JP2020192793A - Inkjet recording device - Google Patents

Abstract

To reduce occurrence of poor images caused by stain on a sheet.SOLUTION: An inkjet recording device comprises a recording head 36, wiper members 821, cleaning liquid supply parts 83, a cleaning liquid flow path 87 and a control part. The cleaning liquid flow path 87 comprises vertical tubular members 871 connected to the cleaning liquid supply parts 83 and extended upward, and lateral tubular members 872 connected to upper end sides of the vertical tubular members 871 and extended in a horizontal direction. The control part controls deforming operation by which cleaning liquid 831 of quantities equal to 0.5 times or more and 0.9 times or less of the total volumes of the cleaning liquid supply parts 83 and the vertical tubular members 871 is pushed out through a cleaning liquid supply port 834 and cleaning liquid supply surfaces 865 of the cleaning liquid supply parts 83 are wiped with the wiper members 821, before controlling cleaning operation of cleaning an ink discharge surface 361 of the recording head 36.SELECTED DRAWING: Figure 5

Description

The present invention relates to an inkjet recording apparatus, and more particularly to a technique for cleaning an ink ejection surface of a recording head.

For example, there is an inkjet recording device that ejects ink from a nozzle of a recording head onto a recording medium such as paper and records an image on the recording medium. The ink column ejected from the nozzle of the recording head is divided into a main droplet and a very small droplet (that is, mist). This mist is greatly affected by air resistance and transport wind, and therefore adheres to the nozzle surface of the recording head. When this adhered mist is water-based ink, it dries gradually and adheres firmly to the nozzle surface. Therefore, a general cleaning method, that is, the ink is extruded from the nozzle (purge), and then a rubber wiper is used. It is difficult to completely remove the mist by the cleaning method of wiping the nozzle surface several times with.

Therefore, in Patent Document 1 below, a cleaning liquid supply unit having a cleaning liquid supply surface having a cleaning liquid supply port for supplying the cleaning liquid is provided on the upstream side of the nozzle surface of the recording head in the wiping movement direction of the wiper, and ink is applied from the nozzle. An inkjet recording device having a mechanism for wiping the nozzle surface with a wiper provided with a cleaning liquid from a cleaning liquid supply port after purging has been proposed. According to this mechanism, the mist adhering to the nozzle surface is removed by wiping the nozzle surface with a wiper soaked with a cleaning liquid.

Japanese Unexamined Patent Publication No. 2018-089829

However, in the above-mentioned inkjet recording apparatus described in Patent Document 1, although the mist adhering to the nozzle surface is removed by the mechanism of wiping the nozzle surface with a wiper soaked with a cleaning liquid, the cause is unknown due to paper stains. There is a problem that image defects may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the occurrence of image defects due to paper stains.

Through diligent research by the inventors, we have identified a causal relationship with the occurrence of image defects due to unexplained paper stains. For example, bubbles may be generated or air may enter the cleaning liquid in the tube connected to the cleaning liquid supply port. Since the cleaning liquid in the cleaning liquid supply port and the tube is supplied in only one direction, if there is air in the cleaning liquid supply port or the tube, the only way to eliminate the air is to push it out. In a normal head cleaning operation, since the amount of cleaning liquid discharged from the cleaning liquid supply port is small, it is not possible to completely expel air bubbles every time, and the air bubbles that occasionally come out become bubbles at the cleaning liquid supply port, and the cleaning liquid containing bubbles is discharged. If the nozzle surface is wiped off with the attached wiper, bubbles with a height will be left at the end of wiping. It was found that when the height of the recording head and the paper at the time of image formation is the narrowest, for example, 1.0 mm, the bubbles come into contact with the paper and cause an image defect. Therefore, the inventors have conceived a configuration for controlling the bubble removal operation of removing bubbles in the cleaning liquid flow path by pushing out the cleaning liquid in the cleaning liquid flow path. Then, it was found that the control of the bubble removing operation is effective. Further, the cleaning liquid flow path is composed of a vertical tubular member extending upward from the cleaning liquid supply portion and a horizontal tubular member connected to the upper end side of the vertical tubular member and extending in the horizontal direction, whereby the vertical tubular member and the horizontal tubular member are formed. From the experimental data, we obtained the control conditions that can separate the air bubbles and can suitably realize the air bubble removal control while suppressing the supply amount of the cleaning liquid.

The present invention has been made based on the above findings, and the inkjet recording apparatus according to one aspect of the present invention is in contact with a recording head having an ink ejection surface having an ink ejection port for ejecting ink and the ink ejection surface. A wiper member that wipes the ink ejection surface by moving in a predetermined wiping direction, and a cleaning liquid supply surface having a cleaning liquid supply port that supplies the cleaning liquid used for wiping the ink ejection surface by the wiper member are provided. , A cleaning liquid supply unit provided on the upstream side of the ink ejection surface in the wiping direction, a cleaning liquid storage unit that stores the cleaning liquid, and a cleaning liquid flow for guiding the cleaning liquid from the cleaning liquid storage unit to the cleaning liquid supply unit. A drive unit that moves the cleaning liquid in the passage and the cleaning liquid flow path to give a power to push out the cleaning liquid from the cleaning liquid supply port, and a control of a cleaning operation in which the ink ejection surface is wiped by the wiper member using the cleaning liquid. A control unit that controls the bubble removing operation executed before the control of the cleaning operation is provided, and one end of the cleaning liquid flow path is connected to the cleaning liquid supply unit, and one end to the other end of the cleaning liquid flow path. The control includes a vertical tubular member extending above the cleaning liquid supply unit, and a horizontal tubular member having one end connected to the upper end side of the vertical tubular member and extending horizontally from one end to the other end. In order to control the bubble removing operation, the unit extrudes (i) a cleaning liquid of 0.5 times or more and 0.9 times or less the total volume of the cleaning liquid supply unit and the vertical tubular member from the cleaning liquid supply port. (Ii) The wiper member is moved in the wiping direction from a movement start position which is a position upstream of the cleaning liquid supply surface in the wiping direction to a position in front of the ink ejection surface, and (iii) the wiper member is moved. It controls the separation from the cleaning liquid supply surface.

According to the present invention, it is possible to reduce the occurrence of image defects due to paper stains.

It is a schematic cross-sectional front view which showed the structure of the inkjet recording apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the state which the transport unit moved to the lower maintenance position, and the cleaning part moved to the position just below a recording part. It is a functional block diagram which roughly showed the main internal structure of the inkjet recording apparatus which concerns on 1st Embodiment. (A) is a view showing the recording unit and the transport unit, and (B) is a view of the transport unit and the recording unit as viewed from above. (A) is a partially broken side view showing a state in which the ink tray and the wiper unit of the cleaning unit are arranged below the recording unit, and (B) is a view of the ink ejection surface of the recording head. It is a figure which showed typically the cleaning liquid flow path for supplying the cleaning liquid to one line head. (A) is a flowchart showing an example of the processing performed by the inkjet recording apparatus according to the first embodiment, and (B) is a flowchart showing an example of the whole system bubble removing process. (A) to (E) are partially broken side views for explaining the bubble removing operation performed before the cleaning operation. (A) to (E) are partially broken side views for explaining a cleaning operation. It is a figure which shows the result of the experimental data of the vertical tube bubble removal. It is a figure which shows the result of the experimental data of the whole system bubble removal. It is a functional block diagram which roughly showed the main internal structure of the inkjet recording apparatus which concerns on 2nd Embodiment.

