JP6953816B2 - Cleaning method for liquid discharge device and liquid discharge head - Google Patents

Description

The present invention relates to a device for discharging a liquid and a method for cleaning a liquid discharge head.

As a method of cleaning dirt adhering to the nozzle surface of the inkjet head, there is a method of supplying a cleaning liquid to the web, transporting the area to which the cleaning liquid is supplied to the pressing portion, and then wiping the nozzle surface (for example, Patent Document 1). reference).

Conventionally, due to restrictions such as layout, the position where the cleaning liquid is supplied to the web is located on the upstream side of the pressing portion in the transport direction of the web. Then, when the area of the web to which the cleaning liquid for cleaning the nozzle to be wiped is supplied is located on the pressing portion, the cleaning liquid for cleaning the nozzle to be wiped next is supplied to the web.

Therefore, in the web, the area corresponding to the position where the pressing portion is pressed and the position where the cleaning liquid is supplied is a useless area where the cleaning liquid is not supplied (a region not used for wiping the nozzle surface). ), And there was a problem that the usage rate of the web was poor.

In order to solve the above problems, the device for discharging the liquid of the present invention includes a sheet-shaped wiping member that wipes the nozzle surface of each of a plurality of liquid discharge heads, a transport member that conveys the wiping member, and the wiping. The wiping member includes a pressing member that presses the member against any of the nozzle surfaces, and a supply member that supplies a cleaning liquid upstream of the pressing member in the transport direction of the wiping member. For each liquid discharge head, the supply member supplies the cleaning liquid to the wiping member to form a supply region, which is a region of the wiping member to which the cleaning liquid is supplied, and the wiping member has a plurality of the cleaning liquids. At least two or more of the liquid discharge heads are wiped, and the supply member has the supply region formed in the wipe member located upstream of the pressing member in the transport direction. Occasionally, the following cleaning liquid is supplied to the wiping member, and the cleaning liquid is supplied according to the positional relationship between the liquid discharge head to be wiped first and the liquid discharge head to be wiped second. When the supply timing is changed and the distance between the first wiping target and the second wiping target is equal to or less than the threshold value, the first transport member indicates the supply area corresponding to the first wiping target. The cleaning liquid for forming the second supply region indicating the supply region corresponding to the second wiping target is supplied to the wiping member while the supply region of the above is being conveyed onto the pressing member. Then, when the distance between the first wiping target and the second wiping target exceeds the threshold value, the transport member covers the first supply region corresponding to the first wiping target on the pressing member. The cleaning liquid for forming the second supply region corresponding to the second wiping target is not supplied to the wiping member during the transportation toward the wiping member .

According to the present invention, the usage rate of the web can be improved.

FIG. 1 is an overall schematic view of the inkjet recording apparatus according to the invention. FIG. 2A is a plan view showing the operation of the wiping unit. FIG. 2B is a plan view showing the operation of the wiping unit. FIG. 3A is a side view showing the operation of the wiping unit. FIG. 3B is a side view showing the operation of the wiping unit. FIG. 4 is a block diagram showing a control unit of the inkjet recording device. FIG. 5 is a diagram showing details of the wiping unit. FIG. 6A is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 6B is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 6C is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 6D is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 6E is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 6F is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 6G is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 6H is a diagram showing a wiping operation by the wiping unit in the conventional configuration. FIG. 7 is a diagram showing a state of the wiping member in the conventional configuration. FIG. 8A is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8B is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8C is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8D is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8E is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8F is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8G is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8H is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 8I is a diagram showing a wiping operation by the wiping unit in the first embodiment. FIG. 9 is a diagram showing a state of the wiping member in the first embodiment. FIG. 10 is a diagram showing a state of the wiping member in the modified example of the first embodiment. FIG. 11A is a diagram showing a wiping operation by the wiping unit in the second embodiment. FIG. 11B is a diagram showing a wiping operation by the wiping unit in the second embodiment.

Hereinafter, an embodiment of a device for discharging a liquid and a method for cleaning a liquid discharge head according to the present invention will be described with reference to the drawings. The "device for discharging a liquid" in each of the following embodiments is a device including a head for discharging the liquid and driving the head to discharge the liquid. The "device for discharging a liquid" includes not only a device capable of discharging a liquid to an object to be discharged, but also a device for discharging the liquid into the air or the liquid. For example, an image forming apparatus, a three-dimensional modeling apparatus, a processing liquid coating apparatus, an injection granulation apparatus, and the like are applicable. In the following, as an example of the “device for discharging a liquid”, an example of application of the image forming device to one inkjet recording device will be shown.

(First Embodiment)
[Overall explanation]
FIG. 1 is a schematic diagram showing a schematic configuration of an inkjet recording device 1 according to the present embodiment. As shown in FIG. 1, the inkjet recording apparatus 1 is mainly composed of a paper feeding unit 100, an image forming unit 200, a drying unit 300, and a paper ejection unit 400.

The inkjet recording device 1 ejects an image, which is a liquid for image formation, from the image forming unit 200 onto the paper P, which is a recording material which is a sheet material as a medium to be fed from the paper feeding unit 100. To form. Then, after the ink adhering to the paper P is dried by the drying unit 300, the paper is discharged from the paper ejection unit 400.

