Printed element substrate

Abstract

A print element substrate includes: a first drive element array including a plurality of first drive elements configured to drive a plurality of first heating resistance elements, the plurality of first drive elements being arranged in an array; a second drive element array including a plurality of second drive elements configured to drive a plurality of second heating resistance elements, the plurality of second drive elements being arranged in an array; a first wiring configured to connect the first heating resistance elements and the first drive elements; and a second wiring configured to connect the second heating resistance elements and the second drive elements. The second drive element array is arranged side by side with the first drive element array on the same layer as the first drive element array, and the second drive element array is arranged at a position farther from a heating resistance element region than the first drive element array.

Description

Technical Field

[0001] This invention relates to the arrangement technology of driving elements in a printed element substrate. Background Technology

[0002] Circulating liquid jetting devices are well known, which circulate ink within a liquid jetting head. Japanese Patent Publication No. 2020-104493 (hereinafter referred to as Document 1) discloses a configuration as a circulating liquid jetting device, which includes a jetting energy generating element for jetting ink and a circulation energy generating element for circulating the ink. Furthermore, this circulating liquid jetting device uses drive elements to drive the jetting energy generating element and the circulation energy generating element, respectively.

[0003] Document 1 discloses a configuration in which an array of jet energy generating elements and an array of circulating energy generating elements are arranged side by side. Accordingly, driving elements for the jet energy generating elements and the circulating energy generating elements are respectively provided in the printing element substrate, but there are cases where the driving elements cannot be properly arranged in the printing element substrate. Summary of the Invention

[0004] A printed element substrate according to one aspect of this disclosure includes: a first driving element array including a plurality of first driving elements configured to drive a plurality of first heating resistor elements, the plurality of first driving elements being arranged in an array; a second driving element array including a plurality of second driving elements configured to drive a plurality of second heating resistor elements, the plurality of second driving elements being arranged in an array; a plurality of first wirings configured to connect the plurality of first heating resistor elements and the plurality of first driving elements; and a plurality of second wirings configured to connect the plurality of second heating resistor elements and the plurality of second driving elements, the second driving element array being arranged side-by-side with the first driving element array on the same layer as the first driving element array, and the second driving element array being arranged at a position further away from the heating resistor element region than the first driving element array, the heating resistor element region including the plurality of first heating resistor elements and the plurality of second heating resistor elements, and the plurality of second wirings being formed in a different layer than the plurality of first wirings.

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

[0006] Figure 1A It is a schematic perspective view of a liquid jetting device, in which the ink cartridge is disposed outside the liquid jetting head as a liquid reservoir; Figure 1BIt is a schematic perspective view of a liquid jetting device, in which the sub-cartridge is positioned directly above the liquid jetting head; Figure 2A yes Figure 1A and Figure 1B Exploded perspective view of the liquid injection head; Figure 2B This diagram illustrates a liquid jetting chip that can spray out four colors. Figure 2C This diagram illustrates a liquid jetting chip that can spray out two colors. Figure 2D This is a diagram illustrating a liquid jetting chip that can spray out a single color; Figure 3A It is a plan view taken along the direction in which the droplets are ejected from the nozzle of a single ejection unit; Figure 3B yes Figure 3A Sectional view of IIIB-IIIB; Figure 3C yes Figure 3A The cross-sectional view of IIIB-IIIB, and the internal configuration of the printed element substrate. Figure 3B Different cross-sectional views are configured in the middle; Figure 3D This is a diagram illustrating the flow of ink when the first energy-generating element is driven; Figure 4A yes Figure 3A The cross-sectional view of the individual injection unit is shown in sections IIIB-IIIB, and is used to illustrate the generation and growth process of bubbles generated by heating the ink with a second energy generating element and causing the ink to boil in a film state. Figure 4B yes Figure 3A The cross-sectional view of the individual injection unit is shown in section IIIB-IIIB, and is used to illustrate the process of bubble contraction generated by heating the ink with a second energy generating element and causing the ink to boil in a film state. Figure 4C yes Figure 3A The cross-sectional view of the individual injection unit is shown in section IIIB-IIIB, and is used to illustrate the process after the bubbles disappear when the ink is heated by the second energy generating element and the film boiling of the ink is caused. Figure 5A This is a diagram showing the state where the ink circulation flow has temporarily stopped; Figure 5B It is shown in Figure 5A The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element in the state following the previous state; Figure 5C It is shown in Figure 5B The diagram shows the state where the ink circulation flow temporarily stops after the initial state. Figure 5D It is shown in Figure 5C The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element in the state following the previous state; Figure 6A This is a diagram showing the state where the ink circulation flow has temporarily stopped; Figure 6B It is shown in Figure 6A The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element in the state following the previous state; Figure 6C It is shown in Figure 6B The diagram shows the state where the ink circulation flow temporarily stops after the initial state. Figure 6D It is shown in Figure 6C The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element in the state following the previous state; Figure 7A This is a plan view taken along the direction in which the droplet is ejected from the injection hole 11; Figure 7B yes Figure 7A Sectional view of VIIB-VIIB; Figure 7C yes Figure 7A Enlarged schematic diagram of a single channel in the middle; Figure 8A It is a plan view taken along the direction in which the droplet is ejected from the nozzle; Figure 8B yes Figure 8A Sectional view of VIIIB-VIIIB; Figure 8C yes Figure 8A The cross-sectional view of VIIIB-VIIIB, and the internal configuration of the printed element substrate therein. Figure 8B Different cross-sectional views are configured in the middle; Figure 9A It is a plan view taken along the direction in which the droplet is ejected from the nozzle; Figure 9B yes Figure 9A IXB-IXB cross-sectional view; Figure 9C yes Figure 9A The IXB-IXB cross-sectional view shows the internal configuration of the printed component substrate. Figure 9B Different cross-sectional views are configured in the middle; Figure 10 This is a diagram illustrating an example of the circuit configuration of a printed element substrate according to this embodiment; Figure 11AIt 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 circuit configuration for a loop group selection circuit; Figure 12 This is a diagram illustrating an example arrangement of the heater and drive element in a first case according to this embodiment; Figure 13 yes Figure 12 A partially enlarged view of an example arrangement of the heater and drive element in the first case; Figure 14 It is shown Figure 13 A diagram of the cross-sectional structure along line XIV-XIV; Figure 15 This is a diagram showing a comparative example of the arrangement of the heater and drive element; Figure 16 This is a diagram illustrating an example arrangement of the heater and drive element in a second case according to this embodiment; and Figure 17 This is a diagram illustrating an example arrangement of the heater and drive element in a third case according to this embodiment. Detailed Implementation

[0007] Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Please 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 necessarily necessary for the solutions provided in the present disclosure. Please note that the same constituent elements are denoted by the same reference numerals.

[0008] (summary) For example, inkjet printheads that eject ink (also known as liquids) are often referred to as liquid printheads. An inkjet printhead consists of ejection orifices that eject ink. Volatile components in the ink sometimes evaporate from these orifices. Therefore, the ink in the orifices sometimes thickens due to the evaporation of these volatile components. This thickening of the ink changes the ink ejection speed. When the ink ejection speed changes, the ink landing accuracy may not be as high as expected. Specifically, reduced ink landing accuracy can lead to ejection failures. In particular, the increase in ink viscosity can become significant when there are long pauses in the ink ejection operation. If the ink viscosity increases significantly, solid components in the ink may adhere firmly to the inside of the ejection orifice. In this case, the ink flow resistance increases. Therefore, ink ejection failures may easily occur.

[0009] To address the aforementioned liquid thickening phenomenon, a known countermeasure is to direct fresh liquid towards the jet nozzle. For example, one method of liquid flow is to use a pump, positioned on the body side, in addition to the jetting components. Using this pump creates a pressure differential within the liquid inside the inkjet printhead. This pressure differential can be used to circulate the liquid. Alternatively, another method is to incorporate a circulation element within the jetting components themselves. When using a heating resistor element as the circulation element, the heating resistor element can cause the liquid to foam. This foaming action allows for liquid circulation.

[0010] This document discloses a technique in which, after a prolonged period of no liquid ejection from the inkjet nozzle, a jet heater for ink ejection operation and a circulation heater for ink circulation operation are used. The jet heater enables liquid to be ejected from the inkjet nozzle on demand. In this technique, multiple jet heaters (hereinafter also referred to as first heating resistance elements) are arranged in an array, and multiple circulation heaters (hereinafter also referred to as second heating resistance elements) are arranged in an array, and these arrays are arranged side by side.

[0011] To drive the jet heater and the circulation heater, it is envisioned 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 arranged. For balance with other circuits, sometimes the driver for driving the jet heater and the driver for driving the circulation heater are arranged on one side. In the above-described technique, multiple ink supply ports are arranged in an array. These multiple supply ports arranged in the array are shared. Alternatively, based on the number of heaters (such as jet heaters and circulation heaters), each segment unit can be provided with a separate ink supply port. In the case of separate supply ports, the driver and the heater are arranged on opposite sides of the separate supply port. Therefore, the drain wiring only needs to be arranged to pass between each separate supply port.

[0012] However, in recent years, the number of inkjet nozzles has been increasing to achieve higher resolution printing. With the increase in the number of inkjet nozzles, the ink supply also tends to increase. As a measure to address the increased ink supply, increasing the size of the individual supply ports is a possible solution. However, the usable area on the printed element substrate is limited. Therefore, with an increase in the size of the individual supply ports, the area between the individual supply ports becomes smaller. With a smaller area between the individual supply ports, the area available for the drain wiring to pass through becomes smaller.

[0013] When circulating heaters are installed on the printed circuit board, the number of drain wirings and drivers increases compared to when circulating heaters are not installed on the printed circuit board. For example, if the number of circulating heaters is the same as that of jet heaters, the number of drain wirings and drivers could potentially double. In this case, the total number of drain wirings increases. Therefore, if all drain wirings (including the additional wirings) are arranged across the area between individual supply ports, it may be impossible to guarantee that the wiring width of each drain wiring meets expectations.

[0014] Furthermore, in the aforementioned technology, the jet heater consumes more energy than the circulating heater. Therefore, the energy consumed in the drain wiring connecting the jet heater and the driver configured to drive the jet heater tends to be higher than the energy consumed in the drain wiring connecting the circulating heater and the driver configured to drive the circulating heater. However, if it is possible to make the energy consumed in the drain wiring connected to the jet heater less than the energy consumed in the drain wiring connected to the circulating heater, it becomes possible to achieve efficient heater driving.

[0015] In this disclosure, the driver and drain wiring for driving each of the jet heater and the circulating heater is configured as follows. Specifically, the printed element substrate includes a first driving element array, a second driving element array, a plurality of first wirings, and a plurality of second wirings. The first driving element array is an array in which a plurality of first driving elements are arranged in an array, these first driving elements being configured to drive a plurality of first heating resistor elements. The second driving element array is an array in which a plurality of second driving elements are arranged in an array, these second driving elements being configured to drive a plurality of second heating resistor elements. The plurality of first wirings connect the plurality of first heating resistor elements and the plurality of first driving elements to each other. The plurality of second wirings connect the plurality of second heating resistor elements and the plurality of second driving elements to each other. The second driving element array is an array arranged side-by-side with the first driving element array on the same layer as the first driving element array, and the second driving element array is arranged on the same layer as the first driving element array at a position further away from the heating resistor element region than the first driving element array, the heating resistor element region being the area in which the plurality of first heating resistor elements and the plurality of second heating resistor elements are arranged. Multiple second wirings are wirings formed in layers different from the multiple first wirings. In this configuration, the energy consumed by the drain wiring of the jet heater can be reduced, and the heater can be driven more efficiently, while the wiring width of the drain wiring can be designed as needed, and the size of the driver can be ensured. Specifically, the driving elements can be suitably arranged in the printed element substrate.

