided on the carriage 60. The carriage 60 reciprocates along a guide shaft 51 in the main scanning direction (also referred to as direction X). Therefore, the liquid jetting head 1 records the target medium P by jetting ink while moving in the main scanning direction together with the carriage 60. The feed rollers 55, 56, 57, and 58 feed the target medium P in a secondary scanning direction (also referred to as the feed direction Y) intersecting (orthogonal in this embodiment) the main scanning direction. In other words, the liquid ejection device 50 is configured as a serial inkjet liquid ejection device by ejecting liquid from the liquid ejection head 1 to the ejection target medium P being fed in the feed direction Y while the liquid ejection head 1 performs scanning in the X direction. Note that the application of this disclosure is not limited to serial inkjet liquid ejection devices. This disclosure is also applicable to page-width inkjet liquid ejection devices, which eject liquid to the ejection target medium P being fed in the feed direction Y by using a line head (page-width head) that is long in the page-width direction of the ejection target medium P. Note that in Figure 1A and Figure 1B In this context, direction Z indicates the vertical direction. In other words, direction Z is the direction that intersects (or is orthogonal to) the XY plane identified by direction X and feed direction Y.

[0021] 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 record panchromatic images using these four types of ink. Note that the ink that can be ejected from the liquid ejector head 1 is not limited to the four types mentioned above. This disclosure also applies to liquid ejector heads 1 used for ejecting other types of ink, such as special color inks. In other words, the type and quantity of ink ejected from the liquid ejector head 1 are not limited.

[0022] Next, we will describe Figure 1A and Figure 1B The different parts between them. In Figure 1AIn this assembly, an ink sub-tank 54 is mounted on the liquid jet head 1. Four ink supply pipes (liquid communication paths) 59 are attached to the ink sub-tank 54. Furthermore, the liquid jet device 50 includes an ink tank 2 and an external pump 71. The ink tank 2 stores ink. The ink stored in the ink tank 2 is supplied to the ink sub-tank 54 through the four ink supply pipes 59 by means of the driving force of the external pump 71. On the other hand, in... Figure 1B In the middle, the ink sub-tank 54 is positioned directly above the liquid jet head 1. Figure 1B and Figure 1A The difference lies in the fact that since there is no ink tank 2 outside the liquid jet head 1, the four ink supply pipes 59 are not attached, and there is no external pump 71. Note that in Figure 1A and Figure 1B In either case, the liquid ejector head 1 can be integrally disposed with the ink sub-reservoir 54 and configured to be detachable from or attachable to the carriage 60. Alternatively, the ink sub-reservoir 54 can be integral with the carriage 60, and only the ink sub-reservoir 54 can be configured to be detachable or attachable. The following will use... Figure 1A The configuration in [the document] provides a description.

[0023] <Basic Configuration of Liquid Jet Head 1> Figure 2A This is an exploded perspective view of the liquid jet head 1 in Figure 1. Figure 2B , Figure 2C and Figure 2D It is shown Figure 2A A diagram illustrating an example of the liquid ejection chip 3 is provided. The liquid ejection head 1 includes a container portion 53, an ink sub-reservoir 54, and the liquid ejection chip 3. The ink sub-reservoir 54 temporarily stores ink in the liquid ejection head 1. The ink sub-reservoir 54 is housed within the container portion 53. Although details will be described later, the liquid ejection chip 3 is disposed at the bottom of the container portion 53. The liquid ejection chip 3 ejects ink supplied from the ink sub-reservoir 54 onto the target medium P.

[0024] Note that, although not shown, the liquid connector insertion port is located on the wall of container section 53. Figure 1AThe liquid connector at the tip of the ink supply tube 59 is inserted into these liquid connector insertion ports, thereby forming a liquid-tight connection thereto. This configuration forms an ink supply path from the ink tank 2 to the liquid ejector head 1 via the external pump 71. This means that the ink in the liquid ejector head 1 can be circulated by the driving force of the external pump 71. In this embodiment, four types of ink are used. Therefore, four sets of ink tanks 2, external pumps 71, ink supply tubes 59, and ink sub-tanks 54 are provided for each ink. Thus, four ink supply channels corresponding to each ink are independently formed. Therefore, in this embodiment, the liquid ejector device 50 includes an ink supply system that supplies ink from the ink tank 2 located outside the liquid ejector head 1.

[0025] A first support member 4 and a second support member 7 are disposed between the container portion 53 and the liquid ejection chip 3. An electrical wiring member 5 is disposed below the liquid ejection chip 3. Specifically, the first support member 4 is provided with an ink supply port and an ink collection port. The second support member 7 is provided with an opening. The liquid ejection chip 3 is fixed to the first support member 4 by adhesive bonding. The first support member 4 is fixed to the second support member 7 by adhesive bonding. The second support member 7 holds the electrical wiring member 5 so that it is electrically connected to the liquid ejection chip 3. The electrical wiring member 5 applies an electrical signal to the liquid ejection chip 3 for ejecting ink or for circulating ink.

[0026] Note that in this embodiment, the liquid jetting device 50 does not include an ink collection system that collects ink from the liquid jetting head 1 into the ink tank 2. Therefore, although the liquid jetting head 1 is provided with a liquid connector insertion port for connecting a liquid connector to the ink supply tube 59, it is not provided with a connector insertion port for connecting the tube for collecting ink to the ink tank 2.

[0027] Figure 2B This illustrates a configuration where the liquid jet chip 3 consists of one chip for every four colors. In other words, Figure 2B This diagram illustrates a liquid jet chip 3 capable of jetting four colors. The liquid jet chip 3 includes multiple jet nozzles and pads for electrical mounting. The four colors are, for example, black, cyan, magenta, and yellow, and are arranged in rows according to color. The rows are formed in the feed direction Y and spaced apart in the direction X. Each row includes multiple jet nozzles. The multiple jet nozzles are evenly spaced in the Y direction. The individual jet nozzles in each row may not be spaced apart in the X direction, but can be arranged in a single row in the Y direction. Alternatively, only black can be arranged in two rows, and the other three colors can be arranged in three rows, thus the four colors can be arranged in a total of five rows. Note that... Figure 2A The liquid jet chip 3 in the image shows an example of a configuration with one chip for every four colors. In other words, Figure 2AThe liquid jet chip 3 in the middle shows Figure 2B Examples of situations in [the context].

[0028] Figure 2C The diagram shows a configuration where the liquid jet chip 3 consists of one chip for each of the two colors. In this case, two chips are used. In other words, Figure 2C This illustrates a scenario where one liquid spray chip 3 can spray two colors. When the liquid spray chip 3 is mounted on a liquid spray head 1, two liquid spray chips 3 can be mounted on one liquid spray head 1, or two liquid spray heads 1 can each be equipped with one liquid spray chip 3.

[0029] Figure 2D The diagram shows a configuration where the liquid jet chip 3 consists of one chip for each color. In this case, four chips are used. In other words, Figure 2D This illustrates a scenario where one liquid jet chip 3 can jet one color. When the liquid jet chip 3 is mounted on a liquid jet head 1, four liquid jet chips can be mounted on one liquid jet head 1, or four liquid jet heads 1 can be prepared, each with one liquid jet chip 3 mounted on it.

[0030] Note that, as Figure 2C and Figure 2D As shown, when assuming multiple liquid jet chips 3 are mounted on a single liquid jet head 1, the chip lengths of the liquid jet chips 3 can be different. Furthermore, there is no particular limitation on the number of colors of the liquid jet chips 3, and various numbers of colors can be combined. For example, although... Figure 2A An example of liquid jet chip 3 with 4 colors is shown, but the number of colors of liquid jet chip 3 can be greater than 4.

[0031] <Separate flow channel; straight type> The liquid injection head 1 includes a plurality of individual injection units, each including a separate flow channel. The liquid injection head 1 also includes a supply flow channel for supplying liquid to the separate flow channel of each individual injection unit. Figure 3A This is a plan view of a single jetting unit as seen from the direction in which droplets are ejected from jet nozzle 11. Figure 3B It is along Figure 3A The cross-sectional view taken from IIIB-IIIB in the diagram. Figure 3C It is along Figure 3A The cross-sectional view taken from IIIB-IIIB shows the arrangement of components on the substrate 18. Figure 3B The configurations are different.

[0032] Each individual injection unit includes injection ports 11A and 11B, pressure chambers 12A and 12B, a first injection heater RhA, and a second injection heater RhB. When injection ports 11A and 11B are not distinguished, they are referred to as injection ports 11. A flow channel is formed connecting pressure chambers 12A and 12B. When pressure chambers 12A and 12B are collectively referred to as pressure chamber 12.

[0033] The pressure chamber 12 is formed corresponding to each ejector nozzle 11 by separating the space between the recording element substrate 18 and the perforated plate 19 using a partition 21. The ejector nozzle 11 is an opening formed in a portion of the perforated plate 19. A meniscus is formed in the ejector nozzle 11 to allow ink to flow through the pressure chamber 12, and an ejector nozzle interface is formed as the interface between the ink and the atmosphere. Liquid is ejected from the ejector nozzle 11.

[0034] A separate flow channel 23 extends in a second direction intersecting the direction in which the injection ports 11 are arranged in rows (the first direction). The separate flow channel 23 includes a pressure chamber 12, a supply flow channel 14 (described later in Figure 4), and an outlet flow channel 15 (described later in Figure 4). The supply flow channel 14 communicates with the pressure chamber 12B. The outlet flow channel 15 communicates with the pressure chamber 12A.

[0035] A supply port 22 is provided at one end of the individual flow channel 23. Supply port 22 is an opening through a common flow channel (not shown) upstream of the individual flow channel 23, passing through the recording element substrate 18. A supply port 32 is provided at the other end of the individual flow channel 23. Supply port 32 is an opening through a common flow channel (not shown) downstream of the individual flow channel 23, passing through the recording element substrate 18. Liquid is supplied to the individual flow channel 23 through supply ports 22 and 32.

[0036] On the recording element substrate 18, a first jet heater RhA is formed at a position closer to the supply port 32 than the supply port 22. The first jet heater RhA is a component that generates energy for ejecting liquid from the pressure chamber 12A through the jet port 11A. Specifically, the first jet heater RhA causes the liquid (also referred to as ink) in the pressure chamber 12A to bubble by thermal drive, thereby enabling the energy generated by the bubbles to be used to eject ink from the jet port 11A. Although an electrothermal conversion element is used for the first jet heater RhA in this embodiment, there are no particular limitations. For example, a piezoelectric element can be used for the first jet heater RhA.

