JP2015229328A - Inkjet recording device, inkjet recording method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording device which allows the temperature control of a recording head to be performed with a heat element while a thermal storage state of the recording head is incorporated in the control.SOLUTION: On the basis of a head internal temperature T3 calculated based on information about first and second temperatures detected at first and second timings within a period in which a recording element is not driven (S11), and a substrate temperature Ti, heating conditions for the heat element (subheater) are determined (S13).

Description

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

  2. Description of the Related Art Conventionally, an inkjet recording apparatus that records an image by ejecting ink onto a recording medium by driving the recording element while a recording head having a plurality of recording elements for ejecting ink is scanned with respect to the recording medium is known. It has been.

  In such an ink jet recording apparatus, it is known to use a recording head having a substrate formed of a semiconductor, a plurality of recording elements provided on the substrate, and a support member for supporting the substrate. Patent Document 1 discloses the use of a support member with high heat dissipation formed of alumina (Al2O3), SUS, or the like having a high heat capacity.

  On the other hand, it is known that when the temperature of ink at the time of ejecting ink is low, the ejection amount may decrease or non-ejection may occur. When such a phenomenon occurs, the image quality of the recorded image is degraded. In Patent Document 2, a temperature control heater (hereinafter also referred to as a sub-heater or a heating element) for heating ink in the vicinity of the recording element and a temperature sensor are provided on a substrate, and the temperature acquired by the temperature sensor during scanning of the recording head. Discloses that the temperature of the ink is controlled by driving a sub-heater when the value becomes equal to or less than a threshold value. This document describes that since the temperature of ink when ejecting ink can be kept high to some extent, a decrease in image quality due to a decrease in ejection amount or the like can be suppressed.

JP 2007-296776 JP 2002-240252 A

  However, when using a recording head having a support member having a high heat capacity, it has been found that there is a possibility that even a method disclosed in Patent Document 2 cannot sufficiently suppress a decrease in ejection amount and a decrease in image quality due to non-ejection.

  This problem will be described in detail below.

  When the heat capacity of the support member is high, most of the heat generated on the substrate as the ink is ejected moves to the support member and is stored. Since the temperature sensor in the print head is generally provided on the substrate, the temperature sensor can detect the temperature in the vicinity of the print element when ink is ejected, but it can accurately detect the heat storage state of the print head. I can't.

  FIG. 1 is a diagram for explaining temperature distributions in the thickness direction of the element substrate and the support member in two states where the heat storage states of the recording head are different. Note that the solid line in FIG. 1 indicates the temperature distribution when a high-duty image is recorded in the first scan. Also, the broken line in FIG. 1 shows the temperature distribution when a low duty image is printed in the 100th scan. The duty is a value proportional to the amount of ink ejected to a unit area on the recording medium.

  As can be seen from FIG. 1, on the substrate detected by the temperature sensor, the case where a high duty image is recorded in the first scan and the case where a low duty image is recorded in the 100th scan are almost the same. It becomes temperature.

  Since the support member is not stored heat in the first scanning, the heat generated on the substrate as the ink is ejected moves to the support member. For this reason, the temperature of the substrate is unlikely to rise. On the other hand, at the time of the 100th scan, since a high amount of heat has already been stored in the support member due to ink ejection in the scans performed so far, heat transfer from the substrate to the support member occurs. Hateful. Therefore, the temperature of the substrate is likely to rise.

  As a result, it is considered that the temperatures of the substrates are almost the same even though images with different duties are recorded.

  As shown in FIG. 1, even if the substrate temperature detected by the temperature sensor is the same, the heat storage state of the support member may be different. If the heat storage state is different, even if the same amount of thermal energy is given by driving the sub-heater, the amount of increase in the temperature of the substrate or ink will be different.

  FIG. 2 is a diagram showing the change over time in the temperature of the substrate when the same amount of thermal energy is applied when the temperature of the support member is different. Here, the temperature change with time when the temperature of the support member is 25 ° C., 30 ° C., and 35 ° C. is shown.

  As described above, since the heat transfer from the substrate to the support member hardly occurs as the heat storage amount of the support member increases, the temperature of the substrate easily increases. Also in FIG. 2, when the temperature of the support member having a relatively large heat storage amount of the support member is 35 ° C., the temperature of the substrate is likely to rise relatively, and the support member has a relatively small heat storage amount. It can be seen that the temperature of the substrate is relatively less likely to rise when the temperature is 25 ° C.

  Here, for simplicity, the case where the threshold value for driving the sub-heater is 50 ° C. and the temperature is detected by the temperature sensor immediately after the start of scanning (after 0 seconds) will be described below. Further, it is assumed that the amount of heat energy per unit time (hereinafter also referred to as drive power) given by the sub heater is the same value Q (W / s) regardless of the amount of heat stored.

  When the temperature of the support member is 35 ° C., it is necessary to drive the sub heater for t1≈2.6 seconds in order to raise the substrate temperature to 50 ° C. at which the sub heater is stopped. Therefore, in order to raise the substrate temperature to 50 ° C., a total of 2.6 × Q (W) of thermal energy is applied by the sub heater. Similarly, when the amount of heat energy from the sub-heater required to raise the substrate temperature to 50 ° C. is calculated, when the temperature of the support member is 30 ° C., t2 × Q≈3.3 × Q (W), It can be seen that t3 × Q≈4.7 × Q (W) when the temperature of the member is 35 ° C.

