Recording device and control method

Abstract

The objective is to provide a recording device capable of highly reliable temperature control. [Solution] The recording device comprises a recording element array, a heating element, an element substrate on which a sensor is provided, a first determination means, a second determination means, a third determination means, and a driving means. The heating element and the sensor are provided in each of the plurality of divided regions. The first determination means determines the first driving intensity of the heating element, the second determination means determines a correction value to correct the first driving intensity, the third determination means determines the second driving intensity of the heating element based on the correction value, and the driving means drives the heating element according to the second driving intensity. The correction value is determined based on the temperature detected by the sensor and the position of the divided region.

Description

[Technical Field]

[0001] The present disclosure relates to a recording apparatus and a control method. [Background Art]

[0002] Generally, there is a recording apparatus that records an image on a recording medium, including a recording head having an element substrate including a plurality of recording elements that generate thermal energy for ejecting liquid. In this type of recording apparatus, the element substrate is divided into a plurality of regions, a heating element is provided for each of these regions (divided regions), and the driving intensity of the heating element is adjusted for each divided region, whereby control is sometimes performed to adjust the temperature of the element substrate to a target temperature suitable for recording.

[0003] Patent Document 1 discloses a recording apparatus that determines a driving intensity for a heating element for each divided region, determines a correction value for correcting the driving intensity, and adds the driving intensity and the correction value to determine a corrected driving intensity. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Laying-Open No. 2020-32696 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, in the recording apparatus of Patent Document 1 (hereinafter referred to as "prior art"), although the correction value for correcting the driving intensity is adjusted according to the position of the divided region, it is not adjusted according to the target temperature. That is, in a divided region associated with a correction value that increases the driving intensity, such as a divided region located at an end portion of the element substrate, even when the temperature slightly drops below the target temperature, the correction value that increases the driving intensity is used. For this reason, in the prior art, after the temperature of the element substrate once reaches the target temperature, the temperature drops slightly, and when the temperature is returned to the target temperature again, the temperature may exceed the target temperature.

[0006] Therefore, the purpose of this disclosure is to provide a recording device that can perform highly reliable temperature control. [Means for solving the problem]

[0007] The recording device comprises a recording element array consisting of a plurality of recording elements that discharge liquid onto a recording medium, an element substrate provided with a heating element for heating the liquid, and a sensor for detecting temperature, wherein the heating element and the sensor are provided for each of a plurality of divided regions obtained by dividing the element substrate into a plurality of regions, and further comprises a first determination means for determining a first drive strength for the heating element based on the temperature detected by the sensor for each divided region, a second determination means for determining a correction value for correcting the first drive strength for each divided region, a third determination means for determining a second drive strength for each divided region by correcting the first drive strength based on the correction value, and a drive means for driving the heating element according to the second drive strength for each divided region, wherein the second determination means determines the correction value based on the temperature and the position of the divided region. [Effects of the Invention]

[0008] The recording device of this disclosure enables highly reliable temperature control. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram showing an example of a recording device in one embodiment. [Figure 2] A block diagram showing an example of a control system in one embodiment. [Figure 3] A block diagram showing an example of a recording control unit in one embodiment. [Figure 4] A schematic perspective view showing an example of a recording head in one embodiment. [Figure 5] A schematic diagram showing an example of a recording element substrate in one embodiment. [Figure 6]A schematic plan view of a recording element substrate according to one embodiment. [Figure 7] A sectional view taken along line VII-VII in FIG. 5(a). [Figure 8] An explanatory diagram of a recording element substrate according to one embodiment. [Figure 9] A flowchart showing processing for maintaining a target temperature. [Figure 10] A diagram showing area numbers of divided areas. [Figure 11] A diagram showing an example of a first table. [Figure 12] A diagram showing an example of a second table. [Figure 13] A graph showing the relationship between driving time and voltage for a sub-heater. [Figure 14] An explanatory diagram of a conventional technique. [Figure 15] An explanatory diagram of a comparative example. [Figure 16] An explanatory diagram of the effect of one embodiment. [Figure 17] An explanatory diagram of the data capacity required for a comparative example. [Figure 18] An explanatory diagram of the data capacity required for one embodiment. [Figure 19] An explanatory diagram of temperature control of a recording element substrate according to one embodiment. [Figure 20] A diagram showing an example of a third table. [Figure 21] A diagram showing a comparative example of a third table. DETAILED DESCRIPTION OF EMBODIMENTS

[0010] [First Embodiment] <Recording Apparatus 100> FIG. 1 is a schematic diagram showing an example of a recording apparatus 100 applicable to the present embodiment.

[0011] The coordinate axes shown in the drawings of this disclosure will now be described. The X direction corresponds to the width direction (overall length direction) of the recording device 100. The Y direction corresponds to the depth direction of the recording device 100. The Z direction corresponds to the height direction (gravity direction) of the recording device 100. In this embodiment, the recording medium 102 is transported in the X direction. Therefore, the X direction also corresponds to the transport direction of the recording medium 102. And the Y direction also corresponds to the width direction of the recording medium 102.

[0012] In this disclosure, “recording” does not mean only forming meaningful information (for example, letters or figures that are made visible to human eyes). “Recording” also means forming meaningless information. Furthermore, in this disclosure, “recording” broadly means forming images, patterns, structures, or combinations thereof on a recording medium, or processing the medium.

[0013] "Recording medium" includes not only paper, which is commonly used in recording devices, but also other ink-receiving media such as cloth, plastic film, metal plates, glass, ceramics, resin, wood, and leather.

[0014] As shown in Figure 1, the recording device 100 is configured to discharge a liquid (for example, ink) and record onto the recording medium 102. In this embodiment, the description will assume that the recording device 100 is an inkjet recording device and the recording medium 102 is cut paper.

[0015] The recording device 100 includes a feeding unit 104 for feeding the recording medium 102, a recording head 101 for recording on the recording medium 102, a transport unit 103 for transporting the recording medium 102, and an ejection unit 105 from which the recording medium 102 is ejected.

[0016] When the recording medium 102 is transported from the supply unit 104 to directly below the recording head 101 by the transport unit 103, an image is recorded on the recording medium 102 by the discharge of liquid from a number of nozzles (not shown) formed on the recording head 101. When recording on the recording medium 102 is complete, the transport unit 103 discharges the recording medium 102 to the discharge unit 105.

[0017] <Recording head 101> In this embodiment, a full-line head extending in the width direction (Y direction) of the recording medium 102 is used as the recording head 101. Multiple recording element substrates 401 (see Figure 4, etc.) are provided at the bottom of the recording head 101. Multiple ejection ports 501 (see Figure 5(b), etc.) are formed on the ejection port surface (the downward-facing surface in Figure 1) of these recording element substrates 401 along the width direction (Y direction) of the recording head 101. These ejection ports 501 are formed to cover the width (length in the Y direction) of the maximum size image recording area that can be used as the recording medium 102.

[0018] In this embodiment, five recording heads 101, each discharging a processing solution, cyan ink, magenta ink, yellow ink, and black ink, are arranged along the transport direction (X direction). The type of liquid, the color of the liquid, the order in which the five recording heads 101 are arranged, and the number of recording heads 101 are not limited to the example described above. The liquid discharged from the recording heads 101 is stored in a tank (not shown). The liquid is supplied from the tank to the recording heads 101 via tubes.

[0019] <Control System 200> Figure 2 is a block diagram showing an example of a control system 200 that can be applied to this embodiment.

[0020] As shown in Figure 2, the control system 200 that controls the recording device 100 includes, as components, a recording data generation unit 201, an operation control unit 202, a recording control unit 203, a transport control unit 204, and a recording device 205.

[0021] The recording data generation unit 201 is a module that generates recording data and sends the generated recording data to the recording control unit 203. The recording data generation unit 201 may be located inside the recording device 100, or it may include a print server or the like located outside the recording device 100.

[0022] The operation control unit 202 is a module that is operated by a user or service technician, or that receives instructions from a user or service technician. Specifically, the operation control unit 202 includes an operation panel installed on the recording device 100, and an operation PC connected to the recording device 100. In this embodiment, the description will assume that the operation control unit 202 is an operation panel.

[0023] The recording control unit 203 is a module that performs the recording process. The transport control unit 204 is a module for transporting the recording medium 102 (see Figure 1, etc.). The recording device 205 is a module used to control the operation of the recording head 101 (see Figure 1, etc.).

[0024] Figure 3 is a block diagram showing an example of a recording control unit 203 that can be applied to this embodiment.

[0025] As shown in Figure 3, the recording control unit 203 includes a CPU 301, ROM 302, RAM 303, ASIC 304, and a head control unit 305.

[0026] The CPU 301 controls the entire operation of the recording device 100. The ROM 302 stores the control program for the CPU 301, etc. The RAM 303 temporarily stores data. The RAM 303 is used as work memory when executing a program. The ASIC 304 is an application-specific integrated circuit that incorporates a network controller, serial IF controller, head data generation controller, and motor controller, among others.

[0027] The head control unit 305 generates ejection data used by the recording device 205, and generates voltages to drive the ejection heater 502 (see Figure 5(b)) and heating elements for adjusting the liquid temperature (e.g., subheater 517 (see Figure 8(b))).

[0028] <Recording head 101> Figure 4 is a schematic perspective view showing an example of a recording head 101 that can be applied to this embodiment.

[0029] Figure 4 shows one of the five recording heads shown in Figure 1. Note that the configuration of these four recording heads is the same, except for the type of liquid being dispensed.

[0030] As shown in Figure 4, the recording head 101 includes a recording element substrate 401, a signal input terminal 402, a power supply terminal 403, and a flexible wiring board 404.

