JP2010017875A - Suction restoration method and inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suction restoration method reducing an amount of waste ink generated in the restoration treatment while keeping the suction restoration performance of an ink flow path, and an inkjet recording device. <P>SOLUTION: The inkjet recording device includes a recording head discharging ink droplets from a nozzle row, a cap member abutting on the nozzle row, an ink tank supplying ink to an ink chamber of the recording head, and the ink flow path feeding ink from the ink tank to the ink chamber. In the suction restoration method, the nozzle row of the inkjet recording device is subjected to a negative pressure generation process generating a negative pressure in the recording head via the cap member for suction restoration. In the negative pressure generation process, a flexible valve set between the ink chamber and ink flow path and a control valve controlling flow of gas and liquid of the negative pressure generation process are opened/closed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a suction recovery method and an ink jet recording apparatus, and more particularly to a suction recovery method and an ink jet recording apparatus that perform suction recovery by generating a negative pressure on a recording head via a cap member.

  In an inkjet recording apparatus, there is an off-carriage tank recording apparatus in which a main ink tank is not mounted on a carriage on which a recording head is mounted. In such a recording apparatus, a main ink tank connected to the recording head via a pipe such as a tube is arranged at a place other than the carriage. The off-carriage tank system does not require a large space on the carriage and can hold a large amount of ink to be supplied to the recording head without imposing a large load on the carriage. Therefore, the off-carriage tank system is suitable for an ink jet recording apparatus having a large capacity ink tank. In this configuration, since the positional relationship between the recording head and the ink tank can be set relatively freely, a negative pressure and a back pressure are often generated using a water head difference. On the other hand, since it is difficult to supply ink at high speed, a method is also used in which an ink tank is pressurized and ink is supplied to a recording head. In many cases, the ink filling or recovery process of the recording head is performed by a method in which the inside of the cap in contact with the recording head is decompressed.

  In the off-carriage tank type, since ink is filled through a tube, the volume that requires maintenance by the suction process increases. In addition, since the gas barrier property of the tube is relatively low among the members forming the ink flow path, moisture evaporation in the tube and bubble intrusion into the tube may occur. In addition, the ink liquid remaining in the tube flow path for a long time evaporates, causing the ink liquid to thicken and the ink flow in the ink flow path to be discontinuous due to air bubbles, so that the ink is not correctly fed to the recording head. There is. In particular, the pigment ink in which the pigment resin is dispersed tends to increase the viscosity of the ink. In addition, when bubbles mixed in the tube flow path move into the nozzles of the recording head, the foaming energy for ejecting ink may not be sufficiently transmitted to the ink, resulting in problems such as non-ejection.

  A tube with an improved gas barrier property is known in order to correct the adverse effects caused by the low gas barrier property. However, even if the gas barrier property of the tube is improved, it is difficult in terms of construction to make the air intrusion into the tube zero.

  In addition, when pigment ink is used, a phenomenon that the pigment resin settles in the ink liquid remaining in the tube for a long time occurs. When the settled pigment ink is used, a gradient of the colorant concentration in the ink is generated, so that the ink consumed first is dark and the ink consumed later becomes thin, which may cause a bad effect on the recording result.

  On the other hand, a method is known in which the ink in the ink flow path is collectively sucked and discarded. Further, a technique is known in which a flexible film-like valve is provided between the ink liquid chamber and the ink flow path, and the negative pressure in the ink liquid chamber is accumulated and released together with the nozzle suction means (for example, , See Patent Document 1). With such a technique, the ink in the ink flow path can be efficiently led out to the recording head, and bubbles can be prevented from entering the recording head.

JP 2006007493 A

  However, in the above-described technique, the ink drawn out to the recording head is sucked and discarded, so that the amount of waste ink increases. As a result, a large amount of ink is consumed, and the running cost cannot be reduced.

  The present invention has been made in view of the above points, and provides a suction recovery method and an ink jet recording apparatus capable of reducing the amount of waste ink generated in the recovery process while maintaining the suction recovery performance of the ink flow path. With the goal.