[Paper feed section]
The paper feed unit 100 mainly feeds the paper feed tray 110 on which a plurality of sheets P are loaded, the feeding device 120 that separates and feeds the paper sheets one by one from the paper feed tray 110, and the paper to the image forming unit 200. It is composed of a pair of resist rollers 130 to be fed.

As the feeding device 120, any feeding device such as a device using rollers and rollers and a device using air suction can be used. The paper P fed from the paper feed tray 110 by the feeding device 120 is fed to the image forming unit 200 by driving the resist roller pair 130 at a predetermined timing after the tip of the paper P reaches the resist roller pair 130. Will be done.

In the present embodiment, the paper feeding unit 100 is not limited in its configuration as long as it feeds the paper P to the image forming unit 200.

[Image forming part]
The image forming unit 200 mainly has a receiving cylinder 201 that receives the fed paper P (recording medium) and a cylindrical paper conveying drum that carries the paper P conveyed by the receiving cylinder 201 by supporting it on the outer peripheral surface. 210 (conveying member), an ink ejection unit 220 that ejects ink toward the paper P conveyed by the paper conveying drum 210, and a delivery cylinder 202 that delivers the paper P conveyed by the paper conveying drum 210 to the drying unit 300. It is composed of and.

The tip of the paper P transported from the paper feeding unit 100 to the image forming unit 200 is gripped by the paper gripper 210a provided on the surface of the receiving cylinder 201, and is conveyed as the surface of the receiving cylinder 201 moves. The paper P transported by the receiving cylinder 201 is delivered to the paper transport drum 210 at a position facing the paper transport drum 210. A known structure of the paper gripper can be used.

A paper gripper 210a is also provided on the surface of the paper transport drum 210, and the tip of the paper is gripped by the paper gripper 210a. Further, a plurality of suction holes are dispersedly formed on the surface of the paper transport drum 210, and a suction device 211 generates a suction airflow toward the inside of the paper transport drum 210 in each suction hole.

The tip of the paper P delivered from the receiving cylinder 201 to the paper transport drum 210 is gripped by the paper gripper 210a and is attracted to the surface of the paper transport drum 210 by the suction airflow to move the surface of the paper transport drum 210. It is transported along with it.

The ink ejection unit 220 of the present embodiment ejects four colors of ink, C (cyan), M (magenta), Y (yellow), and K (black) to form an image, and each ink is individually ejected. Line heads 220C, 220M, 220Y, 220K are provided.

The line heads 220C, 220M, 220Y, 220K are not limited in their configuration as long as they discharge liquid, and any configuration can be adopted. If necessary, a liquid ejection head that ejects a special ink such as white, gold, or silver may be provided, or a liquid ejection head that ejects a liquid that does not form an image, such as a surface coating liquid, may be provided.

The line heads 220C, 220M, 220Y, and 220K of the ink ejection unit 220 each have a plurality of liquid ejection heads, which will be described later, and the ejection operation is controlled by a drive signal corresponding to the image information. When the paper P conveyed by the paper transfer drum 210 passes through the area facing the ink ejection unit 220, each color ink is ejected from the lower surface (nozzle surface) of each liquid ejection head, and an image corresponding to the image information is displayed. It is formed. A known configuration can be used for the liquid discharge head. The liquid discharge head means a component that discharges a liquid.

In the present embodiment, the image forming unit 200 is not limited as long as it has a structure in which a liquid is adhered to the paper P to form an image.

[Dry part]
The drying unit 300 mainly includes a drying mechanism 301 for drying the ink adhering on the paper P in the image forming unit 200, and a conveying mechanism 302 for conveying the paper P conveyed from the image forming unit 200. Has been done.

The paper P conveyed from the image forming unit 200 is received by the conveying mechanism 302, then conveyed so as to pass through the drying mechanism 301, and is delivered to the paper ejection unit 400. When passing through the drying mechanism 301, the ink on the paper P is subjected to a drying process, which evaporates liquids such as water in the ink, the ink adheres to the paper P, and the paper P is curled. It is suppressed.

[Paper ejection section]
The paper ejection unit 400 is mainly composed of a paper ejection tray 410 on which a plurality of sheets P are loaded. The paper P conveyed from the drying unit 300 is sequentially stacked and held on the output tray 410.

In the present embodiment, the paper ejection unit 400 is not limited in its configuration as long as it ejects the paper P.

[Other functional parts]
The inkjet recording device 1 of the present embodiment is composed of a paper feeding unit 100, an image forming unit 200, a drying unit 300, and a paper ejection unit 400, but other functional units may be added as appropriate. For example, after adding a pre-processing unit that performs pre-processing of image formation between the paper feeding unit 100 and the image forming unit 200, or after performing post-processing of image formation between the drying unit 300 and the paper discharging unit 400. A processing unit can be added.

Examples of the pretreatment unit include a treatment liquid coating process for applying a treatment liquid to the paper P to react with the ink to suppress bleeding, but the content of the pretreatment is not particularly limited. ..

Further, as the post-processing unit, for example, a paper reversal transfer process for reversing the paper on which the image is formed by the image forming unit 200 and sending it to the image forming unit 200 again to form an image on both sides of the paper, or an image The process of binding a plurality of sheets of paper on which the above is formed can be mentioned, but the content of the post-processing is not particularly limited.

In the present embodiment, the device that discharges the liquid is described by the example of the inkjet recording device 1, but the “device that discharges the liquid” is a liquid that discharges the liquid toward the surface to be dried of the sheet material. It is not limited to those provided with a discharge head and in which significant images such as characters and figures are visualized by the discharged liquid, and for example, those that form a pattern or the like that has no meaning in itself are also included.

