JP7310396B2 - Head wiping device and image forming apparatus - Google Patents

Description

The present invention relates to a head wiping device and an image forming apparatus.

2. Description of the Related Art Conventionally, there has been known an image forming apparatus that forms an image on a recording medium by ejecting ink from nozzles provided in an ejection head. This type of image forming apparatus is equipped with a cleaning unit that cleans the nozzle surface to which ink adheres. As such a cleaning unit, for example, a head wiping device is known that wipes away ink stains adhering to the nozzle surface of the ejection head with a wiping member such as a web.

The head wiping device includes, for example, a fibrous web and a web transport section that transports the web. Ink adhering to the nozzle surface is wiped off by the web conveying unit conveying the web in contact with the nozzle surface. Also, among such head wiping devices, there is one that can selectively attach one of a plurality of types of webs made of different materials (see, for example, Patent Document 1).

In the head wiping device of Patent Document 1, when the type of web is changed, the state of contact of the web with the nozzle surface also changes. In addition, if the nozzle surface is wiped under the same wiping conditions regardless of how the web contacts the nozzle surface, variations in wiping performance may occur.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such problems, and provides a head wiping device for wiping the nozzle surface of an ejection head, in which a stable wiping performance can be obtained even if the type of wiping member is changed. intended to provide

In order to solve the above-described problems, one aspect of the present invention provides a wiping member that wipes a nozzle surface of an ejection head in a wiping direction, and an attachment portion that can selectively attach one of a plurality of wiping members of different types. and an adjustment mechanism for adjusting a contact width of the wiping member that contacts the nozzle surface in the wiping direction according to the type of the wiping member attached to the mounting portion, wherein the mounting portion includes: A nonwoven fabric can be attached as the wiping member, and when the nonwoven fabric is attached to the attachment portion, the adjustment mechanism increases the contact width as the density of the fibers constituting the nonwoven fabric is lower. and

According to the present invention, stable wiping performance can be obtained even if the type of wiping member is changed.

1 is a diagram showing a schematic configuration of an inkjet recording apparatus according to an embodiment; FIG. 2 is a diagram showing the hardware configuration of an inkjet recording apparatus; FIG. FIG. 2 is an exploded perspective view of the head wiping device; FIG. 3 is an assembly perspective view of the head wiping device; Fig. 2 is a plan view of the wiping web; Sectional drawing in VI-VI of FIG. FIG. 4 is a view showing the positional relationship between the ink ejection section and the head wiping device; A flowchart of cleaning processing. FIG. 5 is a diagram showing an adjustment mechanism according to Modification 1; FIG. 11 is a diagram showing an adjustment mechanism according to Modification 2; The figure which shows the adjustment mechanism which concerns on the modified example 3. FIG. FIG. 4 is a diagram showing the relationship between the density of fibers forming the nonwoven fabric and the size of the contact width.

[Overall description]
FIG. 1 is a diagram showing a schematic configuration of an inkjet recording apparatus (image forming apparatus) 1 according to an embodiment of the invention. FIG. 2 is a diagram showing the hardware configuration of the inkjet recording apparatus 1. As shown in FIG.

As shown in FIGS. 1 and 2 , the inkjet recording apparatus 1 includes a paper feeding section 100 , an image forming section 200 , a drying section 300 , a paper discharging section 400 and a head wiping device 500 . The inkjet recording apparatus 1 forms an image by ejecting ink from the image forming section 200 onto a sheet P as a recording medium fed from the sheet feeding section 100 . After drying the ink adhering to the paper P in the drying unit 300 , the paper P is discharged from the paper discharge unit 400 .

[Paper feed section]
The paper feeding unit 100 includes a paper feeding tray 110 on which a plurality of papers P are stacked, a feeding device 120 that separates and feeds the papers one by one from the paper feeding tray 110, and a registration roller that feeds the papers to the image forming unit 200. pair 130. As the feeding device 120, any known feeding device having a feeding function, such as a device using rollers, a device using air suction, or the like, can be used.