  In this way, even when the temperature of the substrate obtained by the temperature sensor is the same, the amount of thermal energy given by driving the sub-heater to raise the temperature to a sufficient temperature to suppress a decrease in discharge amount, non-discharge, etc. Varies depending on the heat storage state. For this reason, when the driving time and driving power of the sub-heater are set regardless of the heat storage state, the ink may be overheated or insufficiently heated depending on the heat storage state. When such an excessive temperature rise or insufficient heating occurs, the image quality of the recorded image may be deteriorated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to perform temperature control of a recording head using a heating element that reflects the heat storage state of the recording head.

  Accordingly, the present invention provides a substrate, a recording element that generates energy used to eject ink provided on the substrate, and a detection element that is provided on the substrate and detects the temperature of the recording element substrate. And a heating element for heating ink in the vicinity of the recording element, and a recording element substrate, and a support member that supports the recording element substrate and has a higher heat capacity than the substrate. The recording element is driven while performing a plurality of relative scans of the recording head and the recording medium including at least a head, a first scan, and a second scan next to the first scan. Recording control means for ejecting ink onto the recording medium, first acquisition means for acquiring information about the temperature of the recording element substrate detected from the detection element, and the recording control means. When the temperature of the recording element substrate indicated by the information acquired by the first acquisition unit is equal to or lower than a predetermined threshold during the second scanning, the heating element is heated, and the recording element Heating that controls heating by the heating element according to information about the temperature acquired by the first acquisition means so that heating by the heating element is not performed when the temperature of the substrate is higher than the predetermined threshold value An ink jet recording apparatus including: a control unit, wherein the first acquisition unit is configured to perform a first operation after the first scan by the recording control unit is completed until the second scan is started. 1st information about the temperature of the recording element substrate at the timing 1 and the temperature of the recording element substrate at the second timing after the first timing 2, and the heating control unit performs the second scanning by the recording control unit based on the first and second information acquired by the first acquisition unit. The heating by the heating element is controlled.

  According to the ink jet recording apparatus, the ink jet recording method, and the program according to the present invention, it is possible to perform the temperature control of the recording head by the heating element reflecting the heat storage state of the recording head.

It is a figure which shows the temperature distribution in a board | substrate and a supporting member. It is a figure for demonstrating the correlation of a thermal storage state and the required thermal energy. 1 is a perspective view of an image recording apparatus according to an embodiment. FIG. 2 is a schematic diagram of a recording head according to an embodiment. FIG. 2 is a perspective view of a recording head according to an embodiment. It is a schematic diagram for demonstrating the recording control system in embodiment. It is a figure for demonstrating drive control of the sub heater in embodiment. It is a figure for demonstrating the temperature transition in embodiment. It is a figure for demonstrating the calculation method of the head internal temperature in embodiment. It is a figure which shows the drive power of the sub heater in embodiment. It is a figure for demonstrating drive control of the sub heater in embodiment. It is a figure which shows the drive power of the subheater in embodiment, and heating target temperature.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
(Inkjet recording device)
FIG. 3 is a perspective view showing an appearance of the ink jet recording apparatus according to the embodiment of the present invention. This is a so-called serial scanning type printer that records an image by scanning the recording head 5 in a scanning direction (X direction) orthogonal to the conveyance direction (Y direction) of the recording medium 4.

  The recording medium 4 is transported in the Y direction by a transport motor (not shown) (transport operation). A guide shaft 3 is arranged in parallel along the X direction intersecting with the Y direction of the recording medium 4 so as to be along the paper surface of the recording medium 4. The carriage 1 (scanning means) on which the recording head 5 is mounted is reciprocally moved (reciprocated scanning) in the X direction (scanning direction) by driving a carriage motor (not shown) while being supported by the guide shaft 3. Further, the ink jet recording apparatus is provided with an ink tank (not shown), and this ink is supplied to the recording head 5 via the ink supply path 2.

  When the carriage 1 performs reciprocating scanning, the recording head 5 discharges ink according to the recording data, thereby recording on the recording medium (recording operation). By repeatedly performing such a recording operation and a conveying operation, an image is formed on the recording medium by a plurality of scans.

  In the present embodiment, a so-called bidirectional recording method is employed in which recording is performed on a recording medium by ejecting ink both when the recording head 5 moves along the forward path and when the recording head 5 moves along the backward path. When one scan accompanied by recording by the recording head 5 is performed, the recording medium 4 is transported by a predetermined amount by a transport motor (not shown).

(Recording head)
FIG. 4 is a schematic perspective view of the recording head 5 mounted on the carriage 1 of the ink jet recording apparatus. FIG. 4A is a perspective view of the surface of the recording head that faces the recording medium. FIG. 4B is a perspective view when the recording element substrate provided on the surface facing the recording medium of the recording head is viewed from a direction perpendicular to the XY plane. FIG. 4C is an enlarged perspective view of one of the six recording element substrates shown in FIG. 4B.

  FIG. 5 is a perspective view of the recording element substrate 6 in the present embodiment. 5A is a cross-sectional view schematically showing the state of the cut surface when the recording element substrate is cut perpendicularly to the XY plane along the line segment AA ′ shown in FIG. 4C. FIG. FIG. 5B is an enlarged view of the portion of the recording element 34 in FIG.