The material of the sheet material is not limited, and any material such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, etc., to which a liquid can adhere even temporarily may be used, for example. It may be used for film products, cloth products for clothing, building materials such as wallpaper and flooring, and leather products. In the present embodiment, a medium to which a liquid can adhere even temporarily is referred to as a "medium".

Further, the "device for discharging the liquid" can include means for feeding, transporting, and discharging paper to which the liquid can adhere, and also includes a pretreatment device, a posttreatment device, and the like.

The "liquid" may have a viscosity and surface tension that can be discharged from the head, and is not particularly limited, but has a viscosity of 30 mPa · s or less at room temperature, under normal pressure, or by heating or cooling. It is preferable to have.

More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functionalizing materials such as surfactants, biocompatible materials such as DNA, amino acids and proteins, and calcium. , Solvents, suspensions, emulsions and the like containing edible materials such as natural dyes, and the like, and these can be used in applications such as inks for inkjets and surface treatment liquids.

Further, the "device for discharging the liquid" includes, but is not limited to, a device in which the liquid discharge head and the sheet material move relative to each other. Specific examples include a serial type device that moves the liquid discharge head, a line type device that does not move the liquid discharge head, and the like.

The "liquid discharge head" is a functional component that discharges and ejects a liquid from a discharge hole (nozzle). Piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heat-generating resistors, and electrostatic actuators that consist of a vibrating plate and counter electrodes are discharged as energy sources for discharging liquid. Although energy generating means can be used, the discharge energy generating means to be used is not limited.

As will be described later, in the present embodiment, a plurality of liquid discharge heads are arranged in the paper width direction (direction orthogonal to the paper P transport direction) to form a long liquid discharge head (line head).

In addition, "wiping" shall include the meanings of cleaning, recovery, cleaning, maintenance, wiping, cleaning, etc. Unless otherwise specified, these terms are treated as synonyms.

Next, the configuration around the wiping unit will be described with reference to FIGS. 2A and 2B.

FIG. 2A is a plan view of a main part of the image forming unit 200. The line head 220C includes liquid discharge heads 221a to 221h along the paper width direction (direction orthogonal to the paper transport direction). In the following description, when the liquid discharge heads 221a to 221h are not distinguished from each other, they are referred to as "liquid discharge head 221". The same configuration is used for line heads of other colors. In the present embodiment, eight liquid discharge heads 221 are arranged side by side, but the number of liquid discharge heads 221 does not matter. Further, in the present embodiment, the arrangement of the liquid discharge heads is staggered, but the arrangement is not limited to this.

Further, a wiping mechanism 70 is arranged on the outside of each line head in the paper width direction. The wiping mechanism 70 is mainly composed of a wiping unit 700C, 700M, 700Y, 700K (hereinafter, referred to as a wiping unit 700 unless otherwise specified), a rail member 790, and the like.

The wiping unit 700 includes at least a wiping member made of a web or the like, and moves along the arrangement direction of the plurality of liquid discharge heads 221 so that the wiping member comes into contact with the liquid discharge head 221 to bring the wiping member into contact with the liquid discharge head 221 to contact the nozzle surface of the liquid discharge head 221. Can be wiped off. The wiping unit 700 is provided at the end of the rail member 790, and as shown in FIG. 2b, the rail member 790 moves in the paper width direction to move the wiping unit 700, and the wiping member of the wiping unit 700 is a liquid discharge head. It is configured so that it can come into contact with 221 and wipe off dirt on the nozzle surface.

In the present embodiment, the liquid discharge heads 221 are arranged in a staggered arrangement, and the line head 220 has a row of liquid discharge heads 221a to 221d and a row of liquid discharge heads 221e to 221d. In this embodiment, a plurality of wiping units 700 are provided so as to correspond to each head row. That is, each liquid discharge head 221 is provided with two head rows and two wiping units 700 corresponding to one-to-one, but the present invention is not limited to this, and for example, one wiping unit 700 combines two head rows. It may be configured to be wiped off.

Next, the movement around the wiping unit 700 when the apparatus is viewed from the transport direction of the paper P will be described with reference to FIGS. 3A and 3B. As described above, the wiping unit 700 is arranged on the outside of the line head 220 in the paper width direction. The wiping unit 700 includes a wiping member 701 and a pressing member 703. The wiping member 701 is a sheet-like member that wipes each nozzle surface of the liquid discharge head, and examples thereof include a sheet such as a web.

The pressing member 703 is configured to urge the wiping member 701 upward, and presses the wiping member 701 toward the nozzle surface of the liquid discharge head 221.

Then, as shown in FIG. 3B, when the rail member 790 moves in the paper width direction, the wiping member 701 provided in the wiping unit 700 comes into contact with the liquid discharge head 221a and wipes the nozzle surface of the liquid discharge head 221. can.

Next, the control unit 500 of the present apparatus will be described with reference to FIG. The control unit 500 includes a main control unit 500A including a CPU 501 that controls the entire device, a ROM 502 that stores fixed data such as various programs including a program executed by the CPU 501, and a RAM 503 that temporarily stores image data and the like. I have.

The control unit 500 includes a rewritable non-volatile memory 604 (NVRAM) for holding data even while the power of the device is cut off. The control unit 500 includes an ASIC 505 that processes various signal processing for image data, image processing for sorting, and other control input / output signals.