[0031] In this embodiment, multiple recording element substrates 401 are arranged linearly along the longitudinal direction (Y direction) of the recording head 101. A drive signal for discharging liquid is sent from the main body of the recording device 100 (see Figure 1) to the recording head 101 through the signal input terminal 402. Power necessary for discharging liquid is supplied from the main body of the recording device 100 to the recording head 101 through the power supply terminal 403. The signal input terminal 402 and the power supply terminal 403 are connected to the recording element substrates 401 through the flexible wiring board 404.

[0032] <Recording element substrate 401> Figure 5(a) is a schematic bottom view of a recording element substrate 401 that can be applied in this embodiment. The bottom surface of the recording element substrate 401 is appropriately referred to as the "discharge port surface".

[0033] As shown in Figure 5(a), the discharge port surface of the recording element substrate 401 is provided with terminals 503 that supply power to an electrothermal conversion element (for example, a discharge heater 502 (see Figure 5(b), etc.)) which serves as a recording element for discharging liquid. A flexible wiring board 404 (see Figure 4) is connected to terminals 503. A pulse signal is supplied from outside the recording head 101 (see Figure 1, etc.) via the flexible wiring board 404 and terminals 503. A current is generated to drive the discharge heater 502 in response to this pulse signal.

[0034] Figure 5(b) is an enlarged view of area 500a in Figure 5(a).

[0035] As shown in Figure 5(b), multiple discharge ports 501 for discharging liquid are formed on the discharge port surface of the recording element substrate 401 along the Y direction. The direction in which the multiple discharge ports 501 are formed is called the "discharge port row direction".

[0036] At the positions corresponding to each of these discharge ports 501, discharge heaters 502, which serve as recording elements for discharging liquid onto the recording medium 102 (see Figure 1), are provided. A single row of recording elements is formed when the recording elements are formed along the Y direction. Multiple rows of recording elements are formed when the rows of recording elements are arranged along the X direction.

[0037] In this embodiment, an electrothermal conversion element (specifically, a discharge heater 502) that uses thermal energy to foam a liquid is used as the recording element. Alternatively, an electromechanical conversion element (for example, a piezoelectric element) may be used instead of the electrothermal conversion element. Even in this case, it is possible to discharge the liquid. The discharge heater 502 is electrically connected to terminal 503 by electrical wiring (not shown) formed inside the recording element substrate 401.

[0038] Then, based on the pulse signal input from the head control unit 305 (see Figure 3) via the signal input terminal 402 and the power supply terminal 403 (see Figure 4), the discharge heater 502 generates heat, causing film boiling in the liquid.

[0039] Utilizing the foaming force caused by this film boiling, the liquid is discharged from the discharge ports 501. Also, a pressure chamber 505 is partitioned by a partition wall 504 at a position corresponding to each of these discharge ports 501. A liquid supply passage 506 is formed along the direction of the row of discharge ports to supply liquid to the pressure chamber 505. A supply port 507 for supplying liquid to the pressure chamber 505 is formed in the liquid supply passage 506. The liquid supplied to the liquid supply passage 506 is supplied to the pressure chamber 505 through the supply port 507. When liquid is supplied to the pressure chamber 505 and the discharge heater 502 is driven, the liquid is discharged from the discharge ports 501.

[0040] Figure 5(c) is an enlarged view of area 500b in Figure 5(a).

[0041] As shown in Figure 5(c), on the opposite side of the liquid supply passage 506, across the row of discharge ports, a liquid recovery passage 508 is formed along the direction of the discharge port row for recovering the liquid. The liquid supplied to the pressure chamber 505 that is not discharged is recovered through the recovery port 509 into the liquid recovery passage 508.

[0042] Figure 6 is a schematic plan view of the recording element substrate 401 in this embodiment. Specifically, Figure 6 shows the back surface of the ejection port surface of the recording element substrate 401.

[0043] As shown in Figure 6, a cover plate 510 is provided on the back side of the recording element substrate 401. It is laminated on the back side of the surface of the recording element substrate 401 where the discharge port 501 is formed. The cover plate 510 has a supply opening 511 connected to the liquid supply passage 506 (see Figure 5(b), etc.) and a recovery opening 512 connected to the liquid recovery passage 508 (see Figure 5(b), etc.).

[0044] In this embodiment, four supply openings 511 are formed for one liquid supply passage 506, and three recovery openings 512 are formed for one liquid recovery passage 508. However, the number of openings that can be formed in the cover plate 510 is not limited to this example.

[0045] Figure 7 is a cross-sectional view taken along line VII-VII in Figure 5(a).

[0046] As shown in Figure 7, the recording element substrate 401 is constructed by stacking a cover plate 510, a substrate 513, and an ejection port forming member 514 in this order. By stacking the cover plate 510, substrate 513, and ejection port forming member 514 in this order, the cover plate 510 functions as a lid that forms part of the walls of the liquid supply passage 506 and liquid recovery passage 508 formed in the substrate 513.

[0047] The substrate 513 is made of Si or the like. The discharge port forming member 514 is made of a photosensitive resin. The cover plate 510 is fixed to the back surface of the substrate 513. A discharge heater 502 is provided on the side of the substrate 513 that is in contact with the discharge port forming member 514. On the back surface of the heater, grooves are formed that constitute a liquid supply passage 506 and a liquid recovery passage 508 that extend along the row of discharge ports.

[0048] Thus, the liquid supply passage 506 and the liquid recovery passage 508 are formed by fixing the cover plate 510 to the substrate 513. The liquid supply passage 506 is connected to a common supply passage (not shown) through a supply opening 511. On the other hand, the liquid recovery passage 508 is connected to a common recovery passage (not shown) through a recovery opening 512.

[0049] The following describes the flow of liquid inside the recording element substrate 401. A pressure difference exists between the liquid supply passage 506 and the liquid recovery passage 508. Due to this pressure difference, the liquid inside the liquid supply passage 506 flows to the liquid recovery passage 508, passing through the supply port 507, pressure chamber 505, and recovery port 509 in that order (see arrow C).

[0050] This flow allows the thickened ink, foam, and foreign matter generated by evaporation from the discharge port 501 to be recovered into the liquid recovery path 508 in the discharge port 501 and pressure chamber 505, where the discharge operation is not in progress. Furthermore, it is possible to suppress the thickening of the ink in the discharge port 501 and pressure chamber 505, and the increase in the concentration of the colorant.

[0051] The above explains the flow of liquid inside the recording element substrate 401.

[0052] Figure 8(a) illustrates the temperature control of the ejection port surface of the recording element substrate 401.

[0053] Figure 8(b) is a schematic bottom view of the substrate 513.

[0054] As shown in Figures 8(a) and 8(b), in this embodiment, the substrate 513 of the recording element substrate 401 is divided into multiple regions, and temperature control is performed for each of these regions. In Figures 8(a) and 8(b), for the sake of explanation, each of the divided regions will be referred to as a divided region 515. Note that in Figure 8(a), dashed lines are shown to demarcate each of the divided regions 515, but these dashed lines are imaginary lines. This is the same in drawings other than Figure 8(a).

[0055] The element substrate (substrate 513) includes a temperature sensor 516 for detecting temperature and a subheater 517 for heating liquid. The temperature sensor 516 and the subheater 517 are provided in each of the multiple divided regions 515 obtained when the substrate 513 is divided into multiple regions. The temperature sensor 516 functions as a temperature acquisition unit that acquires the temperature of the divided region 515. The subheater 517 functions as a temperature adjustment unit that adjusts the temperature of the divided region 515.

[0056] This configuration allows for the individual acquisition of the temperature of each of the multiple divided regions 515, and enables appropriate heating according to the acquired temperature. In other words, even if a temperature distribution occurs on the substrate 513, different heating control can be performed for each location where the temperature distribution occurs. Note that the position, number, and shape of the temperature sensors 516 and subheaters 517 are not limited to the example shown in Figure 8(b).

[0057] <Control process for sub-heater 517> If the temperature differs in each of the multiple divided regions 515, a difference in the viscosity of the liquid will occur, resulting in a difference in the amount of liquid discharged from each outlet 501. Therefore, a temperature sensor 516 and a sub-heater 517 are provided near the outlet 501. The operation of the sub-heater 517 is controlled according to the temperature detected by the temperature sensor 516 to adjust the temperature so that the temperature of all divided regions is the same. The temperature set when this control is performed is called the "target temperature".

[0058] The ease with which the recording element substrate 401 heats up may vary depending on its position. Therefore, different target temperatures may be set for each divided region 515 according to its ease of heating. Alternatively, a common target temperature value may be set for all divided regions 515. If the temperature detected by the temperature sensor 516 is lower than the target temperature, the subheater 517 for that divided region 515 is turned ON. This allows the temperature of that divided region 515 to be raised.

[0059] Conversely, if the temperature detected by the temperature sensor 516 is higher than the target temperature, the subheater 517 in that divided region 515 is turned OFF. This allows the temperature in that divided region 515 to be lowered by heat dissipation.

[0060] The following explains the difference in how easily the central part of the recording element substrate 401 heats up compared to how easily the edges of the recording element substrate heat up.

[0061] Generally, at room temperature, the temperature of the recording element substrate 401 is lower than the target temperature suitable for ejection. Therefore, at the time when temperature control is initiated, such as when the device is powered on, it is necessary to turn on all the subheaters 517 and raise the temperature of the recording element substrate 401 until the target temperature is reached.