  In order to achieve the above object, the present invention provides a recording head that ejects ink droplets from a nozzle row, a cap member that contacts the nozzle row, an ink tank that supplies ink to an ink liquid chamber of the recording head, A negative pressure generating step of generating a negative pressure on the recording head via the cap member, the nozzle row of the ink jet recording apparatus having an ink flow path for sending ink from the ink tank to the ink liquid chamber; A suction recovery method for performing suction recovery of the recording head, wherein the negative pressure generating step includes a flexible valve provided between the ink liquid chamber and the ink flow path, and a negative pressure generating means. A control valve for controlling the flow of gas and liquid is opened and closed.

  According to the above configuration, it is possible to maximize the suction amount for removing thickened ink and bubbles in the ink tube, sub tank, and ink jet recording head per unit time. As a result, it is possible to reduce the amount of waste ink generated by the recovery while maintaining the recovery performance.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram showing an ink jet recording apparatus used in the present embodiment. A recording head 5 that ejects ink droplets is mounted on a carriage 6. The recording head 5 has a recording head portion provided with a plurality of recording elements for ejecting ink as droplets. Further, the recording head 5 has an ink tank portion (sub tank) for holding ink fed from the main tanks 3C, 3M, 3Y and 3K and for replenishing each recording element with ink.

  Further, the recording head 5 is provided with a connector for transmitting and receiving a signal for driving the recording head portion, and the carriage 6 has a connector holder for transmitting a driving signal and the like to the recording head 5 through the connector. Is provided.

  The carriage 6 is guided and supported by a guide shaft 9, and can reciprocate in the main scanning direction along the direction in which the guide shaft 9 extends. The carriage 6 is moved by the main scanning motor 11 through drive mechanisms such as the motor pulley 12, the driven pulley 18 and the timing belt 10, and the position and amount of movement of the carriage 6 are controlled.

  Before the start of recording, the recording medium 14 is stacked on the auto sheet feeder 15. When recording is started, the paper feed motor 13 is driven, and this driving force is transmitted to the pickup roller 16 via a gear. As a result, the pickup roller 16 rotates, and the recording medium 14 is separated from the auto sheet feeder 15 one by one and fed into the recording apparatus. The fed recording medium 14 is transported by the rotational force of the transport roller 8. The transport roller 8 is rotated by the rotational force generated by the transport motor 24 being transmitted by a gear. Further, the conveying roller 8 and the driven roller 7 are connected by the belt member 22, and the driven roller 7 is rotated by the rotation of the conveying roller 8. The rotation amount and rotation speed of the conveyance roller are detected by confirming the position of a slit carved in the code wheel 23 attached to the conveyance roller by a rotation angle sensor (not shown), and the information is obtained from the conveyance motor 24. It is controlled by being fed back to the control driver. When the recording medium 14 is conveyed between the conveying roller 8 and the driven roller 7, the recording medium 14 is smoothly supported by the platen 19 so as to form a flat recording surface at the discharge port surface. When the recording medium 14 passes below the discharge main port surface, the recording head 5 ejects ink to the recording medium 14 according to a predetermined image signal. The pinch roller 17 and the spur roller 21 are auxiliary rollers for increasing the holding force of the recording medium 14. An ink absorber 20 is provided between the transport roller 8 and the driven roller 7. Since the ink overflowed during borderless recording is absorbed by the ink absorber 20, contamination of the platen can be prevented.

  A suction cap 26 for capping the nozzle is brought into contact with the nozzle in order to prevent the nozzle from drying during non-recording. The suction pump 25 is a pump for sucking ink in the nozzles through the suction cap 26.

  The main tanks 3C, 3M, 3Y and 3K and the recording head 5 are connected by tube flow paths 4C, 4M, 4Y and 4K for each color. The ink can be supplied from the main tanks 3C, 3M, 3Y and 3K to the recording head 5 through the flow paths 4C, 4M, 4Y and 4K. When supplying ink, the main tanks 3C, 3M, 3Y and 3K are pressurized by the pressurizing pump 1, and ink is fed to the recording head 5 through the tube flow paths 4C, 4M, 4Y and 4K. The main tank 3 has atmospheric communication valves 2C, 2M, 2Y and 2K for each tank, and the presence or absence of pressurization can be controlled.