  A plurality of discharge ports 30 are arranged on the surface of the substrate 31 in the Y direction (arrangement direction) to form a discharge port array 51 (shown as one line segment in FIGS. 4A and 4B for simplicity). It is provided as follows. The substrate 31 is fixed to a support member 38 such as alumina, SUS, or resin with an adhesive. An electrical wiring member 600 is provided around the recording element substrate 6 on the support member 38, and the electrical wiring member 600 is fixed to the support member 38 with an adhesive. Each recording element substrate 6 is electrically connected to the electric wiring member 600 and performs communication using signals with the print head via the electric wiring member 600.

  Six recording element substrates 6 are mounted on the recording head 5 in order to perform a recording operation using six types of ink. As shown in the enlarged view of FIG. 4C, the ejection port array 51 in each recording element substrate 6 has a plurality of ejection ports 30 for ejecting the same color ink arranged in the Y direction (predetermined direction). This is formed by providing four rows of ejection openings corresponding to the same color ink. Specifically, the discharge port array 51 is provided with four columns formed of 640 discharge ports arranged at 600 dpi (dot / inch), and the adjacent two columns are shifted by 1200 dpi in the Y direction. Are arranged in different directions. A plurality of temperature detection sensors (detection elements) 20 for measuring the temperature of the recording element substrate are provided on each recording element substrate 6. Hereinafter, the temperature of each recording element substrate 6 measured by the temperature detection sensor 20 is also referred to as a substrate temperature. A sub-heater (heating element) 50 that generates thermal energy for heating the ink in the vicinity of the recording element through the substrate 31 is formed of a continuous member (for example, aluminum) so as to surround the periphery of the ejection port array 51. ing. In the present embodiment, a substrate on which a temperature detection sensor, a sub-heater, a recording element and a discharge port member described later are formed is referred to as a recording element substrate.

  As shown in FIG. 5A, the substrate 31 is provided with a flow path member 35 that forms discharge ports 30 facing the recording elements that generate energy used for discharging ink. ing. As the recording element, an electrothermal conversion element or a piezoelectric element can be used. Further, when the discharge port member 35 and the substrate 31 are in contact with each other, a flow path 36 communicating with each discharge port 30 is formed between the discharge port member 35 and the substrate 31, and between the adjacent flow paths 36. A partition wall 37 is formed. The temperature detection sensor 20 is provided on the surface of the substrate 31.

  FIG. 5B is a diagram for explaining the layer structure of the substrate 31. A heat storage layer 401, a heat generating material layer 402, and a pair of electrode layers 403 are stacked over a base material 400 made of silicon provided with a driving element such as a transistor. The heat storage layer 401 is formed of an insulating material whose main component is silicon. The heat generating material layer 402 is formed of a material that generates heat when energized, such as TaSiN. The pair of electrode layers 403 is formed of aluminum or the like serving as an electrode for energization. A portion of the heat generating material layer 402 positioned between the pair of electrode layers 403 is used as the recording element 34.

  An insulating layer 404 made of an insulating material containing silicon as a main component is stacked on the heat generating material layer 402 and the pair of electrode layers 403 to protect the recording element 34 from ink or the like. Further, a protective layer 405 made of a metal material such as Ta is provided on the insulating layer 404 corresponding to the recording element 34 in order to protect the recording element 34 from cavitation generated when bubbles disappear.

  The ink supplied from the ink supply path 2 of the ink jet recording apparatus through the joint 7 to the recording head 5 passes through the ink flow path 39 formed by the support member 38 inside the recording head 5, and reaches the recording element substrate 6. It is carried to the ink supply port 32. Then, it is conveyed to the upper side of the recording element 34 through the flow path 36.

  Further, by driving the recording element 34 of the recording head according to a recording signal received from the ink jet recording apparatus, a driving pulse is applied to the recording element 34 to energize and generate heat. The ink on the recording element 34 is boiled by this thermal energy and foams, and the ink is ejected from the ejection port 30 by the pressure of bubbles generated at this time, and the recording operation is performed.

(Control configuration)
FIG. 6 is a block diagram showing a control configuration of the ink jet recording apparatus in the present embodiment.

  In the control system 24, a CPU 200, a ROM 201, a RAM 202, and a gate array 203 are provided. The ROM 201 is used as a storage unit that stores a program executed by the CPU 200 and can be used to store a drive pulse table for performing ejection control. The RAM 202 is storage means that can be used to temporarily store various data (image data, recording signals supplied to the recording head, etc.). The gate array 203 is used for supplying a recording signal to the recording head 5, and is also used for data transfer between the interface 23, the CPU 200, and the RAM 202.

  The motor driver 26 is used to drive the carriage motor 8 in order to move the recording head 5 to a predetermined recording position in the X direction in accordance with a signal output from the control system 24. Similarly, the recording head driver 25 drives the recording head 5 in accordance with the recording signal output from the control system 24. Further, the motor driver 26 drives the transport motor 9 in accordance with the signal output from the control system 24, and performs the recording medium transport operation.

  Also, the print head 5 is obtained during a factory inspection such as a temperature detection sensor 20 for detecting the temperature of the print head 5, a sub-heater 50 for heating the print head 5, and an ejection amount, a heating element, and wiring resistance. An EEPROM 21 for storing the characteristics to be recorded is provided.