[0062] In the central part of the recording element substrate 401, the subheater 517 provided in the division region 515 of interest (the region of interest) is turned ON, and the subheaters 517 provided in the division region 515 adjacent to the region of interest (the adjacent region) are also turned ON. In other words, in the central part of the recording element substrate 401, heat is supplied to the region of interest from the surrounding adjacent regions as well. Therefore, the central part of the recording element substrate 401 can be said to heat up relatively easily.

[0063] On the other hand, at the edges of the recording element substrate 401, the number of adjacent regions adjacent to the region of interest is smaller than at the center of the recording element substrate 401. In other words, the edges of the recording element substrate 401 have fewer surrounding adjacent regions that can supply heat to the region of interest, and are therefore relatively difficult to heat up. For this reason, the degree of dependence on the subheater 517 provided in the region of interest is greater at the edges of the recording element substrate 401 than at the center of the recording element substrate 401. Therefore, it is preferable to increase the driving intensity of the subheater 517 at the edges of the recording element substrate 401 compared to the center of the recording element substrate 401 to raise the temperature.

[0064] The above explains the difference in how easily the central part of the recording element substrate 401 heats up compared to how easily the edges of the recording element substrate 401 heat up.

[0065] Furthermore, it is desirable to maintain the temperature of the recording element substrate 401 at the target temperature after it has reached that target temperature. Even if the temperature of the recording element substrate 401 deviates from the target temperature after it has reached it, it is desirable that the amount of deviation be as small as possible. To achieve this, the driving intensity of the sub-heater 517 needs to be weaker than it was immediately after the start of temperature adjustment.

[0066] Furthermore, once the target temperature is reached, the difference between the driving intensity of the subheater 517 at the center of the recording element substrate 401 and the driving intensity of the subheater 517 at the edges of the recording element substrate 401 does not need to be as strong as it was immediately after the start of temperature adjustment.

[0067] <Regarding the process for maintaining the target temperature> The process for maintaining the target temperature will be explained below using Figure 9.

[0068] Figure 9 is a flowchart showing the process for driving the subheater 517 in this embodiment to maintain the target temperature. Each process in the flowchart shown in Figure 9 is performed by the CPU 301 loading program code stored in ROM 302 or the like into RAM 303 and executing it.

[0069] Some or all of the functions of the steps in Figure 9 may be performed by hardware such as an ASIC, FPGA, or electrical circuit. Hereafter, "step S~" will be simply referred to as "S~".

[0070] The following explanation assumes that the recording control unit 203 is the entity responsible for each process.

[0071] The flow shown in Figure 9 represents an interrupt process that occurs at regular intervals during recording, and is triggered when such an interrupt occurs. It is also assumed that the target temperature has been set and stored in a storage unit such as ROM302 before the flow shown in Figure 9 begins.

[0072] In S901, the recording control unit 203 acquires the temperature value detected by the temperature sensor 516 for each divided region 515.

[0073] Figure 10 shows the positions and region numbers of the multiple divided regions 515 on the recording element substrate 401.

[0074] As shown in Figure 10, the recording element substrate 401 of this embodiment is provided with 40 divided regions 515, and each of these divided regions 515 is individually assigned a region number from 0 to 39. As shown in Figure 8, the shape of the recording element substrate 401 and the divided regions 515 in this embodiment is a parallelogram. However, in Figure 10, for the sake of explanation, the shape of the recording element substrate 401 and the divided regions 515 is shown as a rectangle.

[0075] As long as the recording element substrate 401 is divided into multiple divided regions 515 and the temperature can be adjusted for each of these divided regions 515, the technology of this disclosure can be applied regardless of the shape of the recording element substrate 401 and the divided regions 515. Return to Figure 9.

[0076] In S902, for each divided region 515, the difference ΔT (= target temperature value - detected temperature) is calculated by subtracting the temperature value acquired in S901 from a pre-stored target temperature value. A positive value for ΔT means that the detected temperature is lower than the target temperature. A negative value for ΔT means that the detected temperature is higher than the target temperature.

[0077] In S903, the recording control unit 203 selectively determines a first drive intensity (provisional drive intensity) for the subheater 517 for each divided region 515 based on the difference ΔT calculated in S902.

[0078] Figure 11 shows an example of the first table 1100 used in S903.

[0079] As shown in Figure 11, the first table 1100 defines values ​​indicating a provisional drive strength for each range of the difference ΔT. The first table 1100 is stored in a storage unit such as the ROM 302. In this embodiment, the provisional drive strength is shown as an integer for convenience, and the larger the value, the greater the drive strength.

[0080] If the difference ΔT is less than or equal to "0", the value indicating the provisional drive strength is determined to be "0". On the other hand, if the difference ΔT is greater than "0", the provisional drive strength is determined to be a value greater than "0".

[0081] The larger the difference ΔT, the larger the provisional drive strength value selected. However, there are lower and upper limits for the provisional drive strength. For example, if the difference ΔT is 0 or less, the provisional drive strength is determined to be 0. On the other hand, if the difference ΔT exceeds 2.2, the provisional drive strength is determined to be 12. Return to Figure 9.

[0082] In S904, the recording control unit 203 determines a correction value for each divided region 515 to correct the provisional drive intensity determined in S903. This correction value is determined based on the difference ΔT and a value (region number) indicating the position of the divided region 515.

[0083] Figure 12 shows an example of the second table 1200 used in S904. The second table 1200 is stored in a storage unit such as ROM 302.

[0084] As shown in Figure 12, the second table 1200 specifies a correction value for correcting the first drive strength (provisional drive strength) according to the magnitude of the difference ΔT for each value (region number) indicating the position of the divided region. A lower limit (-2) and an upper limit (+8) are set for this correction value.

[0085] In this embodiment, the number of values ​​that can be selected as correction values ​​for correcting the provisional drive strength is fewer than the number of values ​​that can be selected as the first drive strength (provisional drive strength).

[0086] For example, in this embodiment, the number of types of values ​​that can be selected as correction values ​​for correcting the provisional drive strength is 11, ranging from "-2" to "+8", including "0". On the other hand, the number of types of values ​​that can be selected as the first drive strength (provisional drive strength) is 13, ranging from "0" to "12" (see Figure 11). By reducing the number of types of values ​​that can be selected as correction values ​​to fewer than the number of types of values ​​that can be selected as provisional drive strength, it is possible to reduce the data capacity, which will be discussed later.

[0087] In the second table 1200, if the difference ΔT is "0" or less, the correction value is determined to be 0, regardless of the region number (i.e., the location of the divided region 515 (see Figure 8(b), etc.) that is subject to temperature control). In this case, the temperature of the divided region 515 that is subject to temperature control has reached or exceeded the target temperature, and the value (0) indicating the driving strength of the subheater 517 (see Figure 8(b)), which was temporarily determined as a provisional driving strength, should be applied as the actual driving strength. In other words, for such a divided region 515, there is no need to drive the subheater 517, or the subheater 517 should be turned off until the detected temperature drops to the target temperature due to heat dissipation.

[0088] On the other hand, if the difference ΔT is greater than 0, the value of the correction value will differ depending on the position of the divided region 515. For example, the correction value of the subheater 517 provided in a divided region 515 located at the corner of the recording element substrate 401 (see Figure 11, etc.) is determined to be a positive value greater than "0". In other words, for such divided regions 515, a correction is performed that further strengthens the provisional correction intensity. Also, the larger the difference ΔT, the larger the absolute value of the correction value becomes.

[0089] As shown in Figure 11, regions "0", "3", "36", and "39" are located at the corners of the recording element substrate 401 and have the characteristic of not heating up easily. Therefore, in these regions, even after the target temperature has been reached, if the temperature drops below the target temperature, the correction value for correcting the provisional drive strength is determined to be a positive value greater than "0" in order to further strengthen the provisional correction strength.

[0090] Furthermore, for example, the correction value of the subheater 517 provided in the divided region 515 located in the central part of the recording element substrate 401 (for example, region "5" shown in Figure 11) is determined to be a negative value smaller than "0". In other words, for such a divided region 515, a correction is performed that weakens the provisional correction strength. Also, the larger the difference ΔT, the larger the absolute value of the correction value becomes.

[0091] The divided region 515 located in the center of the recording element substrate 401 has a large number of adjacent divided regions 515 and is prone to heating up. Therefore, in these regions, once the target temperature is reached, even if the temperature drops, not much heating is required to return it to the target temperature again. For this reason, the correction value for correcting the provisional drive strength is determined to be a negative value in order to weaken the provisional correction strength.

[0092] Furthermore, the correction value of the subheater 517, which is provided in the divided region 515 located on the edges (ends) of the recording element substrate 401 other than the corners, is determined to be "0" regardless of the magnitude of the difference ΔT.

[0093] The edges of the recording element substrate 401 other than the corners (for example, region "1" shown in Figure 11) have more adjacent divided regions 515 compared to the corners of the recording element substrate 401. On the other hand, there are fewer adjacent divided regions 515 compared to the central part of the recording element substrate 401. Therefore, the edges of the recording element substrate 401 other than the corners heat up more easily than the corners of the recording element substrate 401, but heat up less easily than the central part of the recording element substrate 401. Accordingly, in this embodiment, it is assumed that no correction is necessary for the provisional correction strength in the edges of the recording element substrate 401 other than the corners, and a correction value of "0" is defined regardless of the magnitude of the difference ΔT.

[0094] With this configuration, even if the recording element substrate 401 heats up differently at different locations, it becomes possible to take into account the heat-generating characteristics specific to each location and correct the driving intensity of the sub-heater 517 provided at that location.