[0037] In the recording element substrate 18, a second jet heater RhB is formed at a position closer to the supply port 22 than the supply port 32. The second jet heater RhB is a component that generates energy for ejecting liquid from the pressure chamber 12B through the jet port 11B. Specifically, the second jet heater RhB causes the liquid (also referred to as ink) in the pressure chamber 12B to bubble by thermal drive, thereby enabling the energy generated by the bubbles to be used to eject ink from the jet port 11B. Although an electrothermal conversion element is used for the second jet heater RhB in this embodiment, there are no particular limitations. For example, a piezoelectric element can be used for the second jet heater RhB.

[0038] Note that, as shown in the example of Figure 4 described later, when there is no jet nozzle 11B above the second jet heater RhB, it is assumed that the second jet heater RhB has the following function. In other words, it is assumed that the second jet heater RhB is a component that generates energy for producing a circulating ink flow in the separate flow channel 23 in the direction indicated by arrow 27.

[0039] Now, the linear type will be described. The linear type means that the shape of the individual flow channel 23 is configured such that both ends of the individual flow channel 23 are positioned to clamp the injection nozzle 11, and the direction passing through both ends of the individual flow channel 23 extends in a second direction intersecting the first direction. In other words, in the individual flow channel 23, the first injection heater RhA is arranged in a second direction intersecting the first direction along the row of injection nozzles 11A. Similarly, the second injection heater RhB is arranged in a second direction intersecting the first direction along the row of injection nozzles 11B.

[0040] Furthermore, a supply channel 14 is formed on the side of the second jet heater RhB (see Figure 4). The supply channel 14 consists of a separate channel 23 on a portion of the second jet heater RhB side and a supply port 22. On the other hand, an outflow channel 15 is formed on the side of the first jet heater RhA (see Figure 4). The outflow channel 15 consists of a separate channel 23 on another portion of the first jet heater RhA side and a supply port 32.

[0041] Next, the flow of ink through the individual flow channel 23 will be described. The flow of ink through the individual flow channel 23 is classified into two types. The first type of ink flow is the flow used for refilling after the liquid jetting device 50 drives the first jetting heater RhA to eject ink from the jetting port 11A. The second type of ink flow is the flow used to operate the external pump 71 to generate a circulating flow in the direction of arrow 27.

[0042] <First Ink Flow> Figure 3D This illustrates how the liquid jetting device 50 drives the first jetting heater RhA to jet ink from the jetting nozzle 11. Figure 3DThis is a diagram illustrating the inflow of ink when either the first jet heater RhA or the second jet heater RhB is activated. Figure 3D In the example, when the first jet heater RhA is driven to jet ink from the jet port 11A, ink is supplied from each of the supply ports 22 and 32. Therefore, ink flows into the pressure chamber 12 from both supply ports 22 and 32.

[0043] <Second type of ink flow> On the other hand, when the liquid jetting device 50 operates the external pump 71 to generate circulating flow, ink flows into a separate flow channel 23 through the supply port 22, and ink flows out of the separate flow channel 23 through the supply port 32. In this embodiment, the liquid jetting device 50 circulates the ink flowing out of the supply port 32 back to the supply port 22, thereby generating circulating ink flow in the separate flow channel 23 in the direction indicated by arrow 27. Figure 3B An example is shown where supply port 22 and supply port 32 are shared in the liquid jet chip 3. On the other hand, Figure 3C An example is shown in which supply port 22 and supply port 32 are configured as separate flow channels and the separate flow channels are shared outside the liquid jet head 1.

[0044] The circulating ink flow will be described further. Ink contains volatile components such as water and solids. When using the liquid ejector head 1, the ejection of ink from the ejector nozzle 11 may become unstable due to the evaporation of volatile components from the ejector nozzle 11 and the concentration of solids in the ink around the ejector nozzle 11 caused by the evaporation of volatile components. Therefore, various devices have been employed to prevent the ejection of ink from the ejector nozzle 11 from becoming unstable.

[0045] For example, a cover member (not shown) may be provided at a position in the X direction offset from the feed path of the target medium P. The cover member is shaped to cover the nozzle surface of the nozzle 11 on which the liquid injection head 1 is provided. When the liquid injection head 1 is not performing a recording operation on the target medium P, the cover member can prevent the nozzle 11 from drying out or protect the nozzle 11 by covering the nozzle surface of the nozzle 11 on which the liquid injection head 1 is provided.

[0046] In addition, an ink suction mechanism (not shown) can be provided. When a cover member and an ink suction mechanism are provided, the cover member is used in conjunction with the ink suction operation from the ejector 11. The ink suction operation refreshes the ink around the ejector 11. Therefore, the image quality level of the acquired image can be maintained.

[0047] Furthermore, when the liquid ejector head 1 is not performing a recording operation on the target medium P, it performs an ejection operation called pre-ejection (also known as pre-ejection). This discards concentrated ink. Additionally, when the liquid ejector head 1 is performing a recording operation on the target medium P, it can perform an ejection operation called pre-ejection (also known as on-paper pre-ejection or in-page pre-ejection). On-paper pre-ejection or in-page pre-ejection is an ejection operation that ejects a small amount of ink at a location on the target medium P where the ink is not significant in terms of image quality. Although these ejection operations greatly contribute to improving image quality, they refresh the ejector nozzle 11. Therefore, some ink is discarded. Thus, the amount of waste ink can be minimized as much as possible.

[0048] For example, the circulating ink flow generated by using an external pump 71 reduces waste ink while preventing the nozzle 11 from drying out and the ink around the nozzle 11 from concentrating. From another perspective, it minimizes the number of ink pre-jet attempts and ink suction attempts. Furthermore, minimizing the number of ink pre-jet attempts increases the overall throughput or output of the liquid jetting device 50.

[0049] Note that the circulating ink channels inside and outside the liquid ejector head 1 can be configured as follows: Figure 3A The filter 31 shown is used to remove foreign matter contained in the ink. The filter 31 is a protrusion formed by a portion of the perforated plate 19 protruding towards the recording element substrate 18. Figures 3A-3D In the example, filter 31 is positioned at both one end and the other end of a separate flow channel 23. In the circulating ink flow channel, one end of the separate flow channel 23 corresponds to the ink inflow side, and the other end corresponds to the ink outflow side. Filter 31 can be positioned in the separate flow channel 23 between the first jet heater RhA and the second jet heater RhB. If filter 31 is positioned in the separate flow channel 23 between the first jet heater RhA and the second jet heater RhB, it is not necessary to position filter 31 at both one end and the other end of the separate flow channel 23. Next, the principle of generating the circulating ink flow will be described using FIG4. Note that FIG4 shows an example where the jet nozzle 11A is positioned only above the first jet heater RhA.

[0050] <The principle behind the generation of circulating ink flow> exist Figure 4A , Figure 4B and Figure 4C For ease of description, the illustration of filter 31 has been omitted. Figure 4A It is truncated along IIIB-IIIB. Figure 3AA cross-sectional view of a separate jetting unit is shown to illustrate the generation and growth process of bubbles B generated by film boiling of the ink when the ink is heated by the second jetting heater RhB. Figure 4B It is truncated along IIIB-IIIB. Figure 3A A cross-sectional view of a separate jetting unit is shown to illustrate the contraction process of bubbles B generated by film boiling of the ink when the ink is heated by the second jetting heater RhB. Figure 4C It is truncated along IIIB-IIIB. Figure 3A A cross-sectional view of a separate jetting unit is shown to illustrate the post-defoaming process of bubbles B generated by film boiling of the ink when the ink is heated by the second jetting heater RhB. The generation and growth process, contraction process, and post-defoaming process of bubble B will then be described.

[0051] <The generation and growth process of bubble B> like Figure 4A As shown, the second jet heater RhB is positioned closer to the supply port 22 between the supply port 22 and the supply port 32. Therefore, due to the generation of circulating ink flow, the flow resistance R1 generated in the flow channel between the second jet heater RhB and the supply port 22 is less than the flow resistance R2 generated in the flow channel between the second jet heater RhB and the supply port 32. Therefore, as... Figure 4A As shown, due to the difference between flow resistance R1 and flow resistance R2, the bubbles B generated by the film boiling of the ink grow obliquely towards the channel side where the flow resistance R1 is relatively small. Therefore, the magnitude of the flow vector Fa of the ink towards the channel that generates flow resistance R1 is larger than the magnitude of the flow vector Fb of the ink towards the channel that generates flow resistance R2. Note that the circuit including flow resistances R1 and R2 is an equivalent circuit representing the flow resistance generated in the channel including the separate flow channel 23 due to the circulating ink flow, represented by resistance.

[0052] <The contraction process of bubble B> During the shrinkage of bubble B, ink flows in to compensate for the shrinkage volume of bubble B. In this case, as... Figure 4B As shown, the flow vector Fc of the ink flowing in from the supply port 22 on the flow resistance R1 side is larger than the flow vector Fd of the ink flowing in from the supply port 32 on the flow resistance R2 side. Furthermore, the defoaming position of bubble B is offset from above the second jet heater RhB towards the supply port 32 in the flow channel.

[0053] <The process after bubble B defogs> If used Figure 4BAs stated, there exists a relationship Fc > Fd. Therefore, a flow vector F is generated for the circulating ink flow from supply port 22 to supply port 32. The magnitude of the flow vector F is affected by the ratio of flow resistances R1 and R2 and the size of bubble B. For example, consider the case where a second jet heater RhB is used. In this case, the location where the second jet heater RhB is deployed is preferably closer to one of the ends of the individual flow channel 23 than the location where the first jet heater RhA is deployed. Specifically, the flow resistance ratio R1 / R2 is preferably set in the range of 0.05 to 0.40. Setting the flow resistance ratio R1 / R2 in the range of 0.05 to 0.40 can locally maximize the flow vector F of the circulating ink flow. By increasing the ink flow vector Fa and increasing the ink flow vector Fc, the flow vector F of the circulating ink flow increases, and the circulating ink flow increases. Therefore, it is preferable to reduce the flow resistance R1. Furthermore, it is preferable to reduce the ink flow vector Fb and reduce the ink flow vector Fd as much as possible. Therefore, it is preferable to increase the flow resistance R2. For this reason, it is preferable to reduce the flow resistance R1 and increase the flow resistance R2. In other words, it is preferable to reduce the flow resistance ratio R1 / R2. Furthermore, when bubble B is large, i.e., when the volume of bubble B is large, this increases the volume of fluid displaced in the individual flow channel 23, thus increasing the circulating flow. Factors contributing to increased circulating flow include, for example, the following: One factor contributing to increased circulating flow is increasing the size of the second jet heater RhB. Another factor contributing to increased circulating flow is widening the width or height of the flow channel on the supply port 22 side to relatively reduce the flow channel resistance R1. Additionally, another factor contributing to increased circulating flow is reducing the viscosity of the ink. Furthermore, another factor contributing to increased circulating flow is applying a double-pulse to the liquid jet head 1. The double-pulse driving pulse means the following: First, a pulse short enough to avoid generating bubbles in the flow channel on the second jet heater RhB is applied to the second jet heater RhB, thereby heating the ink around the flow channel on the second jet heater RhB. Subsequently, a main pulse is applied to the second jet heater RhB to generate bubbles for ink circulation, thereby growing larger bubbles.

