JP2020001345A - Ink jet image formation apparatus - Google Patents

Abstract

To provide an ink jet image formation apparatus which can reduce consumed ink in processing of removing a scorch adhering to a heater part in a recording head nozzle.SOLUTION: Before forming air bubbles 404 by a heater part 402 and removing a scorch, discharge prevention ink 500 is formed on a nozzle end 408 so as to cover a nozzle opening 407 as ink discharge prevention means. Following the formation thereof, a meniscus formed on the nozzle opening 407 is destroyed. Like this, discharge prevention ink 500 in a large volume that is not discharged with the generation of air bubbles by the heater part 402 is formed on the front side in the discharge direction of the heater part 402. Consequently, ink 401 is not consumed even though the formation of air bubbles and defoaming are repeated many times, and the consumption of the ink 401 can be reduced.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that forms an image by discharging ink by a bubble jet method.

  In a print head using the bubble jet method, ink is heated by a heater in a print head nozzle to cause partial film boiling in the ink, and the ink is ejected by a sudden generation pressure of bubbles due to the film boiling. I do. Such rapid heating of the ink may cause thermal decomposition of the ink in the vicinity of the heater, and may generate a thermal decomposition product called kogation. If kogation occurs and adheres to the vicinity of the heater, the ejection speed and ejection amount of ink droplets may be reduced, and image quality may be degraded.

  As a method of removing the adhered kogation, there is a method that utilizes a phenomenon that a local high pressure is generated when bubbles formed in the ink by application of a pulse disappear, that is, a so-called cavitation phenomenon. Here, in Patent Document 1, in the ink jet recording head, the energy intensity of the pulse applied to the heater section is changed in two stages, and bubbles of different sizes are formed and defoamed a predetermined number of times to remove kogation. Those that increase efficiency are described.

JP 2005-28767 A

  However, in the method of removing kogation using the cavitation phenomenon, the formation of bubbles in the ink is repeated a plurality of times. For this reason, every time a bubble is formed, an ink droplet is ejected, and as a result, there is a problem that a large amount of ink is consumed for removing kogation.

  Accordingly, an object of the present invention is to provide an ink jet image forming apparatus capable of reducing the amount of ink consumed in a process for removing kogation adhered to a heater section in a print head nozzle.

  In order to solve the above problems, an inkjet image forming apparatus according to the present invention includes a nozzle for discharging ink, and a heater unit provided in the nozzle for supplying thermal energy to the ink in the nozzle. A print head, an ink discharge preventing unit for preventing ink discharge from the nozzles, and a discharge control unit for driving a heater unit of the print head to generate bubbles in the nozzles and discharge ink. And a discharge control unit for driving the heater unit to perform cleaning of the inside of the nozzle in a state where the ink discharge is prevented by the ink discharge prevention unit.

  According to the present invention, it is possible to provide an ink jet image forming apparatus capable of reducing the amount of ink consumed in a process for removing kogation adhered to a heater section in a recording head nozzle.

1 is a schematic diagram showing a system configuration applied to a first embodiment of the present invention. FIG. 2 is a schematic sectional view of the inkjet image forming apparatus shown in FIG. 1. FIG. 3 is a block diagram illustrating a configuration of a control system of the inkjet image forming apparatus illustrated in FIG. 2. It is sectional drawing for demonstrating the kogation removal which concerns on a comparative example, (a) The state where the kogation adhered to the heater part 402 more than predetermined by recording etc., (b) The state which formed the bubble in order to remove the kogation, ( c) A state in which a part of the kogation attached to the heater unit 402 has been peeled off, respectively. It is sectional drawing for demonstrating the kogation removal which concerns on 1st Embodiment, (a) The state which performed the ink discharge prevention means, (b) The state which formed the bubble in order to remove kogation, (c) The heater A state where a part of the kogation adhered to the portion 402 is peeled off, respectively. 5 is a control flowchart according to the first embodiment. FIG. 10 is a cross-sectional view used for describing an ink discharge prevention unit according to a second embodiment. FIG. 13 is a cross-sectional view used for describing an ink discharge prevention unit according to a third embodiment. FIG. 14 is a cross-sectional view used for describing an ink discharge prevention unit according to a fourth embodiment. It is a control flowchart in a 5th embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing a system configuration applied to the first embodiment of the present invention. The system includes an inkjet image forming apparatus 100 (hereinafter, also simply referred to as an image forming apparatus) and a host computer 104 connected to the image forming apparatus 100 via a printer cable 105. The image forming apparatus 100 includes an image forming apparatus main body 101 provided with an operation unit 102, and a roll paper holder 103 containing a recording medium. The image forming apparatus 100 records the image data received from the host computer 104 on a label (hereinafter, also referred to as a label) attached to the roll paper while transporting the roll paper as a recording medium.