[0016] Furthermore, according to this disclosure, arranging the drain wiring in two layers doubles the area that the drain wiring can pass through between independent supply ports. Additionally, by designing the drain wiring width as needed and arranging the drivers in two arrays, the area available for driver placement is doubled. Therefore, sufficient area can be ensured for driver placement. Consequently, the driver size can be designed according to requirements.

[0017] Furthermore, according to this disclosure, the driver of the jet heater (also called the jet drive element) is located closer to the region where the heating resistor elements of both the jet heater and the circulating heater are arranged, than the driver of the circulating heater (also called the circulating drive element). Therefore, the resistance value of the drain wiring of the jet heater can be less than that of the drain wiring of the circulating heater. Consequently, the energy consumed in the drain wiring of the jet heater can be less than that consumed in the drain wiring of the circulating heater. This allows for efficient driving of the heater.

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

[0019] <Liquid injection device 50> Figure 1A A perspective view of the liquid jetting device 50 is shown schematically, in which the ink cartridge 2 is disposed outside the liquid jetting head 1 as a liquid reservoir. Figure 1B A perspective view of the liquid injection device 50 is shown schematically, in which the sub-ink cartridge 54 is positioned directly above the liquid injection head 1. First, regarding... Figure 1A and Figure 1B The common parts will be explained.

[0020] The liquid jetting device 50 includes a liquid jetting head 1 and transport rollers 55, 56, 57, and 58. The liquid jetting head 1 scans along a direction X intersecting the transport direction Y of the target medium P. The liquid jetting head 1 is mounted in a carriage 60. The liquid jetting head 1 is fixed and supported on the carriage 60 by a positioning device (not shown) and electrical contacts provided in the carriage 60. The carriage 60 reciprocates along a guide shaft 51 in the main scanning direction (also called direction X). Therefore, the liquid jetting head 1 jets ink while moving along the main scanning direction with the carriage 60, thereby printing on the target medium P. The transport rollers 55, 56, 57, and 58 transport the target medium P along a sub-scanning direction (also called the transport direction Y) that intersects (in this embodiment, orthogonal) the main scanning direction. Specifically, the liquid jetting device 50 is configured as a tandem inkjet liquid jetting device by jetting liquid from the liquid jetting head 1 to the target medium P transported along the transport direction Y while scanning in the X direction. Note that the application of this disclosure is not limited to tandem inkjet liquid ejection apparatuses. This disclosure can also be applied to page-width inkjet liquid ejection apparatuses, which use a linear head (page-width head) extending along the page width direction of the target medium P to eject liquid onto the target medium P being conveyed along the transport direction Y. Note that... Figure 1A and Figure 1B The Z direction indicates the vertical direction. Specifically, the Z direction is the direction that intersects (or is orthogonal in this embodiment) the XY plane specified by the X direction and the transport 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 use these four types of ink to print full-color images. Note that the inks ejected by the liquid ejector head 1 are not limited to the four types mentioned above. For example, this disclosure can also be applied to liquid ejector heads 1 configured to eject other types of ink (such as special color inks). Specifically, there are no limitations on the type and quantity of ink ejected by the liquid ejector head 1.

[0022] Next, an explanation Figure 1A and Figure 1B The different parts. In Figure 1A In this assembly, a sub-ink cartridge 54 is installed in the liquid ejector head 1. Four ink supply tubes (liquid communication paths) 59 are attached to the sub-ink cartridge 54. Furthermore, the liquid ejector device 50 includes an ink cartridge 2 and an external pump 71. The ink cartridge 2 stores ink. The ink stored in the ink cartridge 2 is supplied to the sub-ink cartridge 54 via the four ink supply tubes 59 by the driving force of the external pump 71. Simultaneously, in... Figure 1B In the middle, the sub-ink cartridge 54 is positioned directly above the liquid jet head 1. Figure 1B Unlike Figure 1AThe difference is that, since the ink cartridge 2 is not externally mounted on the liquid ejector head 1, there are no four ink supply tubes 59 attached, nor is an external pump 71 installed. Note that in Figure 1A and Figure 1B In either case, the liquid injection head 1 can be configured to be integrated with the sub-cartridge 54 and attachable to or detachable from the bracket 60. Alternatively, it can be configured such that the sub-cartridge 54 is integrated with the bracket 60, and only the sub-cartridge 54 can be attached to or detached from the bracket 60. The following description is for use... Figure 1A The configuration is provided during the setup process.

[0023] <Basic Configuration of Liquid Jet Head 1> Figures 2A to 2D It is shown Figure 1A and Figure 1B A diagram showing a basic configuration example of the liquid injection head 1. Figure 2A yes Figure 1A and Figure 1B Exploded perspective view of liquid injection head 1. Figure 2B , Figure 2C and Figure 2D It is shown Figure 2A A diagram illustrating an example of the liquid ejection chip 3. The liquid ejection head 1 includes a housing portion 53, a sub-ink cartridge 54, and the liquid ejection chip 3. The sub-ink cartridge 54 temporarily stores ink from the liquid ejection head 1. The sub-ink cartridge 54 is housed within the housing portion 53. As detailed later, the liquid ejection chip 3 is disposed at the bottom of the housing portion 53. The liquid ejection chip 3 ejects ink supplied from the sub-ink cartridge 54 onto the target ejection medium P.

[0024] Note that, although omitted in the figure, a liquid connector insertion port is provided on the wall surface of housing portion 53. Figure 1A A liquid connector located at the front end of the ink supply tube 59 is inserted into and connected to these liquid connector insertion ports in a liquid-tight manner. This configuration forms an ink supply path extending from the ink cartridge 2 via the external pump 71 to the liquid ejector head 1. In this embodiment, four types of ink are used. Therefore, four sets of ink cartridges 2, external pumps 71, ink supply tubes 59, and sub-ink cartridges 54 are provided to correspond to the respective inks. Thus, four ink supply paths corresponding to the respective inks are independently formed. As described above, in this embodiment, the liquid ejector device 50 includes an ink supply system in which ink is supplied by ink cartridges 2 disposed outside the liquid ejector head 1.

[0025] A first support member 4 and a second support member 7 are disposed between the housing portion 53 and the liquid jet chip 3. An electrical wiring member 5 is disposed below the liquid jet chip 3. Specifically, the first support member 4 has an ink supply port and an ink collection port. The second support member 7 has an opening. The liquid jet chip 3 is attached to and fixed to the first support member 4. The first support member 4 is attached to and fixed to the second support member 7. The second support member 7 holds the electrical wiring member 5 so that the electrical wiring member 5 is electrically connected to the liquid jet chip 3. The electrical wiring member 5 applies electrical signals for jetting ink and for circulating ink to the liquid jet chip 3.

[0026] Note that in this embodiment, the liquid ejection device 50 does not include an ink collection system for collecting ink from the liquid ejection head 1 into the ink cartridge 2. Therefore, the liquid ejection head 1 is provided with a liquid connector insertion port for connecting to the liquid connector of the ink supply tube 59, but is not provided with a connector insertion port for connecting to the tube configured to collect ink into the ink cartridge 2.

[0027] Figure 2B The diagram shows a configuration where the liquid jetting chip 3 has one chip for every four colors. Specifically, Figure 2B The diagram illustrates a liquid jetting chip 3 capable of jetting four colors. The liquid jetting chip 3 includes multiple jetting orifices and pads for electrical mounting. These four colors are, for example, black, cyan, magenta, and yellow, and arrays are provided for each color. Each array is formed along the transport direction Y and spaced apart along the direction X. Each array includes multiple jetting orifices. The multiple jetting orifices are arranged at equal intervals along the Y direction. The jetting orifices in each array can be arranged as one array along the Y direction without needing to be spaced apart along the X direction. Alternatively, the configuration can also be such that: only two arrays are arranged for jetting orifices for black, three arrays are arranged for jetting orifices for the other three colors, and a total of five arrays are arranged for jetting orifices for all four colors. Note that... Figure 2A The liquid jet chip 3 illustrates an example configuration with one chip for every four colors. Specifically, Figure 2A The liquid jet chip 3 shows Figure 2B An example of the situation.

[0028] Figure 2C The diagram shows a configuration where the liquid jet chip 3 has one chip for every two colors. In this case, two chips are used. Specifically, Figure 2C The illustration shows a case where one liquid spraying chip 3 can spray two colors. When the liquid spraying chip 3 is installed in the liquid spraying head 1, two liquid spraying chips 3 can be installed in one liquid spraying head 1; or two liquid spraying heads 1 can be prepared, with one liquid spraying chip 3 installed in each liquid spraying head 1.

[0029] Figure 2D The diagram shows a configuration where the liquid jetting chip 3 has one chip for each color. In this case, four chips are used. Specifically, Figure 2D The illustration shows a case where one liquid spray chip 3 can spray one color. With the liquid spray chip 3 installed in the liquid spray head 1, four liquid spray chips 3 can be installed in one liquid spray head 1; or four liquid spray heads 1 can be prepared, with one liquid spray chip 3 installed in each liquid spray head 1.

[0030] Note that it is assumed that multiple liquid injection chips 3 are installed in one liquid injection head 1 (e.g., Figure 2C and Figure 2D As shown in the example, the chip lengths of these liquid jetting chips 3 do not need to be the same. Furthermore, the number of colors in the liquid jetting chips 3 is not limited to a specific number, and various combinations of numbers of colors can be used. For example, although described as... Figure 2A The example of liquid jet chip 3 having four colors is shown, but the number of colors in liquid jet chip 3 can exceed four.

[0031] <Single Channel: Straight> The liquid injection head 1 includes multiple individual injection units, each with its own channel. The liquid injection head 1 also includes supply channels for supplying liquid to the individual channels of the respective individual injection units. Figure 3A This is a plan view taken along the direction in which the droplets are ejected from the ejection orifice 11 of the individual ejection unit. Figure 3B yes Figure 3A Sectional view of IIIB-IIIB. Figure 3C yes Figure 3A The cross-sectional view of IIIB-IIIB, and the internal configuration of the printed element substrate 18 therein. Figure 3B Different cross-sectional views are configured in the middle.

[0032] Each individual injection unit includes an injection orifice 11, a pressure chamber 12, a first energy generating element RhA (also known as the injection energy generating element RhA) and a second energy generating element RhB (also known as the circulating energy generating element RhB).

[0033] A pressure chamber 12 corresponding to each ejection orifice 11 is formed by separating the space between the printing element substrate 18 and the perforated plate 19 using a partition 21. The ejection orifice 11 is an opening formed in a portion of the perforated plate 19. A meniscus of ink flowing through the pressure chamber 12 is formed in the ejection orifice 11, and the ejection orifice interface forms an interface between the ink and the atmosphere. The ejection orifice 11 ejects liquid.