[0054] Furthermore, a portion of the ink flowing due to the circulating ink flow enters the ejection port 11. Consequently, the concentrated ink in the ejection port 11 is sent to the flow channel on the supply port 32 side, and fresh ink flows from the flow channel on the supply port 22 side into the ejection port 11 through a separate flow channel 23. This makes it difficult for the concentrated ink to remain in the ejection port 11. Therefore, while suppressing the effect of concentrated ink, the initial ink ejection conditions can be maintained.

[0055] The circulating ink flow is a transient flow associated with the growth and contraction processes when bubble B is generated. Therefore, after bubble B defoams, the inertial circulating ink flow decays over time and stops after a certain period. Therefore, to stably generate circulating flow within a certain time period, it is preferable to repeatedly drive the second jet heater RhB. Note that the driving cycle of the second jet heater RhB is not particularly limited, as long as it can discharge the concentrated ink retained in the jet nozzle 11. However, the circulating ink flow is a transient flow associated with the growth and contraction processes when bubble B is generated. Therefore, considering a time period of 10... When the cycle of ink is driven at a high drive frequency such as 100 kHz, the promotion of circulation that hinders the flow of circulating ink may be reduced. Therefore, for example, it is preferable to drive the second jet heater RhB with a drive cycle of about 100 Hz to tens of kHz.

[0056] Specifically, the higher the driving frequency of the second jet heater RhB, the longer the circulating ink flow is maintained, thereby improving the effect of discharging the concentrated ink caused by the circulating ink flow. However, it is also assumed that the higher the driving frequency of the second jet heater RhB, the higher the ink temperature will be due to the heat generated by the second jet heater RhB. Therefore, it is preferable to appropriately control the number of times the second jet heater RhB is driven. Next, the elimination of ink concentration caused by the circulating ink flow will be described using Figures 5 and 6.

[0057] <Elimination of ink concentration; linear> Figure 5A This is a diagram showing a state where the flow of circulating ink has temporarily stopped. Figure 5B It shows that immediately following Figure 5A The diagram shows the state after the second jet heater RhB is driven to generate circulating ink flow, following the initial state. Figure 5C It is shown in Figure 5B The diagram illustrates a state where the circulating ink flow temporarily stops after the initial state. Figure 5D It shows that immediately following Figure 5C The diagram illustrates the state after the second jet heater RhB is driven to generate circulating ink flow, following the initial state. (See diagram for example.) Figures 5A to 5D As shown, the linear, individual flow channels 23 have separate inlets and outlets for the circulating ink flow. Note that dotted shading is applied to the ink in the individual flow channels 23, and the density of the dotted shading is increased where the ink is concentrated to represent the degree of ink concentration.

[0058] like Figure 5AAs shown, when the circulating ink flow temporarily stops, the volatile components in the ink evaporate from the nozzle 11. Therefore, ink concentration occurs near the nozzle 11. Then, when the second jet heater RhB is activated, the circulating ink flow resumes. As a result, as... Figure 5B As shown, the ink concentration that has occurred near nozzle 11 is eliminated. Then, when the circulating ink flow temporarily stops, as... Figure 5A As shown, ink concentration occurs again near the jet nozzle 11. Then, when the second jet heater RhB is activated, the circulating ink flow restarts. As a result, as... Figure 5D As shown, with Figure 5B As in the previous case, ink concentration that occurred near the nozzle 11 is eliminated. Therefore, ink concentration is eliminated even throughout the entire individual flow channel 23. As described above, in the linear individual flow channel 23, the ink concentration state is reset whenever the repetitive ink flow pauses and resumes.

[0059] <Elimination of ink concentration; U-shape> Figure 6A This is a diagram showing a state where the flow of circulating ink has temporarily stopped. Figure 6B It shows that immediately following Figure 6A The diagram shows the state after the second jet heater RhB is driven to generate circulating ink flow, following the initial state. Figure 6C It is shown in Figure 6B The diagram illustrates a state where the circulating ink flow temporarily stops after the initial state. Figure 6D It shows that immediately following Figure 6C The diagram illustrates the state after the second jet heater RhB is driven to generate circulating ink flow. (See diagram for example.) Figures 6A to 6D As shown, the individual U-shaped flow channels 23 have inlets and outlets for circulating ink flow arranged adjacent to each other. Note that dotted shading is applied to the ink in the individual flow channels 23, and the density of the dotted shading is increased where the ink is concentrated to represent the degree of ink concentration.

[0060] like Figure 6A As shown, when the circulating ink flow temporarily stops, volatile components in the ink evaporate from the nozzle 11. Therefore, ink concentration occurs near the nozzle 11. Then, when the second jet heater RhB is activated, the circulating ink flow resumes. This results in... Figure 6B The state shown in the image. Figure 6A The inlet of the separate flow channel 23 in the middle and Figure 6Ais adjacent to the outlet of the individual flow path 23. Therefore, although the ink concentrated near the ejection port 11 is discharged from the outlet of the individual flow path 23, part of the discharged ink flows back from the inlet of the individual flow path 23. As a result, the entire individual flow path 23 is not replaced with fresh ink, but a phenomenon occurs in which it is replaced with slightly concentrated ink (hereinafter, this phenomenon will be referred to as recirculation concentration). Then, when the circulating ink flow is temporarily stopped, as Figure 6C shown in, with Figure 6A as in, from Figure 6B the state, ink concentration proceeds again near the ejection port 11. Then, when the second ejection heater RhB is driven, the circulating ink flow restarts. As a result, as Figure 6D shown in, due to the influence of recirculation concentration, the entire individual flow path 23 is filled with ink that is more concentrated than Figure 6B in. As described above, in the U-shaped individual flow path 23, each time the temporary stop and circulation operation of the circulating ink flow are repeated, the ink concentration state is not reset, and ink concentration gradually proceeds within the entire individual flow path 23. Therefore, the ink concentration state deteriorates. Note that even without repeating the temporary stop and restart of the circulating ink flow, the progress of ink concentration near the ejection port 11 caused by the long stop time of the circulating ink flow makes it difficult to obtain the effect of improving the ink concentration state even when the circulating ink flow is restarted for the first time. This is because the improvement effect of recirculation concentration on the ink concentration state is small.

[0061] Therefore, the difference in the influence of the discharged concentrated ink between the linear individual flow path 23 and the U-shaped individual flow path 23 leads to a difference in the effect of eliminating the ink concentration state by temporarily stopping and restarting the circulating ink flow. Specifically, in the case of the linear individual flow path 23, it is easy to eliminate the concentrated state of the ink including the entire individual flow path 23. On the other hand, in the case of the U-shaped individual flow path 23, it is difficult to eliminate the concentrated state of the ink including the entire individual flow path 23 due to recirculation concentration. Therefore, in the case of the U-shaped individual flow path 23, ink ejection may become unstable depending on the concentration degree of the entire individual flow path 23. Next, the configuration near the ejection port 11 of the U-shaped individual flow path 23 will be described with reference to Figure 7.

[0062] <Configuration Near Ejection Port 11 of U-Shaped Individual Flow Path 23> Figure 7A is a plan view seen from the direction in which droplets are ejected from the ejection port 11. Figure 7B is a cross-sectional view taken along Figure 7A the VIIB-VIIB in. Figure 7C is an enlarged schematic view of the individual flow path 23 in Figure 7A .

[0063] Figure 7A and Figure 7B The ejection port 11 is an opening formed in a portion of the perforated plate 19. A first ejection heater RhA is formed on the recording element substrate 18 at a position corresponding to the ejection port 11. A second ejection heater RhB is also formed on the recording element substrate 18. The second ejection heater RhB generates circulating ink flow in a channel including a separate flow channel 23 in the direction indicated by arrow 27. A supply groove 42 is formed on the recording element substrate 18 between the row of the first ejection heater RhA and the row of the second ejection heater RhB in the direction along the row of the ejection port 11, so as to penetrate the recording element substrate 18. The supply groove 42 communicates with the separate flow channel 23 and can supply ink to the separate flow channel 23. In this way, not only can multiple separate supply openings be provided by using a configuration such as supply ports 22 and supply ports 32 in FIG. 3, but also by using a configuration such as supply ports 22 and supply ports 32 in FIG. 3, ink can be supplied to the separate flow channel 23. Figure 7A and Figure 7B Large openings, such as supply tank 42, are used to allow liquid to flow in and out. Next, [the following will be used]... Figure 8A , Figure 8B and Figure 8C Describes the configuration near the injection port 11 of the linear, individual flow channel 23.

[0064] <Configuration of a straight, individual flow channel 23 near the nozzle 11> Figure 8A This is a plan view seen from the direction of the liquid droplets ejected from nozzle 11. Figure 8B It is along Figure 8A The cross-sectional view taken from VIIIB-VIIIB in the diagram. Figure 8C It is along Figure 8A The cross-sectional view taken from VIIIB-VIIIB shows the arrangement of components on the substrate 18. Figure 8B The configurations differ. Although... Figure 8B and Figure 8C Two different example shapes of the back side of the recording element substrate 18 are shown according to the type of etching method used on the recording element substrate 18, but the shape of the back side of the recording element substrate 18 can be any shape. In other words, the configuration in the recording element substrate 18 can be any configuration.

