JP7171320B2 - INKJET RECORDING DEVICE, CONTROL METHOD THEREOF, AND PROGRAM - Google Patents

Description

The present invention relates to an inkjet recording apparatus, its control method, and a program.

2. Description of the Related Art Conventionally, there has been known an inkjet printing apparatus that prints an image on a printing medium using a printing head having an element substrate on which a plurality of printing elements that generate thermal energy for ejecting ink are arranged.

For example, in Patent Document 1, an element substrate arranged in a print head is divided into a plurality of areas, and the element substrate is heated by sub-heaters arranged in each of the divided areas so that the element substrate reaches a set temperature. A controlling configuration is disclosed.

JP 2017-222092 A

However, in Patent Document 1, an upper limit is set for the driving power of the sub-heaters. There is a problem that it takes a long time to raise the temperature.

Therefore, in view of the above problems, the present invention provides a print head of a printing apparatus, in which even if the drive power of some of the sub-heaters reaches the upper limit, the temperature of the area that some of the sub-heaters are in charge of is reduced. The purpose is to shorten the time to raise to the set temperature.

The present invention includes an element substrate provided with one or more recording element arrays each composed of recording elements for ejecting ink onto a recording medium, a heating element for heating the ink, and a sensor for detecting temperature, An inkjet recording apparatus in which the heating element and the sensor are arranged for each of a plurality of divided areas obtained by dividing the element substrate into a plurality of areas, first determining means for determining driving strength for the heating element arranged in the divided area based on the difference between the temperature detected by the sensor arranged in the divided area and the target temperature; a second determining means for determining a correction value for correcting the driving strength; and a second determining means for determining the corrected driving strength by adding the driving strength and the correction value for each of the divided areas. 3 determining means, and driving means for driving the heating elements according to the corrected driving intensity for each of the divided regions, wherein the corrected driving intensity for the first heating element group is the corrected driving intensity. When the driving intensity reaches the upper limit value, the second heating element is arranged in a divided area that is close to the divided area where the heating elements of the first heating element group are arranged and has higher heating efficiency than the divided area. The inkjet recording apparatus is characterized in that the correction value for the heating element group is equal to the correction value for the first heating element group.

According to the present invention, even when the drive power of some of the sub-heaters has reached the upper limit, it is possible to shorten the time required to raise the temperature of the area that some of the sub-heaters are in charge of to the set temperature. .

1 is an external perspective view showing a configuration example of a recording apparatus according to the present invention; FIG. FIG. 4 is a diagram showing an example of the control configuration of the printing apparatus according to the present invention; FIG. 2 is a diagram for explaining the outline of the configuration of the print head according to the first embodiment; FIG. 3 is a flowchart of heat retention control processing according to the first embodiment; 4 is a table that holds the correspondence relationship between ΔT and SH rank according to the first embodiment; (a) A diagram for explaining an SH rank correction value in a conventional high-temperature environment. (b) A diagram for explaining a temperature change when the sub-heater is driven by applying this SH rank correction value. (a) A diagram for explaining an SH rank correction value in a conventional low-temperature environment. (b) A diagram for explaining a temperature change when the sub-heater is driven by applying this SH rank correction value. (a) A diagram for explaining an SH rank correction value in a low-temperature environment according to the first embodiment. (b) A diagram for explaining a temperature change when the sub-heater is driven by applying this SH rank correction value. FIG. 10 is a diagram for explaining the outline of the configuration of a print head according to a second embodiment; (a) A diagram for explaining an SH rank correction value in a low temperature environment according to the second embodiment. (b) A diagram for explaining a temperature change when the sub-heater is driven by applying this SH rank correction value.

Preferred embodiments of the present invention will now be described more specifically and in detail with reference to the accompanying drawings. However, unless there is a specific description, the relative arrangement and the like of the components described here are not intended to limit the scope of the present invention only to them.

In this specification, "recording" (sometimes referred to as "printing") means not only the formation of significant information such as characters and graphics, but also meaninglessness. Furthermore, regardless of whether or not it is actualized so that humans can perceive it visually, it also represents the case of forming an image, design, pattern, etc. on a recording medium or processing the medium.

The term "recording medium" refers not only to paper used in general recording devices, but also to a wide range of materials that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, and leather. shall be

Furthermore, "ink" (sometimes referred to as "liquid") should be interpreted broadly in the same way as the definition of "print" above. Therefore, by being applied on a recording medium, it can be used for forming an image, design, pattern, etc., processing the recording medium, or treating ink (for example, solidifying or insolubilizing the coloring agent in the ink applied to the recording medium). It also represents a recording material such as a liquid that is applied.