[0034] A separate channel 23 extends along a second direction that intersects (or is orthogonal in this embodiment) the direction in which the injection holes 11 are arranged in an array (a first direction). The separate channel 23 includes a pressure chamber 12, an inlet (upstream) side connection channel, and an outlet (downstream) side connection channel. The inlet side connection channel communicates with one end of the pressure chamber 12. The outlet side connection channel communicates with the other end of the pressure chamber 12.

[0035] A supply port 22 is provided at one end of the individual channel 23. The supply port 22 is an opening extending from a common channel (not shown) through the interior of the printed element substrate 18 to the upstream side of the individual channel 23. A supply port 32 is provided at the other end of the individual channel 23. The supply port 32 is an opening extending from a common channel (not shown) through the interior of the printed element substrate 18 to the downstream side of the individual channel 23. Liquid is supplied to the individual channel 23 via the supply ports 22 and 32.

[0036] In the printed element substrate 18, the first energy generating element RhA is formed closer to the supply port 32 than to the supply port 22. The first energy generating element RhA is a component used to generate energy to eject liquid from the injection port 11 in the pressure chamber 12. Specifically, the first energy generating element RhA is driven to generate heat and cause bubbles to form in the liquid (also called ink) in the pressure chamber 12. Thus, by utilizing the energy generated from these bubbles, the first energy generating element RhA can eject ink from the injection port 11. In this embodiment, an electrothermal transducer is used as the first energy generating element RhA. However, the first energy generating element RhA is not limited to a specific element. For example, a piezoelectric element can be used as the first energy generating element RhA.

[0037] In the printed element substrate 18, the second energy generating element RhB is formed closer to the supply port 22 than to the supply port 32. The second energy generating element RhB is a component that generates energy to circulate ink within the separate channel 23 in the direction shown by arrow 27. Although an electrothermal transducer is used as the second energy generating element RhB in this embodiment, the second energy generating element RhB is not limited to a specific component. For example, a piezoelectric element can be used as the second energy generating element RhB.

[0038] A description of the straight type is given. The straight type refers to the shape of the individual channel 23 being configured such that the two ends of the individual channel 23 are located on both sides of the injection hole 11, and the direction passing through the two ends of the individual channel 23 intersects the direction along the array of injection holes 11 (in...). Figure 3A In the example, this direction is orthogonal to the direction of the array along the jet holes 11. In other words, in the individual channel 23, the first energy generating element RhA and the second energy generating element RhB are arranged in a direction that intersects with the direction of the array along the jet holes 11.

[0039] Furthermore, a supply channel 14 is formed on the side of the second energy generating element RhB. The supply channel 14 is formed by a supply port 22 and a separate channel 23 on a portion of the side of the second energy generating element RhB. Simultaneously, an outflow channel 15 is formed on the side of the first energy generating element RhA. The outflow channel 15 is formed by a supply port 32 and a separate channel 23 on another portion of the side of the first energy generating element RhA.

[0040] The ink flow in the separate channel 23 will now be described. There are two types of ink flows in the separate channel 23. The first type is a supplementary ink flow that occurs after the liquid jetting device 50 drives the first energy generating element RhA and ejects ink from the jetting orifice 11. The second type is a flow in which the liquid jetting device 50 drives the second energy generating element RhB to generate a circulating flow in the direction of arrow 27.

[0041] <The First Type of Ink Flow> Figure 3D This illustrates how the liquid jetting device 50 drives the first energy generating element RhA and ejects ink from the jetting orifice 11. Figure 3D This diagram illustrates the ink flow when the first energy-generating element RhA is driven. Figure 3D In the example, ink is supplied from both supply port 22 and supply port 32 and ejected from the ejection port 11. Therefore, ink flows into the pressure chamber 12 from both supply port 22 and supply port 32.

[0042] <Second type of ink flow> Simultaneously, as the liquid jetting device 50 drives the second energy generating element RhB to generate a circulating flow, ink flows into the separate channel 23 through the supply port 22 and flows out of the separate channel 23 through the supply port 32. In this embodiment, the liquid jetting device 50 circulates the ink by returning the ink flowing out of the supply port 32 to the supply port 22, thereby generating an ink circulating flow in the separate channel 23 in the direction shown by arrow 27. Figure 3C An example is shown in which supply port 22 and supply port 32 are formed as a common channel in the liquid jet chip 3. Figure 3D This is an example in which supply port 22 and supply port 32 are each configured as separate channels, and these separate channels become a common channel outside the liquid injection head 1.

[0043] Further explanation of the ink circulation flow. Ink includes solid components and volatile components such as water. When using the liquid ejector head 1, the following situations arise: due to the evaporation of volatile components in the ink from the ejection orifice 11, the concentration of solid components in the ink near the ejection orifice 11 increases with the evaporation of volatile components, thus making the ink ejection from the ejection orifice 11 unstable. Therefore, various measures are taken to prevent the ink ejection from the ejection orifice 11 from becoming unstable.

[0044] For example, a cover member (not shown) can be provided in the X direction at a location outside the transport path of the target medium P. The cover member is shaped such that it can cover the surface of the nozzle 11 on which the liquid jet head 1 is mounted. When the liquid jet head 1 is not printing the target medium P, the cover member can prevent the nozzle 11 from drying out and protect the nozzle 11 by covering its surface.

[0045] In addition, an ink-drawing mechanism (not shown) may be provided. When a cover member and an ink-drawing mechanism are provided, the cover member cooperates with the operation of drawing ink from the ejection orifice 11. The ink-drawing operation refreshes the ink near the ejection orifice 11, thereby maintaining the image quality of the acquired image.

[0046] Furthermore, when the liquid ejector head 1 is not printing on the target medium P, an ejection operation called pre-ejection (also known as pre-discharge) is performed. This discards concentrated ink. Additionally, when the liquid ejector head 1 is printing on the target medium P, an ejection operation called pre-ejection (also known as paper pre-ejection or in-page pre-ejection) can also be performed. Paper pre-ejection or in-page pre-ejection is an ejection operation in which a small amount of ink is ejected onto the target medium P at a location imperceptible to image quality. These ejection operations significantly contribute to improved image quality and refresh the ejection orifice 11. Therefore, some ink is discarded. This minimizes waste ink.

[0047] For example, a second energy generating element RhB is provided in the printing element substrate 18 to heat the ink in the individual channel 23. This generates an ink circulation flow. This ink circulation flow can suppress drying of the ejector 11 and the increase in ink concentration near the ejector 11, while also suppressing waste ink. From another perspective, the number of ink pre-ejection times and ink pick-up times can be minimized. Furthermore, minimizing the number of ink pre-ejection times can improve the throughput and yield of the entire liquid ejection device 50. Note that in the multiple individual channels 23 included in the liquid ejection head 1, only at least some of the individual channels 23 need to have the second energy generating element RhB provided. This provides the aforementioned effects.

[0048] also, Figure 1A The liquid ejector head 1 can be configured such that a second energy generating element RhB is provided in all sections corresponding to the four types of ink. Alternatively, Figure 1A The liquid ejector head 1 can be configured such that a second energy generating element RhB is provided only in the portion corresponding to one type of ink. Specifically, the liquid ejector head 1 can be configured to circulate at least one of multiple types of ink.

[0049] Note that, as Figure 3A As shown, a filter 31 can be provided in the ink circulation channel to remove foreign matter included in the ink. The filter 31 is a protrusion formed by a portion of the perforated plate 19 protruding towards the printing element substrate 18. Figures 3A to 3D In the example, filter 31 is positioned at one end and the other end of each individual channel 23. In the ink circulation channel, one end of the individual channel 23 corresponds to the ink inflow side, and the other end of the individual channel 23 corresponds to the ink outflow side. Filter 31 can be positioned between the first energy generating element RhA and the second energy generating element RhB in the individual channel 23. When filter 31 is positioned between the first energy generating element RhA and the second energy generating element RhB in the individual channel 23, filter 31 does not necessarily need to be positioned at one end and the other end of the individual channel 23. Next, by using... Figures 4A to 4C This will explain the principle behind the ink circulation flow.

[0050] <The principle behind ink circulation> For ease of explanation, Figures 4A to 4C The illustration of filter 31 is omitted. Figure 4A yes Figure 3A The diagram shows a cross-sectional view of the individual injection unit (IIIB-IIIB), and is used to illustrate the generation and growth process of bubble B generated by heating the ink with the second energy generating element RhB and causing the ink to boil in a film state. Figure 4B yes Figure 3A The diagram shows a cross-sectional view of the individual injection unit (IIIB-IIIB), and is used to illustrate the contraction process of bubble B generated by heating the ink with the second energy generating element RhB and causing the ink to boil in a film state. Figure 4C yes Figure 3A The diagram shows a cross-sectional view (IIIB-IIIB) of the individual injection unit, illustrating the process after the disappearance of bubble B, which is generated by heating the ink with the second energy generating element RhB and causing film boiling of the ink. The generation and growth process, contraction process, and subsequent disappearance of bubble B will be explained below.

[0051] <The generation and growth process of bubble B> like Figure 4A As shown, the second energy generating element RhB is positioned closer to supply port 22 than supply port 32. Therefore, the flow resistance R1 generated in the channel between the second energy generating element RhB and supply port 22 in response to the generation of ink circulation flow is less than the flow resistance R2 generated in the channel between the second energy generating element RhB and supply port 32. Thus, as... Figure 4A As shown, the difference between flow resistance R1 and flow resistance R2 causes bubbles B generated by the film boiling of the ink to grow while being biased toward the channel with relatively lower flow resistance R1. Therefore, the flow vector Fa of the ink flowing toward the channel that generates flow resistance R1 is greater than the flow vector Fb of the ink flowing toward the channel that generates flow resistance R2. Note that the loop including flow resistances R1 and R2 is equivalent to a loop in which the flow resistance generated by the circulating flow of ink in the channel including separate channel 23 is expressed in a manner analogous to resistance.

[0052] <The contraction process of bubble B> During the contraction of bubble B, ink flows in and fills the volume corresponding to the contraction 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 greater than the flow vector Fd of the ink flowing in from the supply port 32 on the flow resistance R2 side. Furthermore, the disappearance position of bubble B shifts from its position above the second energy generating element RhB to a portion of the channel closer to the supply port 32.

[0053] <The process after bubble B disappears> like Figure 4BAs shown, the relationship Fc > Fd is established. This generates a flow vector F for the ink circulation flow from supply port 22 towards 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 energy generating element RhB is used. In this case, the second energy generating element RhB is preferably positioned closer to one of the two ends of the individual channel 23, rather than closer to the first energy generating element RhA. 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 allows the flow vector F of the ink circulation flow to be set at a local maximum. Increasing the ink flow vector Fa and increasing the ink flow vector Fc will increase the flow vector F of the ink circulation flow and increase the ink circulation flow. Therefore, it is preferable to minimize the flow resistance R1 as much as possible. Furthermore, it is preferable to minimize the ink flow vector Fb and decrease the ink flow vector Fd as much as possible. Therefore, it is preferable to increase the flow resistance R2. In view of this, it is preferable to reduce the flow resistance R1 and increase the flow resistance R2. Specifically, it is preferable to reduce the flow resistance ratio R1 / R2. Furthermore, a larger bubble B, i.e., a larger bubble volume, leads to an increase in fluid displacement within the individual channel 23, thereby increasing the circulating flow. For example, the following factors can be cited as contributing factors to the increase in circulating flow: Increasing the size of the second energy generating element RhB. In addition, increasing the width and height of the channel on the supply port 22 side and reducing the flow resistance R1 relative to the flow resistance R2. Furthermore, reducing the viscosity of the ink. Furthermore, configuring the liquid ejector head 1 as a dual-pulse. Configuring the drive pulse as a dual-pulse means as follows: First, a short pulse is applied to the second energy generating element RhB to heat the ink around a portion of the channel above the second energy generating element RhB, the pulse having a level such that the pulse does not generate bubbles in that portion of the channel above the second energy generating element RhB. Then, the main pulse that generates bubbles for ink circulation is applied to the second energy generating element RhB to grow large bubbles.