Hereinafter, the inkjet recording apparatus according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional front view showing the configuration of an inkjet recording device according to the first embodiment of the present invention. FIG. 2 is a diagram showing a state in which the transport unit has moved to a lower maintenance position and the cleaning unit has moved to a position directly below the recording unit. The inkjet recording device 1 is a multifunction device having a plurality of functions such as a copy function, a printer function, a scanner function, and a facsimile function. The device main body 11 includes an operation unit 47, a document feeding unit 6, and a document. It includes a reading unit 5, an image recording unit 12, a paper feeding unit 14, a paper transport unit 19, a transport unit 125, and a cleaning unit 8.

The operation unit 47 receives instructions such as an image recording operation execution instruction from the operator for various operations and processes that can be executed by the inkjet recording device 1. The operation unit 47 includes a display unit 473 that displays operation guidance and the like to the operator. The display unit 473 is a touch panel, and the operator can operate the inkjet recording device 1 by touching the buttons and keys displayed on the screen.

A case where the document reading operation is performed by the inkjet recording device 1 will be described. The document reading unit 5 optically reads the image of the document fed by the document feeding unit 6 or the document placed on the platen glass 161 and generates image data. The image data generated by the document reading unit 5 is stored in an image memory or the like (not shown).

The document reading unit 5 includes a reading mechanism 163 having a light source emitting unit, a CCD (Charge Coupled Device) sensor, and the like, and the document reading unit 5 irradiates a document using a light irradiation unit having a light source and reflects the document. An image is read from a document by receiving light with a CCD sensor.

A case where the image recording operation is performed by the inkjet recording device 1 will be described. Based on the original image data generated by the original reading operation, the original image data stored in the image memory, the original image data received from the computer connected to the network, and the like, the image recording unit 12 sets the paper feeding unit 14 The image is recorded on the paper P which is fed from the paper and is conveyed by the paper conveying unit 19.

The paper feed unit 14 includes a paper feed cassette 141. A paper feed roller 145 is provided above the paper feed cassette 141, and the paper P housed in the paper feed cassette 141 is fed out toward the transport path 190 by the paper feed roller 145.

Further, the paper feed unit 14 includes a manual feed tray 142 that is openably and closably provided on the wall surface of the apparatus main body 11. The paper P set in the bypass tray 142 is fed out toward the transport path 190 by the paper feed roller 146.

The paper transport unit 19 includes a transport path 190 for transporting the paper P from the paper feed section 14 toward the discharge tray 151, a transport roller pair 191 provided at an appropriate position in the transport path 190, and a discharge roller pair 192.

The paper P fed from the paper feed unit 14 is conveyed in the transfer path 190 by the transfer roller pair 191. Further, the paper P on which the image is recorded by the image recording unit 12 is face-up and is discharged to the discharge tray 151 by the discharge roller pair 192 through the paper discharge transport path 193 (a part of the transport path 190).

Further, the paper transport unit 19 has an offset mechanism (not shown) that moves the discharge roller pair 192 in a direction perpendicular to the paper transport direction and shifts the paper P to be discharged to the discharge tray 151 in the paper width direction.

The image recording unit 12 records an image based on the original image data on the paper P that is fed from the paper feeding unit 14 and conveyed through the conveying path 190, and the conveying unit 125, the suction roller 126, and the recording unit 3 And an ink tank 122.

The transport unit 125 includes a drive roller 125A, a driven roller 125B, a tension roller 127, and a transport belt 128. The transport belt 128 is an endless belt, and is bridged over a drive roller 125A, a driven roller 125B, and a tension roller 127. The drive roller 125A is a roller that is rotationally driven counterclockwise by a motor (not shown). When the drive roller 125A is rotationally driven, the transport belt 128 travels counterclockwise, and the driven roller 125B and tension Roller 127 rotates in a counterclockwise direction.

The tension roller 127 is a roller for keeping the tension state of the transport belt 128 in an appropriate state. The suction roller 126 is arranged to face the driven roller 125B in contact with the transport belt 128, and by charging the transport belt 128, the paper P fed from the paper feed unit 14 is electrostatically charged to the transport belt 128. It is intended to be adsorbed.

The recording unit 3 ejects ink droplets of four different colors (black, cyan, magenta, and yellow) toward the paper P transported by the paper transport unit 19, and sequentially records images. The ink tank 122 is filled with ink corresponding to each color.

Specifically, the recording unit 3 has line heads 31, 32, 33, and 34 corresponding to each color of black, cyan, magenta, and yellow. Therefore, the inkjet recording device 1 is a line head type inkjet recording device. Further, the recording unit 3 has a head frame 35 (see FIGS. 4 (A) and 4 (B)) that supports the line heads 31 to 34. The head frame 35 is supported by the device main body 11.

The elevating mechanism 129 supports the transport unit 125 from below, and raises and lowers the transport unit 125 up and down with respect to the line heads 31 to 34. That is, the elevating mechanism 129 separates and approaches the transport unit 125 and the line heads 31 to 34 by moving the transport unit 125 relative to the line heads 31 to 34. Specifically, the elevating mechanism 129 has a recording position (position shown in FIG. 1) where printing by the recording unit 3 is possible and a maintenance position (position shown in FIG. 2) separated from the recording position by a predetermined distance. ), And the transport unit 125 is moved.

FIG. 3 is a functional block diagram schematically showing the main internal configuration of the inkjet recording device according to the first embodiment. The inkjet recording device 1 includes a control unit 10, a document feeding unit 6, a document reading unit 5, an image recording unit 12, a paper feeding unit 14, a paper transport unit 19, an operation unit 47, a drive mechanism 88, a transport unit 125, and an elevating mechanism. It includes 129, a cleaning liquid pump 130, and a cleaning unit 8. The same components as those of the inkjet recording device 1 shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted here.

The paper feed unit 14 and the paper transport unit 19 include roller drive units 14A and 19A, respectively. The roller drive units 14A and 19A are composed of a motor, a gear, a driver, and the like, and the roller drive unit 14A functions as a drive source for applying a rotational driving force to the paper feed rollers 145 and 146. The roller drive unit 19A functions as a drive source for applying a rotational driving force to the drive rollers of the transport roller pair 191 and the discharge roller pair 192.

The control unit 10 includes a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and a dedicated hardware circuit. The processor is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), an MPU (Micro Processing Unit), or the like. The control unit 10 includes a control unit 100.

The control unit 10 functions as a control unit 100 by operating the processor according to a control program stored in a built-in non-volatile memory or the like. However, the control unit 100 and the like can be configured by a hardware circuit regardless of the operation according to the control program by the control unit 10. Hereinafter, the same applies to each embodiment unless otherwise specified.