  FIG. 2 is a schematic sectional view of the inkjet image forming apparatus shown in FIG. The roll paper holder 103 places the built-in roll paper 200 on a pair of roll paper transport rollers 206, and supplies the roll paper 200 to the image forming apparatus main body 101 by rotating the roll paper 200. The image forming apparatus main body 101 is configured to place the roll paper 200 supplied from the roll paper holder 103 on an endless transport belt 204 stretched between transport rollers 203, and further transport the roll paper 200. ing. Further, the image forming apparatus main body 101 faces the sheet detection sensor 207 that can detect the presence or absence of the label attached to the roll paper 200 and the recording medium transport surface of the transport belt 204 in order from the upstream in the transport direction of the roll paper 200. A recording head unit 202 is provided at the position. The recording head unit 202 holds a recording head 201 having 6000 nozzles therein. The recording head unit 202 is provided for each ink color. In FIG. 2, units corresponding to one color ink are shown, and units for other color inks are not shown. The recording head 201 is connected to an ink cartridge 205 of a corresponding color disposed below the transport belt 204 via a flexible tube or the like (not shown). A negative pressure is applied to the ink in the recording head 201 due to the head difference of the ink corresponding to the height difference between the recording head 201 and the ink cartridge 205, and a meniscus of the ink is formed at the ejection port of the nozzle 400 in the recording head 201. (See FIG. 4A).

  A recovery unit (not shown) such as a recording head cap member is provided for each recording head 201. By the recovery processing using the recovery unit, it is possible to maintain good ink ejection performance from the nozzles in each recording head. In the present embodiment, pressure recovery processing and suction recovery processing are performed as recovery processing. For this purpose, a tube pump is provided as a cleaning pump (not shown). By using this tube pump, in the pressure recovery process, the ink in the print head 201 is pressurized. In the suction recovery process, the ink in the print head cap member is set to a negative pressure, and the ink is forced from each nozzle 400. Discharge. This makes it possible to discharge the thickened ink in the nozzles and maintain a good ejection state. In the present embodiment, the tube pump is used for a kogation removal process described later with reference to FIG.

  FIG. 3 is a block diagram for explaining a configuration of a control system of the inkjet image forming apparatus shown in FIG.

  The main controller 301 controls the entire image forming apparatus 100, and functions as a storage unit that stores data, a data control unit, and a function as a setting unit that changes the operation of the main body based on the setting data. Having. The main controller 301 is connected to the host computer 104, and can exchange signals with each other. The ROM 302 stores control programs described later with reference to FIGS. 6 and 10 and the like, and the RAM 303 is used as a working memory according to those programs. The image buffer memory (recording data storage means) 304 stores the image data transmitted from the host computer 104. The print head 201 controls the head drive circuit 305 according to the bitmap image data of each color stored in the image buffer memory 304 by the driver controller 306, and drives a built-in heating element (not shown) to print an image. A record is made. The main controller 301 controls a motor 308 for driving a transport unit and the like via a drive circuit 307. Further, the sensor circuit 309 detects the sheet detection sensor 207 and the like.