Furthermore, unless otherwise specified, the term "printing element" generally refers to an ink ejection port, a liquid path communicating therewith, and an element that generates energy used for ink ejection.

Further, the term "element substrate" (sometimes called "head substrate" or "heater board") does not simply refer to a substrate made of a silicon semiconductor, but rather a printing element substrate on which elements, wiring, etc. are provided. It indicates the configuration of Incidentally, "on the substrate" means not only the top of the element substrate but also the surface of the element substrate and the inside of the element substrate in the vicinity of the surface.

An ink jet print head (hereinafter simply referred to as a "print head"), which is the most important feature of the present invention, includes a print element array composed of a plurality of print elements and a drive circuit for driving the plurality of print elements. Mounted on the same board. Further, as will be understood from the description given later, the printhead has a structure in which a plurality of element substrates are incorporated and these element substrates are cascade-connected. Therefore, since the print head of the present invention can achieve a relatively long print width, it can be used not only in a serial type print apparatus commonly seen but also in a full-line print head whose print width corresponds to the width of a print medium. It is also used in a recording device with a recording head. Among serial type recording apparatuses, the recording head of the present invention is used in a large format printer for recording on a recording medium of a large size such as A0 or B0. First, a recording apparatus using the recording head of the present invention will be described.

<Outline of recording device>
FIG. 1 shows, as an example of a recording apparatus according to the present invention, an inkjet recording apparatus 1 equipped with full-line recording heads 100K, 100C, 100M, and 100Y, and a recovery system unit for always ensuring stable ink ejection. It is a perspective see-through view for explaining the structure. In the following description, the "inkjet recording apparatus 1" is simply referred to as the "recording apparatus 1".

The recording paper 15 set in the feeder unit 17 is conveyed in the +X direction in the drawing by the conveying unit 16, and reaches a position (recording position) where recording is actually performed by the recording head of each color. In recording on the recording paper 15, first, while the transport unit 16 is transporting the recording paper 15, when the reference position set in the recording paper 15 reaches below the recording head 100K that ejects black (K) ink. Then, black ink is ejected from the recording head 100K. Similarly, the recording head 100C ejecting cyan (C) ink, the recording head 100M ejecting magenta (M) ink, and the recording head 100Y ejecting yellow (Y) ink have their reference positions on the printing paper 15 in this order. When it reaches the bottom of the recording head, each color ink is ejected. The recording paper 15 on which the color image has been printed in this manner is discharged and stacked on the stacker tray 20 .

The recording apparatus 1 further includes an ink cartridge (not shown) that can be replaced for each ink supplied to the recording heads 100K, 100C, 100M, and 100Y. The front door 19 is a door that is opened and closed when replacing the ink cartridge. The printing apparatus 1 further includes a pump unit (not shown) for ink supply to the printing head 100 and recovery operation, a control board (not shown) for controlling the printing apparatus 1 as a whole, and the like.

The coordinates shown in FIG. 1, that is, the relationship between the X-axis indicating the conveying direction of the recording medium, the Z-axis indicating the direction of gravity, and the Y-axis perpendicularly intersecting the X-axis and the Z-axis will be described later. However, it shall be used in common. The above is the outline of the recording apparatus according to the present invention.

<Regarding the control configuration of the recording device>
Next, a configuration (so-called control configuration) for executing recording control of the recording apparatus 1 described with reference to FIG. 1 will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the control circuit of the recording apparatus 1. As shown in FIG. In FIG. 2, the controller 30 includes an MPU 31, a ROM 32, a gate array (GA) 33, and a DRAM .

The interface 40 is an interface for inputting recording data. The ROM 32 is a non-volatile storage area and is a ROM that stores control programs executed by the MPU 31 . The DRAM 34 is a DRAM that temporarily stores data such as print data and print signals supplied to the print head 100 . The gate array 33 is a gate array that controls the supply of recording signals to the recording head 100 , and also controls data transfer between the interface 40 , MPU 31 and DRAM 34 . The carriage motor 90 is a motor for transporting the recording heads 100 (100K, 100C, 100M, 100Y). The transport motor 70 is a motor for transporting the recording medium. A head driver 50 drives the recording head 100 . A motor driver 60 is a motor driver for driving the carry motor 70 , and a motor driver 80 is a motor driver for driving the carriage motor 90 .