[0095] The relationship between the correction strength of the divided regions 515 of the recording element substrate 401 described above is summarized below. When the difference ΔT is "0" or less, the correction value is determined to increase the provisional correction strength in corners that are difficult to heat, and to decrease the provisional correction strength in the central area that heats up easily. In this embodiment, "0" is determined as the correction value in the edges (ends) that heat up more easily than the corners but less easily than the center. This is just one example, and from the viewpoint of ease of heating, it is sufficient to set a value between the correction value at the corners and the correction value at the center. Also, as shown in Figure 12, for the same difference ΔT, the correction value set in a divided region 515 with few adjacent areas is greater than or equal to the correction value set in a divided region 515 with many adjacent areas. Furthermore, the absolute value of the correction value when the difference ΔT is greater than "0" is greater than or equal to the absolute value of the correction value when the difference ΔT is "0" or less, regardless of location.

[0096] In this embodiment, the correction value and provisional drive strength are determined based on whether the difference ΔT is greater than or less than "0". However, it is not limited to the value "0", and a predetermined value may be set. In other words, if the difference ΔT is a first value that is less than the predetermined value, the correction value is set to "0", that is, a value that does not correct the provisional drive strength. If the difference ΔT is a value greater than the predetermined value (a second value that is higher than the first value), the correction value is determined for each location.

[0097] Returning to Figure 9, in S905, the recording control unit 203 adds the correction value selected in S904 to the provisional drive strength value selected in S903, and determines the actual drive strength (second drive strength) of the subheater 517 for each of the multiple divided regions 515.

[0098] In S906, the recording control unit 203 drives the subheater 517 according to the second drive intensity determined in S905.

[0099] Figure 13 is a graph showing the relationship between time and voltage when the subheater 517 is driven according to the second drive intensity. Here, a timing chart with period W is shown for each drive intensity. When the subheater is actually driven in S906, a voltage according to such a timing chart with period W is repeatedly applied for a predetermined period.

[0100] As shown in Figure 13, the recording control unit 203 applies a voltage with a pulse width corresponding to the second drive intensity to drive the subheater 517.

[0101] In this embodiment, the larger the value of the second drive intensity of the subheater 517, the longer the time for which voltage is continuously applied to the subheater 517. Specifically, when the second drive intensity is "0", no voltage is applied to the subheater 517. When the second drive intensity is "1", a voltage V is applied to the subheater 517 for a period w at cycles W.

[0102] Furthermore, when the second drive intensity is "2", a voltage V is applied to the subheater 517 for a period of 2W at cycles of W. Additionally, when the second drive intensity is "19", a voltage V is applied to the subheater 517 for a period of 19W at cycles of W. In this embodiment, since W = 20W, when the second drive intensity is "20", a voltage V is continuously applied to the subheater 517.

[0103] As a result, the larger the value indicating the second drive intensity, the greater the amount of heat supplied to the divided region 515 that is to be heated, and the higher the temperature of that divided region 515 can be raised.

[0104] As shown in Figure 13, the larger the value indicating the second drive intensity, the more the pulse width used to drive the subheater 517 may be changed, specifically made longer. However, this disclosure is not limited to this configuration. For example, the larger the value indicating the second drive intensity, the greater the voltage applied to the subheater 517 may be, or the frequency may be increased. Returning to Figure 9.

[0105] In S907, the recording control unit 203 determines whether recording has finished. If recording has not finished, the recording control unit 203 executes the process in S901. On the other hand, if recording has finished, the recording control unit 203 terminates the series of processes shown in Figure 9.

[0106] The above is a description of the process for maintaining the target temperature during recording.

[0107] <Specific example> The following describes specific examples of temperature control that can be applied to the technology disclosed herein.

[0108] Here, we show an example of selecting a correction value for the provisional drive intensity of the subheater 517 provided in the target area, depending on the number of adjacent divided areas 515 to the target area to be temperature controlled. As a prerequisite, as shown in Figure 10, temperature control is performed by dividing the recording element substrate 401 into 40 divided areas 515.

[0109] For the sake of explanation, here we will simply refer to each of the divided regions 515, numbered 0 through 39 as shown in Figure 10, as a "region," according to its assigned region number. For example, the divided region 515 with region number 0 will simply be called "region 0." We will then explain assuming that the current detected temperature in each divided region 515 is 35°C and the target temperature is 40°C. In other words, we will explain assuming that the temperature in each divided region 515 is raised by 5°C and maintained at around 40°C.

[0110] First, let's explain an example of temperature adjustment for "Region 0". In this case, the recording control unit 203 acquires information indicating that the temperature in "Region 0" is 35°C (S901). Next, the recording control unit 203 calculates the difference ΔT (= target temperature value - detected temperature = 5°C) between the target temperature value (40°C) and the temperature value acquired in S901 (35°C) (S902).

[0111] Then, the recording control unit 203 refers to the first table 1100 and selects a provisional drive intensity for the subheater 517 located in region 0 (S903). In this example, the difference ΔT is 5°C, which is greater than 2.2°C, so "12" is selected as the value indicating the provisional drive intensity (see Figure 11).

[0112] Then, the recording control unit 203 refers to the second table 1200 and selects a correction value for the selected provisional drive intensity (S904). In this example, since the difference ΔT in region 0 is 5°C, "8" is selected as the correction value for the provisional drive intensity (see the intersection of the correction value "2.2<ΔT" and "region number 0" in Figure 12).

[0113] Then, the recording control unit 203 adds the correction value (8) selected in S903 to the provisional drive strength (12) selected in S903 to determine the actual drive strength of the subheater 517 located in region 0 (S905). In this example, the actual drive strength of the subheater 517 is determined to be "20".

[0114] The recording control unit 203 then drives the subheater 517 located in region 0 with a determined drive intensity (20).

[0115] Then, once recording is complete (YES in S907), temperature adjustment for region 0 is terminated.

[0116] Next, an example of temperature adjustment for "region 5" will be explained. In this case, the recording control unit 203 acquires information indicating that the temperature of "region 5" is 35°C (S901). Subsequently, the recording control unit 203 calculates the difference ΔT (= target temperature value - detected temperature = 5°C) between the target temperature value (40°C) and the temperature value acquired in S901 (35°C) (S902).

[0117] Then, the recording control unit 203 refers to the first table 1100 and selects a provisional drive intensity for the subheater 517 provided in region 5 (S903). In this example, the difference ΔT is 5°C, which is greater than 2.2°C, so "12" is selected as the value indicating the provisional drive intensity (see Figure 11).

[0118] Then, the recording control unit 203 refers to the second table 1200 and selects a correction value for the selected provisional drive intensity (S904). In this example, since the difference ΔT in region 5 is 5°C, "-2" is selected as the correction value for the provisional drive intensity (see the intersection of the correction value "2.2<ΔT" and "region number 5" in Figure 12).

[0119] Then, the recording control unit 203 adds the correction value (-2) selected in S903 to the provisional drive strength value (12) selected in S903 to determine the actual drive strength of the subheater 517 located in region 0 (S905). In this example, the actual drive strength of the subheater 517 is determined to be "10".

[0120] The recording control unit 203 then drives the subheater 517 located in region 5 with a determined drive intensity (10).

[0121] Then, once recording is complete (YES in S907), temperature adjustment for region 5 is terminated.

[0122] As explained above, in the technology of this disclosure, regions with fewer adjacent regions receive less heat from the regions adjacent to them. Therefore, in those regions, the driving intensity when driving the subheater 517 is increased to compensate for this.

[0123] For example, referring to Figure 10, when driving the subheater 517 located in region 0, which is adjacent only to regions 1 and 4, the drive intensity is determined to be the largest value, "20". On the other hand, regions with a large number of adjacent regions receive a larger amount of heat from the adjacent regions. Therefore, in those regions, the drive intensity when driving the subheater 517 is corrected to be weaker.

[0124] For example, when driving the subheaters 517 located in regions 1, 4, 6, and region 5 adjacent to region 9, the driving intensity is determined to be "10", which is half the driving intensity of the subheater 517 located in region 0.

[0125] To facilitate understanding of the effects of the technology disclosed herein, prior art and hypothetical comparative examples will be described below.

[0126] Figure 14(a) shows an example of Table 1400 of the prior art. In the prior art, the correction value is determined based only on the position of the divided region, regardless of the difference ΔT between the detected temperature and the target temperature. Table 1400 in Figure 14(a) focuses on shortening the time from the start of temperature adjustment to reaching the target temperature, and is consistent with the contents of the row "2.2 < ΔT" in the second Table 1200 shown in Figure 12. Figure 14(b) is a graph showing the temperature change in region 0 in this example from the start of temperature adjustment to reaching the target temperature. Figure 14(c) is a graph showing the temperature change in region 0 in this example after reaching the target temperature.

[0127] As shown in Figures 14(a) to (c), in this example, in region 0, a correction value of "+8" is selected regardless of the detected temperature of region 0. According to the conventional technology, a large value (specifically "+8") is set as the correction value for the driving intensity of the subheater provided in region 0, which is located at the corner of the recording element substrate (a position that does not heat up easily), regardless of the detected temperature of region 0. For this reason, the driving intensity of the subheater provided at the corner of the recording element substrate is always set to be strong.

[0128] For example, if the difference ΔT between the detected temperature and the target temperature in region 0 is 5°C, "12" is selected as the provisional drive strength of the subheater. Then, by adding a correction value (+8) to the provisional drive strength (12), the actual drive strength of the subheater is determined to be "20". Therefore, according to this example, the actual drive strength of the subheater installed in a hard-to-heat location can be increased, so that the temperature of region 0, which is located in a hard-to-heat location, can be brought from room temperature to the target temperature in a relatively short time, as shown in Figure 14(b).