[0054] Furthermore, some of the ink flowing due to the ink circulation flow enters the interior of the ejector nozzle 11. This causes the concentrated ink within the ejector nozzle 11 to be discharged through the channel on the supply port 32 side, while fresh ink flows into the ejector nozzle 11 through a separate channel 23 from the channel on the supply port 22 side. Therefore, the possibility of concentrated ink remaining within the ejector nozzle 11 is relatively small. Thus, the initial inkjet state can be maintained while suppressing the influence of concentrated ink.

[0055] When bubble B is generated, the ink circulation flow is a transitional flow generated during the growth and contraction processes. Therefore, after bubble B disappears, the inertial circulation flow of the ink decays over time and stops after a certain period. Therefore, to generate a regular circulation flow within a certain time period, it is preferable to repeatedly drive the second energy generating element RhB. Note that the driving cycle of the second energy generating element RhB is not limited to a specific cycle, as long as it can discharge the concentrated ink retained in the ejection orifice 11. Note that when bubble B is generated, the ink circulation flow is a transitional flow generated during the growth and contraction processes. Therefore, when the second energy generating element RhB is driven at a high driving frequency (e.g., approximately 100 kHz considering a 10 μs cycle (which is the time period from bubble B's generation to its disappearance), the promotion of ink circulation may be hindered. Therefore, it is preferable to drive the second energy generating element RhB with a driving cycle of, for example, approximately 100 Hz to tens of kHz.

[0056] Specifically, the higher the driving frequency of the second energy generating element RhB, the better the ink circulation flow can be maintained. Therefore, the effect of discharging concentrated ink caused by the ink circulation flow increases. However, assuming the driving frequency of the second energy generating element RhB is higher, the ink temperature will increase more due to the heat generated by the second energy generating element RhB caused by its driving. Therefore, it is preferable to appropriately control the driving frequency of the second energy generating element RhB. Next, by using... Figures 5A to 5D and Figures 6A to 6D This demonstrates how to use ink circulation to eliminate the increase in ink concentration.

[0057] <Eliminates increased ink concentration; Straight type> Figure 5A This is a diagram showing the state where the ink circulation flow has temporarily stopped. Figure 5B It is shown in Figure 5A The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element RhB in the state of the previous state. Figure 5C It is shown in Figure 5B The diagram shows the state where the ink circulation flow temporarily stops after the initial state. Figure 5D It is shown in Figure 5C The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element RhB, following the initial state. (See diagram for example.) Figures 5A to 5D As shown, the straight individual channel 23 is configured such that the inlet and outlet of the ink circulation flow are separated from each other. Note that the ink in the individual channel 23 is filled with a dot pattern, and the density of the dot pattern filling is increased in the ink concentration section to indicate the level of increased ink concentration.

[0058] like Figure 5AAs shown, when the ink circulation flow is temporarily stopped, the volatile components of the ink evaporate from the nozzle 11. Therefore, the ink concentration near the nozzle 11 increases. Then, when the second energy generating element RhB is activated, the ink circulation flow resumes. As a result, as... Figure 5B As shown, the increase in ink concentration near nozzle 11 was eliminated. Then, in the case of a temporary cessation of ink circulation, as... Figure 5C As shown, the ink concentration increased again near the nozzle 11, as... Figure 5A That's how it happened. Afterwards, with the second energy-generating element RhB activated, the ink circulation resumed. As a result, as... Figure 5D As shown, the increase in ink concentration near nozzle 11 was eliminated, as... Figure 5B Therefore, the increase in ink concentration throughout the entire individual channel 23 is eliminated. As described above, in the straight individual channel 23, the ink concentration increase state is reset each time the ink circulation flow is temporarily stopped and resumed.

[0059] <Eliminate the increase in ink concentration; U-shaped> Figure 6A This is a diagram showing the state where the ink circulation flow has temporarily stopped. Figure 6B It is shown in Figure 6A The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element RhB in the state of the previous state. Figure 6C It is shown in Figure 6B The diagram shows the state where the ink circulation flow temporarily stops after the initial state. Figure 6D It is shown in Figure 6C The diagram shows the state that immediately appears after the ink circulation flow is generated by driving the second energy generating element RhB, following the initial state. (See diagram for example.) Figures 6A to 6D As shown, the U-shaped individual channel 23 is configured such that the inlet and outlet of the ink circulation flow are adjacent to each other. Note that the ink in the individual channel 23 is filled with a dot pattern, and the density of the dot pattern filling is increased in the ink concentration section to indicate the level of increased ink concentration.

[0060] like Figure 6A As shown, when the ink circulation flow is temporarily stopped, the volatile components of the ink evaporate from the nozzle 11. Therefore, the ink concentration near the nozzle 11 increases. Subsequently, the ink circulation flow resumes when the second energy generating element RhB is activated. As a result, a system is established as shown... Figure 6B The state shown. Figure 6A The entrance to the separate passage 23 and Figure 6AThe outlets of the individual channels 23 are adjacent to each other. Therefore, the ink concentrated near the ejection port 11 is discharged from the outlets of the individual channels 23, but part of the discharged ink flows back into the individual channels 23 from the inlets of the individual channels 23. This causes a phenomenon in which not all the ink in the individual channels 23 is replaced with fresh ink, but is replaced with slightly concentrated ink (this phenomenon is hereinafter referred to as "recirculation concentration increase"). Then, when the ink circulation flow is temporarily stopped, as Figure 6C shown, the increase in ink concentration near the ejection port 11 progresses again from the state Figure 6B shown, as Figure 6A such. Thereafter, when the second energy generating element RhB is driven, the ink circulation flow is restored. As a result, as Figure 6D shown, due to the influence of the recirculation concentration increase, the ink in the entire individual channel 23 is replaced with ink that is further concentrated than the ink in Figure 6B . As described above, in the U-shaped individual channel 23, each time the temporary stop and circulation operation of the ink circulation flow is repeated, the ink concentration increase state is not reset, and the ink concentration increase gradually progresses throughout the entire individual channel 23. Therefore, the ink concentration increase state becomes more serious. Further, assume a case where the temporary stop and restoration of the ink circulation flow are not repeated. Also in this case, if the temporary stop period of the ink circulation flow is long and the increase in ink concentration near the ejection port 11 progresses, it is unlikely to obtain the effect of improving the ink concentration increase state of the ink even when the ink circulation flow is restored for the first time. The reason is that the recirculation concentration increase results in a small effect of improving the ink concentration increase state.

[0061] Therefore, the straight-type individual channel 23 and the U-shaped individual channel 23 are different from each other in the effect of discharging concentrated ink, and this leads to a difference in the effect of eliminating the ink concentration increase state by the temporary stop and restoration of the ink circulation flow. Specifically, in the case of the straight-type individual channel 23, it is easier to eliminate the ink concentration increase state including the entire individual channel 23. Meanwhile, in the case of the U-shaped individual channel 23, it is unlikely to eliminate the ink concentration increase state including the entire individual channel 23 due to the recirculation concentration increase. Therefore, in the case of the U-shaped individual channel 23, the ejection of ink may become unstable depending on the degree of concentration increase in the entire individual channel 23. Next, using Figures 7A to 7C the configuration of the portion of the U-shaped individual channel 23 near the ejection port 11 will be described.

[0062] <Configuration of the portion of U-shaped individual channel 23 near ejection port 11> Figure 7A is a plan view viewed along the direction in which droplets are ejected from the ejection port 11. Figure 7B is Figure 7ASectional view of VIIB-VIIB. Figure 7C yes Figure 7A Enlarged schematic diagram of the single channel 23.

[0063] exist Figure 7A and Figure 7B In this configuration, each jet hole 11 is an opening formed in a portion of the perforated plate 19. In the print element substrate 18, a first energy generating element RhA is formed directly below and corresponding to each jet hole 11. A second energy generating element RhB is also formed in the print element substrate 18. The second energy generating element RhB generates an ink circulation flow in the direction indicated by arrow 27 within a channel including a separate channel 23. In the print element substrate 18, a supply groove 42 is formed between the array of the first energy generating elements RhA and the array of the second energy generating elements RhB, along the direction of the array of jet holes 11, to pass through the print element substrate 18. The supply groove 42 communicates with the separate channel 23 and can supply ink to the separate channel 23. As described above, this configuration is not limited to having multiple independent supply openings (such as...). Figures 3A to 3D The configuration of supply ports 22 and 32 shown can be achieved by using large openings (such as...). Figures 7A to 7C The shared supply tank 42 in the middle allows liquid to flow in and out. Next, by using... Figures 8A to 8C This describes the configuration of the portion of the straight individual channel 23 near the injection port 11.

[0064] <Configuration of the portion of the straight single channel 23 near the injection port 11> Figure 8A It is a plan view along the direction in which the droplet is ejected from the injection hole 11. Figure 8B yes Figure 8A Sectional view of VIIIB-VIIIB. Figure 8C yes Figure 8A The cross-sectional view of VIIIB-VIIIB, and the internal configuration of the printed element substrate 18 therein. Figure 8B Different cross-sectional views are configured in the middle. Figure 8B and Figure 8C Two examples are shown, differing from each other in the shape of the back side of the printed element substrate 18. The shape of the back side depends on the type of etching method applied to the printed element substrate 18, and the shape of the back side of the printed element substrate 18 can be any shape. Specifically, the internal configuration of the printed element substrate 18 can be arbitrary.

[0065] This configuration differs from the configuration of the portion of the U-shaped individual channel 23 near the injection port 11 in that the individual channel 23 has a straight configuration, wherein the inlet and outlet of the individual channel 23 are not adjacent to each other as in the U-shaped individual channel 23, but are separate from each other. Furthermore, the direction connecting the two ends of the straight individual channel 23 is orthogonal to the direction in which the injection ports 11 are arranged in an array, such as... Figure 8A As shown. This arrangement separates the location where the ink circulation flow enters the individual channel 23 from the location where the ink circulation flow exits the individual channel 23. Therefore, it can suppress the re-flow of concentrated ink from the ejection orifice 11 into the individual channel 23. This, in turn, suppresses the effect of increased ink concentration. Next, by using... Figures 9A to 9C This describes another configuration of the portion of the straight single channel 23 near the injection port 11.