It should be noted that the carriage motor 90 and the motor driver 80 for driving the motor do not exist in the recording apparatus using the full-line recording head as shown in FIG. With this in mind, the motor driver 80 and the carriage motor 90 are bracketed in FIG.

The operation of the control circuit described above will be described. Print data (bitmap image data) input via the interface 40 is converted into a print signal by the MPU 31 and the gate array 33 . A print signal is an ON/OFF signal representing ejection or non-ejection for an ink ejection port. The motor drivers 60 and 80 are driven, and the recording head 100 is driven according to the recording signal sent to the head driver 50 to perform recording.

Hereinafter, embodiments of the present invention will be described using a full-line type printhead as an example. The present invention may be applied. The above is the content of the control configuration of the recording apparatus 1 according to the present invention.

[First embodiment]
A first embodiment of the present invention will be described below.

<Construction of the recording head>
FIG. 3 is a diagram for explaining the outline of the configuration of the print head according to this embodiment. As shown in FIG. 3, in the print head 100 according to this embodiment, a plurality of element substrates 301 are arranged along the direction (Y direction) in which the print head 100 extends. For convenience of explanation, FIG. 3 omits printing elements (specifically, ejection openings) for ejecting ink and heaters for generating thermal energy corresponding to the ejection openings.

A plurality of sub-heaters (heating elements) 302 are provided on the element substrate 301 . The sub-heaters 302 are heaters that are different from the heaters that are provided in association with the respective printing elements (specifically, ejection openings) that eject ink. In FIG. 3, the element substrate 301 is divided into 40 regions in a grid pattern, and sub-heaters corresponding to each of the divided regions (divided regions) are provided. However, the number and arrangement of the sub-heaters 302 are not particularly limited to those shown in FIG.

Further, each sub-heater 302 is provided with a temperature detection means (temperature sensor) 303 . The number and arrangement of the temperature detecting means 303 are not particularly limited to those shown in FIG. Also, the arrangement configuration and shape of the element substrate 301 are not limited to those shown in FIG. For example, the shape of the element substrate may be a quadrangle such as a rectangle or a trapezoid, in addition to a parallelogram instead of a rectangle as shown. Furthermore, the printhead 100 may be configured with a plurality of rows (of element substrates), or the arrangement of the element substrates in the printhead 100 may be in a staggered arrangement.

<Regarding heat retention control processing>
The heat retention control process according to this embodiment will be described below with reference to FIG. FIG. 4 is a flow chart of heat retention control processing accompanied by sub-heater driving according to the present embodiment. Each process of the flow shown in FIG. 4 is implemented by, for example, the MPU 31 reading and executing a program stored in the ROM 32 or the like. In the following description, it is assumed that the controller 30 is the subject of each process. Also, the following flow is started in response to receiving a print job execution instruction.

In step S<b>400 , the controller 30 focuses on one unprocessed divided region of each element substrate 301 . The area to be focused on in this step is set as a target divided area. For example, in the case shown in FIG. 3, one of the 40 divided areas is selected as the target divided area in this step. In the following description, "step S~" will be simply written as "S~".

In S401, the controller 30 acquires the temperature of the target divided area. Here, the temperature of the target divided area can be obtained by the temperature detection means 303 corresponding to the target divided area.

In S402, the controller 30 calculates a difference (ΔT) between the temperature of the divided region of interest acquired in S401 and the target temperature (Ttgt). Here, the "target temperature" indicates the temperature to be maintained in each target divided area for image formation, and is set as a default value. In this embodiment, a value common to both the plurality of element substrates and the plurality of divided regions of each element substrate is used as the target temperature. The target temperature value is defined in advance and stored in the ROM 32 or the like.

In S403, the controller 30 determines an index indicating the driving intensity for the sub-heater 302 corresponding to the target divided area based on the temperature difference ΔT calculated in S402. Specifically, the controller 30 refers to a table such as that shown in FIG. 5 and selects the sub-heater rank corresponding to the temperature difference ΔT calculated in S402. The sub-heater rank (abbreviated as SH rank) is an index indicating the driving strength for the sub-heater employed in this embodiment. FIG. 5 shows a table holding the correspondence between the temperature difference ΔT and the SH rank. As shown in FIG. 5(a), the SH rank of this embodiment can take values in the range of 0 to 31. In FIG. The higher the SH rank, the longer the pulse width for driving the sub-heater, that is, the longer the time for driving the sub-heater.