[0129] However, in domain 0 of the conventional technology, the drive intensity is set high even during temperature control after the target temperature has been reached. As a result, temperature control performed when the temperature is slightly below the target temperature can cause the temperature to exceed the target temperature by a large margin. If this type of temperature control continues, the temperature will remain higher than the target temperature, as shown in Figure 14(c).

[0130] Ideally, the temperature should change with the target temperature as the median. To achieve this, once region 0 reaches the target temperature, there is no need to drive the subheater in region 0 too strongly when the temperature falls below the target temperature. Nevertheless, in conventional technology, a large value is set as a correction value to drive the subheater in region 0 even after region 0 has reached the target temperature. As a result, the driving intensity of the subheater in region 0 becomes too strong even after the target temperature has been reached.

[0131] After the temperature in region 0 exceeds the target temperature, the subheater is turned off, and the temperature in region 0 decreases. However, under conventional technology, repeatedly turning the subheater on and off results in repeated drastic temperature fluctuations in region 0, as shown in Figure 14(c). In other words, while conventional technology can shorten the time from the start of temperature adjustment to reaching the target temperature, it is difficult to maintain the target temperature properly.

[0132] Figure 15(a) shows another example of a table from the prior art. Table 1500 in Figure 15(a) focuses on maintaining the target temperature once it has been reached, and corresponds to the contents of the row "0 < ΔT < 0.2" in the second table 1200 shown in Figure 12. Figure 15(b) is a graph showing the temperature change in region 0 in this example after the target temperature has been reached. Figure 15(c) is a graph showing the temperature change in region 0 in this example from room temperature to the target temperature.

[0133] As shown in Figures 15(a) to (c), in this example, in region 0, a correction value of "+1" is selected regardless of the detected temperature in region 0. With this configuration, a small value (specifically "+1") is set as the correction value for the drive intensity of the subheater installed in region 0, regardless of the detected temperature.

[0134] For example, if the difference ΔT between the detected temperature in region 0 and the target temperature is 0.2 degrees, a provisional drive intensity of "2" is selected for the subheater. Then, a correction value of "1" is added to this provisional drive intensity of "2," resulting in the actual drive intensity of the subheater being determined to be "3." As a result, according to this example, as shown in Figure 15(b), compared to Figure 14(c), the temperature in region 0 can be maintained at a value close to the target temperature after it has reached the target temperature.

[0135] However, in this configuration, even if a subheater is placed in region 0, a location that is difficult to heat, such as the corner of the recording element substrate, the correction value for the drive intensity will always be set to a small value (specifically, "3"). Therefore, in this configuration, the time from when temperature adjustment for region 0 is started until region 0 reaches the target temperature becomes longer, as shown in Figure 15(c) compared to Figure 14(b).

[0136] In contrast, in this embodiment, by preparing a second table as shown in Figure 12, an appropriate correction value can be set according to the difference ΔT between the detected temperature and the target temperature. For example, the table in Figure 14(a) is set when temperature adjustment is started, and the table in Figure 15(a) is set after the target temperature is reached. Figure 16(a) is a graph showing the temperature change of each divided region 515 in this embodiment. Figure 16(b) is a graph showing the temperature change of each divided region 515 after the temperature has reached the target temperature in this embodiment.

[0137] As shown in Figures 16(a) and 16(b), the time from the start of temperature adjustment for each divided region 515 in this embodiment until the target temperature is reached is about the same as in the prior art (see Figure 14(b)). After the temperature of each divided region 515 reaches the target temperature, the temperature of each divided region 515 is maintained near the target temperature, as shown in Figure 15(b).

[0138] For example, immediately after the start of temperature adjustment for region 0, the actual drive intensity of the subheater 517 provided in region 0 is determined to be "20". In this way, the subheater 517, which is located in a position that is difficult to heat, is driven with a relatively strong drive intensity, which allows that region to reach the target temperature in a relatively short time. After the temperature of region 0 reaches the target temperature (for example, 40°C), the technology of this disclosure selects a provisional drive intensity for the subheater 517 provided in region 0.

[0139] For example, if the difference ΔT between the temperature of region 0 after reaching the target temperature and the target temperature is 0.2 degrees, then "2" is selected as the provisional drive intensity of the subheater 517 provided in region 0.

[0140] Then, referring to the second table 1200 (see Figure 12), a correction value ("+1") for when the difference ΔT in region 0 is 0.2 degrees is added to the provisional value indicating the drive intensity. As a result, the actual drive intensity value of the subheater 517 installed in region 0 after reaching the target temperature is determined to be "3". In this way, the configuration of this embodiment makes it possible to reach the target temperature in region 0 in a relatively short time and to maintain the temperature of region 0 near the target temperature.

[0141] Furthermore, region 5 is adjacent to regions 1, 4, 6, and 9. Therefore, compared to region 0, which is adjacent only to regions 1 and 4, region 5 receives more heat from the surrounding regions when temperature control is initiated. Accordingly, a correction value of "-2" is specified for the subheater 517 installed in region 5 when the difference ΔT exceeds 2.2 (see Figure 12). Consequently, immediately after the start of temperature control for region 5, the actual drive intensity of the subheater 517 installed in region 5 is determined to be "10".

[0142] Thus, in the technology of this disclosure, the subheater 517, which is installed in a location that heats up easily, is driven with an appropriate drive intensity, and as a result, that region can reach the target temperature in about the same amount of time as it would take to heat a region that heats up less easily. In other words, in the technology of this disclosure, whether the object to be heated is in a location that heats up easily or a location that heats up less easily, the target temperature can be reached in about the same amount of time. After the temperature of region 5 reaches the target temperature (for example, 40°C), in the technology of this disclosure, a temporary drive intensity for the subheater 517 installed in region 5 is selected again.

[0143] For example, if the difference ΔT between the temperature in region 5 after reaching the target temperature and the target temperature is 0.2 degrees, then "2" is selected as the provisional drive strength of the sub-heater 517 installed in region 5. Then, referring to the second table 1200 (see Figure 12), a correction value ("-1") for when the difference ΔT in region 5 is 0.2 degrees is added to the value representing the provisional drive strength. As a result, the actual drive strength of the sub-heater 517 installed in region 5 after reaching the target temperature is determined to be "+1".

[0144] Thus, according to the configuration of this embodiment, the value indicating the actual driving intensity of the subheater 517 provided in a region with a large number of adjacent regions is determined to be smaller than the value indicating the actual driving intensity of the subheater 517 provided in a region with a small number of adjacent regions. As a result, region 5 can reach the target temperature in a relatively short time, and the temperature of region 5 can be maintained near the target temperature.

[0145] Furthermore, the correction value for each region can be set according to the difference ΔT between the detected temperature and the target temperature. As a result, it becomes possible to reliably perform appropriate temperature control for each region, both from the start of temperature adjustment until the target temperature is reached, and even after the target temperature is reached.

[0146] <Reducing data capacity> The technology described herein can reduce the amount of data required to calculate the actual drive intensity of the subheater 517. This will be explained below with reference to a comparative example.

[0147] Figure 17(a) shows Table 1701 used when selecting a provisional drive intensity for the subheater in the comparative example. Here, we show a case where the drive intensity can be adjusted in 21 steps from 0 to 20. The "0~20" shown in each column indicates that one of the values ​​(integers) from "0" to "20" is set.

[0148] As shown in Figure 17(a), if we try to represent the provisional drive strength using binary integers from 0 to 20, we would need 5 bits for each difference ΔT to store the provisional drive strength.

[0149] When setting a provisional drive intensity for each of the 13 controllable difference ΔT, 65 bits (5 bits x 13 steps) are required as data capacity for selecting the provisional drive intensity of the subheater.

[0150] On the other hand, Figure 17(b) shows a table 1702 that is prepared to directly set the actual drive intensity of the subheater based on the position of the divided region and the difference ΔT between the detected temperature and the target temperature, without setting a provisional drive intensity.

[0151] As shown in Figure 17(b), the recording element substrate of this comparative example is divided into divided regions numbered 0 to 39, similar to the recording element substrate 401 of this embodiment. The actual driving intensity of the subheater is set to one of the values ​​(integers) from "0" to "20" for each of these divided regions.

[0152] In this case, a table (65 bits) for selecting a temporary drive intensity is not required, but 2600 bits (5 bits x 13 levels x 40 areas) are needed as data capacity to determine the drive intensity of the subheaters provided in all divided areas.

[0153] Figure 18(a) shows a table 1801 that can be applied when selecting a provisional drive strength for the subheater 517 in this embodiment. For the sake of explanation, Figure 18(a) shows an example in which the provisional drive strength in the first table 1100 can be adjusted within the range of "0" to "20", similar to the comparative example above.

[0154] In the example in Figure 11, the provisional drive intensity of the subheater 517 was selected as an integer from 0 to 12. However, here, as shown in Figure 18(a), we will explain the case where the provisional drive intensity is selected as an integer from 0 to 20 in order to clarify the difference from the comparative examples shown in Figures 17(a) and 17(b).

[0155] As mentioned above, if we try to represent the provisional drive intensity values ​​using 21 different integers from 0 to 20 in binary, we would need 5 bits of data for each ΔT. In this case, 65 bits (5 bits x 13 levels) of data would be needed to select the provisional drive intensity of the subheater.

[0156] Figure 18(b) shows Table 1802, which is used when selecting the correction value for the subheater in this embodiment. For the sake of explanation, Figure 18(b) shows an example in which the correction value in the second Table 1200 can be adjusted within the range of "-6" to "8", similar to the comparative example above.