  FIG. 2 is a detailed view showing the main tank in detail. The pressure pump 1 is used in common for the cyan ink tank 3C, the magenta ink tank 3M, the yellow ink tank 3Y, and the black ink tank 3K. The ink tanks 3C, 3M, 3Y and 3K have ink bags 31C, 31M, 31Y and 31K. Each ink tank is provided with atmospheric communication valves 2C, 2M, 2Y and 2K. Further, gaps 32C, 32M, 32Y and 32K are provided between the ink bags 31C, 31M, 31Y and 31K and the tank wall. The pressurizing pump 1 is connected to the gaps 32C, 32M, 32Y and 32K. Tubes 4C, 4M, 4Y and 4K are connected to the ink bags 31C, 31M, 31Y and 31K and are connected to the recording head 5.

  Here, since the functions of the ink tanks of the respective colors are the same, the cyan ink tank 3C will be described.

  First, the pressurizing pump 1 is pressurized with the atmospheric communication valve 2C closed. Then, the air in the gap 32C between the ink bag 31C and the ink tank 3C is pressurized and presses the ink bag 31C. By pressing the ink bag 31C, the ink inside is sent to the recording head 5 through the tube 4C. Here, when the atmosphere communication valve 2C is opened, the air in the gap 32C between the ink bag 31C and the ink tank 3C becomes atmospheric pressure, so the ink bag 31C is not pressurized.

  In the recording apparatus of this embodiment, since the atmosphere communication valve can be controlled to open and close for each ink tank, the presence or absence of pressurization for each ink tank can be controlled. In addition, you may provide the pressure detection means 35C, 35M, 35Y, and 35K for each ink tank or supply path. Based on the output results of the pressure detection means 35C, 35M, 35Y and 35K, it can be used as a supply pressure adjustment or as a timing trigger at the time of cleaning.

  FIG. 3 is a detailed view showing the carriage 6 in detail. The carriage 6 has sub tanks 6C, 6M, 6Y, and 6K that serve as ink liquid chambers that hold ink and supply ink to the recording head 5 for each ink color. The sub tanks 6C, 6M, 6Y and 6K are necessary for maintaining a negative pressure in the recording head and supplying an appropriate ink. The sub tanks 6C, 6M, 6Y and 6K are provided with tube flow paths 4C, 4M, 4Y and 4K through which ink is fed from the main tanks 3C, 3M, 3Y and 3K.

  Next, the interior of the sub tank (ink liquid chamber) will be described in detail.

  FIG. 4 is a detailed view showing details of the cyan sub tank 6C. A recording nozzle 51 is provided in the sub tank 6C. The interior of the sub tank 6C is configured to maintain a negative pressure by the spring bag 52 and the spring 53 biased in the direction of expanding the spring bag. The tube 4C connected to the ink bag 32C of the main tank 3C is connected to the sub tank 6C by a joint 56. A flexible valve (choke valve) 54 is provided at a port to which ink is supplied, and the valve opens when pressurized from the tube 4C side. Further, in order to make the amount of ink in the sub tank appropriate, a supply restriction valve 57 is provided. When the ink is consumed and the spring 53 contracts, the lever is pushed in the direction of the arrow in the figure to open the supply restriction valve 57. Then, the ink is introduced into the sub tank, and the supply restriction valve 57 is closed when the sub tank is filled with ink.

  FIG. 5 is a diagram showing an outline of the recording head 5 as viewed from the nozzle side of the present embodiment. Each nozzle of C, M, Y and K is arranged on one chip 101. The nozzle hole interval of each nozzle row is 600 dpi. The cap 26 that comes into contact is sized to cover the chip 101.