The control unit 500 includes a print control unit 508 including a data transfer means for driving and controlling each liquid discharge head 221 of the ink discharge unit 220, a drive signal generation means, and a bias voltage output means, and a drive for driving each head. It is equipped with an IC (here referred to as a "head driver") 509.

The control unit 500 includes a supply system control unit 512 that drives and controls the liquid feed pump 580. Although not shown in this embodiment, the liquid feed pump 580 is driven when ink stored in an ink container such as a cartridge is fed to the liquid discharge head 221.

The control unit 500 has a wiping mechanism driving unit 515 for operating each part of the wiping mechanism 70. The wiping mechanism drive unit 515 includes a rail member motor 523, a supply member motor 524, and a transport member motor 709.

By driving the rail member motor 523, the rail member 790 can be reciprocated in the paper width direction. By driving the supply member motor 524, the cleaning liquid 777 can be applied to the wiping member 701 by the supply member 717 described later. By driving the transport member motor 709, the transport member 707 can be rotated and the wiping member 701 can be transported.

The control unit 500 has an I / O unit 513. The I / O unit 513 can process various sensor information and acquires information from various sensor groups 570. Then, the information necessary for controlling the device is extracted and used for control by the print control unit 508, the supply system drive unit 512, the wiping mechanism drive unit 515, and the like.

An operation panel 514 for inputting and displaying information necessary for this device is connected to the control unit 500.

The configuration of the control unit 500 is an example and can be changed as appropriate. For example, the control unit can be composed of the CPU 501 and the wiping mechanism drive unit 515, or the wiping mechanism drive unit 515 alone can be regarded as the control unit. When only the wiping mechanism drive unit 515 is used as the control unit, for example, a control signal may be output from a separate PC.

Next, the details of the wiping unit 700 will be described with reference to FIG. The wiping unit 700 includes a wiping member 701, a pressing member 703, a spring 715, a take-up roller 705 and 707, a transport member motor 709, rollers 711 and 713, and a supply member 717.

The wiping member 701 is a sheet-like member that wipes the nozzle surface of each of the plurality of liquid discharge heads 221. Examples thereof include a sheet such as a web. The pressing member 703 presses the wiping member 701 against any nozzle surface. The pressing member 703 of the present embodiment is configured to urge the wiping member 701 upward, and presses the wiping member 701 toward the nozzle surface of the liquid discharge head 221. The spring 715 urges the pressing member 703 upward. The spring 715 can also be made of an elastic member such as rubber.

A wiping member 701 is wound around the take-up roller 705, and an end portion of the wiping member 701 is wound around the take-up roller 707. Further, the wiping member 701 is arranged so as to be bridged over the roller 711, the pressing member 703, and the roller 713. The transport member motor 709 can rotate the take-up roller 707 by driving, and by this rotation, the wiping member 701 can be taken up and conveyed. At this time, the wiping member 701 is conveyed in the direction of arrow A.

Unless otherwise specified, the take-up rollers 705 and 707, the rollers 711 and 713, and the transport member motor 709 are collectively referred to as a "convey member" in the present embodiment. However, the configuration of the transport member is not limited to these, and for example, the number and arrangement of rollers may be different, or transport may be possible by a drive source other than the motor. In short, the transport member may have a configuration capable of transporting the wiping member 701.

The supply member 717 is located upstream of the pressing member 703 in the transport direction A of the wiping member 701, and supplies the cleaning liquid 777 to the wiping member 701. The supply member 717 can be operated by driving and controlling the supply member motor 524 described above. A pump or the like can be used instead of the motor, and a known technique can be applied to the mechanism for supplying the cleaning liquid 777 to the wiping member 701. Details will be described later, but here, for each liquid discharge head 221 to be wiped, the supply member 717 supplies the cleaning liquid to the wiping member 701, so that the supply area of the wiping member 701 that is the area to which the cleaning liquid is supplied is defined. It is formed. The supply member 717 supplies the cleaning liquid so that the plurality of supply areas do not overlap.

The cleaning liquid 777 is a liquid for increasing the cleaning power by wiping, and the type is not limited.

The control unit 500 controls the movement operation of the wiping unit 700, the transfer operation of the wiping member 701 by the transfer member, and the supply operation of the cleaning liquid by the supply member 717. Here, the control unit 500 controls the timing of the moving operation, the conveying operation, and the supplying operation so that the cleaning liquid supplied to the wiping member 701 comes into contact with the nozzle surface within a predetermined time.

It may be considered that the CPU 501 provides a function (“control unit”) for controlling the moving operation of the wiping unit 700, the transporting operation of the wiping member 701 by the transport member, and the supply operation of the cleaning liquid by the supply member 717. However, it may be considered that it is provided by the main control unit 500A.

Next, a method of cleaning the liquid discharge head 221 according to the conventional configuration will be described with reference to FIGS. 6A to 6H. 6A to 6H are views showing the cleaning process step by step by enlarging the main part of FIG. 3 described above. Note that FIG. 6 shows a case where the liquid discharge head 221a and the liquid discharge head 221b are wiped in order. That is, in this example, the first wiping target is the liquid discharge head 221a, and the second wiping target is the liquid discharge head 221b.