After the leading edge of the paper P sent out from the paper feeding tray 110 by the paper feeding device 120 reaches the pair of registration rollers 130, the pair of registration rollers 130 is driven at a predetermined timing, whereby the paper P is fed to the image forming section 200. be printed. Note that, in the present embodiment, the configuration of the paper feeding section 100 is not particularly limited as long as it has a function of feeding the paper P to the image forming section 200 .

[Image forming section]
The image forming section 200 includes a receiving cylinder 201 , a sheet conveying drum 210 (conveying member), an ink discharge section 220 and a transfer cylinder 202 . The receiving cylinder 201 receives the fed paper P (recording medium), and the paper transport drum 210 is a cylindrical transport member that carries and transports the paper P transported by the receiving cylinder 201 on its outer peripheral surface. The ink ejection section 220 ejects ink onto the paper P transported by the paper transport drum 210 . The delivery cylinder 202 delivers the paper P transported by the paper transport drum 210 to the drying section 300 .

The paper P transported from the paper feeding unit 100 to the image forming unit 200 is gripped at the leading end by the paper gripper 210a provided on the surface of the receiving cylinder 201 and transported as the surface of the receiving cylinder 201 moves. The paper P transported by the receiving cylinder 201 is transferred to the paper transport drum 210 at a position facing the paper transport drum 210 . The paper gripper 210a has a known structure.

A paper gripper 210a is also provided on the surface of the paper transport drum 210, and the leading edge of the paper P is gripped by the paper gripper 210a. In addition, a plurality of suction holes are dispersedly formed on the surface of the paper transport drum 210 . A suction device 211 generates a suction airflow toward the inside of the paper transport drum 210 in each suction hole, and the paper P is attracted to the surface of the paper transport drum 210 by this suction airflow. The paper P transferred from the receiving cylinder 201 to the paper transport drum 210 is gripped by the paper gripper 210a at the leading end, and is attracted to the surface of the paper transport drum 210 by the suction air current, and is moved by the surface movement of the paper transport drum 210. transported with it.

The ink ejection section 220 ejects four colors of ink, C (cyan), M (magenta), Y (yellow), and K (black), to form an image. The ink ejection section 220 includes individual line heads (ejection heads) 220C, 220M, 220Y, and 220K for each ink color. The line heads 220C, 220M, 220Y, and 220K eject ink supplied from ink cartridges of respective colors mounted in the inkjet recording apparatus 1 .

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

The line heads 220C, 220M, 220Y, and 220K of the ink ejection section 220 are ejection heads whose ejection operations are controlled by drive signals corresponding to image data. When the paper P conveyed by the paper conveying drum 210 passes through the area facing the ink ejection section 220, each color ink is ejected from the nozzles provided on the lower surface (nozzle surface) of each ejection head, and the image data is obtained. A corresponding image is formed. An ejection head having a known configuration can be used. Here, the “ejection head” means a functional part that ejects liquid.

Note that, in the present embodiment, the image forming section 200 only needs to have a function of forming an image by depositing liquid on the paper P, and the configuration for ejecting liquid or depositing liquid is particularly limited. isn't it.

[Drying section]
The drying section 300 includes a drying mechanism 301 and a transport mechanism 302 . The drying mechanism 301 dries ink adhering to the paper P in the image forming section 200 . The transport mechanism 302 transports the paper P transported from the image forming section 200 to the paper discharge section 400 side. That is, the paper P conveyed from the image forming section 200 is received by the conveying mechanism 302 , conveyed by the conveying mechanism 302 so as to pass through the drying mechanism 301 , and delivered to the paper discharge section 400 . When the paper P passes through the drying mechanism 301, the ink on the paper P is subjected to a drying process, whereby liquids such as moisture in the ink evaporate, the ink adheres to the paper P, and the paper P curls. Suppressed.

[Paper output section]
The paper discharge section 400 includes a paper discharge tray 410 on which a plurality of sheets P are stacked. The sheets P conveyed from the drying section 300 by the conveying mechanism 302 are sequentially stacked and held on the discharge tray 410 . Note that, in the present embodiment, the paper discharge unit 400 only needs to have a function of discharging the paper P, and the configuration thereof is not particularly limited.