  The recording head 5 of the present embodiment is an ink jet recording head that discharges ink using thermal energy, and includes a plurality of electrothermal transducers for generating thermal energy. Specifically, thermal energy is generated by a pulse signal applied to the electrothermal transducer, and film boiling occurs inside the ink liquid by this thermal energy. Further, the ink is discharged from the ejection port using the foaming pressure of film boiling. Recording is performed by discharging.

  Next, the suction pump of this embodiment will be described.

  FIG. 6 is a detailed view showing details of the suction pump. In the suction pump 25, when the shaft 61 on which the roller 60 is arranged rotates in the direction of the arrow, the suction tube 62 of the portion held by the roller 60 and the guide 66 is sequentially crushed. Cause a degree of vacuum. As a result, the recording head 5 is depressurized through the cap 26 and sucks ink from the ink discharge nozzles by generating negative pressure. This suction amount is controlled by the rotation speed and rotation speed of the roller 60 defined in advance. After the predetermined number of rotations is performed, the pump drive is stopped. Next, the cap is opened or the atmosphere release valve 64 is opened to open the inside of the cap to atmospheric pressure.

  A charge valve 63 is provided in the suction tube 62. The charge valve 63 is a control valve for controlling the flow of gas and liquid in the tube 62. If the charge valve 63 is closed when the shaft 61 on which the roller 60 is arranged rotates in the direction of the arrow, the degree of pressure reduction on the roller side increases from the charge valve of the tube 62. Next, by opening the charge valve 63 at a predetermined rotational speed or when the pressure reduction degree is reached, a suction process with a high pressure reduction degree can be performed when the recording head 5 does not use the charge valve via the cap. As a method of the charge valve, a tube may be mechanically pressed and sealed, or an electromagnetic valve may be provided. From the viewpoint of cost and size, a method of mechanically pressing the tube is preferable.

  Next, the recovery sequence used in this embodiment will be described.

  FIG. 7 is a flowchart showing a recovery sequence used in the present embodiment. When cleaning is started (S701), an appropriate cleaning strength is selected from preset cleaning strengths (S702). The selection of the cleaning intensity is selected according to the non-recording time, the resting time of the recording apparatus, the situation after the main tank replacement or the replacement of the ink jet recording head, the number of ejection dots, and the like.

  FIG. 8 is a table showing an example of the preset cleaning mode selected in S702. In the table of FIG. 8, the suction pump drive (1), the suction pump drive (2), the number of repetitions of the suction control, the preliminary discharge (1), and the preliminary discharge (2) performed in the recovery sequence of the present embodiment are as follows. It is predetermined according to the cleaning strength. That is, according to the cleaning strength, the suction amount, the number of slits, the suction time, the internal pressure, the number of rotations of the pump, etc. performed by the suction pump drive (1) and the suction pump drive (2) B or suction C is predetermined. Further, according to the cleaning intensity, the number of ejections per one nozzle performed in the preliminary ejection (1) and the preliminary ejection (2), the ejection pattern, or the like is preset as the preliminary ejections S4, S5, and S6. In this embodiment, the suction performed by the suction pump drive (1) is defined as suction A or suction B, and the suction performed by the suction pump drive (2) is defined as suction C. The suction A, the suction B, and the suction C may be determined in advance for the suction amount or the rotation amount of the pump, and may be determined each time before performing the recovery sequence.

  In step S702, when the cleaning 1 is selected and the cleaning 1 flag is set, the cap 26 is closed (S703). Next, driving of the suction pump is started (S704). When cleaning 1 is selected, the suction pump drive (1) is a suction amount determined as suction A or the like. In the suction pump drive (1) at this time, the charge valve 63 provided in the pump is opened, and ink is sucked from the suction cap. Further, the pressure pump 1 on the main tank side is set in a non-driven state, or the valves 2C, 2M, 2Y and 2K are set in an open state so that ink is not supplied to the recording head. That is, the ink starts to flow out from the sub tank by suction, but since the ink is not supplied from the main tank, the flexible valve (choke valve) 54 provided in the sub tank is closed. This state is maintained for a predetermined time and the pressure reduction degree on the nozzle side from the choke valve is increased to a predetermined pressure.