First, as shown in FIG. 6a, the wiping unit 700 moves to the vicinity below the liquid discharge head 221a. In the present embodiment, the line head 220 can be raised and lowered in the vertical direction, and the wiping unit 700 can pass under the line head 220 while the line head 220 is raised. ..

Then, as shown in FIG. 6B, the supply member 717 supplies the cleaning liquid 777 to the wiping member 701. At this time, the cleaning liquid 777 is supplied upstream of the pressing member 703 in the transport direction of the wiping member 701. As a result, the supply region S1 which is the region to which the cleaning liquid 777 is supplied is formed in the wiping member 701.

Since the supply region S1 formed at this time corresponds to the liquid discharge head 221a to be wiped first (used for wiping the liquid discharge head 221a), it can be considered as the first supply region.

Next, as shown in FIG. 6C, the wiping member 701 is conveyed in the direction of the arrow by driving the conveying member (specifically, the conveying member motor 709). At this time, the supply region S1 is conveyed above the pressing member 703.

Next, the line head 220 is lowered so that the supply region S1 has a height that allows contact with the lower surface (nozzle surface) of the liquid discharge head 221a. Of course, the wiping unit 700 may be configured to be able to move up and down.

Then, as shown in FIGS. 6E and 6F, by moving the wiping unit 700, the supply region S1 can be wiped so as to be pressed against the liquid discharge head 221a.

Then, as shown in FIG. 6G, the supply region S2 is formed by the same procedure. That is, the supply member 717 supplies the next cleaning liquid 777 (cleaning liquid for forming a supply region used for wiping the next wiping target). Since the supply region S2 formed at this time corresponds to the liquid discharge head 221b which is the second wiping target, it can be considered as the second supply region.

Next, as shown in FIG. 6H, the wiping member 701 is conveyed in the direction of the arrow by the conveying member. At this time, the distance between the first supply area S1 and the second supply area S2 is set to X. In the case of such a conventional configuration, the distance X is substantially equal to the distance between the supply member 717 and the pressing member 703 in the transport path of the wiping member 701.

FIG. 7 is a part of the wiping member 701 used for wiping, and shows the state of the formed supply region. Note that S1'and S2' indicate dirty portions adhering to the supply areas S1 and S2, respectively.

As described above, there is a distance X between the first supply area S1 and the second supply area S2. That is, of the wiping member 701, the area within the distance X does not wipe the nozzle surface of the liquid discharge head 221 and is wasted, so that the usage rate of the wiping member 701 is poor. In particular, when a plurality of liquid discharge heads 221 are wiped, the wasted area becomes large, and the frequency of replacement of the wiping member 701 is accelerated.

Therefore, in the present embodiment, the supply member 717 supplies the next cleaning liquid 777 to the wiping member 701 when the supply region formed on the wiping member 701 is located upstream of the pressing member 703 in the transport direction. do. That is, in the supply member 717, the distance between the plurality of supply regions (distance between the first supply region S1 and the second supply region S2) formed on the wiping member 701 is the cleaning liquid by the supply member 717 in the wiping member 701. The cleaning liquid 777 is supplied so as to be smaller than the distance (corresponding to the above distance X) between the position where the 777 is supplied and the position where the pressing member 703 presses. As a result, the area of the area of the wiping member 701 that is not used for wiping the nozzle surface of the liquid discharge head 221 can be reduced as compared with the conventional configuration, so that the usage rate of the wiping member 701 can be improved. can.

Hereinafter, the specific contents of the present embodiment will be described with reference to FIGS. 8A to 8J. The description of FIGS. 8A and 8B is almost the same as that of FIGS. 6A and 6B. As described above, each operation of the wiping unit 700 such as the moving operation of the wiping unit 700, the transport operation of the wiping member 701 by the transport member, and the supply operation of the cleaning liquid by the supply member 717 is controlled by the control unit 500. In this example, the control unit 500 (computer) supplies the cleaning liquid 777 to the wiping member 701 for each liquid discharge head 221 to be wiped, so that the supply area of the wiping member 701 is the region to which the cleaning liquid 777 is supplied. Control for supplying the next cleaning liquid 77 to the wiping member 703 when the supply region formed in the wiping member 701 is located upstream of the pressing member 703 in the transport direction of the wiping member 701. To execute.

First, as shown in FIG. 8a, the wiping unit 700 moves to the vicinity below the liquid discharge head 221a. In the present embodiment, the line head 220 can be raised and lowered in the vertical direction, and the wiping unit 700 can pass under the line head 220 while the line head 220 is raised. ..

Then, as shown in FIG. 8b, the supply member 717 supplies the cleaning liquid 777 to the wiping member 701. At this time, the cleaning liquid 777 is supplied upstream of the pressing member 703 in the transport direction of the wiping member 701. As a result, the supply region S1 which is the region to which the cleaning liquid 777 is supplied is formed in the wiping member 701.

Since the supply region S1 formed at this time corresponds to the liquid discharge head 221a to be wiped first, it can be considered as the first supply region. Hereinafter, it may be referred to as “first supply area S1”.

FIG. 8c is a feature of this embodiment, which is one of the differences from the prior art. In the present embodiment, when the formed supply area S1 (first supply area S1) is located upstream of the pressing member 703, the next cleaning liquid 777 is supplied to the wiping member 701. At this time, the supply region S2 formed on the wiping member 701 can be considered as a second supply region because it corresponds to the liquid discharge head 221b which is the second wiping target. Hereinafter, it may be referred to as “second supply area S2”. Here, the upstream means the upstream in the transport path of the wiping member 701.