[Other functional units]
The ink jet recording apparatus 1 of the present embodiment includes a paper feeding section 100, an image forming section 200, a drying section 300, and a paper discharging section 400, but other functional sections may be added as appropriate. For example, after adding a preprocessing unit for performing preprocessing for image formation between the paper feeding unit 100 and the image forming unit 200, or after performing postprocessing for image formation between the drying unit 300 and the paper discharging unit 400 Processing units can be added.

Examples of the pretreatment unit include those that perform a treatment liquid coating process for applying a treatment liquid to the paper P to suppress bleeding by reacting with the ink, but the contents of the pretreatment are particularly limited. isn't it. As a post-processing unit, for example, a sheet on which an image is formed in the image forming unit 200 is reversed and conveyed to the image forming unit 200 again to form images on both sides of the sheet, or a sheet reversing and conveying process for forming images on both sides of the sheet. For example, a process of binding a plurality of sheets of paper that have been bound together. Here, the content of post-processing is not particularly limited either.

In the present embodiment, the "image forming apparatus" is explained using the inkjet recording apparatus 1 as an example. However, the "image forming apparatus" is limited to those equipped with an ejection head for ejecting liquid toward the surface to be dried of the sheet material and capable of visualizing significant images such as letters and figures by the ejected liquid. Instead, for example, those that form patterns that have no meaning per se are also included.

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

In addition, the "image forming apparatus" can include means for feeding, transporting, and ejecting an object to which liquid can adhere, as well as a pre-processing device, a post-processing device, and the like.

Further, the "liquid" is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, but the viscosity is 30 mPa s or less at normal temperature and pressure, or by heating or cooling. Preferably.

More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional-imparting materials such as polymerizable compounds, resins, and surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium. , edible materials such as natural pigments, and the like. These can be used for applications such as inkjet inks and surface treatment liquids.

Further, the "image forming apparatus" includes an apparatus in which an ejection head and a recording medium move relative to each other, but is not limited to this. Specific examples include a serial type apparatus in which the ejection head is moved and a line type apparatus in which the ejection head is not moved.

Also, the “ejection head” is a functional component that ejects and ejects liquid from an ejection hole (nozzle). Piezoelectric actuators (laminated piezoelectric element and thin film piezoelectric element), thermal actuators using electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and a counter electrode are used as energy sources for liquid ejection. Energy generating means can be used, but the ejection energy generating means to be used is not limited.

In addition, "wiping" includes the meanings of cleaning, recovery, washing, maintenance, wiping, cleaning, etc. Unless otherwise specified, these words are treated as synonyms.

[Head wiping device]
The head wiping device 500 is hardware for wiping each of the line heads 220C, 220M, 220Y and 220K. The inkjet recording apparatus 1 includes head wiping devices 500C, 500M, 500Y, and 500K (hereinafter collectively referred to as "head wiping devices 500") corresponding to the line heads 220C, 220M, 220Y, and 220K, respectively. .

As shown in FIG. 1, the head wiping devices 500C, 500M, 500Y, 500K are arranged at positions facing the lower surfaces (nozzle surfaces) of the line heads 220C, 220M, 220Y, 220K. The head wiping devices 500C, 500M, 500Y, and 500K are arranged adjacent to the paper transport drum 210 in the direction orthogonal to the transport direction of the paper P, for example.

The line heads 220C, 220M, 220Y, and 220K face the paper transport drum 210 when performing image forming processing, which will be described later, and face the head wiping devices 500C, 500M, 500Y, and 500K when performing cleaning processing, which will be described later. to face This arrangement change may be realized by moving the line heads 220C, 220M, 220Y, and 220K, or may be realized by moving the paper transport drum 210 and the head wiping device 500. FIG.

FIG. 3 is an exploded perspective view of the head wiping device 500. FIG. 4 is an assembled perspective view of the head wiping device 500. FIG. FIG. 5 is a plan view of the wiping web 511. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5. FIG. FIG. 7 is a diagram showing the positional relationship between the ink ejection section 220 and the head wiping device 500. As shown in FIG. A head wiping device 500 according to this embodiment mainly includes a wiping unit 510, a mounting portion 520, a pressing member 530, a holder 540, and a motor 220a.