The control unit 100 controls the overall operation of the inkjet recording device 1. The control unit 100 includes a document feeding unit 6, a document reading unit 5, an image recording unit 12, a paper feeding unit 14, a paper transport unit 19, a cleaning unit 8, an operation unit 47, a drive mechanism 88, a transport unit 125, and an elevating mechanism 129. , And the cleaning liquid pump 130, and controls the drive of each of these parts.

As will be described later, the control unit 100 controls a cleaning operation in which the ink ejection surface 361 is wiped by the wiper member 821 using the cleaning liquid 831 and a bubble removing operation executed before the control of the cleaning operation. ..

Here, the configuration of the recording unit 3 will be described in detail with reference to the drawings. FIG. 4A is a diagram showing a recording unit and a transport unit. FIG. 4B is a view of the transport unit and the recording unit as viewed from above.

As shown in FIG. 4A, the transport unit 125 is arranged below the line heads 31 to 34. The transport unit 125 transports the paper P while facing the ink ejection surface 361. The gap between the transport belt 128 and the ink ejection surface 361 is adjusted so that the gap between the surface of the paper P and the ink ejection surface 361 at the time of image recording is, for example, 1 mm.

As shown in FIG. 4B, the recording unit 3 includes line heads 31 to 34. The line heads 31 to 34 are long in the width direction D2 (width direction of the paper P) perpendicular to the transport direction D1 of the paper P. The width of the line heads 31 to 34 has a length corresponding to the width of the maximum width of the paper P to be conveyed. Each of the line heads 31 to 34 is fixed to the head frame 35 at predetermined intervals along the transport direction D1 of the paper P. Each of the line heads 31 to 34 has a plurality of (for example, three) recording heads 36. Therefore, the recording unit 3 includes 12 recording heads 36.

The recording head 36 has a plurality of ink nozzles 37 having an ink ejection port 371 from which ink is ejected. Although the plurality of ink nozzles 37 are simply shown in the manner of being arranged in one row in FIG. 4B, they are arranged in three rows in a staggered manner as shown in FIG. 5B described later. Has been done. The lower surface of the recording head 36 is an ink ejection surface 361 provided with an ink ejection port 371. In the present embodiment, in the line head 31, three recording heads 36 are arranged in a staggered pattern along the width direction D2. Further, in each of the other line heads 32 to 34, similarly to the line head 31, three recording heads 36 are arranged in a staggered pattern along the width direction D2.

The recording unit 3 records an image on the paper P by ejecting ink from each ink nozzle 37 of each recording head 36 with respect to the paper P conveyed by the transport unit 125. As the ink ejection method of the line heads 31 to 34, for example, a piezo system in which ink is ejected by using a piezo element, a thermal system in which bubbles are generated by heating to eject ink, and the like are adopted.

As shown in FIG. 1, the ink tank 122 includes ink tanks 41, 42, 43, and 44 containing inks corresponding to each of the black, cyan, magenta, and yellow colors. The ink tanks 41 to 44 are connected to the line heads 31 to 34 of the same color by ink tubes (not shown). The line heads 31 to 34 are replenished with ink from each of the ink tanks 41 to 44. Here, as the ink, for example, an ink in which a color material corresponding to each color is contained in a solvent and water is used.

As shown in FIG. 2, the cleaning unit 8 performs a bubble removing operation, which will be described later, and a subsequent cleaning operation (including a purging operation) when the transport unit 125 is in the maintenance position, whereby the line heads 31 to 31 34 A device that restores the function of each recording head 36. As shown in FIGS. 1 and 5A, the cleaning unit 8 has an ink tray 81 and a wiper unit 82. FIG. 5A is a partially broken side view showing a state in which the ink tray and the wiper unit of the cleaning unit are arranged below the recording unit. FIG. 5B is a view of the ink ejection surface of the recording head.

The ink tray 81 receives the ink discharged from the ink nozzles 37 of the respective recording heads 36. The ink tray 81 is movably supported in the horizontal direction (horizontal direction in FIG. 1) by a first moving mechanism (not shown). The first movement mechanism is a drive mechanism 88 that moves the ink tray 81 in the horizontal direction by using, for example, a rack-pinion mechanism that converts the rotational movement of a gear connected to the rotation shaft of a motor into a linear movement. .. In the normal state (during printing), the ink tray 81 is arranged at a retracted position (see the position indicated by the alternate long and short dash line in FIG. 2) retracted to the downstream side of the transport direction D1 from the recording unit 3.

Then, when an instruction for performing a cleaning operation is input to the ink tray 81, the transport unit 125 is moved to the maintenance position by the elevating mechanism 129, so that the space created in the opposite position of the line heads 31 to 34 is reached. , Moved by the first moving mechanism (see the position shown by the solid line in FIG. 2). Further, the ink tray 81 is supported so as to be able to move up and down in the vertical direction (vertical direction in FIG. 1). When the ink tray 81 moves to the opposite position of the line heads 31 to 34, the transport unit 125 is raised by a predetermined distance from the maintenance position by the elevating mechanism 129, so that the ink tray 81 moves upward.

The wiper unit 82 has a configuration in which a plurality of wiper members 821 for cleaning ink and the like adhering to each ink ejection surface 361 are supported by a pair of side frames 823 via a plurality of stays 822. Further, the wiper unit 82 can move along the width direction D2. In particular, the plurality of wiper members 821 can come into contact with the ink ejection surface 361 and move from the cleaning liquid supply unit 83 in the wiping direction D21 (see FIG. 9 described later).

The plurality of wiper members 821 move along the wiping direction D21 to clean the ink ejection surface 361 with the cleaning liquid 831 (see FIG. 8) supplied from the cleaning liquid supply unit 83.

Here, the plurality of wiper members 821 are formed in a plate shape having a thickness of 1 mm to 2 mm by, for example, an elastomer, and have elasticity. Examples of the elastomer include urethane rubber, ethylene propylene diene rubber (EPDM), nitrile rubber (NBR), styrene rubber (SBR), chloroprene rubber, silicone rubber, and fluorine rubber.

The plurality of stays 822 extend along the transport direction D1 and are connected to the pair of side frames 823. In the present embodiment, the number of the plurality of stays 822 is three. Four wiper members 821 are fixed to each stay 822. That is, the number of the plurality of wiper members 821 is 12 corresponding to the number of the recording heads 36.

The pair of side frames 823 can be reciprocated along the width direction D2 by a second moving mechanism (not shown). The second moving mechanism is a drive mechanism 88 such as the rack-pinion mechanism. For example, by applying a rotational force to the side frame 823 that functions as a rack via a pinion gear (not shown), the side frame 823 reciprocates along the width direction D2. As a result, the entire wiper unit 82 including the plurality of wiper members 821 reciprocates along the width direction D2.

As shown in FIGS. 5A and 5B, the recording head 36 is provided with a cleaning liquid supply unit 83 on the upstream side of the ink ejection surface 361 in the wiping direction D21. The cleaning liquid supply unit 83 includes a cleaning liquid supply surface 865 having a cleaning liquid supply port 834 for supplying the cleaning liquid 831 used for wiping the ink ejection surface by the wiper member 821, and is provided on the upstream side of the ink ejection surface 361 in the wiping direction D21. ing.