[0157] As shown in Figure 18(b), in this embodiment, the correction value for the subheater is expressed as an integer ranging from -6 to +8, including 0, for each of the 40 divided regions 515, corresponding to the magnitude of the difference ΔT in 13 steps. If we were to represent the correction value as 15 different integers ranging from "-6" to "+8" including "0" in binary, 4 bits would be required as data capacity for each combination of difference ΔT and divided region.

[0158] Therefore, in this embodiment, 2132 bits (5 bits × 13 stages + 4 bits × 13 stages × 40 regions) are required as data capacity to select a provisional drive intensity for the subheater and determine the actual drive intensity of the subheater. In this case, the data capacity can be reduced compared to table 1702 (2600 bits), which is prepared so that the actual drive intensity of the subheater can be directly determined based on the position of the divided region and the difference ΔT, as shown in Figure 17(b).

[0159] Specifically, correction values ​​corresponding to the positional characteristics of each of the multiple regions are added to a value indicating a provisional drive strength, which is selected according to the magnitude of the acquired difference ΔT. As a result, the configuration of this embodiment reduces the data capacity required to determine the actual drive strength compared to a configuration in which the provisional drive strength acquired according to the magnitude of the difference ΔT for each of the multiple divided regions is directly applied as the actual drive strength. In other words, the technology of this disclosure allows the use of a ROM 302 with a smaller capacity than the ROM used in the comparative example in Figures 17(a) and (b).

[0160] In this embodiment, where a table for determining the provisional drive strength and a table for determining the correction value are prepared independently, the contents of each table can be rewritten individually or the memory can be replaced. However, in this embodiment, each parameter in the table for determining the provisional drive strength and the table for determining the correction value has a certain degree of controllability. Therefore, the frequency of individual rewriting or memory replacement can be reduced. In other words, even if the condition of the element substrate or the ease with which each divided region heats up changes depending on the operating environment and years of use of the device, it is possible to reduce data capacity and perform highly reliable temperature control without the need to rewrite the contents of individual tables.

[0161] As described above, according to the configuration of this embodiment, a temperature value is acquired for each of the multiple divided regions. Then, the difference ΔT between the acquired temperature value and the target temperature value is calculated. Then, a provisional drive intensity of the subheater is selected according to the magnitude of the difference ΔT. The value indicating the provisional drive intensity is predetermined to increase as the difference ΔT increases. A table is then referenced in which a correction value based on the difference ΔT and the region number indicating the position of the divided region is predetermined.

[0162] In the table of this embodiment, for regions with a small number of adjacent regions, a larger correction value (a correction value that increases the driving strength) is selected as the difference ΔT increases.

[0163] On the other hand, for regions with a large number of adjacent regions, a smaller correction value (a correction value that weakens the drive strength) is selected as the difference ΔT increases. Then, the value representing the actual drive strength of the subheater is calculated for each of the divided regions by adding the correction value selected by referring to the table above to the value representing the provisional drive strength of the subheater. The subheater is driven based on the calculated actual drive strength. Temperature adjustment using the subheater in this embodiment is repeated from the start of temperature adjustment until the end of recording. As a result, even in regions with few adjacent regions, the temperature of that region can reach the target temperature in a relatively short time.

[0164] Furthermore, even in regions with many adjacent areas, it is possible to suppress the temperature of a region from exceeding the target temperature significantly after it has reached the target temperature. After the target temperature is reached, the subheater is driven with a drive intensity corresponding to the number of adjacent areas, so that the temperature of all divided regions can be maintained near the target temperature.

[0165] For example, in regions with many adjacent areas, the actual driving intensity of the subheater will be relatively weak. This helps to prevent the temperature in those regions from significantly exceeding the target temperature.

[0166] Therefore, the recording device of this disclosure enables highly reliable temperature control.

[0167] Furthermore, the recording device of this disclosure can also reduce the amount of data required to determine the actual drive intensity of the subheater.

[0168] [Second Embodiment] In the second table 1200 of the first embodiment (see Figure 12), correction values ​​for multiple divided regions were defined, taking into account the number of adjacent regions. However, the method for selectively determining the correction values ​​is not limited to the example in Figure 12, as long as the ease with which the region to be temperature-controlled heats up and the difficulty in heating up (how easily it cools down) are taken into account.

[0169] This embodiment aims to provide a method for selectively determining a correction value by taking into account the type of flow path provided in the region to be controlled by temperature.

[0170] The following description will primarily focus on the differences from the first embodiment, and the same or corresponding components as in the first embodiment will be indicated by the same reference numerals, and their descriptions will be omitted.

[0171] Figure 19 illustrates the temperature control of the ejection port surface of the recording element substrate 401 in this embodiment.

[0172] As shown in Figure 19, in this embodiment, we assume that a recovery opening 512 (see Figure 5(c)) is formed in region 21 and a supply opening 511 (see Figure 5(b)) is formed in region 25.

[0173] Generally, when circulating liquid between a tank (not shown) that stores liquid and a recording head 101 (see Figure 1, etc.) that discharges liquid, a heat exchanger (chiller) for cooling the liquid is provided between the tank and the recording head 101. With this configuration, it is possible to suppress overheating of the liquid supplied to the recording head 101 in a configuration in which liquid is circulated.

[0174] When liquid circulation is performed, the region 25 in which the supply opening 511 is formed will be supplied with liquid cooled by the heat exchanger.

[0175] In addition, regardless of whether an electrothermal or electromechanical conversion element is used, the viscosity of the ink changes with its temperature, which in turn changes the amount of ink dispensed. Therefore, even when an electromechanical conversion element is used, circulation is preferable.

[0176] Although region 25 has a large number of adjacent regions, considering that it is cooled by the supplied liquid, the actual driving intensity of the subheater 517 (see Figure 8(b)) provided in region 25 needs to be strong.

[0177] On the other hand, in region 21 where the recovery opening 512 is formed, liquid that has been heated by the discharge heater 502 (see Figure 5(b)) and the sub-heater 517, and that has not been discharged from the discharge port 501 (see Figure 5(b), etc.), is recovered. Therefore, considering that region 21 has a large number of adjacent regions, and that liquid heated by the discharge heater 502 and the sub-heater 517 is recovered, the actual driving strength of the sub-heater 517 provided in region 21 needs to be weak.

[0178] Therefore, in this embodiment, different correction values ​​are prepared for the region where the supply opening 511 is formed, the region where the recovery opening 512 is formed, and the other regions. Figure 20 shows an example of the third table 2000 used to select the provisional drive strength correction values ​​in this embodiment.

[0179] In Figure 20, for the sake of explanation, only the correction values ​​for correcting the provisional drive intensity of the subheaters 517 provided in regions 21 and 25 are shown. For other regions, the correction values ​​shown in Figure 12 can be used. Also, for example, if the thermal influence from adjacent regions is sufficiently small, all differences ΔT may be set to "0" for other regions. Other values ​​may also be set.

[0180] As shown in Figure 20, in region 21, as the magnitude of the difference ΔT increases, a negative value (a value that weakens the drive strength) is selected as the correction value to compensate for the provisional drive strength of the subheater 517.

[0181] For example, in region 21, if the difference ΔT satisfies 0 < ΔT ≤ 0.2, then from the first table, the value representing the provisional drive strength of the subheater 517 is "2". Also, from the third table, the correction value for the provisional drive strength is "-1". Therefore, in this case, the actual drive strength of the subheater 517 installed in region 21 is determined to be "1 = 2 + (-1)".

[0182] Furthermore, in region 21, if the difference ΔT satisfies 2.2 < ΔT, then from the first table, the value representing the provisional drive strength of the subheater 517 is "12". Also, from the third table, the correction value for the provisional drive strength is "-5". Therefore, in this case, the actual drive strength of the subheater 517 is determined to be "7 = 12 + (-5)".

[0183] On the other hand, in region 25, as the magnitude of the difference ΔT increases, a positive value (a value that increases the driving strength) is selected as a correction value to correct the provisional driving strength of the subheater 517.

[0184] For example, in region 25, if the difference ΔT satisfies 0 < ΔT ≤ 0.2, then from the first table, the value representing the provisional drive strength of the subheater 517 is "2". Also, from the third table, the correction value for the provisional drive strength is "+1". Therefore, in this case, the actual drive strength of the subheater 517 is determined to be "3 = 2 + 1".

[0185] Furthermore, in region 25, if the difference ΔT satisfies 2.2 < ΔT, then from the first table, the provisional drive strength of the subheater 517 is "12". Also, from the third table, the correction value for the provisional drive strength is "+5". Therefore, in this case, the actual drive strength of the subheater 517 is determined to be "17 = 12 + 5".

[0186] To make it easier to understand the effects of this embodiment, comparative examples will be provided below.

[0187] Figure 21(a) shows Table 2101, which is used to select a provisional correction value for the drive intensity in the comparative example. In this comparative example as well, the correction value is set based only on the position of the divided region, regardless of the difference ΔT between the detected temperature and the target temperature. In this comparative example as well, a recovery opening 512 is formed in region 21 and a supply opening 511 is formed in region 25. Therefore, a relatively low-temperature liquid is supplied to region 25, and a relatively high-temperature liquid is recovered from region 21.

[0188] As shown in Figure 21(a), Table 2101 contains predefined correction values ​​for correcting the temporary drive intensity of the subheaters provided in region 21 and region 25, respectively.

[0189] Table 2101 specifies correction values ​​that can be applied to the time it takes to reach the target temperature after the start of temperature adjustment. Therefore, it matches the content of the row "2.2 < ΔT" in the third table 2000 shown in Figure 20.