[0065] The difference between this configuration and the configuration near the nozzle 11 of the separate flow channel 23 in the latter case is that the inlet and outlet of the separate flow channel 23 are not adjacent as in the U-shaped separate flow channel 23, but rather in a straight configuration where the inlet and outlet of the separate flow channel 23 are separate. Furthermore, as... Figure 8AAs shown, the directions of the two ends of the single, linear flow channels 23 are orthogonal to the direction in which the nozzles 11A and 11B are aligned side-by-side. With this arrangement, the point where the circulating ink flows into the single flow channel 23 is separated from the point where the circulating ink flows out of the single flow channel 23. Therefore, it is possible to prevent ink concentrated at nozzles 11A and 11B from flowing back into the single flow channel 23. Thus, the effect of ink concentration can be suppressed. Next, we will use... Figure 9A , Figure 9B and Figure 9C Other configurations near the nozzle 11 of the linear, individual flow channel 23 are described.

[0066] <Other configurations near the nozzle 11 of the straight, individual flow channel 23> Figure 9A This is a plan view seen from the direction of the liquid droplets ejected from nozzle 11. Figure 9B It is along Figure 9A The cross-sectional view taken from IXB-IXB in the diagram. Figure 9C It is along Figure 9A The cross-sectional view taken from IXB-IXB shows the arrangement of components on the substrate 18. Figure 9B The configurations differ. Although... Figure 9B and Figure 9C Two different example shapes of the back side of the recording element substrate 18 are shown according to the type of etching method used on the recording element substrate 18, but the shape of the back side of the recording element substrate 18 can be any shape. In other words, the configuration in the recording element substrate 18 can be any configuration. Furthermore, in Figure 9B and Figure 9C Filter 31 is not shown in the text. Furthermore, compared to... Figure 8A , Figure 8B and Figure 8C The difference lies in that the number of rows of ink supply openings increases from two rows to three rows. This allows the number of rows of nozzles 11A and 11B to double, and the row of nozzle 11A can be arranged closer to the center of the ink supply opening. In other words, the row of nozzles 11A is arranged on both sides of the arrangement direction of the multiple ink supply openings in the center, and the row of nozzles 11B is also arranged. This arrangement allows the number of rows of ink supply openings to increase from two rows to three rows, and the number of pairs of nozzles 11A and 11B can be doubled from one pair to two pairs. Furthermore, as... Figure 9AAs shown, pairs of nozzles 11A and 11B, as well as other pairs of nozzles 11A and 11B, can be arranged at an offset spacing. Furthermore, wiring areas may not be included between the supply openings in the row of central ink supply openings. Therefore, there is a high degree of freedom in terms of the size and resolution of the openings in the row of central ink supply openings. This allows for faster refilling in nozzles 11A and 11B, thus supporting high productivity. Note that the positions of nozzles 11A and 11B, as well as the positions of the ink supply openings, can be offset according to the wiring. Next, the ink according to this embodiment will be described.

[0067] <Ink> As described above, although the degree of ink concentration reduction varies depending on the channel configuration including the individual flow channels 23, the following effect can be achieved by generating circulating ink flow in the individual flow channels 23 using the second jet heater RhB. In other words, the effect of concentrated ink thickened due to the evaporation of volatile components in the ink at the jet nozzle 11 can be suppressed. Therefore, since the ink jetting conditions can be maintained well, the influence of variations in ink jetting speed can be further reduced. Thus, ink jetting can be stabilized.

[0068] On the other hand, based on the application of the liquid ejector head 1 and the liquid ejection device 50 equipped with the liquid ejector head 1, it can be assumed that inks with different types of ink coloring materials and different solid content ratios are used. In other words, for the performance of the liquid ejector head 1, it is preferable that the ink ejection stability can be maintained regardless of the type of ink used.

[0069] For example, conditions caused by water in ink include changes that may occur on ordinary paper, such as curling (also known as warping) and wrinkling (also known as wavy wrinkling). In such cases, it is conceivable to use ink with reduced water content. Furthermore, inks with low water content have a higher concentration of solids such as organic solvents, pigments, and resins other than water. Therefore, as the water in the ink evaporates, the viscosity of the ink tends to increase rapidly. Consequently, inks with low water content tend to reduce ink jetting stability. Therefore, when using inks with low water content, the increase in ink viscosity can be suppressed by generating circulating ink flow in a flow channel configuration including a separate flow channel 23, as in this embodiment. Generally, inks with high solids content exhibit 10 wt% solids. In other words, this embodiment preferably applies inks with a solids ratio of 10 wt% (also known as mass %) or higher.

[0070] The relationship between the operating temperature of the liquid ejector head 1 and the viscosity of the ink will be described. The following scenario exists: the drive of the second ejector heater RhB, arranged throughout the liquid ejector chip 3, is controlled to increase the temperature of the liquid ejector head 1 until it reaches a certain temperature, at which point the liquid ejector head 1 is used. The viscosity of the ink varies depending on its temperature. Therefore, the ink viscosity at the operating temperature of the liquid ejector head 1 affects the ink ejection stability.

[0071] The relationship between the circulating ink flow velocity and the driving frequency of each of the first jet heater RhA and the second jet heater RhB will be described. When the second jet heater RhB generates circulating ink flow, an instantaneous ink flow velocity of tens of mm / s to 1000 mm / s can be achieved. The average flow velocity over a duration in the hundreds of microseconds depends on the driving frequency of the second jet heater RhB. This is because when the second jet heater RhB generates circulating ink flow, the circulating ink flow is a transient circulating flow that decays over time and stops after a certain period of time. On the other hand, when the first jet heater RhA generates circulating ink flow, it can be driven at a frequency of about 10 to 20 kHz, which is approximately the same as the driving frequency of the first jet heater RhA (also referred to as the jet frequency). In this case, the average flow velocity of the circulating ink flow 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.

[0072] (Ink with high pigment concentration) The case of inks with high pigment concentration will be described. For example, when using inks with a concentration such that the ink viscosity is 3-6 cP (inclusive) at the operating temperature of the liquid jet head 1, ink thickening near the jet nozzle 11 may occur depending on the non-jetting time of the ink (also known as the resting time of the circulating ink flow). Therefore, the ink jetting speed may vary. For this reason, ink jetting stability may deteriorate. To prevent the deterioration of ink jetting stability, it is preferable to circulate the ink by generating a circulating ink flow when the resting time of the circulating ink flow is short. Therefore, it is preferable to eliminate ink concentration by frequently performing regular ink circulation or instantaneous ink circulation. Therefore, instantaneous ink circulation can be performed if the second jet heater RhB is driven. Therefore, by frequently restarting the circulating ink flow from the resting state of the circulating ink flow, it is helpful to eliminate ink concentration near the jet nozzle 11.

[0073] (Ink with low pigment concentration) The case of inks with low pigment concentration will be described. For example, when using inks with a concentration such that the ink viscosity at the operating temperature of the liquid jet head 1 is 1-2 cP (inclusive), the thickening of the ink near the jet nozzle 11 may occur depending on the non-jetting time of the ink (also known as the resting time of the circulating ink flow). Therefore, although the ink jet speed may vary, the variation in ink jet speed is relatively small compared to high-concentration inks. On the other hand, when the resting time of the circulating ink flow is long, for example, the thickening of the ink near the jet nozzle 11 may occur depending on the non-printing drive time (also known as the stop time). Therefore, in the case of restarting after a period of inactivity, it is preferable to implement recovery processes involving waste ink, such as ink suction operations, wiping operations, and pre-jetting combined with them. Therefore, if the second jet heater RhB is driven, the ink concentration near the jet nozzle 11 can be eliminated without generating waste ink by restarting the circulating ink flow as a recovery operation. Furthermore, depending on the stop time, waste ink can be avoided by only driving the second jet heater RhB to restart the circulating ink flow as a recovery operation. Alternatively, waste ink can be minimized by restarting the circulating ink flow for restoration and by combining it with a suction operation, separate from the elimination of ink concentration, for removing air bubbles B in the liquid jet head 1.

[0074] (A configuration better suited for eliminating ink concentration) As mentioned above, regardless of whether the ink is high-concentration or low-concentration, it is preferable to restore the ink to its initial fresh state as much as possible in order to suppress the effects of concentrated ink. Therefore, when driving the second jet heater RhB, the lower the effect of recirculation concentration, the better the circulation effect can be obtained. In other words, the configuration of a straight-line individual flow channel 23 can achieve a better circulation effect than the configuration of a U-shaped individual flow channel 23. Next, we will use... Figure 10 Figure 17 illustrates the circuit configuration for controlling the drive of the first jet heater RhA and the second jet heater RhB according to this embodiment.

[0075] <Heater Selection Circuit> Figure 10This is a diagram illustrating an example of the circuit configuration of the recording element substrate 18 according to this embodiment. Various signals are supplied to the recording element substrate 18 from the main PCB 100. The main PCB 100 includes a power supply circuit 102 and a controller 101. The power supply circuit 102 applies a power supply voltage to the recording element substrate 18 via a power supply voltage wiring VH. The power supply circuit 102 and the recording element substrate 18 are connected via a GNDH wiring 115. The GNDH wiring 115 is included in a ground wiring layer. The ground wiring layer sets the reference potential of the recording element substrate 18. Therefore, the GNDH wiring 115 serves as the reference potential of the recording element substrate 18. The controller 101 mainly includes a ROM, RAM, and CPU, and supplies various electrical signals to the recording element substrate 18. The controller 101 is connected to the recording element substrate 18 via an enable signal line HE, a latch signal line LT, a data signal line DATA, and a clock signal line CLK. The controller 101 supplies an enable signal via the enable signal line HE. The enable signal is a signal that uses pulse width to control the timing of turning on a target control element and applying current to it. The enable signal is used to adjust for manufacturing deviations in the heater resistance values ​​in the recording element substrate 18, manufacturing deviations in the power supply circuit 102, and voltage drops in the power supply wiring when multiple heaters are driven simultaneously, in order to allow for the generation of more desired thermal energy. This embodiment describes an example where the enable signal line HE is shared for jetting and cycling to reduce the number of signal terminals, but if jetting and cycling are set separately, different pulse widths can be used for jetting and cycling. Note that this embodiment assumes that the first jetting heater RhA and the second jetting heater RhB share the enable signal line HE, and assumes the following: In other words, assuming that the first jetting heater RhA and the second jetting heater RhB are formed in the same step of the semiconductor manufacturing process and have the same manufacturing deviation (the amount of deviation of the resistance value from the ideal value), the pulse width of the enable signal is preferably adjusted. The controller 101 supplies a latch signal to the recording element substrate 18 via the latch signal line LT. The controller 101 supplies a data signal to the recording element substrate 18 via the data signal line DATA. The controller 101 supplies a clock signal to the recording element substrate 18 via the clock signal line CLK.