  Next, the charge valve 63 is closed (S705). This state is maintained for a predetermined time, and the pressure reduction degree on the pump side from the charge valve 63 is increased to a predetermined pressure.

  Next, the choke valve 54 is opened (S706). In order to open the choke valve 54, the pressure pump 1 on the in-tank side is driven, or the valves 2C, 2M, 2Y and 2K are closed and ink supply is started. In this case, since the main purpose is to improve the recoverability in the recovery process, the supply pressure is rapidly increased by closing the valves 2C, 2M, 2Y and 2K from the state in which the pressure pump 1 is driven in advance. It is possible and suitable. Since ink supply is started and the flexible valve (choke valve) 54 is opened, thickened ink, bubbles, etc. in the ink flow path start to flow into the sub tank 53.

  Next, the charge valve 63 is opened (S707). As a result, discharge of thickened ink and bubbles from the sub tank 6 through the suction cap is started.

  Next, after a predetermined time has elapsed, the atmosphere is released (S708). Opening to the atmosphere is possible by releasing the cap, but considering the certainty of opening and time management, it is preferable to use the air release valve provided in the cap.

  Thereafter, idle suction for discharging the waste ink in the cap and preliminary discharge for discharging the mixed color ink in the nozzle are performed (S709). In this preliminary discharge, preliminary discharge after standby for 1.5 seconds is performed as preliminary discharge S4, and preliminary discharge after standby for 0.5 seconds is performed as preliminary discharge S4. Then, wiping for contacting and cleaning the face surface that constitutes the nozzles of the ink jet recording head is performed (S710), and after wiping, preliminary ejection after waiting for 1 second is performed as preliminary ejection S5 (S711). Preliminary discharge S5 is performed (S712), empty suction in the cap is performed (S713), and the process ends (S714).

  If it is determined in step S702 that stronger cleaning than cleaning 1 is necessary and cleaning 2 is selected, the suction control when cleaning 1 is selected is repeated a plurality of times.

  When the cleaning 2 is selected (S702), the cleaning 2 flag is set and the cap 26 is closed (S715). Next, driving of the suction pump is started (S716). When cleaning 2 is selected, the suction pump drive (1) is suction A as in cleaning 1. In the suction pump drive (1) at this time, the charge valve 63 provided in the pump is opened, and the choke valve 54 is closed (S716). Next, the charge valve 63 is closed, and the suction pump continues to be driven (S717). Then, the choke valve 54 is opened to start choke cleaning (S718). Next, the charge valve 63 is opened and charge cleaning is started (S719). Thereafter, the air is released after a predetermined time (S720).

  When the cleaning 2 is selected, the processes from step S716 to step S720 are repeated a plurality of times (N times). The number N of repetitions is 2 in this embodiment.

  After the processes from step S716 to step S720 are repeated a plurality of times (N times), the process of step S709 is performed.

  If it is determined in step S702 that cleaning stronger than cleaning 1 is necessary, and cleaning 3 or 4 is selected, the process proceeds to step S722. When the cleaning 3 or 4 is selected (S702), the cleaning 3 or 4 flag is set and the cap 26 is closed (S722).

  Next, driving of the suction pump is started (S723). If cleaning 3 or 4 is selected, the suction pump drive (1) is suction C. In the suction pump drive (1) at this time, the charge valve 63 provided in the pump is opened, and the choke valve 54 is also opened (S723). That is, ink is supplied from the main tank. This is continued for a predetermined time. This state is a suction recovery state using the simplest tube pump.

  Next, only the choke valve 54 is closed (S724). That is, the supply of ink from the main tank is stopped. As a result, the degree of pressure reduction on the nozzle side increases from the choke valve described above. Steps S723 and S724 are repeated a plurality of times (N times) (S725). The number N of repetitions is one when the cleaning 3 is selected in this embodiment, and is two when the cleaning 4 is selected. By repeating this, an intermittent suction waveform can be given to the tube, sub tank, and ink nozzle by the opening / closing operation of the choke valve 54.