[0066] <Another configuration of the section of the straight single channel 23 near the injection port 11> Figure 9A This is a plan view taken along the direction in which the droplet is ejected from the ejection orifice 11. Figure 9B yes Figure 9A IXB-IXB cross-sectional view. Figure 9C yes Figure 9A The IXB-IXB cross-sectional view shows the internal configuration of the printed element substrate 18. Figure 9B Different cross-sectional views are configured in the middle. Figure 9B and Figure 9C Two examples are shown, differing from each other in the shape of the back side of the printed element substrate 18. The shape of the back side depends on the type of etching method applied to the printed element substrate 18, and the shape of the back side of the printed element substrate 18 can be any shape. Specifically, the internal configuration of the printed element substrate 18 can be arbitrary. Furthermore, Figure 9B and Figure 9C The illustration of filter 31 is omitted. Furthermore, this configuration is... Figures 8A to 8C The difference in the configuration lies in that the number of ink supply opening arrays is increased by one, from two to three. Therefore, the number of arrays of jet holes 11 can be doubled, and the array of jet holes 11 can be arranged on the side closer to the central ink supply opening. Specifically, the array of jet holes 11 is arranged on both sides of the multiple ink supply openings along the array direction of the central multiple ink supply openings. This arrangement can increase the number of ink supply opening arrays by one, from two to three, and double the number of arrays of jet holes 11 from one to two. Furthermore, as... Figure 9AAs shown, the two arrays of jet orifices 11 can be arranged such that the spacing between the corresponding two arrays of jet orifices 11 can be staggered. Furthermore, the wiring area between the supply openings in the central ink supply opening array may be excluded. Therefore, this configuration offers high flexibility in terms of the size and resolution of the openings in the central ink supply opening array. This configuration allows for rapid replenishment of the jet orifices 11 and enables high productivity. Note that the positions of the jet orifices 11 and the ink supply openings can be staggered to accommodate wiring routing. Next, the ink according to this embodiment will be described.

[0067] <Ink> As described above, although the level of elimination of increased ink concentration varies depending on the configuration of the channels, including the individual channel 23, the following effects can be provided by generating an ink circulation flow in the individual channel 23 using the second energy generating element RhB. Specifically, the effects of concentrated ink that thickens due to the evaporation of volatile components in the ink within the ejection orifice 11 can be suppressed. Therefore, the ink ejection state can be maintained at an excellent level, and the effects of ink ejection speed variations can be further reduced. Thus, ink ejection can be stabilized.

[0068] Furthermore, based on the application of the liquid ejector head 1 or the liquid ejection device 50 equipped with the liquid ejector head 1, it is conceivable to use inks with different types of ink color materials, different contents of ink solid components, etc. Specifically, the liquid ejector head 1 is preferably capable of maintaining ink ejection stability regardless of the type of ink used.

[0069] For example, due to the water in the ink, changes such as curling (also known as warping) and wrinkling (also known as ripples) may occur in ordinary paper. In this case, it is conceivable to use ink with reduced water content. Furthermore, in inks with low water content, the concentration of organic solvents other than water, as well as ink solids such as pigments and resins, is high. Therefore, the viscosity of the ink tends to increase rapidly as the water in the ink evaporates. Thus, inks with low water content tend to lead to decreased inkjet stability. In view of this, when using inks with low water content, the increase in ink viscosity can be suppressed by generating an ink circulation flow in a channel configuration including a separate channel 23, as in this embodiment. Typically, inks with a high solids content have a solids content of 10 wt%. Specifically, this embodiment is preferably applied to inks containing a solids content of 10 wt% (also known as mass%) or more.

[0070] The relationship between the operating temperature of the liquid ejector head 1 and the viscosity of the ink is explained. Consider a scenario where the second energy generating element RhB, arranged throughout the liquid ejector chip 3, is driven and controlled to heat the liquid ejector head 1 until its temperature reaches a certain value, and then 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 ink circulation flow rate and the respective drive frequencies of the first energy generating element RhA and the second energy generating element RhB is explained. When the ink circulation flow is generated by the second energy generating element RhB, a circulation flow rate can be achieved where the instantaneous ink flow rate is from tens of mm / s to 1000 mm / s. The average flow rate observed over a time width on the order of hundreds of μs depends on the drive frequency of the second energy generating element RhB. The reason is as follows: When the ink circulation flow is generated by the second energy generating element RhB, the ink circulation flow is a transitional circulation flow that decays over time and stops after a certain period. Meanwhile, when the ink circulation flow is generated by the first energy generating element RhA, it can be driven at a frequency of approximately 10 to 20 kHz, which is roughly at the same level as the drive frequency (also called the jetting frequency) of the first energy generating element RhA. In this case, the average flow rate of the ink circulation flow can be from several mm / s to 100 mm / s. Next, the relationship between pigment concentration and the elimination of ink concentration increases will be explained.

[0072] (Ink with high pigment concentration) The case of inks with high pigment concentration will be explained. For example, when the concentration of the ink used results in a viscosity of 3 cP or greater and 6 cP or less at the operating temperature of the liquid jet head 1, the thickening of the ink tends to proceed near the jet nozzle 11, depending on the non-jetting period of the ink (also known as the pause period of the ink circulation flow). Therefore, changes in inkjet speed are likely to occur. Consequently, a decrease in inkjet stability is likely to occur. To suppress the decrease in inkjet stability, it is preferable to generate a certain amount of ink circulation and circulate the ink when the pause period of the ink circulation flow is short. Therefore, it is preferable to perform ink transition circulation at a high frequency or to perform regular ink circulation to eliminate the increase in ink concentration. Ink transition circulation can be performed by driving the second energy generating element RhB. Driving the second energy generating element RhB and restoring a high-frequency ink circulation flow from the pause state of the ink circulation flow can help eliminate the increase in ink concentration near the jet nozzle 11.

[0073] (Ink with low pigment concentration) The case of inks with low pigment concentration is explained. For example, if the concentration of the ink used results in a viscosity of 1 cP or greater and 2 cP or less at the operating temperature of the liquid ejector head 1, thickening of the ink may proceed near the ejector nozzle 11, depending on the non-inkjet period (also known as the pause period of the ink circulation flow). Therefore, a change in inkjet speed may occur, but this change is less than the inkjet speed change of high-concentration inks. Meanwhile, if the pause period of the ink circulation flow is long, for example, thickening of the ink near the ejector nozzle 11 may proceed, depending on the non-printing drive period (also known as the stop period). Therefore, in the case where the liquid ejector head 1 stops and does not print for a certain period before restarting, it is preferable to perform a waste ink recovery process, such as an ink suction operation, a wiping operation, or a pre-jet process combining these operations. Resuming the ink circulation flow by driving the second energy generating element RhB as a recovery operation can contribute to eliminating the increase in ink concentration near the ejector nozzle 11 without generating waste ink. Furthermore, depending on the stop period, waste ink generation can be avoided by driving the second energy generating element RhB and performing a recovery process sufficient to restore the ink circulation flow. Alternatively, a recycling process can be performed in which waste ink is minimized by combining a suction operation for removing air bubbles B from the liquid jet head 1, separate from the elimination of increased ink concentration, while restoring and recycling the ink circulation flow.

[0074] (A more appropriate configuration to eliminate increased ink concentration) As described above, to suppress the effect of concentrated ink, it is preferable to replace as much of the concentrated ink as possible with initial fresh ink for both high-concentration and low-concentration inks. Therefore, when driving the second energy generating element RhB, the smaller the effect of increased recycling concentration, the higher the obtained recycling effect. Specifically, a higher recycling effect can be obtained in the configuration of the straight single channel 23 than in the configuration of the U-shaped single channel 23. Next, by using... Figures 10 to 17 This embodiment describes the circuit configuration for driving and controlling the first energy generating element RhA and the second energy generating element RhB.

[0075] <Heater Selection Circuit> Figure 10This diagram illustrates an example of the circuit configuration of the printed element substrate 18 according to this embodiment. Various signals are supplied from the main PCB 100 to the printed element substrate 18. 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 printed element substrate 18 via a power supply voltage wiring VH. The power supply circuit 102 and the printed element substrate 18 are interconnected via a GNDH wiring 115. The GNDH wiring 115 is included in a ground wiring layer. The reference potential of the printed element substrate 18 is set by the ground wiring layer. Therefore, the GNDH wiring 115 serves as the reference potential of the printed element substrate 18. The controller 101 is mainly formed by ROM, RAM, and CPU, and supplies various electrical signals to the printed element substrate 18. The controller 101 is connected to the printed 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 pulse-width-controlled time period during which the element to be controlled is turned on and current flows to it. This enable signal is used for adjustment, allowing for more desired heat generation by taking into account manufacturing errors in the heater resistance values ​​in the printed element substrate 18, manufacturing errors in the power supply circuit 102, and voltage drops on the power supply lines when multiple heaters are driven simultaneously. In this embodiment, an example is given where the enable signal line HE is shared between jetting and cycling to reduce the number of signal terminals. However, providing separate enable signal lines HE for jetting and cycling allows for different pulse widths for jetting and cycling. Note that in this embodiment, it is assumed that the enable signal line HE is shared between jetting and cycling, configured as follows. Specifically, it is preferable that the jetting heater RhA and the cycling heater RhB are formed in the same step of the semiconductor manufacturing process, and the pulse width of the enable signal is adjusted under the assumption that the heaters have the same manufacturing error (the same amount of resistance value deviation relative to the ideal value). The controller 101 supplies a latch signal to the printed element substrate 18 via the latch signal line LT. The controller 101 supplies data signals to the printing element substrate 18 via the data signal line DATA. The controller 101 supplies clock signals to the printing element substrate 18 via the clock signal line CLK.

[0076] The printing element substrate 18 includes multiple jetting modules 104 and multiple circulation modules 105. Each jetting module 104 includes a jetting heater RhA, a jetting drive element MD1, and a jetting logic circuit AND1. The jetting heater RhA is a jetting energy generating element. The first energy generating element RhA is also a jetting energy generating element. In other words, the jetting heater RhA and the first energy generating element RhA refer to the same element. These terms are used selectively depending on whether the element is a circuit element or an element arranged in a structure of separate channels 23. The jetting heater RhA, the first energy generating element RhA, and the jetting energy generating element are collectively referred to as the first heating resistor element. The jetting drive element MD1 (also called the first drive element) is an element for causing current to flow in the jetting heater RhA. The jetting logic circuit AND1 is an element for selectively driving the jetting drive element MD1 included in one of the multiple jetting modules 104. The printing element substrate 18 generates heat by causing current to flow in the jetting heater RhA. This causes ink to bubble and be jetted. Therefore, printing can be performed on the jetting target medium P. Furthermore, in this embodiment, the jet heater array 112 is formed by arranging a plurality of jet heaters RhA in an array.

[0077] Assume that each jet driving element MD1 is formed of a metal-oxide-semiconductor field-effect transistor (MOSFET). Figure 10 In the example, the source terminal of the jet drive element MD1 is interconnected with GNDH wiring 115. Furthermore, the gate terminal of the jet drive element MD1 is interconnected with the output side of the jet logic circuit AND1. Additionally, the drain terminal of the jet drive element MD1, the jet heater RhA, and the power supply voltage wiring VH are interconnected. The drain terminal of the jet drive element MD1 and the jet heater RhA are interconnected via jet drain wiring 107. When a gate drive voltage is applied between the gate terminal and the source terminal of the jet drive element MD1 in response to a signal output from the jet logic circuit AND1, the following occurs: Specifically, drive current flows to the jet heater RhA via jet drain wiring 107. The jet heater RhA thus generates heat. Therefore, ink bubbles and is jetted, becoming printable on the jet target medium P. Note that the jet drive element MD1 can be formed from components other than MOSFETs. For example, the jet drive element MD1 can be formed from a bipolar transistor. Alternatively, the jet drive element MD1 can be formed from an insulated gate bipolar transistor (IGBT).