[0076] The recording element substrate 18 includes a plurality of first ejection modules 104 and a plurality of second ejection modules 105. Each first ejection module 104 includes a first ejection heater RhA, a first ejection drive element MD1, and a first ejection logic circuit AND1. The first ejection heater RhA is also referred to as a first resistance heating element. The first ejection drive element MD1 (also referred to as a first drive element) is an element for applying current to the first ejection heater RhA. The first ejection logic circuit AND1 is an element for selectively driving the first ejection drive element MD1 included in the corresponding first ejection module 104 from among the plurality of first ejection modules 104. The recording element substrate 18 generates heat by applying current to the first ejection heater RhA. This causes ink to bubble and eject. This allows recording to be performed on the ejection target medium P. Furthermore, in this embodiment, the plurality of first ejection heaters RhA are arranged in rows to form a first ejection heater row 112.

[0077] Here, it is assumed that the first jet driving element MD1 is composed of a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). Figure 10 In the example, the source terminal of the first jet driving element MD1 is connected to the GNDH wiring 115. Furthermore, the gate terminal of the first jet driving element MD1 is connected to the output side of the first jet logic circuit AND1. Additionally, the drain terminal of the first jet driving element MD1, the first jet heater RhA, and the power supply voltage wiring VH are connected to each other. The drain terminal of the first jet driving element MD1 and the first jet heater RhA are connected to each other via the first jet drain wiring 107. When a gate drive voltage is applied between the gate terminal and the source terminal of the first jet driving element MD1 according to the signal output from the first jet logic circuit AND1, the following occurs: In other words, drive current flows to the first jet heater RhA via the first jet drain wiring 107. This causes the first jet heater RhA to generate heat. Therefore, ink bubbles and jets, allowing recording on the jet target medium P. However, the first jet driving element MD1 can be composed of devices other than MOSFETs. For example, the first jet driving element MD1 can be composed of a bipolar transistor. Alternatively, the first jet driving element MD1 can be composed of an IGBT (Insulated Gate Bipolar Transistor).

[0078] Each second jetting module 105 includes a second jetting heater RhB, a second jetting drive element MD2, and a second jetting logic circuit AND2. The second jetting heater RhB is also referred to as a second resistance heating element. The second jetting drive element MD2 (also referred to as a second drive element) is an element for applying current to the second jetting heater RhB. The second jetting logic circuit AND2 is an element for selectively driving the second jetting drive element MD2 included in the corresponding second jetting module 105 from among the plurality of second jetting modules 105. The recording element substrate 18 generates heat by applying current to the second jetting heater RhB. This causes the ink to bubble and jet. This allows recording to be performed on the jetting target medium P. Furthermore, in this embodiment, the plurality of second jetting heaters RhB are arranged in rows to form a second jetting heater row 113.

[0079] Here, it is assumed that the second jet driving element MD2 is composed of a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). Figure 10 In the example, the source terminal of the second jet driving element MD2 is connected to the GNDH wiring 115. Furthermore, the gate terminal of the second jet driving element MD2 is connected to the output side of the second jet logic circuit AND2. Additionally, the drain terminal of the second jet driving element MD2, the second jet heater RhB, and the power supply voltage wiring VH are connected to each other. The drain terminal of the second jet driving element MD2 and the second jet heater RhB are connected to each other via the second jet drain wiring 108. When a gate drive voltage is applied between the gate terminal and the source terminal of the second jet driving element MD2 according to the signal output from the second jet logic circuit AND2, the following occurs: In other words, drive current flows to the second jet heater RhB via the second jet drain wiring 108. This causes the second jet heater RhB to generate heat. Therefore, ink bubbles B grow, generating a circulating flow as described above. However, the second jet driving element MD2 can be composed of devices other than MOSFETs. For example, the second jet driving element MD2 can be composed of a bipolar transistor. Alternatively, the second jet driving element MD2 can be composed of an IGBT (Insulated Gate Bipolar Transistor).

[0080] Note that the first jet heater RhA may use a piezoelectric element as the element for jetting ink. The second jet heater RhB may use a piezoelectric element as the element for circulating ink. At least one of the first jet heater RhA and the second jet heater RhB may be used as an element for heating a specific area in the recording element substrate 18. Alternatively, at least one of the first jet heater RhA and the second jet heater RhB may be used as a temperature sensing element for monitoring its own temperature.

[0081] Assume that the first injection drive element MD1 and the second injection drive element MD2 are N-type high-voltage MOSFETs. Compared with the drive elements used in logic circuits, high-voltage MOSFETs are drive elements with a higher withstand level. This embodiment assumes that the high-voltage MOSFETs are configured to not fail even when subjected to a large voltage (e.g., 32V) that cannot be withstood by the drive elements used in the general logic circuits constituting the controller 101.

[0082] The recording element substrate 18 includes a control data supply circuit 106. The recording element substrate 18 is provided with a first injection group selection signal line 109, a second injection group selection signal line 110, a time-division selection signal line 111, and an enable signal line HE. The control data supply circuit 106 is electrically connected to each of the first injection group selection signal line 109, the second injection group selection signal line 110, the time-division selection signal line 111, and the enable signal line HE. Each of the first injection group selection signal line 109, the time-division selection signal line 111, and the enable signal line HE is electrically connected to a first injection module 104. Each of the second injection group selection signal line 110, the time-division selection signal line 111, and the enable signal line HE is electrically connected to a second injection module 105. Therefore, the control data supply circuit 106 can send various signals to and receive various signals from the first injection module 104 via the first injection group selection signal line 109 and the time-division selection signal line 111. In addition, the control data supply circuit 106 can send various signals to and receive various signals from the second injection module 105 via the second injection group selection signal line 110 and the time division selection signal line 111.

[0083] Specifically, each of the first injection group selection signal line 109, the time-division selection signal line 111, and the enable signal line HE is connected to the input side of the first injection logic circuit AND1. The output side of the first injection logic circuit AND1 is connected to the gate terminal of the first injection drive element MD1. Therefore, according to the output of the first injection logic circuit AND1, the first injection drive element MD1 becomes on and is selectively controlled to allow current to flow to the first injection heater RhA. Furthermore, each of the second injection group selection signal line 110, the time-division selection signal line 111, and the enable signal line HE is connected to the input side of the second injection logic circuit AND2. The output side of the second injection logic circuit AND2 is connected to the gate terminal of the second injection drive element MD2. Therefore, according to the output of the second injection logic circuit AND2, the second injection drive element MD2 becomes on and is selectively controlled to allow current to flow to the second injection heater RhB.

[0084] In this embodiment, the time-division selection signal line 111 is shared by the first injection module 104 and the second injection module 105. Therefore, the time-division selection signal line 111 can help reduce the amount of serial data transmission and reduce the layout area of ​​the wiring for signal lines in the recording element substrate 18.

[0085] Figure 11A This is a functional block diagram of the circuit configuration of the control data supply circuit 106. Figure 11B It is shown Figure 11A A diagram illustrating an example circuit configuration of the second injection group selection circuit 201 is provided. The control data supply circuit 106 includes shift registers 203a and 203b, latch circuits 204a and 204b, a decoder circuit 205, and the second injection group selection circuit 201. The control data supply circuit 106 is provided with external input terminals. The control data supply circuit 106 is supplied with clock signals, data signals, and latch signals from the controller 101 via the external input terminals. The clock signal is used when transmitting data signals to the shift registers 203a and 203b via serial data transmission. The data signals include selection information for the first injection module 104 and selection information for the second injection module 105. The latch signals are used to retrieve various types of information stored in each of the shift registers 203a and 203b for each latching period and to hold this information in each of the latch circuits 204a and 204b.

[0086] Decoder circuit 205 is a circuit that expands q-bit input data into (2 to the power of q)-bit output data. Specifically, when 4-bit input data is input to decoder circuit 205, decoder circuit 205 converts the 4-bit input data into 16 (=2 to the power of 4)-bit output data. At this time, the output data of decoder circuit 205 is output as information with only 1 bit valid out of 16 bits. This enables time-division driving of each of the plurality of first injection modules 104 and the plurality of second injection modules 105 via time-division selection signal line 111.

[0087] The second injection group selection circuit 201 includes an AND circuit and a NOT circuit. The NOT circuit outputs a signal obtained by logically inverting the first injection group selection signal obtained from the first injection group selection signal line 109 (hereinafter referred to as the logic inversion signal). The AND circuit receives the logic inverted signal and the input of a second flag signal via the second flag signal line 202. The second flag signal is included in the data signal serially transmitted from the controller 101. The second flag signal serves as a flag to set the second injection group selection signal output via the second injection group selection signal line 110 as valid or invalid. In other words, the second injection group selection circuit 201 generates the second injection group selection signal based on the selection information of the first injection group selection signal and the second flag signal. Therefore, when the first injection module 104 is in the selected state, the second injection module 105 is in the unselected state. On the other hand, even when the first injection module 104 is in the unselected state, if the second flag signal is 0, the second injection group selection signal is invalid, and the second injection module 105 does not enter the selected state. In other words, if the first injection module 104 is in an unselected state and the second flag signal is 1, then the second injection group selection signal is valid, and the second injection module 105 enters the selected state. Note that when time-division selection is not performed, neither the first injection module 104 nor the second injection module 105 is selected.

[0088] Since the driving elements typically operate at voltages higher than those of the logic circuits, a substrate is used where high-voltage driving elements and ordinary driving elements coexist. This embodiment, described above, assumes that the first jet driving element MD1 and the second jet driving element MD2 are high-voltage MOSFETs. More specifically, as high-voltage MOSFETs, they are assumed to be composed of DMOSFETs (double-diffused MOSFETs). Logic circuits such as the first jet logic circuit AND1, the second jet logic circuit AND2, the second jet group selection circuit 201, shift registers 203a and 203b, latch circuits 204a and 204b, and the decoder circuit 205 are assumed to be composed of low-voltage MOSFETs.