[0190] However, in this configuration, even after the temperature in region 25 reaches the target temperature, a correction value of "+5" is maintained for the provisional drive intensity of the subheater. In other words, in region 25 of this comparative example, after the temperature reaches the target temperature, it becomes difficult to maintain the temperature near the target temperature, and there is a possibility that the temperature will significantly exceed the target temperature.

[0191] Figure 21(b) shows Table 2102, which is used to select a provisional drive strength correction value in another comparative example. In this comparative example as well, a recovery opening 512 is formed in region 21 and a supply opening 511 is formed in region 25. Therefore, a relatively low-temperature liquid is supplied to region 25, and a relatively high-temperature liquid is recovered from region 21.

[0192] As shown in Figure 21(b), Table 2102 predefines correction values ​​for correcting the provisional drive intensity of the subheaters provided in region 21 and region 25, respectively. Table 2101 predefines correction values ​​suitable for maintaining the target temperature. This corresponds to the contents of the row "0 < ΔT ≤ 0.2" in the third Table 2000 shown in Figure 20.

[0193] However, in this configuration, the correction value for region 25 is too small at the time the temperature adjustment is initiated. Therefore, in this configuration, the time from when the temperature adjustment for region 25 is initiated until the temperature of region 25 reaches the target temperature becomes long.

[0194] As described above, according to the configuration of this embodiment, the actual driving strength of the subheater 517 provided in region 25 to which a relatively low temperature liquid is supplied can be made stronger than the actual driving strength of the subheater 517 provided in region 21 to which a relatively high temperature liquid is supplied. Note that the correction value shown in Figure 20 is just one example. When the difference ΔT is greater than the third value (0 in this configuration), it is important to make the correction value of the subheater provided in region 25 to which the supply opening 511 is formed greater than the correction value of the subheater provided in region 21 to which the recovery opening 512 is formed.

[0195] Therefore, even in region 25, which has characteristics that make it difficult to heat despite having a large number of adjacent regions, the time from the start of temperature adjustment to reaching the target temperature can be made relatively short.

[0196] Furthermore, the actual driving intensity of the subheater 517 provided in the region 21 where relatively high-temperature liquid is discharged can be made weaker than the actual driving intensity of the subheater 517 provided in the region 21 where relatively low-temperature liquid is supplied.

[0197] Therefore, after the temperature of the region 21 having a property of being easily heated reaches the target temperature, the temperature of the region 21 can be maintained near the target temperature. Note that even when the temperature of the region 21 exceeds the target temperature, a large excess over the target temperature is suppressed.

[0198] In the present embodiment, the difference ΔT is calculated for each region, and a provisional driving intensity and a correction value are selected. However, the provisional driving intensity and the correction value may be selected directly from the temperature measured by a sensor. In FIG. 11, the provisional driving intensity can be selected for each ΔT as in the cases of ΔT≦0, 0<ΔT≦0.2, 0.2<ΔT≦0.4, . . . . However, the provisional driving intensity or the correction value may be selectable for each temperature detected by the sensor as in the cases of T≦40.0, 39.8≦T<40.0, 39.6<T≦39.8, . . . .

[0199] [Other Embodiments] In the above embodiments, ink is used as the liquid, but liquids that can be used in the technology of the present disclosure are not limited to ink. In addition to ink, various recording liquids can be used as the liquid, including treatment liquids used for purposes such as improving the fixability of ink on a recording medium, reducing gloss unevenness, and improving abrasion resistance.

[0200] The above description assumes that the recording apparatus is an inkjet printer using an inkjet recording method. However, the recording apparatus may be, for example, a single-function printer having only a recording function, or may be a multi-function printer having a plurality of functions such as a recording function, a facsimile function, and a scanner function. Alternatively, the recording apparatus may be a manufacturing apparatus for manufacturing color filters, electronic devices, optical devices, microstructures, and the like by a predetermined recording method.

[0201] In the above embodiments, the first table 1100 (see FIG. 11) is used to determine the provisional driving intensity. However, it is possible to determine the provisional driving intensity without using the first table 1100. For example, the following linear expression can be used to determine the provisional driving intensity.

[0202] (Equation 1) ... x = a * ΔT + b

[0203] Here, x is a hypothetical drive intensity, ΔT is the difference between the detected temperature and the target temperature, and a and b are predetermined constants.

[0204] In the embodiments described above, a second table 1200 (see Figure 12) was used to determine a provisional correction value for the drive strength. However, it is possible to determine a provisional correction value for the drive strength without using the second table 1200.

[0205] (Formula 2)...y=c*ΔT+d(area number 0)

[0206] (Formula 3)...y=c'*ΔT+d' (area number 1)

[0207] Here, y is the correction value, ΔT is the difference between the detected temperature and the target temperature, c and d are predetermined constants specific to region 0, and c' and d' are predetermined constants specific to region 1.

[0208] Thus, a provisional correction value for the driving intensity may be calculated using a formula that multiplies the difference ΔT by a threshold and adds a value indicating the region number. In addition to linear functions, quadratic functions and exponential functions may also be used in the formula.

[0209] The technology of this disclosure can also be realized by supplying a program that implements one or more of the functions of the embodiments described above to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. Furthermore, the technology of this disclosure can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0210] This disclosure includes the following configurations or methods:

[0211] (Composition 1) A recording device comprising a recording element array consisting of a plurality of recording elements that eject liquid onto a recording medium, a heating element for heating the liquid, and an element substrate provided with a sensor for detecting the temperature, The heating element and the sensor are provided for each of the multiple divided regions obtained by dividing the element substrate into multiple regions. For each of the divided regions, a first determination means for determining a first driving intensity for the heating element based on the temperature detected by the sensor, For each of the divided regions, a second determination means for determining a correction value for correcting the first drive intensity, A third determination means for determining a second drive strength by correcting the first drive strength based on the correction value for each of the divided regions, For each of the divided regions, a driving means for driving the heating element according to the second driving intensity, It further possesses, The second determination means determines the correction value based on the temperature and the position of the divided region. A recording device characterized by the following features.

[0212] (Configuration 2) The first determination means determines the first drive intensity for the heating element for each divided region based on the difference obtained by subtracting the temperature detected by the sensor from the target temperature. The recording device described in Configuration 1.

[0213] (Composition 3) The driving means changes the pulse width for driving the heating element according to the second driving intensity. A recording device as described in configuration 1 or 2.

[0214] (Composition 4) The number of types of values ​​that can be selected as the correction value is less than the number of types of values ​​that can be selected as the first drive intensity. A recording device as described in any one of items 1 to 3 of the configuration.

[0215] (Composition 5) If the difference is a first value, the first determination means determines the value indicating the first drive intensity to a value indicating that the heating element is not driven. If the difference is a second value greater than the first value, the first determination means determines the value indicating the first drive intensity to a value indicating that the heating element is driven. A recording device as described in any one of items 2 to 4 of the configuration.

[0216] (Composition 6) If the difference is the first value, the second determination means determines the correction value to a value indicating that the first drive intensity is not corrected. If the difference is the second value, the second determination means determines the correction value for the divided region located at the corner of the element substrate to a value that increases the first driving intensity. The recording device described in Configuration 5.

[0217] (Composition 7) If the difference is the second value, the second determination means determines the correction value for the divided region located in the central part of the element substrate to a value that weakens the first driving intensity. The recording device described in configuration 6.

[0218] (Composition 8) The second determination means determines the correction value for the divided region located at the edge of the element substrate to a value between the correction value for the divided region located at the corner of the element substrate and the correction value for the divided region located in the central part of the element substrate, if the difference is the second value. The recording device described in Configuration 7.

[0219] (Composition 9) If the difference is the first value, the absolute value of the correction value determined by the second determination means is less than or equal to the absolute value of the correction value determined by the second determination means when the difference is the second value. A recording device as described in any one of items 5 to 8 of the configuration.

[0220] (Composition 10) The divided region includes a first region and a second region having more adjacent regions than the first region. A recording device as described in any one of items 2 to 9 of the configuration.

[0221] (Composition 11) When the difference is the same, the correction value determined by the second determination means in the first region is greater than or equal to the correction value determined by the second determination means in the second region. The recording device described in configuration 10.

[0222] (Composition 12) A tank for storing liquid, A recording head comprising the aforementioned element substrate, A circulation means for circulating liquid between the tank and the recording head, It further possesses, The element substrate includes a supply opening for supplying liquid from the tank and a recovery opening for recovering the liquid into the tank. If the difference is greater than the third value, then in the division region where the supply opening is formed, the correction value determined by the second determination means is greater than the correction value determined by the second determination means in the division region where the recovery opening is formed. A recording device as described in any one of items 2 to 11 of the configuration.

[0223] (Composition 13) The first determination means determines the first drive intensity for each of the plurality of divided regions by referring to a table in which the difference and the first drive intensity are associated. A recording device as described in any one of items 2 to 12 of the configuration.

[0224] (Composition 14) The second determination means determines the correction value for each of the plurality of divided regions by referring to a table which associates the position of the divided region on the element substrate with the difference and the correction value. A recording device as described in any one of items 2 to 13 of the configuration.