When the first heat retention control process is started after the power of the recording apparatus 1 is turned on, the temperature of the element substrate 301 is substantially equal to the environmental temperature, and the difference (temperature difference ΔT) between the temperature of the divided area and the target temperature Ttgt. is large, the SH rank is large. Therefore, the sub-heater 302 driven with high driving intensity heats the divided regions rapidly. After being heated for a while, the temperature difference ΔT becomes smaller, so the SH rank becomes smaller, and the temperature of the divided region is kept substantially equal to the target temperature Ttgt.

FIG. 5(a) is a table showing the correspondence when no upper limit is set for the driving power of the sub-heater, and FIG. 5(b) shows the correspondence when the upper limit is set for the driving power of the sub-heater. is a table. Here, the "upper limit" of the sub-heater driving power is a threshold value of the sub-heater rank before and after correction, which is defined in advance to keep the power consumption of the printing apparatus 1 below a predetermined amount. These thresholds may vary depending on the environmental temperature and the width of the paper to be recorded. Even if the sub-heaters are driven under the same drive conditions, the power consumption of the recording apparatus 1 increases as the environmental temperature decreases and as the width of the paper to be recorded increases. Therefore, in order to suppress the power consumption of the printing apparatus 1 to a predetermined amount or less, it is necessary to reduce the upper limit of the driving power of the sub-heater. A case in which the upper limit value before correction is set to 23 and the upper limit value after correction is set to 31 will be described below.

In S404, the controller 30 determines a value for correcting the SH rank selected in S403 (as an SH rank correction value). In this embodiment, the SH rank correction value is defined in advance according to the position on the sub-heater in consideration of the thermal characteristics of each sub-heater. stored. Thermal characteristics can be broadly divided into two characteristics: heat generation characteristics and heat radiation characteristics. The heat generation characteristic is determined by the resistance variation caused by the manufacturing tolerance of the sub-heater. The smaller the resistance value, the larger the current value. Since the voltage is fixed, the heat value (power consumption) increases. The heat radiation characteristic is determined based on the position of the sub-heater on the element substrate, and generally, the heat radiation amount is greater at the end portions on the element substrate than at the central portion. Since the present embodiment is correction control related to heat radiation characteristics, heat generation characteristics are not considered. (In other words, it is assumed that there is no resistance variation due to the manufacturing tolerance of the sub-heater.)

FIG. 6 is a diagram for explaining the temperature change of the element substrate when the sub-heater is driven in a high-temperature environment using the conventional configuration. Specifically, FIG. 6A shows the SH rank correction value for each sub-heater corresponding to each position on the element substrate, and shows the grouping of the sub-heaters according to the thermal characteristics of each sub-heater arranged on the element substrate. there is FIG. 6(b) shows temperature changes in the divided regions of the element substrate that each sub-heater is in charge of when the sub-heaters are driven by applying the SH rank correction value shown in FIG. 6(a). As shown in FIG. 6(a), the conventional configuration corresponds to sub-heaters arranged at positions with low heating efficiency (specifically, the sub-heaters at the four corners of the upper left, lower left, lower right, and upper right corners). lengthen the pulse width. On the other hand, the pulse width corresponding to the sub-heaters arranged at positions where the heating efficiency is higher than those of these sub-heaters is shortened. This reduces temperature variations on the element substrate. The individual sub-heaters on the element substrate have the same device capability (amount of heat generated with respect to current), but differ in heating efficiency depending on the arrangement position. As described above, the reason why the heating efficiency of the sub-heaters at the four corners of the upper left, lower left, lower right, and upper right corners is low is that there are no sub-heaters in the surroundings, so that heat can easily escape.

Incidentally, in FIG. 6A, the sum of the SH rank correction values in the element substrate is set to 0 in order to equalize the power consumption of each element substrate before and after the SH rank correction. By equalizing the power consumption of each element substrate before and after correction, it is possible to eliminate the influence on control related to power consumption. As described above, FIG. 6 shows the case of a high-temperature environment, and since the difference between the environmental temperature (assumed to be D2) and the target temperature (assumed to be D3) is relatively small, the time from the start of heating to the completion of heating ( (heating time) is T2-T1, which is shorter than the low-temperature environment case described later. In addition, since there is sufficient power to drive the sub-heater, it is possible to control the heating from the environmental temperature to the target temperature without causing temperature variations on the element substrate.