  FIG. 4 is a cross-sectional view for explaining kogation removal according to a comparative example. FIG. 4A shows a state in which kogation has adhered to the heater unit 402 by a predetermined amount or more due to a recording operation or the like, FIG. 4B shows a state in which bubbles are formed for removing kogation, and FIG. A state where a part of the kogation adhered to the portion 402 is peeled off, respectively.

  As shown in FIG. 4A, a heater unit 402 as a heating element is provided near the nozzle opening 407 of the nozzle 400 in order to discharge the ink 401. The kogation 403 generated by the thermal decomposition of the ink adheres to the heater section 402 for a predetermined amount or more, so that the ink cannot be stably ejected. At this time, the inside of the nozzle 400 is filled with the ink 401, and a meniscus having a concave liquid surface at the center is formed in the nozzle opening 407. Here, in the method for removing (cleaning) kogation using the cavitation phenomenon according to the comparative example, as shown in FIG. 4B, the heater 402 is heated to form bubbles 404 in the ink 401. Do. Thereby, as shown in FIG. 4C, a part 406 of the kogation 403 adhered to the heater unit 402 is peeled off by local high pressure generated when the bubbles 404 in the ink 401 disappear. be able to.

  However, when the bubble 404 is formed in the ink 401, the ink droplet 405 is ejected from the nozzle opening 407 (see FIG. 4B). Here, it is necessary to repeat formation and defoaming of air bubbles, for example, 300,000 times per nozzle before peeling / removing the kogation 403 until a state in which stable ink ejection can be performed. Will be done. When the volume of the ink droplet 405 is 10 pl on average, 0.003 ml (10 pl × 300,000) of ink 401 is consumed per nozzle when the formation and defoaming of bubbles are repeated 300,000 times. That is, since the recording head 201 of one ink color of the present embodiment is provided with 6000 nozzles 400, 18 ml (0.003 ml × 6000) of the ink 401 is consumed per recording head 201. .

  FIG. 5 is a cross-sectional view for explaining kogation removal according to the first embodiment of the present invention. 5A shows a state in which the ink discharge preventing means is applied, FIG. 5B shows a state in which bubbles are formed for removing the kogation, and FIG. Partially peeled state is shown.

  As shown in FIG. 5A, a kogation 403 generated by thermal decomposition of the ink adheres to the heater section 402, so that stable ink cannot be ejected. Before the bubble 404 is formed by the heater unit 402 and the kogation is removed, the ejection preventing ink 500 is formed on the nozzle end 408 so as to cover the nozzle opening 407 as an ink ejection preventing unit. With this formation, the meniscus (see FIG. 4A) formed in the nozzle opening 407 is destroyed. In this way, a large volume of the ejection preventing ink 500 is formed in front of the heater unit 402 in the ejection direction so as not to be ejected due to generation of bubbles by the heater unit 402. As a result, as shown in FIG. 5B, even if bubbles are formed in the heater unit 402, the ink droplets 405 are merely swollen in the ejection direction and the direction perpendicular to the ejection direction. (See FIG. 4B) is not ejected. Then, as shown in FIG. 5C, a part of the kogation 403 attached to the heater unit 402 can be peeled off by local high pressure generated when the bubbles 404 in the ink 401 disappear. it can.

  The ejection prevention ink 500 in the present embodiment is formed by performing a pressure recovery process using a cleaning pump (tube pump) used in the recovery unit. Specifically, a valve (not shown) disposed in a communication path between the inside of the recording head 201 and the ink cartridge 205 is closed. At this time, a valve (not shown) arranged in a communication path between the buffer (not shown) and the inside of the recording head 201 is in a closed state. Here, the air in the buffer is pressurized by rotating the tube pump in direct fluid communication with the buffer in one direction. After the pressure sensor (not shown) detects that the inside of the buffer has reached the predetermined pressure Pc, the tube pump is stopped, and the valve disposed in the communication path between the buffer and the recording head 201 is changed from the closed state to the open state. And As a result, the inside of the recording head 201 is pressurized by the predetermined pressure Pc (constant pressure), and the ejection preventing ink 500 is formed at the nozzle end 408 so as to cover the nozzle opening 407. Thereafter, the valve disposed between the buffer and the print head 201 is changed from the open state to the closed state so that the pressure inside the print head 201 is reduced to a predetermined value so that the state where the ejection preventing ink 500 adheres to the nozzle end 408 is continued. Maintain pressure.