The wiping unit 510 is formed by unitizing a strip-shaped wiping web (wiping member) 511 , a drawing roller 512 and a winding roller 513 . More specifically, the wiping web 511 is wound around the draw-out roller 512 . The outer edge of the wiping web 511 wound around the feed roller 512 is fixed to the take-up roller 513 . The wiping unit 510 is configured to be detachable from the mounting portion 520 .

The mounting portion 520 supports the wiping unit 510 and the pressing member 530 inside the inkjet recording apparatus 1 . One of the plurality of wiping units 510 having different types of wiping webs 511 can be selectively attached to the mounting portion 520 . The replacement of the wiping unit 510 with respect to the mounting portion 520 may be manually performed by the user, or may be performed automatically by a replacement unit mounted on the inkjet recording apparatus 1 .

The mounting portion 520 includes, for example, a driven shaft 521 that rotatably supports the drawing roller 512, a drive shaft 522 that rotatably supports the take-up roller 513, and a frame 523 that supports the driven shaft 521 and the drive shaft 522. , and a motor 524 that rotationally drives the drive shaft 522 .

The driven shaft 521 and the drive shaft 522 are supported by the frame 523 at positions spaced apart in the wiping direction. The pressing member 530 is fixed to the frame 523 while being held by a holder 540 (see FIG. 7) between the driven shaft 521 and the driving shaft 522 in the wiping direction.

The draw-out roller 512 is supported by the driven shaft 521 , the take-up roller 513 is supported by the drive shaft 522 , and the wiping web 511 between the draw-out roller 512 and the take-up roller 513 is the upper surface (contact surface) of the pressing member 530 . ), the wiping unit 510 is attached to the attachment portion 520 .

When the motor 524 is rotated with the wiping unit 510 attached to the mounting portion 520 , the wiping web 511 wound around the feed roller 512 is wound around the take-up roller 513 . That is, the motor 524 rotates the take-up roller 513 in a direction to take up the wiping web 511 wound around the draw-out roller 512 . As a result, the wiping web 511 moves in the wiping direction.

The wiping web 511 wipes the nozzle surface of the ink ejection section 220 by moving while being in contact with the nozzle surface. The wiping direction refers to the moving direction of the wiping web 511 . The wiping direction is, for example, the direction along which the paper P is transported. However, the wiping direction is not limited to the above example as long as it is a direction along the nozzle surface.

The wiping web 511 according to this embodiment is a "woven fabric" in which threads (fibers) are combined vertically and horizontally. Also, the wiping web 511 according to the present embodiment is formed in a belt shape whose length in the wiping direction is longer than the direction perpendicular to the wiping direction (hereinafter referred to as "width direction"). Furthermore, it is desirable that the threads forming the wiping web 511 have a flat shape in which the length in the width direction is longer than the direction perpendicular to the wiping direction and the width direction (hereinafter referred to as "thickness direction").

More specifically, the wiping web 511 is constructed by weaving a plurality of warp threads 514 and a plurality of weft threads 515, as shown in FIGS. The plurality of warp threads 514 each extend in the wiping direction and are spaced apart from each other in the width direction. The plurality of weft threads 515 each extend in the width direction and are spaced apart from each other in the wiping direction.

Here, the type of the wiping web 511 is, for example, the rigidity of the wiping web 511, the material of the threads 514 and 515, the softness of the threads 514 and 515, the thickness of the threads 514 and 515, the water absorption of the threads 514 and 515, It refers to the fineness of the weave of the threads 514 and 515, the presence or absence of surface treatment on the wiping web 511, and the like.

The pressing member 530 is made of an elastically deformable material (for example, elastic rubber). The upper surface (contact surface) of the pressing member 530 that contacts the wiping web 511 is curved. Although the wiping web 511 is not shown in FIG. 7, the pressing member 530 is arranged on the opposite side of the nozzle surface of the ink ejection section 220 with the wiping web 511 interposed therebetween.