[0089] (First scenario) Figure 12 This is a diagram illustrating an example arrangement of the heater and drive element according to a first case of this embodiment. Figure 12In this configuration, multiple first jet heaters RhA-1 to RhA-n and multiple second jet heaters RhB-1 to RhB-n are arranged on the recording element substrate 18 as heaters. The multiple first jet heaters RhA-1 to RhA-n are arranged in a row along the longer side of the recording element substrate 18 to form a first jet heater row 112. The multiple second jet heaters RhB-1 to RhB-n are arranged in a row along the longer side of the recording element substrate 18 to form a second jet heater row 113. Furthermore, in... Figure 12 In this embodiment, as driving elements, a plurality of first jet driving elements MD1-1 to MD1-n and a plurality of second jet driving elements MD2-1 to MD2-n are arranged on the recording element substrate 18. The plurality of first jet driving elements MD1-1 to MD1-n are arranged in a row along the longer side of the recording element substrate 18 to form a first jet driving element row 301. The plurality of second jet driving elements MD2-1 to MD2-n are arranged in a row along the longer side of the recording element substrate 18 to form a second jet driving element row 302.

[0090] In addition, Figure 12 In addition to the first jet heater row 112, the second jet heater row 113, the first jet drive element row 301 (also referred to as the first drive element row), and the second jet drive element row 302 (also referred to as the second drive element row), the following are also formed. In other words, supply port rows 303 and 304 are formed on the recording element substrate 18. The supply port row 303 is formed by a plurality of supply ports 32-1 to 32-m arranged in a row along the longer side direction of the recording element substrate 18. The supply port row 304 is formed by a plurality of supply ports 22-1 to 22-m arranged in a row along the longer side direction of the recording element substrate 18. In a first case, the first jet heater row 112 is arranged in parallel to the left side of the supply port row 304. The second jet heater row 113 is arranged in parallel to the left side of the first jet heater row 112. The supply port row 303 is arranged in parallel to the left side of the second jet heater row 113. The first jet drive element row 301 is arranged in parallel to the left side of the supply port row 303. The second row of injection drive elements 302 is arranged in parallel to the left of the first row of injection drive elements 301.

[0091] Furthermore, in this embodiment, one supply port 22 and one supply port 32 are respectively arranged for every four first jet heaters RhA and every four second jet heaters RhB, but the arrangement is not limited to this. Moreover, the sizes of the supply ports 22 and 32 can be different. Furthermore, the number of supply ports 22 and the number of supply ports 32 can be different.

[0092] Furthermore, the first jet heater row 112 is in a first arrangement, wherein, compared to the second jet heater row 113, the first jet heater row 112 is arranged in a region farther from the region where the first jet drive element row 301 and the second jet drive element row 302 are arranged. Furthermore, the first jet drive element row 301 is in a second arrangement, wherein the first jet drive element row 301 is arranged in a region closer to the first jet heater row 112 and the second jet heater row 113 than the second jet drive element row 302. Figure 12 An example is shown in which the first jet heater row 112, the second jet heater row 113, the first jet drive element row 301, and the second jet drive element row 302 are arranged sequentially based on the first arrangement relationship and the second arrangement relationship described above.

[0093] In short, it is only necessary to connect the drive element on the side farther from the heater to the heater on the side closer to the drive element, and connect the drive element on the side closer to the heater to the heater on the side farther from the drive element. For example, it can be assumed that the second jet heater row 113, the first jet heater row 112, the second jet drive element row 302, and the first jet drive element row 301 are arranged in sequence. Under this assumption, the second jet heater row 113 is arranged in a region farther from the region where the first jet drive element row 301 and the second jet drive element row 302 are arranged, compared to the first jet heater row 112. Furthermore, the second jet drive element row 302 is arranged in a region closer to the first jet heater row 112 and the second jet heater row 113 than the first jet drive element row 301. Even under this assumption, they are in a relationship where the drive element on the side farther from the heater is connected to the heater on the side closer to the drive element, and the drive element on the side closer to the heater is connected to the heater on the side farther from the drive element.

[0094] Furthermore, it is assumed that the resistance values ​​of the first jet heater RhA and the second jet heater RhB are substantially the same. Also, it is assumed that the dimensions of the first jet heater RhA and the second jet heater RhB are identical.

[0095] Note that the resistance heating element region is the region on the same layer of the recording element substrate 18 where resistance heating elements are arranged. In this embodiment, at least one of the first jet heater RhA and the second jet heater RhB is used as a resistance heating element. Therefore, the resistance heating element region is the region on the recording element substrate 18 where at least one of the first jet heater RhA and the second jet heater RhB is deployed. For example, the region on the same layer of the recording element substrate 18 that includes the first jet heater row 112 and the second jet heater row 113 is the resistance heating element region. Specifically, a plurality of first jet heaters RhA formed as the first jet heater row 112 are arranged in the first region of the resistance heating element region. Furthermore, a plurality of second jet heaters RhB formed as the second jet heater row 113 are arranged in the second region of the resistance heating element region. Note that when other resistance heating elements are arranged, it is sufficient to arrange the other resistance heating elements in the third region of the resistance heating element region.

[0096] Furthermore, the dimensions of the first injection drive element MD1 are substantially the same as those of the second injection drive element MD2. For example, assume that the dimensions of the first injection drive element MD1 and the second injection drive element MD2 are the same. Under this assumption, the resistance value (conduction resistance value) when driving the first injection heater RhA is the same as the resistance value (conduction resistance value) when driving the second injection heater RhB.

[0097] Figure 13 yes Figure 12 A partially enlarged view of an example arrangement of the heater and drive element in the first case. Figure 13 In this configuration, the first jet drain wirings 107-1 to 107-8 and the second jet drain wirings 108-1 to 108-8 are arranged as constituent elements of the unit 305 formed on the recording element substrate 18. This means that the unit 305 includes the first jet drain wirings 107-1 to 107-8 and the second jet drain wirings 108-1 to 108-8. In addition, the unit 305 also includes supply ports 32-1 and 32-2, first jet driving elements MD1-1 to MD1-8, second jet driving elements MD2-1 to MD2-8, first jet heaters RhA-1 to RhA-8, and second jet heaters RhB-1 to RhB-8.

[0098] Specifically, the second injection drain wirings 108-1 to 108-4 pass through supply port 32-1 to connect the second injection heaters RhB-1 to RhB-4 to the second injection drive elements MD2-1 to MD2-4. The second injection drain wirings 108-5 to 108-8 pass through supply port 32-2 to connect the second injection heaters RhB-5 to RhB-8 to the second injection drive elements MD2-5 to MD2-8.

[0099] The first injection drain wirings 107-1 to 107-4 are connected to the first injection drive elements MD1-1 to MD1-4 via supply port 32-1. The first injection drain wirings 107-5 to 107-8 are connected to the first injection drive elements MD1-5 to MD1-8 via supply port 32-2.

[0100] In short, some of the first jet drain wiring 107 and the second jet drain wiring 108 are arranged to pass through the area between the supply ports 32. Note that although this embodiment arranges four first jet drain wirings 107 and four second jet drain wirings 108 through one supply port 32, the number of wirings arranged is not limited to four. Furthermore, although Figure 13 An example is shown where the width of the first jet drain wiring 107 is the same as the width of the second jet drain wiring 108, but the wiring width is not limited to this. The width of the first jet drain wiring 107 may differ from the width of the second jet drain wiring 108. Next, we will use... Figure 14 Describe the layer configuration of the recording element substrate 18.

[0101] Figure 14 It shows along Figure 13 The diagram shows a cross-sectional structure taken from line XIIIB-XIIIB. The recording element substrate 18 can be manufactured using known semiconductor manufacturing processes. For example, the recording element substrate 18 includes a substrate 312 and a plurality of electrical components. The substrate 312 is composed of a semiconductor such as single-crystal silicon. The plurality of electrical components are disposed on the substrate 312.

[0102] (Insulation layer 311) Specifically, an insulating layer 311 is formed on the substrate 312. For example, an inorganic material such as silicon oxide is used for the insulating layer 311. The insulating layer 311 has an electrical isolation function. For example, in this embodiment, the insulating layer 311 electrically isolates the first jet heater RhA from the second jet heater RhB. Furthermore, although not in... Figure 14 As shown, however, the insulating layer 311 electrically isolates the first jet drive element MD1 from the second jet drive element MD2.

[0103] In this embodiment, insulating layer 311 includes insulating layers 311a, 311b, 311c, 311d, and 311e. A wiring layer including the first jet drain wiring 107-1 is formed in insulating layer 311b. Each wiring layer including the first jet drain wirings 107-2 to 107-8 is also formed in insulating layer 311b. A wiring layer including the second jet drain wiring 108-1 is formed in insulating layer 311c. Each wiring layer including the second jet drain wirings 108-2 to 108-8 is also formed in insulating layer 311c. In other words, the second jet drain wiring 108 (also referred to as the second wiring) is formed in a layer different from the layer containing the first jet drain wiring 107 (also referred to as the first wiring). In this embodiment, the layer in which the second jet drain wiring 108 is formed is located above the layer in which the first jet drain wiring 107 is formed. In addition, power supply voltage wirings VH 114a and VH114b are formed in the insulating layer 311d.

[0104] (Connecting component 313) A connecting member 313 is provided in the through hole penetrating the insulation layers 311b to 311e. Figure 14 In this design, connecting members 313 are also provided for the through holes penetrating insulating layers 311d to 311e and through holes penetrating insulating layers 311c to 311e. By providing contact plugs inside these through holes, the connecting members 313 are configured to be electrically connectable. The connecting members 313 are provided for electrically connecting conductive layer 314, electrical components in the upper layer, electrical components in the lower layer, and electrical components in the layer between the upper and lower layers. The electrical components also include the electrode layers of the first jet driving element MD1 and the second jet driving element MD2. Here, "upper layer" generally refers to the layer in the direction away from the substrate 312 when using a certain layer as a reference. "Lower layer" generally refers to the layer in the direction toward the substrate 312 when using a certain layer as a reference. For example, assuming the reference layer is insulating layer 311d, the upper layer corresponds, for example, to insulating layer 311e, and the lower layer corresponds, for example, to insulating layers 311c, 311b, and 311a. Note that in this embodiment, a conductive layer 314 is provided in each of the insulating layers 311c, 311d, and 311e. This allows for electrical connection via the connecting member 313 and the conductive layer 314 to the electrical components included in each of the insulating layers 311b, 311c, 311d, and 311e.