  The gate array 203 and the CPU 200 of the control system 24 convert the image data received from the external device 22 via the interface 23 into recording data and store it in the RAM 202. Further, the control system 24 drives the motor drivers 26 and 27 and the recording head driver 25 in synchronization with each other, thereby controlling the temperature by the sub heater 50, the recording operation of the recording head 5, the conveying operation of the recording medium, and the recording head 5 An image is formed on a recording medium by reciprocating in the X direction.

  In this embodiment, the ink jet recording apparatus as described above is used, and the drive of the sub heater is controlled according to the substrate temperature and the heat storage state of the support member. Hereinafter, an example of the drive control of the sub heater in the present embodiment will be described in detail.

  FIG. 7 is a flowchart showing a drive control flow of the sub heater in the present embodiment.

  First, when a recording job is input, a head internal temperature (support member temperature) T3 indicating a heat storage state of the recording head is calculated in step S11 during the non-driving period. The method for calculating the head internal temperature in step S11 will be described later.

  Next, the substrate temperature Ti detected by the temperature detection sensor 20 in step S12 is acquired. Note that the temperature detection sensor 20 continuously acquires (monitors) the substrate temperature Ti during recording.

  Next, in step S13, based on the head internal temperature T3 calculated in step S11 and the substrate temperature Ti acquired in step S12, the driving power of the sub-heater (amount of thermal energy per unit time given to the ink). To decide. A specific value of the driving power of the sub heater will be described later. After the driving power is determined, the recording medium is scanned (first scanning).

  Next, in step S14, it is determined whether or not the substrate temperature Ti acquired during execution of the first scan is lower than the heating target temperature. In this embodiment, the heating target temperature is set to 50 ° C. If it is determined that the substrate temperature Ti is lower than the heating target temperature, the process proceeds to step S15, and the sub heater is driven according to the driving power determined in step S13 (sub heater ON). On the other hand, when it is determined that the substrate temperature Ti is equal to or higher than the heating target temperature, the process proceeds to step S16, and the driving of the sub heater is stopped (sub heater OFF).

  Subsequently, in step S17, after a certain amount of time has elapsed since the sub heater is driven or stopped, it is determined whether or not image recording has ended. If it is determined that the image recording has been completed, the driving of the sub-heater is stopped in step S20, and the process ends. On the other hand, if it is determined that the image recording has not ended, the process proceeds to step S18.

  In step S18, it is determined whether or not it is a non-driving period, that is, whether or not the previously performed scanning is completed. If it is determined that it is the drive period (the first scan is being performed), the process proceeds to step S14, and the comparison between the substrate temperature Ti and the heating target temperature is performed again. If it is determined that it is a non-driving period (the first scanning has been completed and the second scanning following the first scanning has not yet been performed), the process proceeds to step S19, and the driving of the sub heater is stopped. . Then, before the second scan is executed, the process proceeds to step S11, and the head internal temperature T3 is calculated again.

  The method for calculating the head internal temperature T3 in step S11 will be described in detail below.

  FIG. 8A shows the transition of the substrate temperature detected by the temperature detection sensor 20 disposed on the recording element substrate 6 when an image of 20% duty for each color is bidirectionally recorded. FIG. 8B is an enlarged view in the period Δt shown in FIG.

  Here, as can be seen from FIG. 8A, the overall temperature of the substrate tends to gradually increase while repeating the increase and decrease as recording proceeds. The increase in temperature is considered to be due to the drive of the recording element accompanying one scan. Further, the decrease in temperature is considered to be due to the fact that the recording element is not driven between scans, while heat is generated from the recording element substrate 6 to the support member 38 having a high heat capacity. Further, since heat is stored in the support member 38 by repeatedly releasing heat to the support member 38, the substrate temperature is likely to rise by driving the recording element as described in detail with reference to FIG. 2, and the temperature gradually increases. It is expected to rise.

  Here, as described above, when the heat capacity of the support member 38 is higher than that of the substrate, heat is radiated from the recording element substrate 6 only to the support member 38. Therefore, the temperature (heat storage state) of the support member 38 can be calculated based on the rate of change of the temperature of the printing element substrate with respect to time during the non-driving period.

  Therefore, in the present embodiment, the first temperature detected at the first timing in the non-driving period and the second temperature detected at the second timing after a predetermined time from the first timing in the non-driving period. Based on the above, the temperature of the support member 38 is calculated. That is, in the present embodiment, the first and second temperatures are detected at the first and second timings while the substrate temperature Ti is decreasing.

  FIG. 9 is a flowchart showing a flow of a method for calculating the in-head temperature (the temperature of the support member 38) in the present embodiment.

  First, the first temperature T1, which is the substrate temperature before the start of the recording scan (second scan) and after the end of the preceding recording scan (first scan), is acquired at the first timing (S21). For example, the first temperature can be acquired by the temperature detection sensor 20 detecting a resistance value as information corresponding to the first temperature T1 and calculating the temperature corresponding to the resistance value. Note that the temperature acquisition interval of the substrate temperature detection means of this embodiment is 50 ms.

  Next, the second temperature T2, which is the substrate temperature after a predetermined time (t seconds) has elapsed since the first temperature T1, is acquired at the second timing (S22). Here, t = 0.1 seconds. The substrate temperature acquisition interval and the predetermined time t are not limited to the above-described setting, and can be set according to the actual system. The substrate temperature acquisition interval must be set to a predetermined time t or less. Also, the acquisition of the first temperature T1 and the second temperature T2 needs to be within a non-driving period required from the end of the first scan to the start of the second scan.