[0078] Each circulation module 105 includes a circulation heater RhB, a circulation drive element MD2, and a circulation logic circuit AND2. The circulation heater RhB is a circulation energy generating element. The second energy generating element RhB is also a circulation energy generating element. In other words, the circulation heater RhB and the second energy generating element RhB refer to the same element. These terms are used selectively depending on whether the element is a circuit element or an element arranged in a structure of individual channels 23. The circulation heater RhB, the second energy generating element RhB, and the circulation energy generating element are collectively referred to as the second heating resistor element. The circulation drive element MD2 (also referred to as the second drive element) is an element for causing current to flow in the circulation heater RhB. The circulation logic circuit AND2 is an element for selectively driving the circulation drive element MD2 included in one of the plurality of circulation modules 105. The printing element substrate 18 generates heat by causing current to flow in the circulation heater RhB. As a result, ink bubbles B grow and a circulating flow is generated in the ink channel including the individual channel 23. Furthermore, in this embodiment, the circulation heater array 113 is formed by arranging a plurality of circulation heaters RhB in an array.

[0079] Assume that each cycle drive element MD2 is formed of a metal-oxide-semiconductor field-effect transistor (MOSFET). Figure 10 In the example, the source terminal of the loop drive element MD2 is interconnected with GNDH wiring 115. Furthermore, the gate terminal of the loop drive element MD2 is interconnected with the output side of the loop logic circuit AND2. Additionally, the drain terminal of the loop drive element MD2, the loop heater RhB, and the power supply voltage wiring VH are interconnected. The drain terminal of the loop drive element MD2 and the loop heater RhB are interconnected via loop drain wiring 108. When a gate drive voltage is applied between the gate terminal and the source terminal of the loop drive element MD2 in response to a signal output from the loop logic circuit AND2, the following occurs: Specifically, drive current flows to the loop heater RhB via loop drain wiring 108. The loop heater RhB thus generates heat. Therefore, ink bubbles B grow, and a circulating flow as described above is generated. Note that the loop drive element MD2 can be formed from components other than a MOSFET. For example, the loop drive element MD2 can be formed from a bipolar transistor. Alternatively, the loop drive element MD2 can be formed from an insulated gate bipolar transistor (IGBT).

[0080] Note that in the jet heater RhA, the piezoelectric element can be used as a component for jetting ink. In the circulation heater RhB, the piezoelectric element can be used as a component for circulating ink. At least one of the jet heater RhA and the circulation heater RhB can be used as a component for heating a specific area of ​​the printing element substrate 18. Alternatively, at least one of the jet heater RhA and the circulation heater RhB can be used as a temperature sensing element that monitors its own temperature.

[0081] Each of the jet drive element MD1 and the cycle drive element MD2 is assumed to be an N-type high-voltage MOSFET. A high-voltage MOSFET is a drive element with a higher voltage withstand capability than the drive elements used in logic circuits. In this embodiment, it is assumed that the high-voltage MOSFET is configured such that it will not fail even if the applied voltage (e.g., 32 V) is too high for the drive elements used in the general logic circuit forming the controller 101.

[0082] The printing element substrate 18 includes a control data supply circuit 106. The printing element substrate 18 includes an ejection group selection signal line 109, a cycle 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 ejection group selection signal line 109, the cycle group selection signal line 110, the time-division selection signal line 111, and the enable signal line HE. Each of the ejection group selection signal line 109, the time-division selection signal line 111, and the enable signal line HE is electrically connected to the ejection module 104. Each of the cycle group selection signal line 110, the time-division selection signal line 111, and the enable signal line HE is electrically connected to the cycle module 105. Therefore, the control data supply circuit 106 can exchange various signals with the ejection module 104 via the ejection group selection signal line 109 and the time-division selection signal line 111. In addition, the control data supply circuit 106 can also exchange various signals with the loop module 105 via the loop group selection signal line 110 and the time division selection signal line 111.

[0083] Specifically, each of the 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 injection logic circuit AND1. The output side of the injection logic circuit AND1 is interconnected with the gate terminal of the injection drive element MD1. Therefore, based on the output of the injection logic circuit AND1, the injection drive element MD1 is selected and controlled, causing it to enter the on state, and current flows in the injection heater RhA. Furthermore, each of the cycle 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 cycle logic circuit AND2. The output side of the cycle logic circuit AND2 is interconnected with the gate terminal of the cycle drive element MD2. Therefore, based on the output of the cycle logic circuit AND2, the cycle drive element MD2 is selected and controlled, causing it to enter the on state, and current flows in the cycle heater RhB.

[0084] In this embodiment, the time-division selection signal line 111 is shared by the jetting module 104 and the circulation module 105. Therefore, the time-division selection signal line 111 can contribute to reducing the amount of serial data transmission and reducing the wiring area of ​​the signal lines in the printed 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 loop group selection circuit 201. The control data supply circuit 106 includes shift registers 203a and 203b, latch circuits 204a and 204b, a decoder circuit 205, and the loop group selection circuit 201. The control data supply circuit 106 is provided with external input terminals. Clock signals, data signals, and latch signals are supplied from the controller 101 to the control data supply circuit 106 via the external input terminals. The clock signal is used when the data signals are transmitted as serial data to the shift registers 203a and 203b. The data signals include selection information for the injection module 104 and selection information for the loop module 105. The latch signals are signals that cause the latch circuits 204a and 204b to acquire and hold various information stored in the respective shift registers 203a and 203b in each latch cycle.

[0086] Decoder circuit 205 is a circuit that expands q-bit input data so that the number of bits in the output data becomes 2 to the power of q. Specifically, when 4-bit input data is input to decoder circuit 205, decoder circuit 205 converts the 4-bit input data into 2 to the power of 4 = 16-bit output data. In this case, the output data of decoder circuit 205 is output as information in which only 1 bit of the 16 bits is enabled. This allows time-division driving of each of a plurality of injection modules 104 and a plurality of loop modules 105 via time-division selection signal line 111.

[0087] The cycle group selection circuit 201 includes AND and NOT circuits. Each NOT circuit outputs a signal obtained by logically inverting the jet group selection signal received from the jet group selection signal line 109 (hereinafter also referred to as the logically inverted signal). Each AND circuit receives the logically inverted signal and also receives a cycle flag signal via the cycle flag signal line 202. The cycle flag signal is included in the data signal serially transmitted from the controller 101. The cycle flag signal, output via the cycle group selection signal line 110, serves as a flag for setting the cycle group selection signal to enabled or disabled. In normal jetting operation without ink circulation, simply setting the cycle flag signal to 0 disables the selection of the cycle module 105. In other words, the cycle group selection circuit 201 generates the cycle group selection signal based on the selection information of the jet group selection signal and the cycle flag signal. Therefore, when the jet module 104 is selected, the cycle module 105 is unselected. Conversely, when the cycle flag signal is 0, even if the jet module 104 is unselected, the cycle group selection signal is disabled, and the cycle module 105 is not selected. Specifically, when injection module 104 is unselected and the cycle flag signal is 1, the cycle group selection signal is enabled, and cycle module 105 is selected. Note that neither injection module 104 nor cycle module 105 will be selected when time-division selection is not performed.

[0088] To enable the driving elements to operate at voltages higher than those of the logic circuits, a substrate where high-voltage driving elements and ordinary driving elements coexist is typically used. In this embodiment, the above description assumes that the jet driving element MD1 and the cycle driving element MD2 are high-voltage MOSFETs. More specifically, it is assumed that the jet driving element MD1 and the cycle driving element MD2 are formed from double-diffused MOSFETs (DMOSFETs) as high-voltage MOSFETs. Logic circuits such as the jet logic circuit AND1, the cycle logic circuit AND2, the cycle group selection circuit 201, the shift registers 203a and 203b, the latch circuits 204a and 204b, and the decoder circuit 205 are assumed to be formed from MOSFETs with low tolerance levels.

[0089] The drive current of the circulating heater RhB generates heat to circulate the ink in the individual channel 23. When the drive current of the circulating heater RhB is less than the drive current of the jet heater RhA, which jets ink onto the target medium P, the drive capability of the DMOSFET may be low. Therefore, in this configuration where the element area of ​​the circulating drive element MD2 is smaller than that of the jet drive element MD1, the drive current of the circulating heater RhB can be supplied as needed.

[0090] In other words, the resistance value of the injection heater RhA is different from that of the circulation heater RhB. Therefore, the element area of ​​the injection drive element MD1 is different from that of the circulation drive element MD2. Furthermore, when the drive current supplied from the circulation drive element MD2 to the circulation heater RhB is less than the drive current supplied from the injection drive element MD1 to the injection heater RhA, the element area of ​​the injection drive element MD1 is larger than that of the circulation drive element MD2.

[0091] (First scenario) Figure 12 This is a diagram illustrating an example arrangement of the heater and drive element in a first case according to this embodiment. Figure 12 In this configuration, multiple jet heaters RhA-1 to RhA-n and multiple circulating heaters RhB-1 to RhB-n are arranged on the printing element substrate 18 as heaters. The multiple jet heaters RhA-1 to RhA-n are arranged in an array along the long side direction of the printing element substrate 18 to form a jet heater array 112. The multiple circulating heaters RhB-1 to RhB-n are arranged in an array along the long side direction of the printing element substrate 18 to form a circulating heater array 113. Furthermore, in... Figure 12 In this design, multiple jetting drive elements MD1-1 to MD1-n and multiple circulating drive elements MD2-1 to MD2-n are arranged on the printing element substrate 18 as drive elements. The multiple jetting drive elements MD1-1 to MD1-n are arranged in an array along the long side direction of the printing element substrate 18 to form a jetting drive element array 301. The multiple circulating drive elements MD2-1 to MD2-n are arranged in an array along the long side direction of the printing element substrate 18 to form a circulating drive element array 302.

[0092] In addition, Figure 12In addition to the jet heater array 112, the circulating heater array 113, the jet drive element array 301 (also referred to as the first drive element array), and the circulating drive element array 302 (also referred to as the second drive element array), supply port arrays 303 and 304 are also formed in the printing element substrate 18. The supply port array 303 is formed by arranging a plurality of supply ports 32-1 to 32-m in an array along the long side direction of the printing element substrate 18. The supply port array 304 is formed by arranging a plurality of supply ports 22-1 to 22-m in an array along the long side direction of the printing element substrate 18. In this embodiment, the circulating heater array 113 is arranged to the left of the supply port array 304 and is arranged side-by-side with the supply port array 304. The jet heater array 112 is arranged to the left of the circulating heater array 113 and is arranged side-by-side with the circulating heater array 113. The supply port array 303 is arranged to the left of the jet heater array 112 and is arranged side-by-side with the jet heater array 112. The injection drive element array 301 is arranged to the left of the supply port array 303 and is arranged side by side with the supply port array 303. The circulation drive element array 302 is arranged to the left of the injection drive element array 301 and is arranged side by side with the injection drive element array 301.