  It is sufficient for the ejection prevention ink 500 to cause, for example, 1 ml of the ink 401 to adhere to each nozzle opening 407 in order to cause meniscus destruction. At this time, since the ink droplets 405 are not ejected, the ink 401 is not consumed no matter how many times the bubble formation and defoaming are repeated, and the consumption of the ink 401 is reduced as compared with the conventional method in which the ink ejection prevention means is not provided. be able to.

  FIG. 6 is a control flowchart according to the first embodiment.

  When the cleaning is started, first, the total foam counter A and the foam counter B before discharge stored in the RAM 303 are set to zero. In S600, an ink ejection prevention unit is formed. Specifically, as described above, by performing a pressure recovery process using a tube pump, the ink 401 in the nozzle 400 is pressurized by a constant pressure Pc, and the ink 401 is exuded from the nozzle opening 407, The ejection prevention ink 500 is formed. With this formation, the meniscus formed in the nozzle opening 407 is destroyed. Here, the constant pressure P needs to be an amount that does not cause ejection by air bubbles generated by the heater unit 402, and is sufficient to cause a total of 1 ml of the ejection preventing ink 500 to seep out from the nozzle opening 407.

  In step S601, the heater 401 heats the ink 401 to form bubbles 404. After that, a part of the attached kogation 403 is peeled off by utilizing a cavitation phenomenon that causes a local high pressure when the bubbles 404 formed in the ink disappear. Forming larger bubbles 404 enhances the effect of exfoliating the kogation. Therefore, it is desirable to apply greater electric energy to the heater unit 402 than during normal image formation.

  In S602, the total foam counter A is incremented by one. This total foam counter A counts how many times foaming has been performed since the start of cleaning.

  In step S603, the pre-discharge foaming counter B is incremented by one. The pre-discharge foaming counter B counts how many times foaming has been performed before the ink 401 in the nozzle 400 is discharged.

  Here, in S601, as shown in FIG. 5B, since the ink 401 is not ejected as the ink droplet 405, the peeled kogation 406 floats in the nozzle 400. In such a state, if the formation and defoaming of air bubbles are repeated, the number of floating koga 406 increases, and the effect of peeling off the attached koga 403 may be reduced.

  In order to prevent the reduction of the peeling effect, in S604, when the pre-discharge foaming counter B reaches a predetermined number β, for example, 100,000 times (Yes), the floating kogation 406 becomes more than a predetermined value, and the peeling effect is reduced. It is determined that it has become less than the predetermined value. At this time, the process proceeds to S605, where the pressurization of the ink 401 is released. Specifically, the valve disposed in the communication path between the inside of the recording head 201 and the ink cartridge 205 is changed from the closed state to the open state. At this time, a valve (not shown) disposed in a communication path between the buffer in fluid communication with the tube pump and the inside of the recording head cap member is in a closed state. In step S606, the ink 401 in the nozzle is discharged by performing a suction recovery process using a tube pump. Specifically, first, the recording head is capped by the recording head cap member, and the air in the buffer is depressurized by rotating the tube pump in the other direction. After the pressure sensor detects that the inside of the buffer has reached a predetermined pressure Pr (<< Pc), the tube pump is stopped, and the valve disposed in the communication path between the buffer and the inside of the recording head cap member is closed. From the open state. Accordingly, the ink 401 including the floating kogation 406 is sucked and discharged from the nozzle opening 407 into the buffer via the inside of the recording head cap member, and a meniscus is formed in the nozzle opening 407. By discharging the floating kogation 406, the peeling effect can be returned to a predetermined value or more. Further, after the suction recovery is completed, the process proceeds to S607, the pre-discharge foaming counter B is cleared to zero, and the process proceeds to S608. On the other hand, when the pre-discharge foaming counter B has not reached the predetermined number β (No), the process proceeds to the confirmation processing S609 to S612 of the nozzle T temperature T.