  Next, from the temperature difference between the first temperature T1 and the second temperature T2 acquired and the time difference between the first timing and the second timing, the head internal temperature as head temperature information when performing the second scan. (Temperature of support member 38) T3 is calculated (S23).

Specifically, the head internal temperature (T3) can be calculated by (Equation 1).
T3 = T2 / (1-exp (A * t))-T1 * exp (A * t) / 1-exp (A * t) (Equation 1)
T3: Head internal temperature (temperature of the support member 38)
T1: First temperature T2: Second temperature exp (A * t): 0.633 (thermal self-constant of recording head)
A: Thermal diffusion coefficient (Thermoelectricity factor)
t: Time The thermal self constant exp (A * t) of the recording head of this embodiment is 0.633. This is a constant that varies depending on the material, volume, and structure of the support member.

  In the non-drive period between recording scans shown in FIG. 8B, the first temperature (T1) is 68.0 ° C., the second temperature (T2) is 66.4 ° C., and the predetermined time t is 0.1 second. is there. Therefore, the head internal temperature T3 is calculated to be 63.6 ° C. by (Equation 1).

  When the recording element is in a non-driven state, the head internal temperature T3 is substantially equal to the temperature of the recording element substrate 6 when the heat of the recording element substrate 6 is completely diffused to the support member 38. It takes a non-driving period of about several tens of seconds to several tens of seconds for this temperature to completely diffuse into the support member 38.

  In the present embodiment, most of the heat generated in the recording element substrate 6 moves to the support member 38 to which the recording element substrate 6 is fixed, so that the movement of heat to the atmosphere and other head members is ignored. However, a term that considers heat radiation to the atmosphere may be added to (Equation 1).

  In the above example, the head internal temperature T3 is calculated from the calculated first temperature T1 and second temperature T2, but is detected at the first and second timings detected by the temperature detection sensor 20. From each of the resistance values, head temperature information corresponding to the head internal temperature may be calculated.

  According to the head internal temperature detection method described above, the head internal temperature at that time can be calculated at a relatively high speed if there is a non-driving period of the recording element during the recording operation. Therefore, when the recording element non-drive period is provided at a certain interval, such as during the reversal operation between recording scans, the internal temperature of the head that reflects the thermal storage state of the recording head periodically during recording is set. It can be said that this is a very effective method in that it can be acquired. Further, this is not limited to the serial scan type ink jet recording apparatus. For example, even in a full line type ink jet printer having a recording head (line head) having a size larger than the paper width, as long as the recording element is not driven during the recording operation (a continuous period in which the recording element is not driven), This embodiment can be applied.

  Further, the acquisition timing of the second temperature (when the predetermined time t seconds has elapsed since the first temperature acquisition) can be arbitrarily set in accordance with the actual system, so that the recording speed is reduced with respect to the previous recording operation, etc. The internal temperature of the head can be acquired without affecting the above.

  Next, determination of the driving power (power amount) of the sub heater based on the substrate temperature Ti and the head internal temperature T3 performed in step S13 of FIG. 7 will be described in detail.

  FIG. 10 is a table for explaining the driving power of the sub heater in the present embodiment.

  When the substrate temperature Ti is a relatively low temperature, it is necessary to apply a large amount of heat energy before reaching the heating target temperature as compared with the case where the substrate temperature Ti is a relatively high temperature. Therefore, in this embodiment, the driving power (power amount) of the sub-heater when the substrate temperature Ti is relatively low is the driving power (power amount) of the sub-heater when the substrate temperature Ti is relatively high. Larger than. Here, the driving power is different in two cases, when the substrate temperature Ti is 35 ° C. or higher and when it is lower than 35 ° C.

  Further, as can be seen from FIG. 2, heat radiation to the support member 38 is more noticeable as the internal temperature T3 is lower (lower heat storage state), so the thermal energy required for the substrate temperature Ti to reach the heating target temperature is growing. Therefore, in this embodiment, the driving power (power amount) of the sub-heater when the internal temperature T3 is relatively low is higher than the driving power (power amount) of the sub-heater when the internal temperature T3 is relatively high. Also make it bigger. Here, when the internal temperature T3 is lower than 30 ° C., 30 ° C. or higher and lower than 40 ° C., and 40 ° C. or higher, the driving power is varied.

  For example, when the substrate temperature is 33 ° C. and the internal temperature is 38 ° C., the driving power is determined to be 80 W. When the substrate temperature is 33 ° C. and the internal temperature is 45 ° C., the driving power is determined to be 50 W. In the present embodiment, since the sub-heater is formed of a thermoelectric conversion element, the driving power is controlled by controlling the width and frequency of the pulse applied to the sub-heater.

  As described above, according to the present embodiment, it is possible to perform recording while suppressing an excessive temperature rise or insufficient temperature of ink generated according to the heat storage state of the recording head, and suppressing a decrease in image quality.

(Second Embodiment)
In the first embodiment, a mode is described in which the heating condition (drive power) of the sub heater is changed according to the substrate temperature Ti and the head internal temperature T3.

  On the other hand, this embodiment describes a mode in which the heating condition (driving power) of the sub heater is changed according to the substrate temperature Ti, and the heating target temperature is changed according to the head internal temperature T3.

  Note that description of the same parts as those of the first embodiment described above will be omitted.

  FIG. 11 is a flowchart showing a drive control flow of the sub heater in the present embodiment.