The cleaning liquid supply unit 83 includes an inclined surface 866 that is continuously located on the upstream side of the wiping direction D21 and is inclined upward with respect to the cleaning liquid supply surface 865 as it advances to the upstream side of the wiping direction D21. ing.

As shown in FIG. 4B, the recording unit 3 includes twelve recording heads 36, and thus has a plurality of (12) cleaning liquid supply units 83. The plurality (12) cleaning liquid supply units 83 supply cleaning liquid 831 for cleaning the ink ejection surface 361. When the ink ejection surface 361 is cleaned by the wiper member 821, the cleaning liquid supply unit 83 supplies the cleaning liquid 831 stored in the storage space 832 via the cleaning liquid nozzle 833 that communicates with the storage space 832.

As shown in FIG. 8A, which will be described later, the cleaning liquid 831 is supplied in a state of hemispherically protruding from the cleaning liquid supply port 834 provided in the cleaning liquid nozzle 833 when cleaning the ink ejection surface 361. On the other hand, the cleaning liquid 831 forms a concave meniscus inside the cleaning liquid nozzle 833 except when cleaning the ink ejection surface 361. Here, the concave meniscus can be formed by adjusting the inner diameter of the cleaning liquid nozzle 833, the negative pressure that the accommodating space 832 acts on the inside of the cleaning liquid nozzle 833, and the like.

Further, as shown in FIGS. 5A and 5B, the recording head 36 is provided with a scattering prevention member 84 downstream of the ink ejection surface 361 in the wiping direction D21. The scattering prevention member 84 has an inclined surface 841 that the wiper member 821 comes into contact with after wiping the ink ejection surface 361 by the wiper member 821. The inclined surface 841 is located on the downstream side of the wiping direction D21 continuously with the ink ejection surface 361, and is inclined upward with respect to the ink ejection surface 361 as it advances to the downstream side of the wiping direction D21. Therefore, as the wiper member 821 advances in the wiping direction D21 while abutting on the inclined surface 841 of the shatterproof member 84, the deflection of the wiper member 821 gradually decreases, and finally the wiper member 821 becomes Gently separate from the slope 841. Therefore, the splattering of the liquid can be reduced as compared with the configuration without the splattering prevention member 84. Further, the shatterproof member 84 is made of, for example, a polyacetal resin (POM). The ink ejection surface 361 of the recording head 36 is, for example, treated with a fluorine-based water-repellent film. Therefore, the water repellency of the scattering prevention member 84 is lower than that of the ink ejection surface 361. Therefore, even if the cleaning liquid remains on the scattering prevention member 84, it is possible to reduce the contact of the droplets with the paper because the height of the droplets is low.

As shown in FIG. 5A, the cleaning liquid storage unit 85 stores the cleaning liquid 831. Here, as the cleaning liquid 831, for example, an ink obtained by removing the coloring material can be used. That is, as the cleaning liquid 831, one containing a solvent and water as main components can be used. Further, a surfactant, an antiseptic and an antifungal agent and the like are added to the cleaning liquid 831 as needed.

FIG. 6 is a diagram schematically showing a cleaning liquid flow path for supplying a cleaning liquid to one line head. FIG. 6 shows a cleaning liquid flow path 87 for the line head 31. The cleaning liquid flow path 87 is a pipe for guiding the cleaning liquid 831 from the cleaning liquid storage unit 85 to the cleaning liquid supply unit 83 of a plurality of (for example, three) recording heads 36. The cleaning liquid flow path 87 is provided for each of the line heads 31 to 34. That is, the cleaning liquid flow path 87 has one path for each color. The cleaning liquid flow path 87 of the other line heads 32 to 34 is the same as that of the line head 31.

The cleaning liquid flow path 87 includes a vertical tubular member 871 and a horizontal tubular member 872. The vertical tubular member 871 is a vertical pipe having one end connected to the cleaning liquid supply unit 83 and extending from one end to the other end above the cleaning liquid supply unit 83, and is shaded in FIG. The horizontal tubular member 872 is a horizontal pipe having one end connected to the upper end side of the vertical tubular member 871 and extending from one end to the other end in the horizontal direction. The capacity of the horizontal tubular member 872 is, for example, five times the total capacity of the cleaning liquid supply unit 83 and the vertical tubular member 871.

Further, the horizontal tubular member 872 includes a check valve 873 that guides the cleaning liquid 831 in the direction of the vertical tubular member 871. As a result, it is possible to prevent the cleaning liquid 831 from returning to the cleaning liquid accommodating portion 85, and it is possible to stably perform the extrusion control of the cleaning liquid 831.

The cleaning liquid pump 130 moves the cleaning liquid 831 in the cleaning liquid flow path 87 to give power to push out the cleaning liquid 831 from the cleaning liquid supply port 834. A cleaning liquid flow path 87 is connected to the output side of the cleaning liquid pump 130, and an input side flow path connected to the cleaning liquid accommodating portion 85 is connected to the input side of the cleaning liquid pump 130. The cleaning liquid pump 130 is one for each cleaning liquid flow path 87, that is, one for each color. The cleaning liquid pump 130 is an example of a driving unit within the scope of claims.

Further, as shown in FIG. 6, the flow path lengths L1, L2, and L3 from the cleaning liquid pump 130 to the cleaning liquid supply unit 83 of the three recording heads 36 of the same color are the same. As a result, in the cleaning liquid flow path 87 composed of the vertical tubular member 871 and the horizontal tubular member 872, the amount of extrusion by each cleaning liquid supply unit 83 can be made the same.

Next, a drawing will be described with respect to an example of the processing performed by the control unit 10 of the inkjet recording device 1 according to the first embodiment. FIG. 7A is a flowchart showing an example of processing performed by the inkjet recording apparatus according to the first embodiment.

As shown in FIG. 7A, the control unit 100 determines whether or not maintenance has started (S1). Specifically, the control unit 100 determines that maintenance has started (YES in S1) when, for example, a predetermined time before the start of printing has elapsed from the power-on of the inkjet recording device 1, and is shown in FIG. As described above, the transport unit 125 is moved to the maintenance position, and the cleaning unit 8 is moved to the position directly below the recording unit 3. The maintenance start timing is not limited to the above case, and when the power off operation of the inkjet recording device 1 is accepted and the operating time of the inkjet recording device 1 elapses, the inkjet recording device 1 It may be at various timings such as when the number of printed sheets exceeds a predetermined cumulative number of sheets.

When the control unit 100 determines that maintenance has started (YES in S1), the control unit 100 determines whether or not a predetermined execution condition (that is, a condition for determining whether or not to control the entire system bubble removal operation) is satisfied. Judgment (S2). The control unit 100 controls the whole system bubble removal operation only when a predetermined execution condition is satisfied before the control of the cleaning operation. The predetermined execution condition is, for example, that the number of times the control of the cleaning operation is executed reaches a predetermined plurality of times (for example, 15 times). Specifically, when the number of cleaning executions has not reached a predetermined plurality of times (for example, 15 times) (NO in S2), the control unit 100 performs a bubble removing operation different from the whole system bubble removing operation. Control (hereinafter, may be appropriately referred to as "vertical tube bubble removal control") is performed (S3).