  Next, the cleaning mode is identified (S726). In the present embodiment, in the case of the cleaning mode 3, the process proceeds to step S708. Note that preliminary ejections (1) and (2) when cleaning 3 is selected are both preliminary ejections S5. On the other hand, in the case of the cleaning mode 4, the process proceeds to step S727.

  If cleaning 4 has been selected, cleaning is started again. First, driving of the suction pump is started (S727). When cleaning 4 is selected, the suction pump drive (2) is suction C. In the suction pump drive (2) at this time, the charge valve 63 provided in the pump is opened and the choke valve 54 is closed (S727). Next, the charge valve 63 is closed, and the suction pump continues to be driven (S728). Then, the choke valve 54 is opened and choke cleaning is started (S729). Next, the charge valve 63 is opened and charge cleaning is started (S730).

  When the cleaning 4 is selected, these steps S727 to S730 are repeated M times. The number M of repetitions is one in this embodiment.

  After the process from step S727 to step S730 is repeated M times, the process of step S709 is performed.

  Note that the preliminary discharges (1) and (2) when the cleaning 4 is selected are the preliminary discharge S5 and the preliminary discharge S6.

  As described above, suction recovery is performed by combining the opening and closing operations of the flexible valve and the control valve a plurality of times. As a result, it is possible to maximize the suction amount for removing thickened ink and bubbles in the ink tube, sub tank, and ink jet recording head per unit time. Therefore, it is possible to reduce the amount of waste ink generated by the recovery while maintaining the recovery performance.

  In the present embodiment, the suction pump 25 is sucked in a predetermined amount until the charge cleaning is completed after the suction pump 25 is driven in steps S704, S716, S723, and S727. However, the present invention is not limited to this. That is, after starting the suction pump 26, the suction amount may be changed at timings such as after opening and closing of the valve, and the suction amount is changed by measuring the internal pressure. Also good. In addition, the suction pressure, the suction amount, each charge pressure, and each choke pressure in each suction process can be set individually.

(Second Embodiment)
In the first embodiment, the inkjet recording apparatus has been described in which the nozzle is one chip and the cap for capping the nozzle is one, but the present invention is not limited to this. That is, the present invention can also be applied to an inkjet recording apparatus provided with a plurality of nozzle tips and caps.

  In this embodiment, an ink jet recording apparatus will be described as an example in which the nozzle has two chips and the cap for capping the nozzle is two.

  FIG. 9 is a configuration diagram showing the entire inkjet recording apparatus of the present embodiment. Unlike the first embodiment, there are two caps 27 and 28 for capping the nozzle, and the rest is the same as the recording apparatus of the first embodiment.

  FIG. 10 is a diagram showing an outline of the recording head 5 as viewed from the nozzle side of the present embodiment. The C and M nozzles are arranged on one chip 201, and the Y and K nozzles are arranged on one chip 202. The nozzle hole interval of each nozzle row is 600 dpi. The abutting cap 27 covers the chip 201, and the cap 28 covers the chip 202.

  FIG. 11 is a flowchart showing a recovery sequence used in this embodiment. When cleaning is started (S1101), an appropriate cleaning strength is selected for each suction cap from preset cleaning strengths (S1102). The cleaning strength is selected for each cleaning cap in accordance with the non-recording time, the rest time of the recording apparatus, the situation after the main tank replacement or the ink jet recording head replacement, the number of ejection dots, and the like.

  For example, when the nozzle chip corresponding to the suction cap 27 selects the cleaning 1 shown in FIG. 8, steps S1103 to S1114 shown in FIG. 11 are performed. When the nozzle chip corresponding to the suction cap 28 is selected as the cleaning 3 shown in FIG. 8, the steps S1108 to S1114 are performed through the steps S1122 to S1126 shown in FIG. At this time, it is preferable from a time point of view that the processes from step S1103 to S1107 and the processes from step S1122 to step S1126 are performed in parallel.