  Steps S31 to S32 and Steps 37 to S40 in the present embodiment are the same as Steps S11 to S12 and Steps S17 to S20 shown in FIG. 7 in the first embodiment, respectively.

  In step S33, the driving power (heating condition) of the sub heater is determined based on the substrate temperature Ti acquired in step S32. Further, the heating target temperature (threshold value) is determined based on the head internal temperature T3 acquired in step S31. The specific sub-heater driving power and heating target temperature will be described later.

  Next, in step S34, it is determined whether or not the substrate temperature Ti acquired during the first scan is lower than the heating target temperature determined in step S33. If it is determined that the substrate temperature Ti is equal to or lower than the heating target temperature (lower than the threshold value), the process proceeds to step S35, and the sub heater is driven (sub heater ON) according to the driving power determined in step S33. On the other hand, when it is determined that the substrate temperature Ti is higher than the heating target temperature, the process proceeds to step S36, and the driving of the sub heater is stopped (sub heater OFF).

  FIG. 12A is a table for explaining the driving power of the sub-heater in this embodiment. FIG. 12B is a table for explaining the heating target temperature of the sub-heater in the present embodiment.

  As in the first embodiment, in this embodiment, the driving power of the sub-heater when the substrate temperature Ti is relatively low is the driving power of the sub-heater when the substrate temperature Ti is relatively high. Larger than. Here, as shown in FIG. 12A, the driving power is varied in two cases, when the substrate temperature Ti is 35 ° C. or higher and when it is lower than 35 ° C.

  Further, when the head internal temperature T3 is low, even if the substrate temperature Ti reaches the target temperature, there is a possibility that the temperature will drop as soon as the sub heater is turned off, and the temperature will deviate from the temperature range where ink is normally ejected. Further, since the sub heater 50 is separated from the discharge port array 51, there is a slight time lag until the substrate temperature rises even if the sub heater is turned on.

  Therefore, in the present embodiment, as shown in FIG. 12B, the heating target temperature Ta when the head internal temperature T3 is relatively low is used as the heating target temperature Ta when the head internal temperature T3 is relatively high. The temperature is set higher than the target temperature Ta. Specifically, the heating target temperature Ta when the head internal temperature T3 is less than 30 ° C. is 55 ° C., and the heating target temperature Ta when the head internal temperature T3 is 35 ° C. or more and less than 40 ° C. is 52 ° C. The heating target temperature Ta when the temperature T3 is 40 ° C. or higher is set to 50 ° C. Accordingly, even when the head internal temperature T3 is low, it is possible to prevent the ink from deviating from the temperature range in which ink is normally ejected, and it is possible to perform stable recording head temperature management.

  As described above, according to the present embodiment, it is possible to perform the heating control in consideration of the heat storage state of the recording head, and the temperature management of the recording head can be performed stably.

  In each of the embodiments described above, the mode in which the driving power of the sub-heater is changed based on the substrate temperature Ti has been described. However, other modes are also possible. For example, the driving power of the sub heater may be determined based only on the head internal temperature T3. Further, the heating target temperature Ta may be determined based on the head internal temperature T3 without changing the driving power of the sub heater.

  Further, in each of the embodiments described above, a mode has been described in which the head internal temperature is calculated and the sub-heater driving is controlled every time one scan is completed. However, other modes are also possible. For example, the head internal temperature may be calculated every two scans. Alternatively, the head internal temperature may be calculated every time recording on one recording medium is completed.

  In each of the embodiments described above, the first temperature at the first timing and the second temperature at the second timing are acquired, and the head internal temperature is calculated based on the first and second temperatures. In the above embodiment, the driving of the sub heater is controlled based on the internal temperature of the head. However, other embodiments are possible. For example, a mode in which the driving of the sub heater is directly controlled based on the first and second temperatures may be employed.

  Further, in each of the embodiments described above, the form in which an image is recorded by performing scanning a plurality of times on the recording medium has been described. However, other forms are possible. For example, a long recording head having a length longer than the width direction of the recording medium is used, and an image is recorded by ejecting ink from the recording head while transporting the recording medium only once in a direction crossing the width direction. Each embodiment can be applied even if it is a form.

  Further, the ink jet recording apparatus can be used for performing a recording operation on a recording medium by discharging ink. Specific examples of applicable equipment include office equipment such as printers, copiers, and facsimile machines, and industrial production equipment. By using such an ink jet recording apparatus, recording can be performed on various recording media such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramics.

  The term “ink” should be broadly interpreted and applied to a recording medium to be used for forming an image, pattern, pattern, etc., processing the recording medium, or processing the ink or recording medium. Liquid.

  Moreover, although each embodiment described the inkjet recording apparatus and the inkjet recording method, it may be a computer or the like that generates data for performing the inkjet recording method described in each embodiment. Furthermore, the present invention can be widely applied to a mode in which a program for functioning heating control by a sub-heater in the ink jet recording apparatus is prepared separately from the ink jet recording apparatus, a mode provided in a part of the ink jet recording apparatus, or the like.