The motor 220a functions as an adjustment mechanism that adjusts the contact width of the wiping web 511 with respect to the nozzle surface by moving the ink ejection section 220 in the direction of contacting and separating from the wiping web 511 . The contact width refers to the width in the wiping direction of the wiping web 511 that contacts the nozzle surface.

More specifically, when the ink ejection section 220 is brought closer to the holder 540 by _ΔHA from the reference position (left diagram in FIG. 7) (center diagram in FIG. 7), the nozzle surface and the pressing member 530 are brought into contact with each other with the wiping web 511 interposed therebetween. abut. At this time, the pressing member 530 presses the wiping web 511 against the nozzle surface while elastically deforming. As a result, the contact width between the nozzle surface and the wiping web 511 is A.

Further, when the ink ejection section 220 is brought closer to the holder 540 by ΔH _B (ΔH _A <ΔH _B ) from the reference position (the right figure in FIG. 7), the pressing member 530 is elastically deformed further, and the wiping web 511 is moved to the nozzle. Press firmly against the surface. At this time, the contact surface of the pressing member 530 shown in the right diagram of FIG. 7 becomes flatter than the central diagram of FIG. 7, and the contact area with the wiping web 511 increases. As a result, the contact width between the nozzle surface and the wiping web 511 is B (A<B).

[Control part]
As shown in FIG. 2, the inkjet recording apparatus 1 includes a CPU (Central Processing Unit) 10, a RAM (Random Access Memory) 20, a ROM (Read Only Memory) 30, a HDD (Hard Disk Drive) 40, and an I/F 50. It has a configuration connected via a common bus 90 .

The CPU 10 is computing means and controls the operation of the entire inkjet recording apparatus 1 . The RAM 20 is a volatile storage medium from which information can be read and written at high speed, and is used as a working area when the CPU 10 processes information. The ROM 30 is a read-only non-volatile storage medium and stores programs such as firmware. The HDD 40 is a non-volatile storage medium that allows reading and writing of information and has a large storage capacity, and stores an OS (Operating System), various control programs, application programs, and the like.

The inkjet recording apparatus 1 processes a control program stored in the ROM 30, an information processing program (application program) loaded from a storage medium such as the HDD 40 to the RAM 20, and the like, using the computing function of the CPU 10. FIG. A software control unit including various functional modules of the inkjet recording apparatus 1 is configured by the processing. A functional block that implements the functions of the inkjet recording apparatus 1 is configured by combining the software control unit configured in this way and the hardware resources installed in the inkjet recording apparatus 1 . That is, the CPU 10 , RAM 20 , ROM 30 and HDD 40 constitute a control section 2 that controls the operation of the inkjet recording apparatus 1 .

The I/F 50 is an interface that connects the LCD 60 , the operating section 70 , the paper feeding section 100 , the image forming section 200 , the drying section 300 and the head wiping device 500 to the common bus 90 . The LCD 60 is a display that displays various screens for notifying the user of information. The operation unit 70 is an input interface that receives input of various information from the user, and includes a touch panel superimposed on the LCD 60, push buttons, and the like.

The control unit 2 controls the paper feeding unit 100, the image forming unit 200, and the drying unit 300 to execute an image forming process of forming an image indicated by the image data on the paper M. FIG. The image data may be received from an external device (for example, a PC) through a communication interface, or may be generated by reading a document with a scanner mounted on the inkjet recording apparatus 1 .

Further, the control section 2 executes a cleaning process for wiping the nozzle surface of the ink ejection section 220 with the head wiping device 500 . FIG. 8 is a flowchart of cleaning processing. In this embodiment, the cleaning process is executed at the timing when the ink cartridge is installed in the inkjet recording apparatus 1 . However, the execution timing of the cleaning process is not limited to this, and may be the timing instructed by the user through the operation unit 70 or the timing when a predetermined time has passed since the most recent cleaning process.

First, the user sets an ink cartridge in the inkjet recording apparatus 1 (S801). Next, the controller 2 identifies the type of ink stored in the ink cartridge based on the information recorded in the recognition chip of the set ink cartridge (S802). The type of ink may be, for example, an ink component (pigment, dye).