More specifically, before the first supply region S1 is conveyed onto the pressing member 703, the next cleaning liquid 777 is supplied to form the second supply region S2. As a result, the distance X can be made smaller than that of the conventional configuration, and the unused portion of the wiping member 701 can be reduced.

After that, as shown in FIGS. 8D to 8G, the nozzle surface of the liquid discharge head 221a, which is the first object to be wiped, is wiped by the first supply area S1. At this time, for example, when there is a third wiping target, as shown in FIG. 8h, when the second supply area S2 is located upstream of the pressing member 703, the third supply area S3 is set. Form.

FIG. 9 shows the state of the wiping member 701 used in the present embodiment. Since the distance X is smaller than that of the conventional configuration, more wiping can be performed with one wiping member 701.

As shown in FIG. 10, by making the distance X as small as possible, it is possible to perform more wiping. However, the wiping member 701 impregnated with the cleaning liquid 777 may have high dirt permeability. When the distance X is small, for example, the dirt wiped by the supply area S1 permeates and permeates to the adjacent supply area S2, and the nozzle surface is wiped by the supply area S2 containing the dirt, and the cleaning ability is increased. It is possible that it will decrease.

Therefore, in the present embodiment, the supply member 717 supplies the cleaning liquid 777 so that the plurality of formed supply regions do not overlap.

In the present embodiment, the wiping operation by the wiping unit 700 is continuously performed for all the liquid discharge heads 221 in the order in which they are arranged (for example, in order from the upstream side in the moving direction of the wiping unit 700). .. However, the present invention is not limited to this, and the liquid discharge head 221 to be wiped may be selectable by, for example, control by the control unit 500 or manual input by the user. For example, the liquid discharge head 221d may be wiped next to the liquid discharge head 221a. As a result, only the liquid discharge head whose nozzle surface is dirty can be wiped, and the consumption of the wiping member 701 can be suppressed.

The timing (trigger) for starting the wiping operation is managed by the control unit 500. When the start timing of the wiping operation is reached, the control unit 500 controls to wipe the nozzle surface of the liquid discharge head 221 to be wiped. The start timing of the wiping operation can be arbitrarily set. For example, the wiping operation may be started when the number of printed sheets exceeds a certain value, or the wiping operation may be started before the start of printing. Of course, the wiping operation may be started by the user operating the panel or the like, and a known technique can be used.

(Second Embodiment)
Next, the second embodiment will be described with reference to FIGS. 11A and 11B. In the present embodiment, the wiping member 701 can be reversely fed by the transport member (the wiping member 701 is fed in the direction opposite to the transport direction A described above). For example, by arranging a drive source such as a motor on the take-up roller 705 side described above, reverse feeding becomes possible.

As shown in FIG. 11A, the distance between the supply region Sa and the supply member 717 can be reduced by causing the supply region Sa in which the transport member is located on the pressing member 703 to run backward toward the supply member 717. ..

More specifically, the transport member is capable of the reverse feed operation of the wiping member 701, and is supplied after the supply region Sa located on the pressing member 703 is back feedd to the upstream side in the transport direction by the reverse feed operation. The member 717 supplies the cleaning liquid 777 to the wiping member 701.

Then, by forming the next supply region S1 as shown in FIG. 11b, the distance X can be made smaller than that of the conventional configuration, as in the first embodiment described above.

(Third Embodiment)
Next, the third embodiment will be described. In the present embodiment, the wiping member 701 wipes at least two or more of the plurality of liquid discharge heads 221 and the supply member 717 and the liquid discharge head 221 (for example, the liquid discharge head 221a) to be wiped first. , The timing of supplying the cleaning liquid 777 is changed according to the positional relationship with the liquid discharge head 221 (for example, the liquid discharge head 221d) to be wiped second. More specifically, when the distance between the first wiping target and the second wiping target is equal to or less than the threshold value, the supply member 717 indicates a supply region in which the transport member corresponds to the first wiping target. The cleaning liquid 777 for forming the second supply region indicating the supply region corresponding to the second wiping target is supplied to the wiping member 701 while the supply region of the above is being conveyed onto the pressing member 703. Further, when the distance between the first wiping target and the second wiping target exceeds the threshold value, the supply member 717 presses the first supply region corresponding to the first wiping target on the pressing member 703. The cleaning liquid 777 for forming the second supply region corresponding to the second wiping target is not supplied to the wiping member 701 during the transportation toward the wiping member 701.

In the present embodiment, of the plurality of liquid discharge heads 221 shown in FIG. 2a, for example, two of the liquid discharge head 221a and the liquid discharge head 221d are targeted for wiping (that is, when the distances between the wiping targets are separated to some extent). ) Is effective.

In this case, the first supply region S1 corresponding to the liquid discharge head 221a to be wiped first is first formed, and immediately after that, the second supply corresponding to the liquid discharge head 221d to be wiped second is formed. If the region S2 is formed, the cleaning liquid 777 in the second supply region S2 may be dried while the wiping unit 700 is moving to the liquid discharge head 221d.

In the present embodiment, for example, when the distance between the liquid discharge head 221d, which is the second object to be wiped, and the wiping unit 700 becomes smaller than the distance stored in advance in the control unit 500 (memory or the like), the supply member The 717 is set to form the second supply region S2. As a result, the liquid discharge head 221d can be wiped off before the cleaning liquid 777 in the second supply region S2 dries. Of course, this configuration is an example and does not limit the configuration.