[0105] exist Figure 14 In this configuration, the first jet heater RhA and the second jet heater RhB are arranged on the upper surface of the insulating layer 311e, which serves as the top layer of the insulating layer 311. In other words, the first jet heater RhA is placed on the same layer as the second jet heater RhB. Furthermore, in... Figure 14In this embodiment, a portion of the first jet heater RhA can be electrically connected to the first jet drain wiring 107-1 via the connecting member 313 and the conductive layer 314. Similarly, a portion of the second jet heater RhB can be electrically connected to the second jet drain wiring 108-1 via the connecting member 313 and the conductive layer 314. Another portion of the first jet heater RhA can be electrically connected to the power supply voltage wiring VH 114a via the connecting member 313 and the conductive layer 314. Another portion of the second jet heater RhB can be electrically connected to the power supply voltage wiring VH 114b via the connecting member 313 and the conductive layer 314. Although in this embodiment, the power supply voltage wirings VH 114a and VH 114b are commonly connected, they can be configured to be individually connected and individually supplied with power voltage.

[0106] Note that, although this embodiment assumes Figure 10 The common cabling layer of GNDH cabling 115 is arranged in Figure 14 The power supply voltage wiring VH 114 is located on the upper layer above it, but this disclosure is not limited thereto. Figure 10 The GNDH wiring 115 can be in a layer lower than the power supply voltage wiring VH 114. Alternatively, Figure 10 The GNDH wiring 115 can be in the same layer as the power supply voltage wiring VH114. Furthermore, the common wiring layer of the GNDH wiring 115 is arranged in the largest possible area within the region included in the recording element substrate 18. This allows the total resistance value of each first jet heater RhA and the GNDH wiring to be substantially the same as the total resistance value of each second jet heater RhB and the GNDH wiring.

[0107] also, Figure 13 The electrode layers of the first injection drive elements MD1-1 to MD1-8 in the middle and Figure 13 The electrode layers of the second jet driving elements MD2-1 to MD2-8 are formed in the same layer as the first jet drain wiring 107. In other words, the second jet driving element rows 302 are arranged in parallel in the same layer as the first jet driving element rows 301. Figure 13 The electrode layers of the first injection drive elements MD1-1 to MD1-8 include Figure 13 The drain electrode, source electrode and gate electrode of the first injection drive elements MD1-1 to MD1-8 in the middle. Figure 13 The electrode layers of the second injection drive elements MD2-1 to MD2-8 include Figure 13The drain electrode, source electrode, and gate electrode of the second jet driving elements MD2-1 to MD2-8 are described above. Furthermore, the electrode layer of the first jet driving element MD1 is connected to the first jet drain wiring 107. The electrode layer of the second jet driving element MD2 is connected to the second jet drain wiring 108. As described above, the second jet drain wiring 108 and the first jet drain wiring 107 are in different layers. Furthermore, the electrode layer of the second jet driving element MD2 is formed in the same layer as the first jet drain wiring 107. Therefore, the second jet drain wiring 108 and the electrode layer of the second jet driving element MD2 are in different layers. For this reason, the electrode layer of the second jet driving element MD2 can be electrically connected to the second jet drain wiring 108 via the connecting member 313 and the conductive layer 314, which is in the same layer as the second jet drain wiring 108. In other words, the wiring layer on which the second jet drain wiring 108 is formed is a different layer from the electrode layer of the second jet driving element MD2, and interlayer electrical connection is made between the electrode layer of the second jet driving element MD2 and this wiring layer through a via. Note that, as described above, the wiring layer in which the first jet drain wiring 107 is formed is in the same layer as the electrode layer of the first jet drive element MD1 and the electrode layer of the second jet drive element MD2.

[0108] Furthermore, the first jet heater RhA and the second jet heater RhB can be made of metals with relatively high electrical resistance, such as silicon nitride tantalum and silicon nitride tungsten. Although not in Figure 14 As shown, but assuming the first jet driving element MD1 and the second jet driving element MD2 are disposed in the same semiconductor layer and are composed of N-type MOSFETs as described above. Furthermore, the connection member 313, conductive layer 314, first jet drain wiring 107-1, second jet drain wiring 108-1, and power supply voltage wiring VH114 are made of metals with relatively low resistance. For example, the connection member 313 is made of tungsten, copper, etc. Furthermore, for example, the conductive layer 314, first jet drain wiring 107-1, second jet drain wiring 108-1, and power supply voltage wiring VH114 are made of aluminum, copper, etc. In this embodiment, the first jet drain wiring 107-1 and the second jet drain wiring 108-1 are formed in different layers, and therefore arranged in a total of two layers. Furthermore, the second jet drain wiring 108-1 is formed in the upper layer compared to the first jet drain wiring 107-1.

[0109] Furthermore, despite Figure 13 In the image, a portion of the first jet drain wiring 107-1 and a portion of the second jet drain wiring 108-1 appear to overlap, but this is an example of wirings with the same width, and as shown... Figure 14 As shown, they are formed in different layers from each other.

[0110] Furthermore, it is assumed that the first jet drain wiring 107 and the second jet drain wiring 108 are identical in material and thickness. It is also assumed that the width and length of each wiring in the first jet drain wiring 107 and the second jet drain wiring 108 are adjusted such that the resistance values ​​of each wiring in the first jet drain wiring 107 and the second jet drain wiring 108 are substantially the same.

[0111] Note that it is desirable for the first jet drain wiring 107 and the second jet drain wiring 108 to be identical in material and thickness, but this disclosure is not limited thereto. For example, when the first jet drain wiring 107 and the second jet drain wiring 108 differ in material and thickness, the width and length of each wiring in the first jet drain wiring 107 and the second jet drain wiring 108 can be adjusted. This adjustment can make the resistance values ​​of each wiring in the first jet drain wiring 107 and the second jet drain wiring 108 as uniform as possible.

[0112] Furthermore, although in this embodiment the electrical components of the conductive layer 314, the first jet drain wiring 107-1, the second jet drain wiring 108-1, and the power supply voltage wiring VH 114 are formed in different layers, thus consisting of a total of four layers, this disclosure is not limited thereto. They may consist of a different number of layers than in this embodiment. Next, we will use... Figure 15 Describe the comparison example.

[0113] (Comparative arrangement example) Figure 15 This is a diagram showing a comparative example of the arrangement of the heater and drive element. Figure 15 In this context, it is assumed that the jet drain wiring and the circulating drain wiring are arranged on the same layer. Therefore, the area between supply port 32-1 and supply port 32-2 cannot be adequately guaranteed for the area traversed by the jet drain wiring and the circulating drain wiring. Therefore, in Figure 15 In the comparative arrangement example, the widths of the jet drain wiring and the circulating drain wiring are thinner than expected. Furthermore, the first jet drive element MD1 and the second jet drive element MD2 are arranged alternately in a single row. Therefore, sufficient space cannot be guaranteed for placing the first jet drive element MD1 and the second jet drive element MD2. Therefore, in Figure 15 In the comparative arrangement example, the dimensions of the first injection drive element MD1 and the second injection drive element MD2 are smaller than expected.

[0114] (The effect of the first scenario) As described above, in the first case, the first jet drain wiring 107 and the second jet drain wiring 108 are arranged in different layers, for a total of two layers. Therefore, the first jet drain wiring 107 and the second jet drain wiring 108 are not arranged in the same layer, but rather a single drain wiring is arranged in one layer. This doubles the area through which the wiring between the supply ports 32 can pass. This allows for ensuring sufficient space for arranging the drain wiring in each layer. Therefore, the wiring width of the drain wiring can be ensured as intended. For this reason, driving elements such as the first jet driving element MD1 and the second jet driving element MD2 can be appropriately arranged on the recording element substrate 18.

[0115] Furthermore, along the longer side of the recording element substrate 18, the first jet driving element row 301 and the second jet driving element row 302 are arranged in two rows. This doubles the area where the driving elements can be arranged. Therefore, the size of the driving elements can be set as desired.

[0116] Furthermore, the drive element on the side farther from the heater is connected to the heater on the side closer to the drive element, while the drive element on the side closer to the heater is connected to the heater on the side farther from the drive element.

[0117] For example, suppose the first jet heater row 112, the second jet heater row 113, the first jet drive element row 301, and the second jet drive element row 302 are arranged sequentially. Under this assumption, the first jet heater row 112 is arranged in a region farther from the region where the first jet drive element row 301 and the second jet drive element row 302 are arranged, compared to the second jet heater row 113. Furthermore, the first jet drive element row 301 is arranged in a region closer to the first jet heater row 112 and the second jet heater row 113 than the second jet drive element row 302. Under this assumption, the following applies. In other words, the second jet drive element MD2 on the side farther from the heater is connected to the second jet heater RhB on the side closer to the drive element via the second jet drain wiring 108. Furthermore, the first jet drive element MD1 on the side closer to the heater is connected to the first jet heater RhA on the side farther from the drive element via the first jet drain wiring 107.

[0118] Alternatively, for example, it can be assumed that the second jet heater row 113, the first jet heater row 112, the second jet drive element row 302, and the first jet drive element row 301 are arranged sequentially. Under this assumption, the second jet heater row 113 is arranged in a region farther from the region where the first jet drive element row 301 and the second jet drive element row 302 are arranged, compared to the first jet heater row 112. Furthermore, the second jet drive element row 302 is arranged in a region closer to the first jet heater row 112 and the second jet heater row 113 than the first jet drive element row 301. Under this assumption, the situation is as follows: In other words, the first jet drive element MD1 on the side farther from the heater is connected to the first jet heater RhA on the side closer to the drive element via the first jet drain wiring 107. Furthermore, the second jet drive element MD2 on the side closer to the heater is connected to the second jet heater RhB on the side farther from the drive element via the second jet drain wiring 108.

[0119] This configuration makes it easier to uniformize the lengths of the first jet drain wiring 107 and the second jet drain wiring 108. Therefore, it is easier to equalize the resistance values ​​of the various wirings in the first jet drain wiring 107 and the second jet drain wiring 108. Thus, the energy losses (hereinafter referred to as voltage drops) occurring in the first jet drain wiring 107 and the second jet drain wiring 108 can be balanced.