Returning to the description of FIG. After S404, in S405, the controller 30 finally determines the SH rank of the sub-heater for the target divided area. Specifically, the SH rank correction value (see FIG. 6A) corresponding to the target divided area determined in S404 is added to the SH rank selected using the table in FIG. 5B in S403. . For example, when .DELTA.T>2.0, the sub-heaters belonging to the first sub-heater group (abbreviated as SH group) arranged at a position with low heating efficiency have an SH rank of 23 before correction and an SH rank correction value of Since it is 8, the SH rank after correction is 31. As a result of adding the correction value, if it becomes larger than 31, it is set to 31, and if it becomes smaller than 0, it is set to 0.

In S406, the controller 30 drives each sub-heater 302 with a pulse width corresponding to the SH rank determined in S405.

In S407, the controller 30 determines whether there is an unprocessed divided area. If the determination result of this step is true, the process returns to S400, and the next target divided area is selected. On the other hand, if the determination result of this step is false, the series of processing ends. The above is the content of the heat retention control process in this embodiment.

<Specific example of the first embodiment>
<<Conventional configuration>>
Before describing a specific example of this embodiment, first, an operation example of a conventional configuration will be described. FIG. 7 is a diagram for explaining the temperature change of the element substrate when the sub-heater is driven in a low-temperature environment using the conventional configuration. Specifically, FIG. 7A shows the SH rank correction value for each sub-heater corresponding to each position on the element substrate, and shows the grouping of the sub-heaters according to the thermal characteristics of each sub-heater arranged on the element substrate. there is Here, as shown in the figure, the group of sub-heaters arranged at the position with the lowest heating efficiency, specifically, the sub-heaters at the four corners of the upper left, lower left, lower right and upper right corners are arranged as the first sub-heaters. A heater group (abbreviated as an SH group, also called a heating element group) is used. A group of sub-heaters arranged in a position close to (also called adjacent to) the sub-heaters of the first SH group in any direction and having higher heating efficiency than the sub-heaters of the first SH group is called the second SH group. do.

FIG. 7(b) shows temperature changes in the divided regions of the element substrate that each sub-heater is in charge of when the sub-heaters are driven by applying the SH rank correction values shown in FIG. 7(a). As described above, FIG. 7 shows the case of the low temperature environment, and since the difference between the environmental temperature (D1, provided that D1<D2) and the target temperature D3 is relatively large, the heating time is T4-T1. longer than the case shown in 6(b). In addition, since there is no margin in the electric power for driving the sub-heaters, the divided regions assigned to the sub-heaters belonging to the first SH group having low heating efficiency are assigned to the sub-heaters belonging to the second SH group having high heating efficiency. Compared to the area, the temperature during heating will be lower. That is, as shown in FIG. 7B, the sub-heater belonging to the first SH group belongs to the second SH group even if the sub-heater is driven with the longest pulse width corresponding to the maximum settable SH rank. Heating time is longer than sub-heater. The “maximum SH rank” in this example is the corrected sub-heater rank value 31 obtained by adding the sub-heater rank correction value 8 to the sub-heater rank upper limit value 23 .

<<In the case of this embodiment>>
Next, an operation example in the configuration according to this embodiment will be described. FIG. 8 is a diagram for explaining the temperature change of the element substrate when the sub-heater is driven in a low-temperature environment using the configuration according to this embodiment. Specifically, FIG. 8A shows the SH rank correction value for each sub-heater corresponding to each position on the element substrate, and shows the grouping of the sub-heaters according to the thermal characteristics of each sub-heater arranged on the element substrate. there is FIG. 8(b) shows temperature changes in the divided regions of the element substrate that each sub-heater is in charge of when the sub-heaters are driven by applying the SH rank correction values shown in FIG. 8(a). As described above, the shape of the element substrate and its divided regions in this embodiment is a parallelogram (see FIG. 3). The divided regions are represented by squares.

As shown in FIG. 8A, the sub-heater rank correction value corresponding to the first SH group is 8 as in the conventional example. However, the SH rank corresponding to the second SH group is 8, which is higher than that of the conventional example. Incidentally, the SH rank for the second SH group in the conventional example is 0 (see FIG. 7(a)).

Therefore, during heating, the temperature of the divided area handled by each sub-heater of the second SH group according to the present embodiment becomes higher than the temperature of the divided area handled by each sub-heater of the second SH group according to the conventional example. As a result, in this embodiment, the amount of heat transferred from the second SH group sub-heater to the first SH group sub-heater is greater than in the conventional example. Therefore, the heating time required to raise the temperature of the first SH group from the ambient temperature D1 to the target temperature D3 is T3-T1, which is shorter than the conventional heating time T4-T1.