In the following, a more specific flow of the entire wiping operation will be described. First, the liquid discharge head 221 to be wiped by the wiping unit 700 (wiping member 701) is selected and targeted for wiping. For example, the control unit 500 back-calculates the dirt on the liquid discharge head 221 from the number of printed sheets and the like, and selects the liquid discharge head 221 that is presumed to need to be wiped. Of course, manual selection may be performed by the user operating the panel or the like. In the following, a case where two wiping targets are continuously wiped will be described as an example. The first wiping target is the first wiping target, and the second wiping target is the second wiping target.

Next, the wiping unit 700 is moved to the vicinity of the first wiping target, and the supply member 717 is operated to form the first supply region S1.

Here, when there are two or more wiping targets, the distance between the first wiping target and the second wiping target (or another information corresponding to the distance may be used) is the control unit 500 (memory or the like). Compares with the threshold value (condition) stored in advance.

At this time, when the distance between the first wiping target and the second wiping target is equal to or less than the threshold value, the supply member 717 wipes while the transport member transports the supply region S1 toward the pressing member 703. By supplying the cleaning liquid 777 to the member 701, the supply region S2 corresponding to the second wiping target is formed. That is, when the distance between the first wiping target and the second wiping target is equal to or less than the threshold value, it is considered that the cleaning liquid 777 is difficult to dry even if the second supply region S2 is formed at an early stage. Such control is performed.

On the contrary, when the distance between the first wiping target and the second wiping target exceeds the threshold value, the second wiping target is set while the transport member is transporting the supply area S1 toward the pressing member 703. It does not form the corresponding supply region S2. That is, when the distance between the first wiping target and the second wiping target exceeds the threshold value, it is considered that the cleaning liquid 777 dries if the second supply region S2 is formed at an early stage. Control.

In addition, for example, "when there are two or more liquid discharge heads interposed between the two wiping targets" may be a condition in which the distance between the wiping targets exceeds the threshold value. In short, even if the distance of the wiping target is not detected, it is determined whether or not the distance between the first wiping target and the second wiping target exceeds the threshold value by using the information and conditions corresponding to the distance. You can do it.

Then, when the distance between the first wiping target and the second wiping target exceeds the threshold value, the transport member transports the first supply region S1 onto the pressing member 703, and the pressing member 703 and the first supply region After the first wiping target is wiped by S1, the supply member 717 supplies the cleaning liquid 777 to the wiping member 701 to form the second supply region S2. As a result, it is possible to suppress the drying of the cleaning liquid 777 in the second supply region S2.

For example, it is assumed that among the liquid discharge heads shown in FIG. 2a, three objects to be wiped are 221a, 221b, and 221d. At this time, since the distance between the liquid discharge head 221a (first wiping target) and the liquid discharge head 221b (second wiping target) is short, the description was described in the first embodiment without worrying about the drying of the cleaning liquid 777. It is desirable to perform such an operation (that is, an operation of forming a second supply region before wiping the first wiping target) to improve the usage efficiency of the wiping member 701.

Since the distance between the liquid discharge head 221b (second wiping target) and the liquid discharge head 221d (third wiping target) is large, before wiping the second wiping target in order to prevent the cleaning liquid 777 from drying. The operation of forming the third supply region is not performed.

This configuration is particularly effective when the number of liquid discharge heads 221 increases and the distance between the heads tends to increase.

Further, more preferably, when the distance between the first wiping target and the second wiping target exceeds the threshold value by using the configuration described in the second embodiment, the wiping unit 700 and the second wiping target are used. After the distance becomes less than a predetermined threshold value, the transport member runs backward in the wiping member 701, and after the reverse running, the supply member 717 supplies the cleaning liquid 777 to the wiping member 701 to form a second supply region S2. It is good to do it. As a result, it is possible to reduce the drying of the cleaning liquid 777 while reducing the unused area of the wiping member 701. Further, the distance X between the supply areas on the wiping member 701 can be made smaller than that of the conventional configuration (the usage rate of the wiping member 701 can be improved) regardless of the position and number of the wiping targets. Here, when the distance between the first wiping target and the second wiping target is equal to or greater than the threshold value, the vehicle is transported after the distance between the wiping unit 700 and the second wiping target becomes less than a predetermined threshold value. The member runs backward through the wiping member 701, but the present invention is not limited to this, and for example, a form in which the reverse running does not occur may be used.

The predetermined threshold value can be arbitrarily changed. For example, the wiping unit 700 may be set so that the reverse run is performed while moving to the second wipe target, or the reverse run may be performed after the movement is completed. Of course, as described above, another information corresponding to the distance may be used.

Although the embodiments according to the present invention have been described above, the present invention is not limited to the above-described embodiments as they are, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments described above. In addition, components spanning different embodiments and variants may be combined as appropriate.

For example, as in Patent Document 1, even in a line head in which liquid discharge heads are arranged diagonally, the present invention can be applied when the cleaning liquid is supplied in a plurality of parts or when the drying of the cleaning liquid is considered.