Next, the control section 2 selects the wiping unit 510 corresponding to the type of ink specified in step S802 from among the plurality of wiping units 510 that can be attached to the attachment section 520 (S803). It is assumed that the wiping unit 510 corresponding to the type of ink is determined in advance.

Next, the controller 2 displays the type (for example, model number) of the wiping unit 510 selected in step S803 on the LCD 60 (S804). As a result, the user sets the wiping unit 510 of the type indicated through the LCD 60 to the mounting portion 520 (S805).

Next, the control section 2 adjusts the contact width of the wiping web 511 with respect to the nozzle surface according to the type of the wiping unit 510 attached to the attachment portion 520 to wipe the nozzle surface (S806). When the head wiping device 500 finishes wiping the nozzles, the control unit 2 ends the cleaning process. Accordingly, the image forming process can be executed.

For example, in step S806, the control unit 2 preferably adjusts the contact width so that the two or more weft threads 515 forming the wiping web 511 contact the nozzle surface. That is, the wider the interval between adjacent weft yarns 515, the wider the contact width, and the narrower the interval between adjacent weft yarns 515, the narrower the contact width.

According to the above embodiment, for example, the following operational effects are obtained.

According to the above embodiment, the wiping web 511 is brought into contact with the nozzle surface with a contact width suitable for the type of the wiping unit 510 (wiping web 511). , stable (constant) wiping performance can be obtained. As a result, the nozzle surface can be kept clean at all times, and the image forming quality in the image forming process is improved.

Further, according to the above embodiment, the contact area of the pressing member 530 with respect to the wiping web 511 is changed by changing the pressing force of the pressing member 530 against the nozzle surface. This makes it possible to easily adjust the contact width of the wiping web 511 with respect to the nozzle surface.

Further, according to the above embodiment, when a woven cloth is attached to the attachment portion 520 as the wiping web 511, the contact width is adjusted so that two or more weft threads 515 contact the nozzle surface. As a result, the wiping performance of the wiping web 511 on the nozzle surface can be prevented from deteriorating. By reducing the number of weft threads 515 in contact with the nozzle surface, the amount of wiping web 511 used in the cleaning process can be reduced. On the other hand, by increasing the number of weft threads 515 in contact with the nozzle surface, the wiping performance is improved. Therefore, the contact width may be appropriately selected depending on the balance between the usage amount of the wiping web 511 and the wiping performance.

In the above embodiment, the wiping unit 510 is selected according to whether the ink is pigment ink or dye ink, and the contact width is adjusted to be suitable for the selected wiping unit 510 . However, the factors for adjusting the contact width are not limited to the above examples. As another example, the wiping unit 510 may be selected according to the ink color or ink physical properties (contact angle, etc.), and the contact width may be adjusted to suit the selected wiping unit 510 . As a result, the difference in wiping performance due to the difference in ink color and physical properties can be reduced.

In the above embodiment, the type of wiping unit 510 is selected based on the information of the recognition chip of the ink cartridge, and the LCD 60 instructs the user to install the selected wiping unit 510. FIG. As another example, the inkjet recording apparatus 1 may include identification means for identifying the type of the wiping unit 510 attached to the attachment portion 520 .

More specifically, the control section 2 may allow the user to input the type of the wiping unit 510 attached to the attachment section 520 through the operation section 70 . In this case, the control section 2 functions as identification means for identifying the type of the wiping unit 510 based on the user's operation on the operation section 70 . Then, the control section 2 may adjust the contact width according to the type of the wiping unit 510 specified by the specifying means in step S806 of FIG.

Further, in the above embodiment, an example in which the contact width is adjusted by moving the ink ejection section 220 with the motor 220a has been described. However, the method of adjusting the width of contact is not limited to the above example, and the width of contact may be adjusted by changing the relative distance between the nozzle surface and the holder 540 . Modifications of the adjusting mechanism will be described below with reference to FIGS. 9 to 11. FIG.

[Modification 1]
FIG. 9 is a diagram showing an adjusting mechanism according to Modification 1. FIG. A detailed description of the common points with the above embodiment will be omitted, and the description will focus on the points of difference.