  In step S608, when the total foaming counter A reaches a predetermined number of times α, for example, 300,000 times (Yes), it is determined that the kogation 403 has peeled off the heater unit 402 by a predetermined amount or more, and a state in which stable ink ejection can be performed. Then, the cleaning is completed. On the other hand, if the total foaming counter A has not reached the predetermined number of times α (No), the process proceeds to S600, where the ink 401 is pressurized in the ejection direction by a constant pressure to destroy the meniscus formed in the nozzle opening 407 in S606. Again.

Here, the confirmation processing S609 to S612 of the nozzle 400 temperature T will be described. When the formation of bubbles in S601 is repeated, the temperature T of the nozzle 400 rises, and there is a possibility that the electric circuit of the nozzle 400, the heater unit 402, and the like may break down. Therefore, a temperature that may lead to a failure, for example, 90 ° C., which is 10 ° C. lower than 100 ° C., is set as the limit temperature τ _l, and a countermeasure that does not exceed the limit temperature τ _l is required.

In order to perform the checking process of the nozzle 400 temperature T, in S609, if the nozzle 400 temperature T exceeds a limit temperature τ ₁ (first predetermined temperature), for example, 90 ° C. (Yes), a failure may be caused. Is determined to be present. At this time, the process proceeds to S610, and waits until the temperature T of the nozzle 400 drops to a temperature τ _m (second predetermined temperature) lower than the limit temperature τ _l by 10 ° C. or more, for example, 80 ° C. or less. On the other hand, when the nozzle 400 temperature T does not exceed the limit temperature tau _l (No), the process proceeds to S611.

In S611, if the temperature T of the nozzle 400 exceeds the temperature near the limit τ _n (third predetermined temperature), for example, 60 ° C. (Yes), the process proceeds to S612, and after waiting for a predetermined time, for example, 10 msec, proceeds to S601. The formation of the bubbles 404 is performed again. Thus, the temperature rise of the nozzle 400 by lengthening the formation period of the bubble 404 is suppressed to prevent the nozzle 400 temperature T exceeds the critical temperature tau _l. On the other hand, if the temperature T of the nozzle 400 does not exceed the temperature near the limit τ _n (No), the process proceeds to S601, and the formation of the bubble 404 is performed again.

(Second embodiment)
A second embodiment of the present invention will be described. Since the basic configuration of the second embodiment is the same as that of the first embodiment, the second embodiment will be described below focusing on parts different from the first embodiment.

  The ink ejection preventing means according to the second embodiment is performed by filling the inside of the recording head cap member 700 with the ejection preventing ink 500 as shown in FIG. Normally, in order to prevent the water content of the ink from evaporating from the nozzle opening 407 and increase the viscosity of the ink, the print head cap member 700 closes the nozzle opening 407 after the print head 201 stops at the home position. Capping. In this capping state, by filling the inside of the recording head cap member 700 with the ejection preventing ink 500, even if bubbles are formed in the heater section 402, the pressure of the ejection preventing ink 500 is temporarily increased. The ejection of 401 is suppressed. That is, ink consumption can be suppressed.

  In this embodiment, the means for filling the inside of the recording head cap member 700 with the ejection preventing ink 500 may heat the heater unit 402 to eject the ink droplets 405, or apply a pressure or suction recovery process to the cleaning pump. Alternatively, the ink 401 may be ejected. In the control flowchart according to the present embodiment, “press the ink in the ejection direction”, which is the ink ejection prevention unit of S600 in FIG. 6, is replaced with “fill the inside of the recording head cap member with the ejection prevention ink in the capping state”. Things. Similarly, the "release of ink pressurization" of S605 in FIG. 6 is replaced with "discharge of the discharge prevention ink in the recording head cap member".

(Third embodiment)
A third embodiment of the present invention will be described. Since the basic configuration of the third embodiment is the same as that of the second embodiment, the third embodiment will be described below focusing on parts different from the second embodiment.