[0225] (Method 15) A control method for a recording device having a recording element array consisting of a plurality of recording elements that eject liquid onto a recording medium, an element substrate provided with a heating element for heating the liquid, and a sensor for detecting the temperature, The heating element and the sensor are provided for each of the multiple divided regions obtained by dividing the element substrate into multiple regions. For each of the divided regions, a first drive intensity for the heating element is determined based on the temperature detected by the sensor. For each of the divided regions, a correction value for correcting the first drive intensity is determined. For each of the divided regions, the second drive strength is determined by correcting the first drive strength based on the correction value. For each of the divided regions, a driving means for driving the heating element according to the second driving intensity, It further possesses, The correction value is determined based on the temperature and the position of the divided region. A control method characterized by the following:

[0226] (Method 16) For each of the divided regions, the first drive intensity for the heating element is determined based on the difference obtained by subtracting the temperature detected by the sensor from the target temperature. The control method described in Method 15.

[0227] (Method 17) The driving means changes the pulse width for driving the heating element according to the second driving intensity. The control method described in method 15 or 16.

[0228] (Method 18) The number of types of values ​​that can be selected as the correction value is less than the number of types of values ​​that can be selected as the first drive intensity. A control method as described in any one of methods 15 to 17.

[0229] (Method 19) If the difference is a first value, the value indicating the first drive intensity is determined to be a value indicating that the heating element is not driven. If the difference is a second value greater than the first value, the value indicating the first drive intensity is determined to be a value indicating that the heating element is driven. A control method as described in any one of methods 16 to 18.

[0230] (Method 20) If the difference is the first value, the correction value is determined to be a value that indicates that the first drive intensity is not corrected. If the difference is the second value, the correction value for the divided region located at the corner of the element substrate is determined to be a value that increases the first driving intensity. The control method described in Method 19.

[0231] (Method 21) If the difference is the second value, the correction value for the divided region located in the center of the element substrate is determined to be a value that weakens the first driving intensity. The control method described in Method 20.

[0232] (Method 22) If the difference is the second value, the correction value for the divided region located at the edge of the element substrate is determined to be a value between the correction value for the divided region located at the corner of the element substrate and the correction value for the divided region located in the center of the element substrate. The control method described in Method 21.

[0233] (Method 23) If the difference is the first value, the absolute value of the correction value is less than or equal to the absolute value of the correction value determined when the difference is the second value. A control method according to any one of methods 19 to 22.

[0234] (Method 24) The divided region includes a first region and a second region having more adjacent regions than the first region. A control method according to any one of methods 16 to 23.

[0235] (Method 25) When the difference is the same, the correction value determined in the first region is greater than or equal to the correction value determined in the second region. The control method described in Method 24.

[0236] (Method 26) The recording device is A tank for storing liquid, A recording head comprising the aforementioned element substrate, A circulation means for circulating liquid between the tank and the recording head, It further possesses, The element substrate includes a supply opening for supplying liquid from the tank and a recovery opening for recovering the liquid into the tank. If the difference is greater than the third value, the correction value determined in the division region where the supply opening is formed is greater than the correction value determined in the division region where the recovery opening is formed. A control method according to any one of methods 16 to 25.

[0237] (Method 27) By referring to a table that associates the difference with the first drive intensity, the first drive intensity is determined for each of the plurality of divided regions. A control method as described in any one of methods 16 to 26.

[0238] (Method 28) By referring to a table that associates the position of the divided region on the element substrate with the difference and the correction value, the correction value is determined for each of the multiple divided regions. A control method as described in any one of methods 16 to 27.

Claims

1. A recording device comprising a recording element array consisting of a plurality of recording elements that eject liquid onto a recording medium, a heating element for heating the liquid, and an element substrate provided with a sensor for detecting the temperature, The heating element and the sensor are provided for each of the multiple divided regions obtained by dividing the element substrate into multiple regions. For each of the divided regions, a first determination means for determining a first driving intensity for the heating element based on the temperature detected by the sensor, A second determination means for determining a correction value for correcting the first drive intensity for each of the divided regions, A third determination means for determining a second drive strength by correcting the first drive strength based on the correction value for each of the divided regions, For each of the divided regions, a driving means for driving the heating element according to the second driving intensity, It further possesses, The second determination means determines the correction value based on the temperature and the position of the divided region. A recording device characterized by the following features.

2. The first determination means determines the first drive intensity for the heating element for each divided region based on the difference obtained by subtracting the temperature detected by the sensor from the target temperature. The recording device according to claim 1.

3. The driving means changes the pulse width for driving the heating element according to the second driving intensity. A recording device according to claim 1 or 2.

4. The number of types of values ​​that can be selected as the correction value is less than the number of types of values ​​that can be selected as the first drive strength. A recording device according to claim 1 or 2.

5. If the difference is a first value, the first determination means determines the value indicating the first drive intensity to a value indicating that the heating element is not driven. If the difference is a second value greater than the first value, the first determination means determines the value indicating the first drive intensity to a value indicating that the heating element is driven. The recording device according to claim 2.

6. If the difference is the first value, the second determination means determines the correction value to a value that indicates that the first drive strength is not corrected. If the difference is the second value, the second determination means determines the correction value for the divided region located at the corner of the element substrate to a value that increases the first driving intensity. The recording device according to claim 5.

7. If the difference is the second value, the second determination means determines the correction value for the divided region located in the central part of the element substrate to a value that weakens the first driving intensity. The recording device according to claim 6.

8. The second determination means determines the correction value for the divided region located at the edge of the element substrate to a value between the correction value for the divided region located at the corner of the element substrate and the correction value for the divided region located in the central part of the element substrate, if the difference is the second value. The recording device according to claim 7.

9. If the difference is the first value, the absolute value of the correction value determined by the second determination means is less than or equal to the absolute value of the correction value determined by the second determination means when the difference is the second value. The recording device according to claim 5.

10. The divided region includes a first region and a second region having more adjacent regions than the first region. The recording device according to claim 2.

11. When the difference is the same, the correction value determined by the second determination means in the first region is greater than or equal to the correction value determined by the second determination means in the second region. The recording device according to claim 10.

12. A tank for storing liquid, A recording head comprising the aforementioned element substrate, A circulation means for circulating liquid between the tank and the recording head, It further possesses, The element substrate includes a supply opening for supplying liquid from the tank and a recovery opening for recovering the liquid into the tank. If the difference is greater than the third value, then the correction value determined by the second determination means in the division region where the supply opening is formed is greater than the correction value determined by the second determination means in the division region where the recovery opening is formed. The recording device according to claim 2.

13. The first determination means determines the first drive intensity for each of the plurality of divided regions by referring to a table in which the difference and the first drive intensity are associated. The recording device according to claim 2.

14. The second determination means determines the correction value for each of the plurality of divided regions by referring to a table which associates the position of the divided region on the element substrate with the difference and the correction value. The recording device according to claim 2.

15. A control method for a recording device having a recording element array consisting of a plurality of recording elements that eject liquid onto a recording medium, an element substrate provided with a heating element for heating the liquid, and a sensor for detecting the temperature, The heating element and the sensor are provided for each of the multiple divided regions obtained by dividing the element substrate into multiple regions. For each of the divided regions, a first drive intensity for the heating element is determined based on the temperature detected by the sensor. For each of the divided regions, a correction value for correcting the first drive intensity is determined. For each of the divided regions, the second drive strength is determined by correcting the first drive strength based on the correction value. For each of the divided regions, a driving means for driving the heating element according to the second driving intensity, It further possesses, The correction value is determined based on the temperature and the position of the divided region. A control method characterized by the following:

16. For each of the divided regions, the first drive intensity for the heating element is determined based on the difference obtained by subtracting the temperature detected by the sensor from the target temperature. The control method according to claim 15.

17. The driving means changes the pulse width for driving the heating element according to the second driving intensity. The control method according to claim 15 or 16.

18. The number of types of values ​​that can be selected as the correction value is less than the number of types of values ​​that can be selected as the first drive strength. The control method according to claim 15 or 16.

19. If the difference is a first value, the value indicating the first drive intensity is determined to be a value indicating that the heating element is not driven. If the difference is a second value greater than the first value, the value indicating the first drive intensity is determined to be a value indicating that the heating element is driven. The control method according to claim 16.

20. If the difference is the first value, the correction value is determined to be a value that indicates that the first drive strength is not corrected. If the difference is the second value, the correction value for the divided region located at the corner of the element substrate is determined to be a value that increases the first driving intensity. The control method according to claim 19.

21. If the difference is the second value, the correction value for the divided region located in the central part of the element substrate is determined to be a value that weakens the first driving intensity. The control method according to claim 20.

22. If the difference is the second value, the correction value for the divided region located at the edge of the element substrate is determined to be a value between the correction value for the divided region located at the corner of the element substrate and the correction value for the divided region located in the center of the element substrate. The control method according to claim 21.

23. If the difference is the first value, the absolute value of the correction value is less than or equal to the absolute value of the correction value determined when the difference is the second value. The control method according to claim 19.

24. The divided region includes a first region and a second region having more adjacent regions than the first region. The control method according to claim 16.

25. When the difference is the same, the correction value determined in the first region is greater than or equal to the correction value determined in the second region. The control method according to claim 24.

26. The recording device is A tank for storing liquid, A recording head comprising the aforementioned element substrate, A circulation means for circulating liquid between the tank and the recording head, It further possesses, The element substrate includes a supply opening for supplying liquid from the tank and a recovery opening for recovering the liquid into the tank. If the difference is greater than the third value, the correction value determined in the division region where the supply opening is formed is greater than the correction value determined in the division region where the recovery opening is formed. The control method according to claim 16.

27. By referring to a table that associates the difference with the first drive intensity, the first drive intensity is determined for each of the plurality of divided regions. The control method according to claim 16.

28. By referring to a table that associates the position of the divided region on the element substrate with the difference and the correction value, the correction value is determined for each of the multiple divided regions. The control method according to claim 16.

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