The adjustment mechanism according to Modification 1 mainly includes a cam 560 and a motor 563 . The cam 560 includes a large-diameter portion 561 and a small-diameter portion 562 having a rotation radius smaller than that of the large-diameter portion 561 . The cam 560 rotates around the rotation axis by transmission of the driving force of the motor 563 .

Further, the holder 550 according to Modification 1 has a holding portion 551 that holds the pressing member 530 at one end and a contact portion 552 that contacts the cam 560 at the other end. The holder 550 reciprocates between the nozzle surface and the cam 560 as the cam 560 rotates.

More specifically, when the small-diameter portion 562 of the cam 560 contacts the contact portion 552 (center view in FIG. 9), the holder 550 approaches the ink discharge portion 220 by _ΔHA from the reference position (left view in FIG. 9). . As a result, the contact width between the nozzle surface and the wiping web 511 is A.

When the large-diameter portion 561 of the cam 560 contacts the contact portion 552 (the right diagram in FIG. 9), the holder 550 approaches the ink discharge portion 220 by _ΔHB ( _ΔHA < _ΔHB ) from the reference position. As a result, the contact width between the nozzle surface and the wiping web 511 is B (A<B).

[Modification 2]
10A and 10B are diagrams showing an adjustment mechanism according to Modification 2. FIG. A detailed description of the common points with Modification 1 will be omitted, and the description will focus on the points of difference.

A holder 570 according to Modification 2 further includes a coil spring (biasing member) 573 between a holding portion 571 that holds the pressing member 530 and a contact portion 572 that contacts the cam 560 . The coil spring 573 plays a role of urging the pressing member 530 toward the nozzle surface.

According to Modification 2, the elasticity of the coil spring 573 enables fine adjustment of the contact width. Also, by replacing the coil spring 573 with a different spring constant, the contact width can be adjusted.

[Modification 3]
11A and 11B are diagrams showing an adjustment mechanism according to Modification 3. FIG. A detailed description of the common points with the above embodiment will be omitted, and the description will focus on the points of difference.

Modification 3 is an example in which the contact width is adjusted by selectively attaching one of a plurality of pressing members 531, 532, and 533 having different shapes of contact surfaces with the wiping web 511 to the holder 540. . That is, in Modification 3, the pressing members 531 to 533 also serve as the adjustment mechanism. In Modification 3, the amount of elastic deformation of the pressing members 531 to 533 when pressed against the nozzle surface is negligibly small.

The pressing members 531, 532, and 533 have different curvatures of contact surfaces. When the pressing member 531 having the smallest curvature is selected (the left diagram in FIG. 11), the contact width becomes A. On the other hand, if the pressing member 532 whose contact surface has a greater curvature than the pressing member 531 is selected (center view in FIG. 11), the contact width is B (A<B). Furthermore, on the other hand, if the pressing member 533 whose contact surface has a larger curvature than the pressing member 532 is selected (the right diagram in FIG. 11), the contact width becomes C (B<C).

[Modification 4]
Further, in the above-described embodiment, an example in which a woven cloth is used as the wiping web 511 has been described. However, as the wiping web 511, the attachment portion 520 may be attached not only with a “woven fabric” but also with a “non-woven fabric”.

Therefore, in Modified Example 4, a method of adjusting the contact width when a wiping web 511 made of nonwoven fabric is employed will be described with reference to FIG. 12 . FIG. 12 is a diagram showing the relationship between the density of fibers forming the nonwoven fabric and the contact width. A detailed description of the common points with the above embodiment will be omitted, and the description will focus on the points of difference.

As shown in FIG. 12, when a nonwoven fabric is attached to the attachment portion 520 as the wiping web 511, the lower the fiber density of the nonwoven fabric, the larger the contact width, and the higher the fiber density of the nonwoven fabric, the smaller the contact width. is desirable. That is, in step S806 of FIG. 8, the control section 2 specifies the contact width corresponding to the fiber density of the wiping web 511 of the wiping unit 510 attached to the attachment section 520, and adjusts the contact width to the specified contact width. The relative distance between the nozzle surface and the holder 540 may be changed.