  As shown in FIG. 8, in a state where the gap between the nozzle opening 407 and the comb tooth member 800 is close to each other, the ink discharge preventing means according to the third embodiment prevents the bridge-like discharge from being caused by surface tension in the close gap. This is performed by allowing the ink 500 to stay. In other words, the ink ejection preventing unit according to the third embodiment can be applied to a case where the comb tooth member 800 for preventing the ink 401 from splashing back to the nozzle opening 407 is mounted in the recording head cap member 700. Things. Usually, after printing is completed, the print head cap member 700 is arranged at a position facing the print head 201 or at a position where the nozzle opening 407 is capped, so that the nozzle opening 407 and the comb tooth member 800 Are close to each other. By keeping the bridge-shaped discharge prevention ink 500 in this gap, even if bubbles are formed in the heater unit 402, the discharge of the ink 401 is suppressed only by temporarily expanding the discharge prevention ink 501 due to surface tension, Ink consumption can be suppressed.

  In the present embodiment, as a means for forming the bridge-shaped ejection prevention ink 500, the heater unit 402 may be heated to eject the ink droplets 405, or the cleaning pump may perform pressure or suction recovery processing. Ink 401 may be ejected. The state in which the gap between the nozzle opening 407 and the comb tooth member 800 is close may be a non-capping state as shown in FIG. 8 or a capping state. In addition, the control flowchart in the present embodiment indicates that “press the ink in the ejection direction”, which is the ink ejection prevention unit of S600 in FIG. Formation). Similarly, "release of ink pressurization" in S605 of FIG. 6 is replaced with "deletion of bridge-like ink".

(Fourth embodiment)
A fourth embodiment of the present invention will be described. Since the basic configuration of the fourth embodiment is the same as that of the second embodiment, the fourth embodiment will be described below focusing on parts different from the second embodiment.

  The ink ejection preventing means in the fourth embodiment is performed by directly pressing the recording head cap member 900 against the nozzle opening 407 and sealing it as shown in FIG. In other words, the ink ejection preventing unit according to the fourth embodiment is not the one in which the recording head cap member 900 has a space capable of receiving the ejection preventing ink 500 (see FIG. 7), but can seal the nozzle opening 407. It is applicable when it is formed by. In the capping state, by directly sealing the nozzle opening 407 with the recording head cap member 900, even when bubbles are formed in the heater section 402, the ejection of the ink 401 is suppressed, and ink consumption can be suppressed.

  The control flowchart in this embodiment replaces “pressing ink in the ejection direction”, which is the ink ejection prevention unit of S600 in FIG. 6, with “pressing the recording head cap member directly against the nozzle opening and sealing”. Similarly, “Release the pressurization of ink” in S605 in FIG. 6 is replaced with “separate the recording head cap member from the nozzle opening”, and “Discharge ink in the nozzle” in S606 is a porous ink capable of absorbing ink. It is assumed that the ink is discharged toward the ink receiving member made of a high quality material or the like.

(Fifth embodiment)
A fifth embodiment of the present invention will be described. Since the basic configuration of the fifth embodiment is the same as that of the first embodiment, the fifth embodiment will be described below focusing on the differences from the first embodiment.