  With the above configuration, further optimized cleaning can be performed, and the amount of waste ink generated by recovery can be reduced while maintaining recovery performance.

  In addition, the process of step S1103 to S1114 of this embodiment respond | corresponds to the process of step S703 to S714 of 1st Embodiment. Further, steps S1115 to S1121 of the present embodiment correspond to steps S715 to S721 of the first embodiment. Furthermore, steps S1122 to S1131 of the present embodiment correspond to steps S722 to S731 of the first embodiment.

  Although the present embodiment has been described with two suction caps, the present invention is not limited to such a configuration. That is, one suction cap may be provided for each color nozzle row. Further, suction caps may be provided for the color ink nozzle rows and the black ink nozzle rows.

  That is, it is possible to optimize the cleaning by determining the suction intensity of each nozzle row for a plurality of suction caps and performing a recovery sequence.

(Third embodiment)
In the present invention, in addition to the first and second embodiments, a normal cleaning process, that is, a non-chalk suction process that is a normal suction process without using a choke valve may be performed.

  FIG. 12 is a flowchart showing a recovery sequence used in this embodiment. When cleaning is started (S1201), an appropriate cleaning intensity is selected from preset cleaning intensity (S1202). Then, before proceeding to the cleaning process based on the selected cleaning intensity, the chalkless cleaning is executed (S1232, S1233, S1234). In addition, after the cleaning process based on the selected cleaning intensity is completed, chalkless cleaning is performed (S1235).

  FIG. 13 is a flowchart showing a non-chalk suction step. Choke-free suction is started (S1301). Next, the suction-side pump is driven with the choke valve 54 in the open state, that is, the state where the ink supply is continued (S1302). At this time, the charge valve 63 may or may not be operated. Further, the presence or absence of the charging operation may be combined. Then, small empty suction is performed (S1303), wiping is performed (S1304), 1 second standby preliminary discharge is performed (S1305), preliminary discharge is performed (S1306), empty suction is performed (S1307), and chokeless suction is terminated. (S1308). Note that the suction operation (S1302) and the small space suction (S1303) may be repeated a plurality of times (n times). Further, the 1-second standby preliminary discharge (S1305) and the preliminary discharge (S1306) may be repeated a plurality of times (m times).

  In this embodiment, chokeless cleaning is performed before and after the cleaning process based on the selected cleaning intensity (S1232, S1233, S1234, S1235), but the present invention is limited to this. Not. Chalkless cleaning may be performed before or after the cleaning process based on the selected cleaning intensity. That is, with the flexible valve maintained in an open state, the operation of opening and closing the control valve a plurality of times to generate a negative pressure on the recording head may be performed at least before and after the cleaning process.

(Other)
In the above-described embodiment, the pump driving of each suction step is performed for a predetermined time, but the present invention is not limited to driving the pump for a predetermined time. That is, the pump drive time may be determined by detecting the pressure in each path and controlling the pump drive with a predetermined pressure, and then proceeding to the next step. Further, although the choke valve 54 is disposed in the vicinity of the sub tank, in the present invention, the valve may be disposed at any position in the ink flow path between the sub tank and the main tank of the ink jet recording head. The valve in the ink flow path is a flexible valve (choke valve) 54 that operates according to the pressure in the flow path, but may be a valve that is connected to a drive source and operates regardless of the pressure.

  In the above embodiment, the ink jet recording apparatus has been described. However, the present invention can be applied to a facsimile machine, a copier, a word processor, a multi-function machine, or the like to which the ink jet recording apparatus is applied, in addition to the ink jet recording apparatus.