[0120] Here, when the first jet heater RhA and the second jet heater RhB are driven, the voltage drop occurring in the portion other than the first jet heater RhA and the second jet heater RhB is as follows. In other words, in addition to the individual wiring resistance values ​​of the first jet drain wiring 107 and the second jet drain wiring 108, the following is also included. In other words, the voltage drop caused by the individual on-resistances of the first jet drive element MD1 and the second jet drive element MD2, as well as the total resistance value of the GNDH wiring 115, is included.

[0121] In the first case, it is assumed that the on-resistance values ​​of the first injection drive element MD1 and the second injection drive element MD2 are substantially the same, and the total resistance value of the GNDH wiring 115 is also substantially the same. Therefore, when the first injection heater RhA and the second injection heater RhB are driven, the voltage drop occurring in the portions other than the first injection heater RhA and the second injection heater RhB is the same. Therefore, each of the first injection heater RhA and the second injection heater RhB can perform a stable heater drive with small deviations.

[0122] Furthermore, when the individual on-resistance values ​​of the first injection drive element MD1 and the second injection drive element MD2 differ from the total resistance value of the GNDH wiring 115, the following measures are sufficient. In other words, by adjusting the individual wiring widths or lengths of the first injection drain wiring 107 and the second injection drain wiring 108, the total wiring resistance value, excluding the first injection heater RhA and the second injection heater RhB, can be made as uniform as possible.

[0123] (Second scenario) Figure 16 This is an example of the arrangement of the heater and drive element according to the second case of this embodiment. The second case differs from the first case in that multiple units 305 are provided. The second case is a layout in which the units 305 are arranged symmetrically with respect to the longer side direction of the recording element substrate 18. Furthermore, the second case has a layout in which supply ports 401-1 and 401-2 are provided between the units 305. In this layout, supply ports 401-1 and 401-2 have the function of supplying ink to the units 305. Therefore, the size of the recording element substrate 18 can be reduced.

[0124] Specifically, unit 305 includes a first row of jet driving elements, a second row of jet driving elements, and a resistance heating element region. The first row of jet driving elements includes first jet driving elements MD1-1 to MD1-8. The second row of jet driving elements includes second jet driving elements MD2-1 to MD2-8. The resistance heating element region includes first jet heaters RhA-1 to RhA-8 and second jet heaters RhB-1 to RhB-8. In this embodiment, two units 305 are formed. Units 305 are arranged symmetrically with respect to the supply port 401, such that the resistance heating element regions face each other. In this arrangement, units 305 are placed on both sides of the supply port 401. Therefore, the supply port 401 can supply ink to units 305. Therefore, the overall size of the recording element substrate 18 can be reduced.

[0125] Note that the dimensions of supply ports 401-1 and 401-2 may be the same as or different from the dimensions of supply ports 32-1 and 32-2. Furthermore, although the second case shows an example where the number of supply ports 401 is the same as the number of supply ports 32, the number of supply ports 401 may differ from the number of supply ports 32. Furthermore, although an example of eight first jet heaters RhA arranged for one supply port 401 is shown, the number is not limited to eight. The same applies to the second jet heaters RhB. Furthermore, although an example of two units 305 is shown, the number may be three or more. In other words, in the second case, at least two units 305 are formed.

[0126] (Third scenario) The third scenario involves placing the first jet heater 14A and the second jet heater 14B on either side of the supply tank 42, without any external pump 71 or other configuration for ink circulation. The first jet heater 14A has the same configuration and function as the first jet heater RhA. The second jet heater 14B has the same configuration and function as the second jet heater RhB. Figure 17A This is a plan view seen from the direction of the liquid droplets ejected from nozzles 11A and 11B. Figure 17B It is along Figure 17A A cross-sectional view taken from lines XVIIB-XBIIB in the diagram. Injector ports 11A and 11B are formed on the orifice plate 19. A first injection heater RhA and a second injection heater RhB are formed directly below injection ports 11A and 11B. Liquid is supplied from the supply tank 42 to a separate flow channel 23. Even in this case, as in the first case, the drain wiring arranged in the two layers connects the first injection heater 14A to the first injection drive element MD1 and the second injection heater 14B to the second injection drive element MD2. Therefore, the same effect as in the first case can be achieved.

[0127] (Other exemplary embodiments) Although the first to third cases of this embodiment have been described above, the invention is not limited to the values, forms, and quantities described above, and they should vary depending on the configuration of the recording element substrate 18. For example, the number of nozzles in each nozzle row is not limited to 8 or 16. For example, the number of nozzles in each nozzle row can be 512. Furthermore, the nozzle row itself can be not only 1 or 2 rows, but also 3 or more rows.

[0128] Although various examples and embodiments of this disclosure have been shown and described above, the purpose and scope of this disclosure are not limited to the specific description herein. This disclosure is not limited to the embodiments described above, and various modifications can be made. Furthermore, the embodiments described above may be appropriately combined in this disclosure.

[0129] (Variation Example 1) For example, although this embodiment describes an example of using vias to make electrical connections with other wiring layers, it is not limited thereto. For example, instead of vias that cause electrical conduction between some wiring layers and other wiring layers in a plurality of stacked wiring layers, a conductive coating can be applied to the vias that penetrate all wiring layers.

[0130] (Variation Example 2) Furthermore, for example, the number of nozzles in each row of multiple nozzles 11 is not limited. It can be 8, 16, or 512. The number of nozzle rows is also not limited. It can be 1 row, 2 rows, 3 rows, or more rows.

[0131] (Variation Example 3) Furthermore, for example, either the first jet heater RhA or the second jet heater RhB can function as a circulation heater for circulating ink. For instance, in the configuration shown in FIG4, where there is no jet nozzle 11 directly above the second jet heater RhB, the function of circulating ink can be assigned to the second jet heater RhB.

[0132] Other embodiments Embodiments of this disclosure can also be implemented by a computer of a system or apparatus and by a method performed by the computer of the system or apparatus, wherein the computer of the system or apparatus 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 of the above embodiments, and / or the computer of the system or apparatus includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing the functions of one or more of the above embodiments, the method being performed by the computer of the system or apparatus, for example, by reading and executing the computer-executable instructions from the storage medium to perform the functions of one or more of the above embodiments, and / or by controlling the one or more circuits to perform the functions of one or more of the above embodiments. The computer may include one or more processors (e.g., a central processing unit (CPU), a microprocessor unit (MPU)) 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 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.

[0133] Other embodiments 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 apparatus via a network or various storage media, and the computer (central processing unit (CPU) or microprocessor unit (MPU) of the system or apparatus) reads and executes the computer program.

[0134] According to this disclosure, driving elements can be suitably arranged on a recording element substrate.

[0135] While this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the following claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A recording element substrate, comprising: The resistance heating element region includes a first row of resistance heating elements and a second row of resistance heating elements. The first row of resistance heating elements includes a plurality of first resistance heating elements arranged in a row, and the second row of resistance heating elements includes a plurality of second resistance heating elements arranged in a row. The second row of resistance heating elements is parallel to the first row of resistance heating elements. The driving element region includes a first driving element row and a second driving element row. The first driving element row includes a plurality of first driving elements for driving the plurality of first resistance heating elements, which are arranged in a row. The second driving element row includes a plurality of second driving elements arranged in a row. The second driving element row is parallel to the first driving element row. The driving element region is positioned parallel to the resistance heating element region. A first wiring layer connects one of the first and second drive element rows that is farther from the resistance heating element region to one of the first and second resistance heating element rows that is closer to the drive element region. as well as A second wiring layer connects the row of first and second driving elements that is closer to the resistance heating element region to the row of first and second driving elements that is farther from the driving element region. The first wiring layer is formed in a different layer than the second wiring layer.

2. The recording element substrate according to claim 1, wherein the first row of resistive heating elements, the second row of resistive heating elements, the first row of driving elements, and the second row of driving elements are arranged in the order of the first row of resistive heating elements, the second row of resistive heating elements, the first row of driving elements, and the second row of driving elements in a direction orthogonal to the row direction of the first row of resistive heating elements.

3. The recording element substrate according to claim 1, wherein the resistance values ​​of the plurality of first resistance heating elements and the plurality of second resistance heating elements are substantially equal.

4. The recording element substrate according to claim 1, wherein a plurality of supply ports for supplying liquid are arranged in a row between the resistance heating element region and the drive element region along the row direction of the first resistance heating element row.

5. The recording element substrate of claim 4, wherein a plurality of first wirings in the first wiring layer and a plurality of second wirings in the second wiring layer are arranged between the plurality of supply ports.

6. The recording element substrate according to claim 1, wherein the first wiring layer is formed in an upper layer above the second wiring layer.

7. The recording element substrate according to claim 1, wherein the resistance value of the first wiring layer is substantially equal to the resistance value of the second wiring layer.

8. The recording element substrate according to claim 1, wherein the second wiring layer is a layer different from the electrode layer of the second driving element, and interlayer electrical connection is made between the electrode layers of the plurality of second driving elements and the second wiring layer through vias.

9. The recording element substrate of claim 4, wherein one of the first row of resistance heating elements and the second row of resistance heating elements generates heat for spraying liquid supplied from the plurality of supply ports.

10. The recording element substrate of claim 4, wherein one of the first row of resistance heating elements and the second row of resistance heating elements generates heat for circulating the liquid supplied from the plurality of supply ports.

11. The recording element substrate according to claim 1, wherein the element area of ​​the first driving element is substantially equal to the element area of ​​the second driving element.

12. The recording element substrate of claim 1, wherein the drive current supplied from the first driving element to the first resistive heating element is substantially equal to the drive current supplied from the second driving element to the second resistive heating element.

13. The recording element substrate of claim 1, wherein the drive current to the first resistive heating element is substantially equal to the drive current to the second resistive heating element.

14. The recording element substrate of claim 1, wherein the first wiring layer is formed in the same layer as the electrode layer of the first driving element and the electrode layer of the second driving element.

15. The recording element substrate according to claim 1, further comprising: A second supply port for supplying ink; as well as At least one unit including the driving element region and the resistance heating element region, wherein The at least one unit comprises at least two units, and the at least two units are formed, and The at least two units are arranged symmetrically with respect to the second supply port, such that the respective resistance heating element regions face each other.

16. The recording element substrate of claim 1, further comprising power wiring configured to be electrically connected to each of the plurality of first resistive heating elements and the plurality of second resistive heating elements for supplying power.

17. The recording element substrate of claim 1, further comprising ground wiring configured to be electrically connected to each of the plurality of first driving elements and the plurality of second driving elements for setting a reference potential.

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