Here, the control of the bubble removing operation (vertical tube bubble removing control) in S3 will be described. 8 (A) to 8 (E) are partially broken side views for explaining the bubble removing operation performed before the cleaning operation.

The control unit 100 drives the elevating mechanism 129 to raise the transport unit 125 by a predetermined distance from the maintenance position in a state where the cleaning unit 8 is moved to a position directly below the recording unit 3 (see FIG. 8A). , The ink tray 81 is arranged at a purge position directly below the ink ejection surface 361 (see FIG. 8B). As a result, the plurality of wiper members 821 of the cleaning unit 8 are located directly below the inclined surface 866 of the cleaning liquid supply unit 83 adjacent to the corresponding recording head 36 (see FIG. 8B). At this time, the tips of the plurality of wiper members 821 are positioned above the plane including the cleaning liquid supply surface 865. The position where the tip of the wiper member 821 is arranged in the region directly below the inclined surface 866 and in the upper region of the plane including the cleaning liquid supply surface 865 is the movement start position of the wiper member 821 in the bubble removing operation.

The control unit 100 controls the bubble removing operation (vertical tube bubble removing control) including the following (i) to (iii) (S3).

The control unit 100 pushes (i) a cleaning liquid 831 having an amount of 0.5 times or more and 0.9 times or less the total capacity of the cleaning liquid supply unit 83 and the vertical tubular member 871 from the cleaning liquid supply port 834 (FIG. 8B). reference). It was confirmed by the experimental data shown in FIG. 10 described later that the cleaning liquid 831 having an amount of 0.5 times or more and 0.9 times or less the total volume is suitable. The cleaning liquid 831 discharged to the ink tray 81 is discharged to a predetermined waste ink storage unit through an ink tube (not shown) from a discharge port provided at the bottom of the ink tray 81.

Subsequently, the control unit 100 drives the second moving mechanism (not shown) to horizontally move the wiper unit 82 along the wiping direction D21, thereby moving the wiper member 821 (ii) to the cleaning liquid supply surface 865. It is moved in the wiping direction D21 from the movement start position, which is the position on the upstream side of the wiping direction D21, to the position in front of the ink ejection surface (see FIGS. 8C and 8D).

Subsequently, the control unit 100 drives the elevating mechanism 129 to lower the transport unit 125 by a predetermined distance and return it to the maintenance position, whereby the wiper member 821 (iii) is cleaned as shown in FIG. 8 (E). Control is performed to separate it from the supply surface 865.

On the other hand, when the number of cleaning executions reaches a predetermined plurality of times (for example, 15 times) (YES in S2), the control unit 100 controls not the vertical pipe bubble removing control but the whole system bubble removing operation. Do (S4). The non-volatile memory built in the control unit 10 stores the number of cleaning executions each time cleaning is executed.

When the number of cleaning executions reaches a predetermined plurality of times (for example, 15 times) (YES in S2), the control unit 100 controls the whole system bubble removing operation (S4). FIG. 7B is a flowchart showing an example of the whole system bubble removal process.

The control unit 100 determines whether or not the extrusion setting of the cleaning liquid 831 at the time of removing air bubbles in the entire system is the extrusion setting a plurality of times (S41). Specifically, the non-volatile memory built in the control unit 10 stores in advance the extrusion setting of the cleaning liquid 831. The control unit 100 determines that if the cleaning liquid 831 is extruded once, which is stored in the non-volatile memory in advance, it is extruded once, and if the cleaning liquid 831 is extruded a plurality of times, the control unit 100 determines that the cleaning liquid 831 is extruded a plurality of times. Judge to push out.

When the control unit 100 determines that the pushing setting of the cleaning liquid 831 at the time of removing all system bubbles is the setting of pushing out multiple times (YES in S41), the control unit 100 controls the whole system bubble removing operation by pushing out multiple times (S42). ..

The control unit 100 controls the whole system bubble removal operation including the following (ia), (ii) and (iii) (S42). The control of the whole system bubble removal operation is different in that the amount of the cleaning liquid 831 pushed out is larger than that in the case of the vertical tube bubble removal control described above, and the operation of the wiper unit 82 is shown in FIGS. 8A to 8A. As shown in (E), it is the same as the case of the vertical tube bubble removal control described above.

When the control unit 100 pushes out the cleaning liquid 831 from the cleaning liquid supply port 834 (iA) a plurality of times, the control unit 100 applies the cleaning liquid 831 in an amount of 0.5 times or more and 1 time or less the capacity of the lateral tubular member 872 multiple times. Extrude from the cleaning liquid supply port 834 multiple times so that the total amount of extrusion is 1.5 times or more the capacity of the lateral tubular member 872 (see FIG. 8B). It was confirmed by the experimental data shown in FIG. 11 which will be described later that the extruded content is suitable.

Subsequently, the control unit 100 moves (ii) the wiper member 821 in the wiping direction D21 from the movement start position, which is a position upstream of the cleaning liquid supply surface 865 in the wiping direction D21, to a position in front of the ink ejection surface. (See FIGS. 8 (C) and 8 (D)). Subsequently, the control unit 100 controls the wiper member (iii) to be separated from the cleaning liquid supply surface 865 as shown in FIG. 8 (E). Since the above (ii) and (iii) are the same as those of (ii) and (iii) in the case of the vertical tube bubble removal control described above, detailed description thereof will be omitted here.

On the other hand, in S41, when the control unit 100 determines that the extrusion setting of the cleaning liquid 831 at the time of removing all system bubbles is the one-time extrusion setting (NO in S41), the control unit 100 controls the whole system bubble removal operation by one-time extrusion. (S43). It was confirmed by the experimental data shown in FIG. 11 which will be described later that the extruded content is suitable.

The control unit 100 controls the whole system bubble removal operation including the following (iB), (ii) and (iii) (S43). When the control unit 100 pushes out the cleaning liquid 831 from the cleaning liquid supply port 834 at one time, the control unit 100 dispenses the cleaning liquid 831 in an amount 1.5 times or more the capacity of the horizontal tubular member 872 from the cleaning liquid supply port 834 at one time. Extrude and perform the above (ii) and (iii) (S43).

As shown in FIG. 7A, the control unit 100 controls the cleaning operation after performing the vertical pipe bubble removal control process (S3) or the whole system bubble removal control process (S4) (S5). ). 9 (A) to 9 (E) are partially broken side views for explaining the cleaning operation.

As shown in FIG. 9A, the control unit 100 supplies the purge ink 45 to the recording head 36, and discharges the purge ink 45 from the ink ejection port 371 of the ink nozzle 37. As a result, the thickening ink, foreign matter, air bubbles, etc. in the ink nozzle 37 are discharged toward the ink tray 81 together with the purge ink 45 supplied to the ink nozzle 37. By performing such a purging operation, clogging of the ink nozzle 37 is eliminated. The ink or the like discharged to the ink tray 81 is discharged to a predetermined waste ink storage unit through an ink tube (not shown) from a discharge port provided at the bottom of the ink tray 81.