  In the first embodiment, as shown in FIG. 6, in S604, if the before-discharge foaming counter B does not reach the predetermined number of times β, for example, 100,000 times (No), the confirmation processing S609 to the nozzle 400 temperature T is performed. S612 and S601 to S603 are repeated. However, the ejection-preventing ink 500 (see FIG. 5) that has oozed out by pressurization drips due to gravity or vibration during bubble formation (S 601 in FIG. 6), and a meniscus is formed in the nozzle opening 407. There are cases (see FIG. 4A). If bubbles are formed (S601) in a state where the ejection preventing ink 500 is not present in the nozzle opening 407, the ink droplets 405 may be ejected similarly to the comparative example (see FIG. 4B). ). Here, by repeating the formation of the bubbles in S601 50,000 times, the ejection preventing ink 500 may drop. Therefore, in the fifth embodiment, as shown in FIG. 10, in S1000, the pre-pressurization foaming counter C whose initial value stored in the RAM 303 is zero is incremented by 1, and the process proceeds to S1001. In S1001, when the pre-pressurization foaming counter C has reached the predetermined number of times γ, for example, 50,000 times (Yes), the process proceeds to S600, where the ink 401 in the nozzle 400 is pressurized again by the constant pressure Pc, and the nozzle opening is opened. At 407, the ejection prevention ink 500 is formed. Thereafter, the process proceeds to S1002, where the pre-pressurization foaming counter C is cleared to zero. On the other hand, if the before-press foaming counter C has not reached the predetermined number of times γ (No), the flow proceeds to S604 because the ejection preventing ink 500 does not hang. With such a control flowchart, the ejection preventing ink 500 can be reliably formed in the nozzle opening 407, the ejection of the ink droplet 405 can be further suppressed, and the ink consumption can be suppressed.

  In the first and fifth embodiments, the threshold values of the total foam counter, the foam counter before discharge, and the foam counter before pressurization, the limit temperature of the nozzle temperature, and the temperature near the limit for the single ink 401 have been described. It is preferable to determine each threshold value and the like for each ink color.

101 Image Forming Apparatus Main Body 201 Recording Head 400 Nozzle 401 Ink 402 Heater 403 Burnt 404 Bubble 407 Nozzle Opening 408 Nozzle End 500 Discharge Prevention Ink 700, 900 Recording Head Cap Member (Cap Member)
800 Comb members

Claims (10)

A recording head comprising: a nozzle for discharging ink; and a heater unit provided in the nozzle for supplying thermal energy to the ink in the nozzle,
An ink ejection prevention unit for preventing ink ejection from the nozzle,
An ejection control unit for ejecting ink by generating a bubble in the nozzle by driving a heater unit of the recording head,
In a state where ink ejection is prevented by the ink ejection preventing unit, an ejection control unit that drives the heater unit to perform cleaning inside the nozzle,
An inkjet image forming apparatus comprising:   2. The ink jet image forming apparatus according to claim 1, wherein the ink ejection preventing unit applies ink to an end of the nozzle so as to cover an opening of the nozzle. Further comprising a cap member closing the opening of the nozzle,
2. The ink jet image forming apparatus according to claim 1, wherein the ink ejection preventing unit causes the ink filled in the cap member to contact an opening of the nozzle. Further comprising a cap member closing the opening of the nozzle,
2. The ink-jet image forming apparatus according to claim 1, wherein the ink ejection preventing unit forms a bridge-like ink between a part of the cap member and an opening of the nozzle.   2. The ink jet image forming apparatus according to claim 1, wherein the ink ejection preventing unit physically closes an opening of the nozzle.   After the ink ejection prevention means has prevented the ejection of ink, if the number of times the formation of bubbles has been performed by the ejection control means has reached a predetermined number, the ink ejection prevention means may again prevent the ejection of ink. The inkjet image forming apparatus according to claim 1 or 2, wherein:   If the temperature of the nozzle exceeds a first predetermined temperature during the cleaning, the cleaning by the discharge control unit is interrupted until the temperature of the nozzle drops below a second predetermined temperature lower than the first predetermined temperature. The inkjet image forming apparatus according to claim 1.   8. The method according to claim 1, wherein, when the temperature of the nozzle exceeds a third predetermined temperature during the cleaning by the ejection control unit, the cycle of forming bubbles is extended by the ejection control unit. The inkjet image forming apparatus according to claim 1.   During the cleaning by the ejection control means, when the amount of accumulated matter floating in the ink in the nozzle becomes a certain amount or more, the ink in the nozzle is discharged, and the accumulated matter is removed from the inside of the nozzle. The inkjet image forming apparatus according to claim 1, wherein:   The inkjet image forming apparatus according to claim 1, wherein energy supplied by the heater unit at the time of the cleaning is larger than energy supplied at the time of image formation.

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