4 Recording medium 5 Recording head 6 Recording element substrate 20 Temperature detection sensor 31 Substrate 34 Recording element 50 Sub-heater (heating element)

Claims (20)

A substrate, a recording element that generates energy used to eject ink provided on the substrate, a detection element that is provided on the substrate and detects the temperature of the recording element substrate, and the recording element A recording head comprising: a heating element for heating a nearby ink; and a support member that supports the recording element substrate and has a higher heat capacity than the substrate;
By driving the recording element while performing a plurality of relative scans of the recording head and the recording medium including at least a first scan and a second scan next to the first scan. Recording control means for ejecting ink onto the recording medium;
First acquisition means for acquiring information about the temperature of the recording element substrate detected from the detection element;
When the temperature of the recording element substrate indicated by the information acquired by the first acquisition unit is equal to or lower than a predetermined threshold during the second scanning by the recording control unit, heating by the heating element is performed, In addition, according to the information on the temperature acquired by the first acquisition unit, the heating element is used so that the heating element is not heated when the temperature of the recording element substrate is higher than the predetermined threshold. An ink jet recording apparatus having a heating control means for controlling heating,
The first acquisition unit is a first unit that relates to the temperature of the recording element substrate at a first timing from the end of the first scan by the recording control unit to the start of the second scan. And second information relating to the temperature of the recording element substrate at a second timing after the first timing, and
The heating control unit controls heating by the heating element during the second scanning by the recording control unit based on the first and second information acquired by the first acquisition unit. An ink jet recording apparatus. Based on the first and second information acquired by the first acquisition means, further comprising second acquisition means for acquiring information on the temperature of the support member;
The heating control means controls heating by the heating element during the second scanning by the recording control means based on information on the temperature of the support member acquired by the second acquisition means. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is an ink jet recording apparatus.   The heating control means determines the amount of thermal energy per unit time given to the ink by heating by the heating element based on the information about the temperature of the support member acquired by the first acquisition means. The inkjet recording apparatus according to claim 2, wherein heating by the heating element during the second scanning by the recording control unit is controlled.   In the heating control unit, the amount of the thermal energy when the temperature of the support member indicated by the information acquired by the second acquisition unit is the first temperature is acquired by the second acquisition unit. Further, the second scanning operation by the recording control means is performed so that the temperature of the support member indicated by the information is larger than the amount of the thermal energy when the temperature is the second temperature higher than the first temperature. The inkjet recording apparatus according to claim 3, wherein heating by the heating element is controlled.   The heating control unit determines the predetermined threshold value based on information on the temperature of the support member acquired by the second acquisition unit, so that the recording control unit performs the second scanning. The inkjet recording apparatus according to claim 2, wherein heating by the heating element is controlled.   In the heating control unit, the predetermined threshold value when the temperature of the support member indicated by the information acquired by the second acquisition unit is the first temperature is acquired by the second acquisition unit. During the second scanning by the recording control means, the temperature of the support member indicated by the information is higher than the predetermined threshold when the temperature is the second temperature higher than the first temperature. 6. The ink jet recording apparatus according to claim 5, wherein heating by the heating element is controlled.   The heating control unit applies the ink to the ink by heating by the heating element based on information on the temperature of the recording element substrate acquired by the first acquisition unit during the second scanning by the recording control unit. The heating by the heating element in the second scanning by the recording control means is controlled by determining the amount of heat energy per unit time to be controlled. The inkjet recording apparatus according to Item.   The heating control unit is configured to provide the heat when the temperature of the recording element substrate indicated by the information acquired by the first acquisition unit during the second scanning by the recording control unit is a third temperature. The amount of energy is such that the temperature of the recording element substrate indicated by the information acquired by the first acquisition means during the second scanning by the recording control means is higher than the third temperature. 8. The inkjet according to claim 7, wherein heating by the heating element during the second scanning by the recording control unit is controlled so as to be larger than an amount of the thermal energy in the case of temperature. Recording device. The heating element is an electrothermal conversion element,
The inkjet according to any one of claims 1 to 8, wherein the heating control unit controls heating by the heating element by determining a width and a frequency of a pulse applied to the heating element. Recording device.   The second acquisition means includes a temperature difference between the temperatures indicated by the first and second information acquired by the first acquisition means, and from the first timing to the second timing. 3. The ink jet recording apparatus according to claim 2, wherein information on the temperature of the support member is acquired based on the time difference. The plurality of scans further includes a third scan following the second scan,
The heating control unit does not perform heating by the heating element during a period from the end of the second scan to the recording medium by the recording control unit to the start of the third scan. The ink jet recording apparatus according to claim 1, wherein heating by the heating element is controlled. The first acquisition unit performs a third operation related to the temperature of the recording element substrate at a third timing from the end of the second scan by the recording control unit to the start of the third scan. And the fourth information related to the temperature of the recording element substrate at a fourth timing after the third timing,
The heating control means controls heating by the heating element during the third scanning by the recording control means based on the third and fourth information acquired by the first acquisition means. The inkjet recording apparatus according to claim 11.   The inkjet recording apparatus according to claim 1, wherein the support member is made of alumina.   The inkjet recording apparatus according to claim 1, wherein the recording element is an electrothermal conversion element. A substrate, a recording element that generates energy used to eject ink provided on the substrate, a detection element that is provided on the substrate and detects the temperature of the recording element substrate, and the recording element A recording head comprising: a heating element for heating a nearby ink; and a support member that supports the recording element substrate and has a higher heat capacity than the substrate;
Recording control means for ejecting ink onto the recording medium by driving the recording element while performing relative scanning between the recording head and the recording medium;
First acquisition means for acquiring information about the temperature of the recording element substrate detected from the detection element;