1 Inkjet recording device 100 Feeding unit 200 Image forming unit 220 Ink ejection unit 221 Liquid ejection head 300 Drying unit 400 Paper ejection unit 500 Control unit 700 Wiping unit 701 Wiping member 703 Pressing member 705 Winding roller 707 Winding roller 709 Conveying member Motor 711 Roller 713 Roller 715 Spring 717 Supply member 777 Cleaning liquid 790 Rail member P Paper (recording medium)
S1 first supply area S2 second supply area

Japanese Unexamined Patent Publication No. 2012-20112

Claims (8)

A sheet-shaped wiping member that wipes the nozzle surface of each of a plurality of liquid discharge heads,
A transport member that transports the wiping member and
A pressing member that presses the wiping member against any of the nozzle surfaces, and
Among the wiping members, a supply member that supplies a cleaning liquid upstream of the pressing member in the transport direction of the wiping member is provided.
For each of the liquid discharge heads to be wiped, the supply member supplies the cleaning liquid to the wiping member, so that a supply region, which is a region of the wiping member to which the cleaning liquid is supplied, is formed.
The wiping member wipes at least two or more of the liquid discharge heads among the plurality of liquid discharge heads.
The supply member supplies the following cleaning liquid to the wiping member when the supply region formed on the wiping member is located upstream of the pressing member in the transport direction .
The timing of supplying the cleaning liquid is changed according to the positional relationship between the liquid discharge head to be wiped first and the liquid discharge head to be wiped second.
When the distance between the first wiping target and the second wiping target is equal to or less than a threshold value, the transport member presses the first supply region indicating the supply region corresponding to the first wiping target. While being conveyed onto the member, the cleaning liquid for forming a second supply area indicating the supply area corresponding to the second wiping target is supplied to the wiping member.
When the distance between the first wiping target and the second wiping target exceeds the threshold value, the transport member directs the first supply region corresponding to the first wiping target onto the pressing member. A device for discharging a liquid, which is characterized in that the cleaning liquid for forming a second supply region corresponding to the second wiping target is not supplied to the wiping member during transportation. The liquid according to claim 1, wherein the supply member supplies the cleaning liquid to the wiping member before the supply region formed on the wiping member is conveyed onto the pressing member. Device. The transport member can perform a reverse feed operation of the wiping member.
The claim is characterized in that the supply member supplies the cleaning liquid to the wiping member after the supply region located on the pressing member is back-fed to the upstream side in the transport direction by the reverse feed operation. The device for discharging the liquid according to 1. The device for discharging the liquid according to any one of claims 1 to 3, wherein the supply member supplies the cleaning liquid so that the plurality of supply regions do not overlap. A wiping unit having at least the wiping member and wiping the plurality of liquid discharge heads by moving along the arrangement direction of the plurality of liquid discharge heads.
A control unit for controlling the moving operation of the wiping unit, the transporting operation of the wiping member by the transport member, and the supply operation of the cleaning liquid by the supply member is provided.
The control unit is characterized in that the timing of the movement operation, the transfer operation, and the supply operation is controlled so that the cleaning liquid supplied to the wiping member comes into contact with the nozzle surface within a predetermined time. The device for discharging the liquid according to any one of claims 1 to 4. The supply member
When the distance between the first wiping target and the second wiping target exceeds the threshold value, the transport member transports the first supply region onto the pressing member, and the pressing member and the first. Any one of claims 1 to 5, wherein after the first wiping target is wiped by the supply region of 1, the cleaning liquid is supplied to the wiping member to form the second supply region. A device that discharges the liquid according to the item. A cleaning unit including at least the wiping member and cleaning the plurality of liquid discharge heads by moving along the arrangement direction of the plurality of liquid discharge heads.
When the distance between the first wiping target and the second wiping target exceeds the threshold value, the transport member is used after the distance between the cleaning unit and the second wiping target becomes less than a predetermined distance. The wiping member is sent back and
The liquid according to any one of claims 1 to 6, wherein after the back feed, the supply member supplies the cleaning liquid to the wiping member to form the second supply region. Equipment to do. A sheet-shaped wiping member that wipes the nozzle surface of each of a plurality of liquid discharge heads,
A transport member that transports the wiping member and
A pressing member that presses the wiping member against any of the nozzle surfaces, and
Among the wiping members, a supply member that supplies the cleaning liquid upstream of the pressing member in the transport direction of the wiping member, and
A method of cleaning a liquid discharge head by a device that discharges a liquid.
By supplying the cleaning liquid to the wiping member for each of the liquid discharge heads to be wiped, a supply region, which is a region to which the cleaning liquid is supplied, is formed in the wiping member.
The wiping member wipes at least two or more of the liquid discharge heads among the plurality of liquid discharge heads.
The supply member supplies the following cleaning liquid to the wiping member when the supply region formed on the wiping member is located upstream of the pressing member in the transport direction .
The timing of supplying the cleaning liquid is changed according to the positional relationship between the liquid discharge head to be wiped first and the liquid discharge head to be wiped second.
When the distance between the first wiping target and the second wiping target is equal to or less than a threshold value, the transport member presses the first supply region indicating the supply region corresponding to the first wiping target. While being conveyed onto the member, the cleaning liquid for forming a second supply area indicating the supply area corresponding to the second wiping target is supplied to the wiping member.
When the distance between the first wiping target and the second wiping target exceeds the threshold value, the transport member directs the first supply region corresponding to the first wiping target onto the pressing member. A method for cleaning a liquid discharge head, which comprises not supplying the cleaning liquid for forming a second supply region corresponding to the second wiping target to the wiping member during transportation.

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