When the purging operation is completed, the cleaning unit 8 performs a cleaning operation. The cleaning operation is an operation for wiping the purge ink 45 and the like adhering to the ink ejection surface 361 with the wiper member 821. In the cleaning operation, the control unit 100 pushes out a predetermined amount (for example, 1.5 mL) of the cleaning liquid 831, and the cleaning liquid 831 is hemispherically projected from the cleaning liquid supply port 834 of the cleaning liquid supply unit 83 and supplied (FIG. FIG. 9 (A)). The predetermined amount (for example, 1.5 mL) is the total extrusion amount of each line head 31 to 34, that is, the extrusion amount for the total of four colors. Further, the cleaning liquid 831 may be supplied at the same time as the purge ink 45 is discharged, or before or after the purge ink 45 is discharged.

As shown in FIGS. 9B to 9D, when the supply of the cleaning liquid 831 is completed, the control unit 100 drives the second moving mechanism (not shown) to drive the wiper unit 82 in the wiping direction D21. Move horizontally along. Specifically, the control unit 100 positions the wiper member 821 at the movement start position (see FIG. 9B), and the wiper is from the movement start position to the end position where the wiper member 84 comes into contact with the scattering prevention member 84. The member 821 is moved (see FIGS. 9 (C) and 9 (D)). At this time, the wiper member 821 moves in contact with the scattering prevention member 84 via the inclined surface 866, the cleaning liquid supply port 834, and the ink ejection surface 361.

Further, as shown in FIG. 9D, when the plurality of wiper members 821 come into contact with the ink ejection surface 361 and move, the purge ink 45 and the like adhering to the ink ejection surface 361 are wiped off. The residual ink or the like wiped off by the plurality of wiper members 821 moves downward along the surface of the wiper member 821 together with the cleaning liquid 831 and falls on the ink tray 81.

Subsequently, the control unit 100 drives the elevating mechanism 129 to lower the transport unit 125 by a predetermined distance and return it to the maintenance position, thereby causing the wiper member 821 to scatter prevention member 84 as shown in FIG. 9E. Separate from.

After that, the control unit 100 drives the elevating mechanism 129 to lower the transport unit 125 to the maintenance position (see FIG. 2), and drives the first moving mechanism to move the ink tray 81 of the cleaning unit 8 to the retracted position. (See Fig. 1). Further, the control unit 100 drives the elevating mechanism 129 to return the transport unit 125 to the recording position (position shown in FIG. 1). Then, the control unit 100 ends the process shown in FIG. 7 (A).

Here, the experimental data of removing air bubbles in the vertical tube will be described with reference to FIG. FIG. 10 is a diagram showing the results of experimental data for removing air bubbles in a vertical tube. As shown in FIG. 6, the line head 31 has three sets of a cleaning liquid supply unit 83 and a vertical tubular member 871. That is, in one color, there are three sets of the cleaning liquid supply unit 83 and the vertical tubular member 871. Therefore, in the four colors, there are 12 sets (= 3 sets x 4 colors) of the cleaning liquid supply unit 83 and the vertical tubular member 871. The total volume of the 12 sets of the cleaning liquid supply unit 83 and the vertical tubular member 871 is, for example, 4 mL.

After introducing air in the vicinity of the vertical tubular member 871 and the cleaning liquid supply port 834 in advance, the bubble removing operation of the cleaning liquid supply port 834, that is, the amount of the cleaning liquid 831 pushed out is 4.0 mL, 3.6 mL, and 2.8 mL, respectively. , 2.0 mL and 1.2 mL were used to remove air bubbles, and then a cleaning operation was performed. The number of experiments N for each extrusion amount was 10 times, respectively, and after the cleaning operation of the recording head 36 was completed, the experiment was performed as ◯ if there were no bubbles in the scattering prevention member 84, and as x if there were bubbles. According to the experimental data shown in FIG. 10, a cleaning liquid 831 having an amount of 0.5 times or more and 0.9 times or less (magnification A of 0.5 or more and 0.9 or less in FIG. 10) is suitable. confirmed.

Next, the experimental data for removing all bubbles will be described with reference to FIG. FIG. 11 is a diagram showing the results of experimental data for removing all system bubbles. As shown in FIG. 6, the line head 31 has three lateral tubular members 872. That is, in one color, there are three horizontal tubular members 872. Therefore, in the four colors, there are 12 horizontal tubular members 872 (= 3 × 4 colors). The total volume of the 12 members of the lateral tubular member 872 is, for example, 20 mL.

After introducing air into the transverse tubular member 872 in advance, the bubble removing operation of the transverse tubular member 872, that is, the amount of the cleaning liquid 831 extruded once at 30 mL, 20 mL once or twice, and 14 mL 1 An experiment was conducted in which a cleaning operation was performed after performing a whole-system air bubble removing operation in which 10 mL was extruded 1 to 3 times and 6.0 mL was extruded 1 to 6 times. The number of experiments N for each extrusion amount was 10 times, respectively, and after the cleaning operation of the recording head 36 was completed, the experiment was performed as ◯ if there were no bubbles in the scattering prevention member 84, and as x if there were bubbles.

From the experimental data shown in FIG. 11, it was confirmed that it is preferable to extrude the cleaning liquid 831 once at 30 mL. That is, it is possible to push out the cleaning liquid 831 in an amount (= 30 mL) of 1.5 times the volume (= 20 mL) of the lateral tubular member 872 (magnification B in FIG. 11 is 1.5) or more from the cleaning liquid supply port 834 at one time. It is suitable.

Further, according to the experimental data shown in FIG. 11, in the case of multiple extrusions, the extrusion amount of the cleaning liquid 831 is extruded twice with 20 mL, the extrusion amount of the cleaning liquid 831 is extruded three times with 14 mL, and the extrusion amount of the cleaning liquid 831 is determined. It was confirmed that 3 times of extrusion with 10 mL was suitable. That is, a cleaning liquid 831 in an amount (= 10 mL to 20 mL) of 0.5 times or more and 1 time or less (magnification B of 0.5 or more and 1.0 or less in FIG. 11) of the volume (= 20 mL) of the lateral tubular member 872. Is preferably extruded from the cleaning liquid supply port 834 multiple times so that the total amount of the plurality of extrudes is 1.5 times or more the capacity (= 20 mL) of the lateral tubular member 872.