When the temperature of the recording element substrate indicated by the information acquired by the first acquisition unit is equal to or lower than a predetermined threshold during the predetermined scanning by the recording control unit, the heating element performs heating, and Heating by the heating element is performed according to the information about the temperature acquired by the first acquisition unit so that the heating element is not heated when the temperature of the recording element substrate is higher than the predetermined threshold. An ink jet recording apparatus having heating control means for controlling,
The first acquisition unit is a period before the predetermined scanning is performed, and in a continuous period in which the recording element is not driven by the recording control unit, the first acquisition unit at the first timing Obtaining first information related to the temperature of the recording element substrate and second information related to the temperature of the recording element substrate at a second timing after the first timing;
The heating control means controls heating by the heating element during the predetermined scanning by the recording control means based on the first and second information acquired by the first acquisition means. An ink jet recording apparatus. The recording head further includes an ejection port array in which a plurality of ejection ports provided to face the recording element are arranged in the predetermined direction in a range longer than a width in the predetermined direction of the recording medium,
The first acquisition means is a period from the end of recording on the first recording medium by the recording control to the start of recording on the second recording medium for recording next to the first recording medium. First information relating to the temperature of the recording element substrate at a first timing and second information relating to the temperature of the recording element substrate at a second timing after the first timing are acquired. The inkjet recording apparatus according to claim 15. A substrate, a recording element that generates energy used to eject ink provided on the substrate, a detection element that is provided on the substrate and detects the temperature of the recording element substrate, and the recording element A recording head comprising: a heating element for heating a nearby ink; and a support member that supports the recording element substrate and has a higher heat capacity than the substrate;
Recording control means for ejecting ink onto the recording medium by driving the recording element while performing relative scanning between the recording head and the recording medium;
First acquisition means for acquiring information about the temperature of the recording element substrate detected from the detection element;
Second acquisition means for acquiring information on the temperature of the support member based on information on the temperature of the recording element substrate acquired by the first acquisition means;
When the temperature of the recording element substrate indicated by the information acquired by the first acquisition unit is equal to or lower than a predetermined threshold during the predetermined scanning by the recording control unit, the heating element performs heating, and Heating by the heating element is performed according to the information about the temperature acquired by the first acquisition unit so that the heating element is not heated when the temperature of the recording element substrate is higher than the predetermined threshold. An ink jet recording apparatus having heating control means for controlling,
In the heating control unit, the predetermined threshold value when the temperature of the support member indicated by the information acquired by the second acquisition unit is the first temperature is acquired by the second acquisition unit. When the predetermined scanning is performed by the recording control unit, the temperature of the support member indicated by the information is higher than the predetermined threshold value when the temperature is the second temperature higher than the first temperature. An ink jet recording apparatus that controls heating by a heating element. A substrate, a recording element that generates energy used to eject ink provided on the substrate, a detection element that is provided on the substrate and detects the temperature of the recording element substrate, and the recording element A recording head comprising: a heating element for heating a nearby ink; and a support member that supports the recording element substrate and has a higher heat capacity than the substrate;
By driving the recording element while performing a plurality of relative scans of the recording head and the recording medium including at least a first scan and a second scan next to the first scan. Recording control means for ejecting ink onto the recording medium;
First acquisition means for acquiring information about the temperature of the recording element substrate detected from the detection element;
When the temperature of the recording element substrate indicated by the information acquired by the first acquisition unit is equal to or lower than a predetermined threshold during the second scanning by the recording control unit, heating by the heating element is performed, In addition, according to the information on the temperature acquired by the first acquisition unit, the heating element is used so that the heating element is not heated when the temperature of the recording element substrate is higher than the predetermined threshold. An ink jet recording apparatus having a heating control means for controlling heating,
The first acquisition unit includes a first unit that relates to a temperature of the recording element substrate at a first timing from the start of the first scan by the recording control unit to the start of the second scan. And second information relating to the temperature of the recording element substrate at a second timing after the first timing, and
The heating control unit controls heating by the heating element during the second scanning by the recording control unit based on the first and second information acquired by the first acquisition unit. An ink jet recording apparatus. A substrate, a recording element that generates energy used to eject ink provided on the substrate, a detection element that is provided on the substrate and detects the temperature of the recording element substrate, and the recording element A recording head comprising: the recording element substrate including a heating element for heating a nearby ink; and a support member that supports the recording element substrate and has a higher heat capacity than the substrate. And the second scanning next to the first scanning, and the recording element is driven while the recording head and the recording medium are scanned a plurality of times. A recording step of discharging to the recording medium;
A first acquisition step of acquiring information on the temperature of the recording element substrate detected from the detection element;
Performing heating by the heating element when the temperature of the recording element substrate indicated by the information acquired by the first acquisition step is equal to or lower than a predetermined threshold during the second scanning by the recording step; and The heating by the heating element according to the information about the temperature acquired by the first acquisition step so that the heating by the heating element is not performed when the temperature of the recording element substrate is higher than the predetermined threshold. An ink jet recording method comprising:
The first acquisition step includes a first timing relating to a temperature of the recording element substrate at a first timing from the end of the first scan in the recording step to the start of the second scan. Information and second information related to the temperature of the recording element substrate at a second timing after the first timing, and
The heating step controls heating by the heating element during the second scanning by the recording step based on the first and second information acquired by the first acquisition step. An inkjet recording method. A program for causing a computer of an ink jet recording apparatus to function in order to execute the ink jet recording method according to claim 19.

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