<Effects of the present embodiment and modifications>
As described above, in this embodiment, the power supplied to the first SH group is the same as that of the conventional example, but the power supplied to the second SH group is increased. Reduce the power supplied to the sub-heater. For example, in the case of FIG. 8A, the correction value for each of the 12 sub-heaters located in the center of the element substrate is -8.

According to this embodiment, the heating time of the entire element substrate can be shortened without changing the power supplied to the entire element substrate (the power consumption of each element substrate).

<<Modification 1>>
In the above embodiment, the configuration (insulating configuration) in which the heat transmitted from the adjacent sub-heaters between the element substrates is smaller than the heat transmitted from the adjacent sub-heaters within the element substrates has been described. However, the present embodiment is applied to a configuration (non-adiabatic configuration) in which the heat transmitted from adjacent sub-heaters within the element substrate (heat transmitted between divided regions) and the heat transmitted from adjacent sub-heaters between element substrates are substantially equal. can be

A detailed description will be given below. In the above-described embodiment, the heating efficiency of the sub-heaters at the four corners of each element substrate is low. On the other hand, in this modified example, the heating efficiency of the sub-heaters at the four corners of the entire print head is low. Specifically, the sub-heaters at the four corners of the entire printhead are the upper left and lower left sub-heaters of the element substrate at the left end of the print head 100, and the upper right and right sub-heaters of the element substrate at the right end of the print head 100. It is a sub heater with the bottom. As described above, in this modification, the element substrate that does not include the end portion of the print head in the first direction (X direction) and the end portion in the second direction (Y direction) is a sub-heater (first SH group). Therefore, while increasing the amount of power supplied to the element substrate including the end portion in the first direction and the end portion in the second direction of the print head, the amount of power supplied to the end portion in the first direction and the end portion in the second direction of the print head is increased accordingly. Reduce the power supplied to the element substrate that does not include the ends in the direction of . However, at this time, it is necessary to set the total SH rank correction value in the print head to zero.

<<Modification 2>>
In the above embodiment, the case where the heating efficiency of the sub-heaters at the four corners of the end portion in the first direction (X direction) and the end portion in the second direction (Y direction) of each element substrate is similarly low has been described. However, this embodiment is not limited to such a case. For example, this embodiment may be applied when the heating efficiency of the upper left and lower right sub-heaters of each element substrate is lower than the heating efficiency of the lower left and upper right sub-heaters of each element substrate. Alternatively, the present embodiment may be applied when the heating efficiency of the lower left and upper right sub-heaters of each element substrate is lower than the heating efficiency of the upper left and lower right sub-heaters of each element substrate.

As a specific example, the shape of each element substrate is a parallelogram, and the interior angle between the upper left and the lower right of each element substrate (the interior angle of the two corners) is the interior angle between the lower left and the upper right (the other two corners ) will be described. In this case, areas corresponding to smaller interior angles (upper left and lower right of each element substrate) are easier to dissipate heat than areas corresponding to larger interior angles (lower left and upper right of each element substrate). That is, in each element substrate, the heating efficiency of the sub-heaters in the upper left and lower right is lower than the heating efficiency of the sub-heaters in the lower left and upper right. Therefore, in each element substrate, the sub-heaters corresponding to the upper left and lower right should belong to the first SH group, and the sub-heaters adjacent to these sub-heaters should belong to the second SH group.

The power supplied to the sub-heaters belonging to the first SH group is the same as in the conventional example, but the power supplied to the sub-heaters belonging to the second SH group is increased. Also, the power supplied to the sub-heaters other than the first and second sub-heater groups is reduced accordingly. As a result, the heating time of the entire element substrate can be shortened without changing the power supplied to the entire element substrate.

[Second embodiment]
In the first embodiment, the case where the heating efficiency of the sub-heater at the end of each element substrate or the sub-heater at the end of the print head is low has been described. In this embodiment, one element substrate has a plurality of ink supply ports, and ink circulates in the recording apparatus 1 via the ink supply ports.