According to the first embodiment, the cleaning liquid flow path 87 has a vertical tubular member 871 having one end connected to the cleaning liquid supply unit 83 and extending from one end to the other end above the cleaning liquid supply unit 83, and one end. Is connected to the upper end side of the vertical tubular member 871 and includes a horizontal tubular member 872 extending from one end to the other end in the horizontal direction. Unless the cleaning liquid 831 is extruded, the air bubbles existing in the vertical tubular member 871 can be stopped in the vertical tubular member 871, and the air bubbles existing in the horizontal tubular member 872 can be stopped in the horizontal tubular member 872. The air bubbles can be separated by the member 871 and the lateral tubular member 872. Further, the vertical tubular member 871 forms a flow path in the vertical direction, and bubbles existing in the vertical tubular member 871 can be roughly divided into two parts, a lower end side and an upper end side, and the lower end side and the upper end side can be collected. Bubbles can be absent or difficult to exist in the flow path portion between the sides. As a result, it is possible to provide a cleaning liquid flow path capable of suitably realizing bubble removal control while suppressing the supply amount of the cleaning liquid 831. Further, the control unit 100 pushes at least a part of the cleaning liquid 831 out of the cleaning liquid flow path 87 from the cleaning liquid supply port 834 before controlling the cleaning operation of wiping the ink ejection surface 361 of the recording head 36. The bubble removing operation of the flow path 87 is controlled. That is, since the bubble removing operation is controlled before the cleaning operation is controlled, the occurrence of image defects due to paper stains can be reduced as compared with the configuration in which the cleaning operation is simply controlled.

Further, as a control of the bubble removing operation (vertical tube bubble removing control), the control unit 100 has (i) 0.5 times or more the total capacity of the cleaning liquid supply unit 83 and the vertical tubular member 871 as shown in FIG. By extruding a cleaning liquid 831 in an amount of 0.9 times or less from the cleaning liquid supply port 834, air bubbles existing in the cleaning liquid supply unit 83 and air bubbles existing on the lower end side of the vertical tubular member 871 can be extruded together with the cleaning liquid 831. The cleaning liquid 831 at the supply port 834 can be in a bubble-free state. By the way, if an amount of cleaning liquid 831 that is once the total capacity is pushed out from the cleaning liquid supply port 834, air bubbles existing on the upper end side of the vertical tubular member 871 reach the cleaning liquid supply port 834, and these air bubbles reach the cleaning liquid supply port 834, and these air bubbles reach the cleaning liquid supply port 834. Bubbles form at the supply port 834. On the other hand, since the amount of the cleaning liquid 831 is limited to 0.9 times or less of the total capacity, it is possible to prevent air bubbles existing on the upper end side of the vertical tubular member 871 from reaching the cleaning liquid supply port 834. It is possible to prevent the generation of bubbles due to the bubbles existing on the upper end side of the vertical tubular member 871, and it is possible to make the cleaning liquid 831 in the cleaning liquid supply port 834 free of bubbles. Then, (ii) the wiper member 821 is moved in the wiping direction D21, and (iii) the wiper member 821 is separated from the cleaning liquid supply surface 865, so that no bubbles remain on the cleaning liquid supply surface 865. Therefore, it is possible to preferably control the bubble removing operation. Then, after the above-mentioned bubble removing operation, the cleaning operation is controlled. That is, since the cleaning operation of wiping the ink ejection surface 361 is controlled by the wiper member 821 using the bubble-free cleaning liquid 831, no bubbles remain on the ink ejection surface 361 of the recording head 36. As a result, it is possible to reduce the occurrence of image defects due to paper stains.

Further, as a control of the cleaning operation, the control unit 100 pushes out the purge ink 45 from the ink discharge port 371 of the recording head 36 and pushes out the cleaning liquid 831 from the cleaning liquid supply port 834, and ejects the wiper member 821 from the movement start position. The wiper member 821 is controlled to be separated from the end position by moving it in the wiping direction D21 to the end position which is a position where the wiper member 84 comes into contact with the shatterproof member 84 through the surface 361. Therefore, since the wiper member 821 is separated from the scattering prevention member 84, no liquid residue is generated on the ink ejection surface 361. Further, the scattering prevention member 84 can prevent the liquid (ink or cleaning liquid) from scattering when the wiper member 821 separates.

Further, the inclined surface of the cleaning liquid supply unit 83 is located on the upstream side of the wiping direction D21 continuously with the cleaning liquid supply surface 865, and is inclined upward with respect to the cleaning liquid supply surface 865 as it advances to the upstream side of the wiping direction D21. ing. The movement start position is a predetermined position where the tip of the wiper member 821 is located directly below the inclined surface and above the plane including the cleaning liquid supply surface 865. As a result, the wiper member 821 can be suitably brought into contact with the cleaning liquid supply surface 865 and the ink ejection surface 361.

Further, when the control unit 100 extrudes the cleaning liquid 831 from the cleaning liquid supply port 834 (iA) a plurality of times as a control of the whole system air bubble removing operation, the capacity of the horizontal tubular member 872 is 0.5 times or more and 1 time. The following amount of cleaning liquid 831 is present in the cleaning liquid supply unit 83 by being extruded from the cleaning liquid supply port 834 multiple times so that the total amount of the multiple extrusions is 1.5 times or more the capacity of the lateral tubular member 872. All the air bubbles, the air bubbles existing in the vertical tubular member 871 and the air bubbles existing in the horizontal tubular member 872 can be pushed out together with the cleaning liquid 831, and the cleaning liquid 831 in the cleaning liquid supply port 834 can be in a state without bubbles. Further, when the control unit 100 pushes out the cleaning liquid 831 from the cleaning liquid supply port (iB) 834 at one time as a control of the whole system bubble removing operation, the amount of the control unit 100 is 1.5 times or more the capacity of the horizontal tubular member 872. By extruding the cleaning liquid 831 from the cleaning liquid supply port 834 at one time, all the air bubbles existing in the cleaning liquid supply unit 83, the air bubbles existing in the vertical tubular member 871 and the air bubbles existing in the horizontal tubular member 872 are extruded together with the cleaning liquid 831. The cleaning liquid 831 at the cleaning liquid supply port 834 can be made free of bubbles. Further, the control of the whole system bubble removal operation is not executed every time before the control of the cleaning operation, but is executed only when the predetermined execution conditions are satisfied before the control of the cleaning operation. Therefore, the consumption of the cleaning liquid 831 can be suppressed. Then, (ii) the wiper member 821 is moved in the wiping direction D21, and (iii) the wiper member 821 is separated from the cleaning liquid supply surface 865, so that no bubbles remain on the cleaning liquid supply surface 865. Therefore, it is possible to preferably control the bubble removing operation. Then, after the above-mentioned bubble removing operation, the cleaning operation is controlled. That is, since the cleaning operation of wiping the ink ejection surface 361 is controlled by the wiper member 821 using the bubble-free cleaning liquid 831, no bubbles remain on the ink ejection surface 361 of the recording head 36. As a result, it is possible to reduce the occurrence of image defects due to paper stains.

Further, the control of the whole system bubble removal operation is executed when the number of executions of the control of the cleaning operation reaches a predetermined plurality of times. That is, the control of the whole system bubble removal operation is executed once every plurality of times. As a result, the consumption of the cleaning liquid 831 can be suppressed.

Next, the inkjet recording apparatus 1 according to the second embodiment will be described. FIG. 12 is a functional block diagram schematically showing the main internal configuration of the inkjet recording device according to the second embodiment.

In the above-described first embodiment, when the number of times of execution of the control of the cleaning operation reaches a predetermined plurality of times (for example, 15 times), the whole system bubble removing operation is controlled, but the ambient temperature of the recording head 36 is controlled. Is lower than the print permission temperature when the power of the inkjet recording device 1 is turned on, and then the ambient temperature of the recording head 36 reaches the print permission temperature once or a plurality of times. The point of controlling is different from the above-described first embodiment.