[0093] Furthermore, although in this embodiment one supply port 22 and one supply port 32 are arranged for every four jet heaters RhA and every four circulating heaters RhB, this disclosure is not limited to this arrangement. Furthermore, the size of the supply port 22 may differ from the size of the supply port 32. Furthermore, the number of supply ports 22 need not be the same as the number of supply ports 32. Furthermore, although the jet heater array 112 is arranged in a region closer to the region where the jet drive element array 301 is arranged than the circulating heater array 113, this disclosure is not limited to this arrangement. The circulating heater array 113 may be arranged in a region closer to the region where the jet drive element array 301 is arranged than the jet heater array 112. Furthermore, in this embodiment, the jet drive element array 301 is arranged in a region closer to the heating resistance element region where the jet heater array 112 and the circulating heater array 113 are arranged than the circulating drive element array 302. Specifically, the circulating drive element array 302 is arranged in a position further away from the heating resistance element region than the jet drive element array 301. Furthermore, the resistance value of the jet heater RhA can be the same as or different from that of the circulating heater RhB. Additionally, the dimensions of the jet heater RhA can be the same as or different from those of the circulating heater RhB.

[0094] Note that the heating resistance element region is the region in which the heating resistance elements are arranged on the same layer in the printing element substrate 18. In this embodiment, at least one of a set of jet heaters RhA and a set of circulating heaters RhB is used as a heating resistance element. Therefore, the heating resistance element region is the region in which at least one of a set of jet heaters RhA and a set of circulating heaters RhB is arranged in the printing element substrate 18. For example, the region including the jet heater array 112 and the circulating heater array 113 on the same layer in the printing element substrate 18 is the heating resistance element region. Specifically, a plurality of jet heaters RhA formed as jet heater array 112 are arranged in the first region of the heating resistance element region. Furthermore, a plurality of circulating heaters RhB formed as circulating heater array 113 are arranged in the second region of the heating resistance element region. Note that if other heating resistance elements are arranged, these other heating resistance elements may be arranged in the third region of the heating resistance element region.

[0095] 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, jet drain lines 107-1 to 107-8 and circulation drain lines 108-1 to 108-8 are arranged as constituent elements of unit 305 formed in the printed element substrate 18. Specifically, unit 305 includes jet drain lines 107-1 to 107-8 and circulation drain lines 108-1 to 108-8. Furthermore, unit 305 also includes supply ports 32-1 and 32-2, jet drive elements MD1-1 to MD1-8, circulation drive elements MD2-1 to MD2-8, jet heaters RhA-1 to RhA-8, and circulation heaters RhB-1 to RhB-8.

[0096] Specifically, circulating drain wirings 108-1 to 108-4 pass around the periphery of supply port 32-1 and interconnect circulating heaters RhB-1 to RhB-4 and circulating drive elements MD2-1 to MD2-4. Circulating drain wirings 108-5 to 108-8 pass around the periphery of supply port 32-2 and interconnect circulating heaters RhB-5 to RhB-8 and circulating drive elements MD2-5 to MD2-8.

[0097] The injection drain wirings 107-1 to 107-4 pass around the periphery of supply port 32-1 and interconnect the injection heaters RhA-1 to RhA-4 and the injection drive elements MD1-1 to MD1-4. The injection drain wirings 107-5 to 107-8 pass around the periphery of supply port 32-2 and interconnect the injection heaters RhA-5 to RhA-8 and the injection drive elements MD1-5 to MD1-8.

[0098] Essentially, between the jet drain wiring 107 and the circulating drain wiring 108, there exists a region where wires are arranged to pass through the supply ports 32. Note that in this embodiment, four jet drain wirings 107 and four circulating drain wirings 108 are arranged for each supply port 32 to pass through the perimeter of the supply port 32. However, the number of wirings is not limited to four. Furthermore, although Figure 13 An example is shown in which the wiring width of the jet drain wiring 107 is the same as the wiring width of the circulating drain wiring 108, but this disclosure is not limited thereto. The wiring width of the jet drain wiring 107 may be different from the wiring width of the circulating drain wiring 108. Next, by using Figure 14 Explain the layer configuration of the printed element substrate 18.

[0099] Figure 14 It shows along Figure 13 A diagram showing the cross-sectional structure of the XIV-XIV line. The printed element substrate 18 can be manufactured using known semiconductor manufacturing processes. For example, the printed element substrate 18 includes a substrate 312 and multiple electronic components. The substrate 312 is made of a semiconductor such as monocrystalline silicon. Multiple electronic components are disposed on the substrate 312.

[0100] (Insulation layer 311) Specifically, an insulating layer 311 is formed on the substrate 312. For example, an inorganic material such as silicon oxide can be used in 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 jet heater RhA and the circulating heater RhB from each other. Furthermore, although... Figure 14 The illustration is omitted, but the insulating layer 311 also electrically isolates the jet drive element MD1 and the circulation drive element MD2 from each other.

[0101] In this embodiment, insulating layer 311 includes insulating layers 311a, 311b, 311c, 311d, and 311e. Insulating layer 311b has a wiring layer including jet drain wiring 107-1. Insulating layer 311b also has wiring layers including corresponding jet drain wirings 107-2 to 107-8. Insulating layer 311c has a wiring layer including circulating drain wiring 108-1. Insulating layer 311c also has wiring layers including corresponding circulating drain wirings 108-2 to 108-8. Specifically, circulating drain wiring 108 (also called the second wiring) and jet drain wiring 107 (also called the first wiring) are formed in different layers. In this embodiment, the layer in which circulating drain wiring 108 is formed is located above the layer in which jet drain wiring 107 is formed. In addition, power supply voltage wirings VH114a and VH114b are formed in the insulation layer 311d.

[0102] (Connecting component 313) The connecting member 313 is disposed in a through-hole passing through the insulating layers 311b to 311e. Figure 14 In this embodiment, connecting members 313 are also provided in vias passing through insulating layers 311d to 311e and through insulating layers 311c to 311e. Contact plugs are provided inside these vias to allow connecting members 313 to be formed in an electrically connectable state. Connecting members 313 are provided to electrically connect conductive layer 314, electronic components in the upper layer, electronic components in the lower layer, and electronic components in layers between the upper and lower layers to each other. The electronic components include the electrode layers of jet driving element MD1 and circulation driving element MD2. In this example, "upper layer" is a collective term for all layers in the direction away from substrate 312 when a certain layer is used as a reference. "Lower layer" is a collective term for all layers in the direction towards substrate 312 when a certain layer is used as a reference. For example, when insulating layer 311d is the reference layer, insulating layer 311e corresponds to the upper layer. Furthermore, insulating layers 311c, 311b, and 311a correspond to the lower layer, for example. Note that in this embodiment, the conductive layer 314 is disposed in the insulating layers 311c, 311d, and 311e, respectively. Therefore, the electronic components included in each insulating layer 311b, 311c, 311d, and 311e can be electrically connected to each other via the connecting member 313 and the conductive layer 314.

[0103] exist Figure 14 In this configuration, the jet heater RhA and the circulating heater RhB are arranged on the top surface of the insulating layer 311e, which is the upper layer of the insulating layer 311. Specifically, the jet heater RhA and the circulating heater RhB are arranged on the same layer. Furthermore, in... Figure 14 In this embodiment, a portion of the jet heater RhA can be electrically connected to the jet drain wiring 107-1 via the connecting member 313 and the conductive layer 314. Similarly, a portion of the circulating heater RhB can be electrically connected to the circulating drain wiring 108-1 via the connecting member 313 and the conductive layer 314. Another portion of the jet heater RhA can be electrically connected to the power supply voltage wiring VH114a via the connecting member 313 and the conductive layer 314. Another portion of the circulating heater RhB can be electrically connected to the power supply voltage wiring VH114b via the connecting member 313 and the conductive layer 314. Although in this embodiment, power supply voltage wiring VH114a and power supply voltage wiring VH114b are commonly connected, they can be configured to be connected separately and supplied with power voltage independently.

[0104] Note that, although in this embodiment it is assumed that... Figure 10 GNDH wiring 115 is arranged in Figure 14 The upper layer of the power supply voltage wiring VH114 is used, but the configuration is not limited to this. Figure 10The GNDH wiring 115 can be located on the lower layer of the power supply voltage wiring VH114. Alternatively, Figure 10 The GNDH wiring 115 can be on the same layer as the power supply voltage wiring VH114.

[0105] also, Figure 13 Electrode layers of the injection drive elements MD1-1 to MD1-8 and Figure 13 The electrode layers of the intermediate circulation drive elements MD2-1 to MD2-8 are formed in the same layer as the jet drain wiring 107. Specifically, the circulation drive element array 302 and the jet drive element array 301 are arranged side by side on the same layer as the jet drive element array 301. Figure 13 The electrode layers of the injection drive elements MD1-1 to MD1-8 include Figure 13 The drain electrode, source electrode, and gate electrode of the injection drive elements MD1-1 to MD1-8. Figure 13 The electrode layers of the intermediate cycle drive elements MD2-1 to MD2-8 include Figure 13 The circulating drive elements MD2-1 to MD2-8 have drain, source, and gate electrodes. Furthermore, the electrode layer of each jet drive element MD1 is interconnected with a corresponding jet drain wiring 107. The electrode layer of each circulating drive element MD2 is interconnected with a corresponding circulating drain wiring 108. As described above, the circulating drain wiring 108 and the jet drain wiring 107 are formed in different layers. Furthermore, the electrode layer of the circulating drive element MD2 is formed in the same layer as the jet drain wiring 107. Therefore, the electrode layer of the circulating drive element MD2 and the circulating drain wiring 108 are located in different layers. Therefore, the electrode layer of the circulating drive element MD2 can be electrically connected to the circulating drain wiring 108 via a conductive layer 314 and a connecting member 313 in the same layer as the circulating drain wiring 108. Specifically, the wiring layer where the circulating drain wiring 108 is formed is a different layer from the electrode layer of the circulating drive element MD2, and is electrically connected to the electrode layer of the circulating drive element MD2 via vias. Note that, according to the above description, the wiring layer in which the jet drain wiring 107 is formed is formed in the same layer as the electrode layer of the jet drive element MD1 and the electrode layer of the cycle drive element MD2.

[0106] Furthermore, the jet heater RhA and the circulating heater RhB can be made of metals with high resistance, such as, for example, silicon tantalum nitride or silicon tungsten nitride. Although Figure 14Although not shown, it is assumed that the jet drive element MD1 and the circulation drive element MD2 are disposed in the same semiconductor layer and are both formed of N-type MOSFETs as described above. Furthermore, the connection member 313, the conductive layer 314, the jet drain wiring 107-1, the circulation drain wiring 108-1, and the power supply voltage wiring VH114 are made of a metal with low resistance. For example, the connection member 313 may be made of tungsten, copper, etc. Additionally, for example, the conductive layer 314, the jet drain wiring 107-1, the circulation drain wiring 108-1, and the power supply voltage wiring VH114 may be made of, for example, aluminum, copper, etc. Furthermore, in this embodiment, the jet drain wiring 107-1 and the circulation drain wiring 108-1 are formed in different layers, thus being arranged in two layers in total. Moreover, the circulation drain wiring 108-1 is formed in the layer above the jet drain wiring 107-1.

[0107] In addition, Figure 13 Although it appears that portions of the jet drain wiring 107-1 and the circulating drain wiring 108-1 overlap, this is merely an example of jet drain wiring 107-1 and circulating drain wiring 108-1 having the same wiring width. Figure 14 As shown, the jet drain wiring 107-1 and the circulating drain wiring 108-1 are formed in different layers.