<Construction of the recording head>
FIG. 9 is a diagram for explaining the outline of the configuration of the print head according to this embodiment. Regarding the positional relationship between the sub-heater and the temperature sensor in the print head, the same configuration as in the first embodiment (see FIG. 3) is also adopted in this embodiment. 3 shows the positional relationship between the sub-heater and the temperature sensor, while FIG. 9 shows the positional relationship between the sub-heater and the ink supply port. Ink flows into the element substrate from an ink supply port (also referred to as an inflow port) 901 on the inflow side, and the ink is supplied to each recording element in the element substrate. Printing is performed on a printing medium using the supplied ink. Ink that has not been used for printing flows out of the element substrate from an ink supply port (also referred to as an outflow port) 902 on the outflow side. The ink that has flowed out of the element substrate passes through the circulation path in the recording apparatus 1 and flows into the element substrate again.

When heat retention control is performed, the temperature of the print head 100 is approximately the same as the target temperature, while the temperature of the circulation path in the printing apparatus 1 is approximately the same as the environmental temperature. Since the target temperature is higher than the ambient temperature, cold (close to the ambient temperature) ink flows from the ink supply port 901 on the inflow side, and is gradually heated while flowing through the element substrate. After that, warm ink (close to the target temperature) flows out from the ink supply port 902 on the outflow side, and is gradually cooled while flowing through the circulation path. In this way, since cold ink is always supplied to the ink supply port 901 on the inflow side, the heating efficiency of the sub-heater corresponding to the ink supply port 901 on the inflow side becomes low.

FIG. 10 is a diagram for explaining the temperature change of the element substrate when the sub-heater is driven in a low-temperature environment using the configuration according to this embodiment. Specifically, FIG. 10A shows the SH rank correction value for each sub-heater corresponding to each position on the element substrate, and shows the grouping of the sub-heaters according to the thermal characteristics of each sub-heater. FIG. 10(b) shows temperature changes in the divided regions of the element substrate that each sub-heater is in charge of when the sub-heaters are driven by applying the SH rank correction values shown in FIG. 10(a). As described above, the shape of the element substrate and its divided regions in this embodiment is a parallelogram (see FIG. 9). The divided regions are represented by squares.

In this embodiment, the positions of the sub-heaters with low heating efficiency (sub-heaters belonging to the first SH group) are the same as the positions where the inflow-side ink supply port 901 is arranged. As shown in FIG. 10(a), as in FIG. 8(a), the power supplied to the sub-heaters belonging to the first SH group is the same as in the conventional example. In addition, the power supplied to the sub-heaters having higher heating efficiency than the first SH group and close to the sub-heaters belonging to the first SH group (that is, the sub-heaters belonging to the second SH group) is increased. Also, the power supplied to the sub-heaters other than the first and second sub-heater groups is reduced accordingly.

<About the effect of this embodiment>
According to this embodiment, the heating time of the entire element substrate can be shortened without changing the power supplied to the entire element substrate (the power consumption of each element substrate).

[Other embodiments]
In the above embodiment, a fixed SH rank correction value that is uniquely determined based on the configuration of the printhead is used (see FIGS. 8A and 10A). However, the SH rank correction value to be applied may be changed according to the heating mode of the printing apparatus. Specifically, even if different SH rank correction values are applied in the first heating mode (before printing) that heats up to the target temperature and in the second heating mode (during printing) that maintains the achieved target temperature, good.

A detailed description will be given below. First, heat retention control and circulation control are started before printing, but since it takes some time to start circulation control, the temperature of the print head reaches the target temperature before the ink circulates at an appropriate flow rate. . Therefore, before printing, the heating efficiency of the sub-heater corresponding to the ink supply port 901 on the inflow side due to circulation control does not decrease, while the heating efficiency of the sub-heater at the edge of the element substrate 301 decreases. Therefore, before printing, the same sub-heater rank correction value as in the first embodiment should be applied.

In addition, since the ink circulates at an appropriate flow rate during printing, the heating efficiency of the sub-heater corresponding to the ink supply port 901 on the inflow side decreases due to the circulation control. As described above, the heating efficiency of the sub-heater at the edge of the element substrate 301 also decreases, but compared to the degree of decrease in heating efficiency due to circulation control, it is negligibly small. Therefore, the same SH rank correction value as in the second embodiment should be applied during printing.

In addition, the present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in the computer of the system or apparatus reads and executes the program. It can also be realized by processing to It can also be implemented by a circuit (for example, ASIC) that implements one or more functions.