As shown in FIG. 12, the image recording unit 12 of the second embodiment is a heater capable of heating ink on the ink supply path leading to the recording head 36 for each of the line heads 31 to 34 shown in FIG. 4 (B). It further includes an H1, an ink temperature sensor TS1 that detects the temperature of the ink heated by the heater H1, and an ambient temperature sensor TS2 that detects the ambient temperature of the recording head 36.

The control unit 100 determines whether or not the ink temperature detected by the ink temperature sensor TS1 is the print permission temperature, and when the ink temperature is determined to be the print permission temperature, the recording unit 3 permits printing. Then, it is determined whether or not the ambient temperature of the recording head 36 detected by the ambient temperature sensor TS2 is the print permission temperature.

Then, as the predetermined execution condition, the control unit 100 determines that the ambient temperature of the recording head 36 is lower than the print permission temperature when the power of the inkjet recording device 1 is turned on, and then the ambient temperature of the recording head 36 is print permission. When the temperature is reached once or multiple times, the whole system bubble removal operation is controlled.

By the way, in an inkjet recording device equipped with a heater in the recording head, the ambient temperature of the recording head (in other words, the temperature inside the device) changes from a low temperature to a high temperature, and even at the low temperature, it becomes higher than the outside air temperature. As a characteristic of the liquid, the dissolved air amount is higher at a low temperature and lower at a high temperature. At this time, if there are minute bubbles in the cleaning liquid, the bubbles grow large from this as a starting point. When the liquid temperature in the cleaning liquid flow path becomes low again, the air that has passed through the cleaning liquid flow path dissolves in the cleaning liquid, so that the cleaning liquid flow path is filled with air bubbles due to repeated temperature ups and downs, and in the worst case, it is extruded. Even if the operation is performed, a predetermined amount of cleaning liquid does not come out from the cleaning liquid supply port 834, and if this state continues, cleaning defects such as sticking ink remaining on the ink ejection surface 361 occur. If the cleaning is poor, the ink ejection port 371 is clogged (for example, the nozzle is clogged), the white streaks due to flight instability, and the ink dries faster than a predetermined value in the cap state, so that an image defect of intermittent ejection failure occurs.

Therefore, in the control of the whole system bubble removal operation, the ambient temperature of the recording head 36 is lower than the print permission temperature when the power of the inkjet recording device 1 is turned on, and then the ambient temperature of the recording head 36 reaches the print permission temperature. Is executed when there is one or more times. For example, when bubbles are generated in the cleaning liquid flow path 87 due to temperature undulations, they cannot be pushed out by simply controlling the bubble removal operation as described above, but according to the second embodiment, they are caused by temperature undulations. When there is a high probability that air bubbles are generated in the cleaning liquid flow path 87, it is possible to control the entire system bubble removal operation, and all the air bubbles generated in the cleaning liquid flow path 87 due to temperature undulations can be controlled. Can be extruded. As a result, cleaning defects can be reduced, and the occurrence of image defects due to intermittent discharge defects can be prevented.

Further, the present invention is not limited to the configuration of the above-described embodiment, and various modifications can be made. Further, in the above embodiment, the multifunction device is described as one embodiment of the inkjet recording device according to the present invention, but this is only an example, and for example, another inkjet recording device having a printer function may be used. Good.

Further, in the above-described embodiment, the configuration and processing shown by the above-described embodiment with reference to FIGS. 1 to 12 are merely one embodiment of the present invention, and the present invention is not intended to be limited to the configuration and processing.

1 Inkjet recording device 8 Cleaning unit 12 Image recording unit 36 Recording head 83 Cleaning liquid supply unit 84 Scattering prevention member 85 Cleaning liquid storage unit 87 Cleaning liquid flow path 100 Control unit 130 Cleaning liquid pump (driving unit)
371 Ink ejection port 821 Wiper member 866 Inclined surface 871 Vertical tubular member 872 Horizontal tubular member 873 Check valve H1 Heater TS1 Ink temperature sensor TS2 Ambient temperature sensor

Claims (4)

A recording head having an ink ejection surface having an ink ejection port for ejecting ink,
A wiper member that wipes the ink ejection surface by contacting the ink ejection surface and moving in a predetermined wiping direction.
A cleaning liquid supply surface having a cleaning liquid supply port for supplying a cleaning liquid used for wiping the ink ejection surface by the wiper member, and a cleaning liquid supply unit provided on the upstream side of the ink ejection surface in the wiping direction.
A cleaning liquid storage unit that stores the cleaning liquid,
A cleaning liquid flow path for guiding the cleaning liquid from the cleaning liquid storage unit to the cleaning liquid supply unit, and
A drive unit that moves the cleaning liquid in the cleaning liquid flow path and gives a power to push out the cleaning liquid from the cleaning liquid supply port.
A control unit that controls a cleaning operation in which the ink ejection surface is wiped by the wiper member using the cleaning liquid and a bubble removing operation executed before the control of the cleaning operation is provided.
One end of the cleaning liquid flow path is connected to the cleaning liquid supply unit, and one end is connected to a vertical tubular member extending above the cleaning liquid supply unit from one end to the other end, and one end is connected to the upper end side of the vertical tubular member. In addition, a lateral tubular member extending from one end to the other end in the horizontal direction is provided.
In order to control the bubble removing operation, the control unit (i) supplies a cleaning liquid in an amount of 0.5 times or more and 0.9 times or less the total volume of the cleaning liquid supply unit and the vertical tubular member from the cleaning liquid supply port. Extrude, (ii) move the wiper member in the wiping direction from a movement start position, which is a position upstream of the cleaning liquid supply surface in the wiping direction, to a position in front of the ink ejection surface, and (iii) the wiper. An inkjet recording device that controls the member to be separated from the cleaning liquid supply surface. The inkjet recording device according to claim 1, wherein the horizontal tubular member further includes a check valve that guides the cleaning liquid in the direction of the vertical tubular member. Further provided is a shatterproof member provided on the downstream side of the ink ejection surface in the wiping direction and in contact with the wiper member after the wiper member wipes the ink ejection surface.
As a control of the cleaning operation, the control unit pushes out purge ink from the ink ejection port of the recording head and pushes out the cleaning liquid from the cleaning liquid supply port to move the wiper member from the movement start position to the ink ejection surface. The inkjet recording apparatus according to claim 1 or 2, wherein the wiper member is moved in the wiping direction to an end position which is a position where it comes into contact with the shatterproof member, and the wiper member is controlled to be separated from the end position. The cleaning liquid supply unit is further provided with an inclined surface that is continuously located on the upstream side in the wiping direction and is inclined upward with respect to the cleaning liquid supply surface as it advances to the upstream side in the wiping direction. ,
The movement start position is any one of claims 1 to 3, wherein the tip of the wiper member is a predetermined position in a region directly below the inclined surface and an upper region of a plane including the cleaning liquid supply surface. The described inkjet recording device.