In addition, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical scope of the invention. All of are covered by the present invention. Although the above embodiment shows a preferred example, a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims.

1 image forming apparatus 2 control unit 10 CPU
20 RAMs
30 ROMs
40 HDDs
50 interface
60 LCDs
70 Operation unit 100 Paper supply unit 110 Paper supply tray 120 Paper supply device 130 Registration roller pair 200 Image forming unit 201 Receiving cylinder 202 Delivery cylinder 210 Paper transport drum 211 Suction device 210a Paper gripper 220 Ink ejection unit 220a, 524 Motor 300 Drying unit 301 drying mechanism 302 conveying mechanism 400 paper discharge unit 410 paper discharge trays 500, 500C, 500M, 500Y, 500K head wiping device 510 wiping unit 511 wiping web (wiping member)
512 Draw-out roller 513 Winding roller 514 Warp 515 Weft 520 Mounting portion 521 Driven shaft 522 Drive shaft 523 Frames 530, 531, 532, 533 Pressing members 540, 550, 570 Holders 551, 571 Holding portions 552, 572 Contact portion 573 Coil spring (biasing member)
560 cam 561 large diameter portion 562 small diameter portion 563 motor

JP 2017-205954 A

Claims (10)

a wiping member that wipes the nozzle surface of the ejection head in a wiping direction;
a mounting portion capable of selectively mounting one of the plurality of wiping members of different types;
an adjusting mechanism for adjusting a contact width of the wiping member that contacts the nozzle surface in the wiping direction according to the type of the wiping member attached to the mounting portion ;
A nonwoven fabric can be attached to the attachment portion as the wiping member,
The head wiping device is characterized in that, when the nonwoven fabric is attached to the attachment portion, the adjustment mechanism increases the contact width as the density of the fibers constituting the nonwoven fabric decreases. a pressing member that presses the wiping member attached to the attachment portion toward the nozzle surface;
A holder that supports the pressing member,
2. The head wiping device according to claim 1, wherein the adjustment mechanism adjusts the contact width by changing the relative distance between the nozzle surface and the holder. the pressing member is elastically deformable and has a curved contact surface with the wiping member;
3. The head wiping device according to claim 2, wherein the adjusting mechanism adjusts the contact width by changing the pressing force of the pressing member against the nozzle surface. 4. The head wiping device according to claim 2, wherein the adjusting mechanism moves the ejection head in a direction toward and away from the wiping member. The adjustment mechanism is
a cam having a large-diameter portion and a small-diameter portion having a rotation radius smaller than that of the large-diameter portion;
and a motor that rotates the cam,
3. A holder having one end that holds said pressing member and the other end that abuts against said cam and reciprocates between said nozzle surface and said cam as said cam rotates. 3. The head wiping device according to 3. 6. The head wiping device according to claim 5, wherein the holder includes a biasing member that biases the pressing member toward the nozzle surface. A woven cloth can be attached to the attachment portion as the wiping member,
The adjusting mechanism, when the woven cloth is attached to the attachment portion, has a plurality of fibers constituting the woven cloth, each of which extends in a direction orthogonal to the wiping direction and is spaced apart in the wiping direction. 7. The head wiping device according to any one of claims 1 to 6, wherein said contact width is adjusted so that two or more fibers that are joined contact said nozzle surface. an identification means for identifying the type of the wiping member attached to the attachment portion;
8. The head wiping device according to claim 1, wherein the adjusting mechanism adjusts the contact width according to the type of the wiping member specified by the specifying means. A wiping unit having a strip-shaped wiping member, a draw-out roller around which the wiping member is wound, and a take-up roller to which the tip of the wiping member wound around the draw-out roller is fixed,
The mounting portion includes a motor that rotates the winding roller in a direction in which the wiping member is wound,
9. The wiping member wipes the nozzle surface in the wiping direction by being wound up from the feed roller to the take-up roller while in contact with the nozzle surface. The head wiping device according to any one of 1. the ejection head forming an image on a recording medium by ejecting ink from nozzles formed on the nozzle surface;
An image forming apparatus comprising the head wiping device according to claim 1 .