1 recording device,
30 controller,
31 MPUs,
32 ROMs,
34 DRAM,
100 recording head

Claims (14)

An element substrate provided with one or a plurality of recording element arrays composed of recording elements for ejecting ink onto a recording medium, a heating element for heating the ink, and a sensor for detecting temperature, wherein the element substrate is provided with An inkjet recording apparatus in which the heating element and the sensor are arranged for each of a plurality of divided areas obtained by dividing into a plurality of areas,
A first determination for determining, for each of the divided areas, a driving strength for the heating element arranged in the divided area based on a difference between a temperature detected by the sensor arranged in the divided area and a target temperature. means and
a second determining means for determining a correction value for correcting the driving intensity for each of the divided regions;
a third determining means for determining a corrected drive strength by adding the drive strength and the correction value for each of the divided regions;
driving means for driving the heating element according to the corrected driving intensity for each of the divided regions;
when the corrected drive strength for the first heating element group reaches the upper limit of the corrected drive strength, the divided region where the heating elements of the first heating element group are arranged; 2. An inkjet recording apparatus, wherein the correction value for a second heating element group arranged in a divided area having higher heating efficiency than the divided area is equal to the correction value for the first heating element group. 2. An inkjet recording apparatus according to claim 1, further comprising a recording head including a plurality of said element substrates. the recording medium is conveyed along a first direction;
the recording element array extends along a second direction that intersects with the first direction;
The plurality of element substrates are arranged along the second direction,
3. An inkjet recording apparatus according to claim 2, wherein said recording head extends along said second direction. 3. The plurality of recording element arrays are arranged such that their respective positions in the first direction are different, and each of the plurality of element substrates has the plurality of recording element arrays. 3. The inkjet recording apparatus according to 3. For each of the plurality of element substrates, the amount of heat transferred between adjacent divided regions in the same element substrate is greater than the amount of heat transferred between different adjacent element substrates,
5. An ink jet recording apparatus according to claim 4, wherein said first heating element group includes four heating elements which are in charge of four corner divided areas of each of said plurality of element substrates. 6. The inkjet recording apparatus according to claim 5, wherein the sum of the correction values for each of the divided regions is 0 on each of the plurality of element substrates. For each of the plurality of element substrates, the amount of heat transferred between different adjacent element substrates is greater than the amount of heat transferred between adjacent divided regions within the same element substrate,
5. An ink jet printing apparatus according to claim 4, wherein said first heating element group includes four heating elements which are in charge of four corner divided areas of said printing head. 8. An inkjet printing apparatus according to claim 7, wherein the sum of said correction values for each of said divided areas in said printing head is zero. each shape of the plurality of element substrates is a parallelogram,
The first heating element group includes two heating elements that are in charge of divided areas of two corners of each of the plurality of element substrates corresponding to the smaller internal angles of the parallelogram. 9. The inkjet recording apparatus according to any one of claims 2 to 8, characterized in that: the ink circulates through a circulation path including the recording head;
The element substrate has an inlet through which the ink flows into the element substrate and an outlet through which the ink flows out from the element substrate,
5. The method according to any one of claims 2 to 4, wherein the first heating element group includes heating elements in charge of the divided regions where the inlets exist on each of the plurality of element substrates. The inkjet recording apparatus described. The inkjet recording apparatus operates in either a first mode of heating the recording head to a target temperature or a second mode of maintaining the target temperature,
11. The inkjet recording apparatus according to any one of claims 2 to 10, wherein said second determination means determines said correction value according to a mode in which said inkjet recording apparatus is operating. 12. The inkjet recording apparatus according to claim 1, wherein said driving means drives said heating element with a pulse width corresponding to said corrected driving intensity. An element substrate provided with one or a plurality of recording element arrays composed of recording elements for ejecting ink onto a recording medium, a heating element for heating the ink, and a sensor for detecting temperature, wherein the element substrate is provided with A control method for an inkjet recording apparatus in which the heating element and the sensor are arranged for each of a plurality of divided areas obtained by dividing into a plurality of areas,
determining, for each of the divided areas, a driving strength for the heating element arranged in the divided area based on a difference between a temperature detected by the sensor arranged in the divided area and a target temperature;
determining a correction value for correcting the driving intensity for each of the divided regions;
determining a corrected drive strength by adding the drive strength and the correction value for each of the divided regions;
driving the heating element according to the corrected driving intensity for each of the divided regions;
when the corrected drive strength for the first heating element group reaches the upper limit of the corrected drive strength, the divided region where the heating elements of the first heating element group are arranged; 2. A control method according to claim 1, wherein said correction value for a second heating element group arranged in a divided area having higher heating efficiency than said divided area is equal to said correction value for said first heating element group. A program for causing a computer to perform the method according to claim 13.

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