1 is a schematic diagram illustrating an ink jet recording apparatus used in a first embodiment of the present invention. It is detail drawing which shows the main tank of 1st Embodiment of this invention in detail. It is detail drawing which shows the carriage of 1st Embodiment of this invention in detail. It is detail drawing which shows the detail of the cyan sub tank of 1st Embodiment of this invention. FIG. 2 is a diagram illustrating an outline of a recording head viewed from a nozzle side according to the first embodiment of the present invention. It is detail drawing which shows the detail of the suction pump of 1st Embodiment of this invention. It is a flowchart which shows the recovery sequence of 1st Embodiment of this invention. It is a table | surface which shows an example of the preset cleaning mode selected in 1st Embodiment of this invention. It is a block diagram which shows the whole inkjet recording device of 2nd Embodiment of this invention. It is a figure which shows the outline of the recording head seen from the nozzle side of 2nd Embodiment of this invention. It is a flowchart which shows the recovery sequence of 2nd Embodiment of this invention. It is a flowchart which shows the recovery sequence of 3rd Embodiment of this invention. It is a flowchart which shows the chalk-less suction process of 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump 5 Recording head 6 Carriage 3C, 3M, 3Y, 3K Main tank 4C, 4M, 4Y, 4K Tube flow path 6C, 6M, 6Y, 6K Sub tank 25 Suction pump 26 Suction cap 54 Choke valve 63 Charge valve

Claims (11)

A recording head that ejects ink droplets from the nozzle array; a cap member that contacts the nozzle array; an ink tank that supplies ink to the ink liquid chamber of the recording head; and ink that is supplied from the ink tank to the ink liquid chamber. A suction recovery method for recovering suction of the recording head by a negative pressure generating step of generating a negative pressure in the recording head via the cap member, in the nozzle row of the ink jet recording apparatus having an ink flow path for feeding Because
The negative pressure generating step opens and closes a flexible valve provided between the ink liquid chamber and the ink flow path, and a control valve for controlling the flow of gas and liquid in the negative pressure generating means. A suction recovery method characterized by operating.   The suction recovery method according to claim 1, wherein the negative pressure generating step combines opening / closing operations of the flexible valve and the control valve a plurality of times.   The negative pressure generating step includes a first step of closing the flexible valve and opening the control valve, and a closing state of the control valve while keeping the flexible valve closed. 2. A second step of performing, and a third step of bringing the control valve from the closed state to the open state after the flexible valve is opened from the closed state. Item 3. The suction recovery method according to Item 2.   The suction recovery method according to claim 3, wherein the first step, the second step, and the third step are repeated a plurality of times.   Before the negative pressure generating step, the control valve is opened and closed a plurality of times with the flexible valve maintained in an open state to generate a negative pressure on the recording head. The suction recovery method according to any one of claims 1 to 4.   The negative pressure is generated in the recording head by performing the opening and closing operation of the control valve a plurality of times after the negative pressure generating step while the flexible valve is kept open. The suction recovery method according to any one of claims 1 to 4.   2. The negative pressure is generated in the recording head by maintaining the flexible valve in an open state and maintaining the control valve in an open state before the negative pressure generating step. The suction recovery method according to claim 6.   2. The negative pressure is generated in the recording head by maintaining the flexible valve in the open state and maintaining the control valve in the open state after the negative pressure generating step. Item 7. The suction recovery method according to any one of Items 6.   9. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus includes a plurality of cap members that contact the nozzle rows, and the negative pressure generating step is performed for each cap member. The suction recovery method described. A recording head that ejects ink droplets from the nozzle array; a cap member that contacts the nozzle array; an ink tank that supplies ink to the ink liquid chamber of the recording head; and ink that is supplied from the ink tank to the ink liquid chamber. An ink jet recording apparatus comprising: an ink flow path for feeding; and suction recovery means for performing suction recovery of the recording head by a negative pressure generating means for generating a negative pressure on the recording head via the cap member. ,
The suction recovery means is configured to supply ink to the ink liquid chamber by pressurizing the ink liquid in the ink tank and a flexible valve provided between the ink liquid chamber and the ink flow path. An ink supply means and a control valve for controlling the flow of gas and liquid in the negative pressure generating means, and controlled by opening and closing the flexible valve and the control valve. An ink jet recording apparatus.   The ink jet recording apparatus according to claim 10, wherein the suction recovery unit combines opening / closing operations of the flexible valve and the control valve a plurality of times.

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