[0108] Note that in this embodiment, the electronic components of the conductive layer 314, the jet drain wiring 107-1, the circulating drain wiring 108-1, and the power supply voltage wiring VH114 are formed in different layers, thus forming a total of four layers. However, this disclosure is not limited to this configuration. The number of layers in which the electronic components are formed may differ from that in this embodiment. Next, by using Figure 15 Explain the comparison example.

[0109] (Example of arrangement comparison) Figure 15 A diagram illustrating a comparative example of the arrangement of the heater and drive elements. 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 routing area for the jet drain wiring and the circulating drain wiring cannot be sufficiently guaranteed between supply port 32-1 and supply port 32-2. Therefore, in... Figure 15 In the arrangement comparison example, the wiring width of each of the injection drain wiring and the circulation drain wiring is smaller than the expected wiring width. Furthermore, the injection drive element MD1 and the circulation drive element MD2 are arranged alternately in the array. Therefore, the arrangement area of ​​the injection drive element MD1 and the circulation drive element MD2 cannot be sufficiently guaranteed. Consequently, in Figure 15 In the arrangement comparison example, the size of each of the injection drive element MD1 and the cycle drive element MD2 is smaller than the expected size.

[0110] (The effect of the first scenario) As described above, in the first case, the jet drain wiring 107 and the circulating drain wiring 108 are arranged in two separate layers. Therefore, the jet drain wiring 107 and the circulating drain wiring 108 are not arranged on the same layer, but rather one type of drain wiring is arranged per layer. This doubles the area through which the wiring passes between the supply ports 32. In this way, the area for arranging drain wiring in each layer is sufficiently ensured. Therefore, the wiring width of each drain wiring can be ensured as desired. Thus, driving elements such as the jet driving element MD1 and the circulating driving element MD2 can be appropriately arranged in the printed element substrate 18.

[0111] Furthermore, the jetting drive element array 301 and the circulating drive element array 302 are arranged in two arrays along the long side of the printing element substrate 18. This doubles the area where the drive elements can be arranged. Therefore, the size of each drive element can be set to the desired size.

[0112] Furthermore, the jet drive element array 301 is arranged in a region closer to the area where the jet heater array 112 and the circulating heater array 113 are arranged, than the circulating drive element array 302. This allows the wiring resistance of the jet drain wiring 107 to be less than that of the circulating drain wiring 108. Therefore, for the jet heater RhA, which consumes more energy than the circulating heater RhB, the energy consumed in the jet drain wiring 107 can be less than that consumed in the circulating drain wiring 108. This allows for efficient driving of the jet heater RhA.

[0113] (Second scenario) Figure 16 This diagram illustrates an example arrangement of the heater and drive element according to a second case of this embodiment. The second case differs from the first case in that multiple units 305 are provided. In the second case, the units 305 are arranged such that they are symmetrically arranged with respect to the long side direction of the printing element substrate 18. Furthermore, in the second case, the units are arranged such that supply ports 401-1 and 401-2 are provided between the units 305. In this arrangement, supply ports 401-1 and 401-2 are used to supply ink to each unit 305. Therefore, a reduction in the size of the printing element substrate 18 is possible.

[0114] Specifically, each unit 305 includes an array of jet driving elements, an array of circulating driving elements, and a region of heating resistor elements. The jet driving element array includes jet driving elements MD1-1 to MD1-8. The circulating driving element array includes circulating driving elements MD2-1 to MD2-8. The region of heating resistor elements includes jet heaters RhA-1 to RhA-8 and circulating heaters RhB-1 to RhB-8. In this embodiment, two units 305 are formed. The units 305 are symmetrically arranged around the supply port 401, such that each heating resistor element region faces each other. In this arrangement, the units 305 are arranged on both sides of the supply port 401. Therefore, the supply port 401 can supply ink to each unit 305. As a result, the overall size of the printing element substrate 18 can be reduced.

[0115] Note that the dimensions of supply ports 401-1 and 401-2 can be the same as or different from the dimensions of supply ports 32-1 and 32-2. Furthermore, while the second case shows an example where the number of supply ports 401 and 32 is the same, the number of supply ports 401 can also be different from the number of supply ports 32. Additionally, while an example is shown where eight jet heaters RhA are arranged for one supply port 401, the number of jet heaters RhA is not limited to eight. This also applies to the circulating heater RhB. Furthermore, while an example is shown where there are two units 305, there can also be three or more units 305. Specifically, in the second case, at least two units 305 are formed.

[0116] (Third scenario) Figure 17 This diagram illustrates an example arrangement of the heaters and drive elements according to a third case of this embodiment. The third case differs from the first and second cases in that the jet heater RhA and the circulating heater RhB are arranged in an array. With this arrangement, it is not necessary to ensure sufficient arrangement areas for the two arrays of jet heater RhA and circulating heater RhB. Therefore, a reduction in the size of the printing element substrate 18 is possible. Specifically, the jet heater RhA and the circulating heater RhB are arranged alternately in an array. With this arrangement configuration, the size of the heating resistance element area including the jet heater RhA and the circulating heater RhB can be reduced. Therefore, the overall size of the printing element substrate 18 can be reduced.

[0117] (Other examples) Although the first to third cases of this embodiment have been described above, the present invention is not limited to the values, forms, and quantities described above, and the elements are arranged according to the configuration of the printed element substrate 18. For example, the number of nozzles in each nozzle array is not limited to 8 or 16. For example, the number of nozzles in each nozzle array may be 512. Furthermore, the nozzle array itself is not limited to one array or two arrays, but may be multiple arrays, i.e., three or more arrays.

[0118] <Other Embodiments> While various examples and embodiments of this disclosure have been shown and described above, the spirit and scope of this disclosure are not limited to the specific description herein. This disclosure is not limited to the above embodiments, but various modifications are possible. Furthermore, parts of the above embodiments may be combined where appropriate in this disclosure.

[0119] (Modified Example 1) For example, while this embodiment illustrates an example of using vias for electrical connections with other wiring layers, this disclosure is not limited to this example. For instance, in a plurality of stacked wiring layers, instead of using vias to achieve conductivity between one wiring layer and another, a conductive overlay can be applied to a via that extends through all wiring layers.

[0120] Other embodiments One or more embodiments of this disclosure can also be implemented by a computer of a system or apparatus that reads and executes computer-executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more fully referred to as a "non-transitory computer-readable storage medium") to perform the functions of one or more embodiments of the above-described embodiments and / or includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) to perform the functions of one or more embodiments of the above-described embodiments, and is implemented by the computer of the system or apparatus by performing methods in such a way as: for example, reading and executing computer-executable instructions from the storage medium to perform the functions of one or more embodiments of the above-described embodiments and / or controlling one or more circuits to perform the functions of one or more embodiments of the above-described 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 separate computers or separate 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. Storage media may include, for example, hard disks, random access memory (RAM), read-only memory (ROM), storage devices for distributed computing systems, and optical discs (such as CDs, DVDs, or Blu-ray discs).TM One or more of the following: flash memory devices, memory cards, etc.

[0121] Other embodiments The embodiments of the present invention can also be implemented by the following method: providing software (including computer program products of computer programs) that performs the functions of the above embodiments to a system or device via a network or various storage media, and the computer (central processing unit (CPU) or microprocessor unit (MPU) of the system or device) reads out and executes the computer program.

[0122] According to this disclosure, driving elements can be appropriately arranged in a printed element substrate.

[0123] Although this disclosure has been described with reference to embodiments, it is to 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 printed component substrate, comprising: A first driving element array, the first driving element array including a plurality of first driving elements, the plurality of first driving elements being configured to drive a plurality of first heating resistor elements, the plurality of first driving elements being arranged in an array; A second driving element array, the second driving element array including a plurality of second driving elements, the plurality of second driving elements being configured to drive a plurality of second heating resistor elements, the plurality of second driving elements being arranged in an array; Multiple first wirings are configured to connect the multiple first heating resistor elements and the multiple first driving elements; as well as Multiple second wirings are configured to connect the multiple second heating resistor elements and the multiple second driving elements, wherein... The second driving element array is arranged side-by-side with the first driving element array on the same layer as the first driving element array, and the second driving element array is arranged further away from the heating resistor element region than the first driving element array. The heating resistor element region includes the plurality of first heating resistor elements and the plurality of second heating resistor elements arranged thereon. The plurality of second wirings are formed in a different layer than the plurality of first wirings.

2. The printed element substrate according to claim 1, wherein, The resistance value of each of the plurality of first heating resistor elements is different from the resistance value of each of the plurality of second heating resistor elements.

3. The printed element substrate according to claim 1, wherein, The component area of ​​the first driving element is different from that of the second driving element.

4. The printed element substrate according to claim 1, wherein, The component area of ​​the first driving element is larger than the component area of ​​the second driving element.

5. The printed element substrate according to claim 1, wherein, The drive current supplied from the first drive element to the first heating resistor element is different from the drive current supplied from the second drive element to the second heating resistor element.

6. The printed element substrate according to claim 1, wherein, The driving current of the first heating resistor element is greater than the driving current of the second heating resistor element.

7. The printing element substrate of claim 1, further comprising a plurality of first supply ports configured to supply liquid and disposed between the heating resistor element region and the group of the plurality of first driving elements and the plurality of second driving elements.

8. The printed element substrate according to claim 7, wherein, The first wiring and the second wiring are arranged to pass between each of the first supply ports.

9. The printed element substrate according to claim 1, wherein, The layer in which the second wiring is formed is located above the layer in which the first wiring is formed.

10. The printed element substrate according to claim 1, wherein, The wiring layer in which the second wiring is formed is a layer different from the electrode layer of the second driving element, and is electrically connected to the electrode layer of the second driving element through vias.

11. The printed element substrate according to claim 1, wherein, The wiring layer in which the first wiring is formed is formed in the same layer as the electrode layer of the first driving element and the electrode layer of the second driving element.

12. The printed element substrate according to claim 1, further comprising: A first heating resistor element array, the first heating resistor element array comprising the plurality of first heating resistor elements, the plurality of first heating resistor elements being arranged in an array in a first region of the heating resistor element region; as well as A second array of heating resistor elements is arranged side-by-side with the first array of heating resistor elements in the same layer as the first array of heating resistor elements in a second region of the heating resistor element region, and the second array of heating resistor elements includes the plurality of second heating resistor elements arranged in an array, wherein... In a direction orthogonal to the array direction of the first driving element array, the first heating resistor element array is arranged closer to the first driving element array than the second heating resistor element array.

13. The printed element substrate according to claim 1, further comprising: A second supply port, configured to supply ink; as well as The unit includes the first driving element array, the second driving element array, and the heating resistor element region, wherein... At least two of the aforementioned units are formed, and Each unit is arranged symmetrically around the second supply port, such that the heating resistor element areas face each other.

14. The printed element substrate according to claim 1, wherein, The plurality of first heating resistor elements and the plurality of second heating resistor elements are arranged alternately in an array.

15. The printed element substrate of claim 1, further comprising a power supply line electrically connected to each of the first heating resistor element and the second heating resistor element, and configured to supply power.

16. The printed element substrate of claim 1, further comprising a grounding wiring, the grounding wiring being electrically connected to each of the first driving element and the second driving element and configured to set a reference potential.

17. The printed element substrate according to claim 1, wherein, The first driving element is a jet driving element, and the second driving element is a cycle driving element.

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