Nozzle face cleaning device and image recording device

A nozzle face cleaning device and an image recording device includes: a wiping member; cleaning liquid adding means which adds a cleaning liquid to the wiping member; pressing means that brings the wiping member to which the cleaning liquid has been added, into pressure-contact with a nozzle face; and wiping means which makes the wiping member and an ejection head relatively move, and wipes the nozzle face. A cleaning liquid supply flow channel is opened to the air in a connected portion of the cleaning liquid supply flow channel and a cleaning liquid adding nozzle.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a nozzle face cleaning device and an image recording device, and particularly to a nozzle face cleaning device and an image recording device which bring a wiping member to which a cleaning liquid has been added into contact with a nozzle face and wipes a nozzle face.

2. Description of the Related Art

Onto a nozzle face of an ink jet head which is used in an image recording device, for instance, an ink jet recording device, various foreign substances such as a residue of ink and paper powder are deposited due to service. When a foreign substance is deposited on the nozzle face, an ink droplet which is ejected from a nozzle is affected by the deposited foreign substance, thereby dispersion occurs in an ejection direction of ink droplets, and it becomes difficult to land the ink droplet at a predetermined position on a recording medium. The deposition of the foreign substance onto the nozzle face causes a deterioration of an image quality. Then, it becomes important in the ink jet recording device to remove the foreign substance with a maintenance method of periodical wiping or the like.

In the following Japanese Patent Application Laid-Open No. 2010-280067 (Patent Literature 1), for instance, a droplet ejecting device is described which has a structure of supplying a cleaning liquid to a wiping member, and wiping an ejection portion of an ejection head with the wiping member. In addition, Japanese Patent Application Laid-Open No. 2004-195908 (Patent Literature 2) describes a technology of ejecting a cleaning liquid onto a wiping sheet, pressing the wiping sheet to a nozzle face, and thereby wiping the nozzle face.

SUMMARY OF THE INVENTION

However, devices described in Patent Literatures 1 and 2 send a compressed air to a tank, supply the cleaning liquid to the wiping member with a spray nozzle or the like, and wipe the nozzle face with the wiping member. However, the spray nozzle and the like need to be replaced, and when a cleaning liquid supply tube is attached to and detached from the spray nozzle, air bubbles are mixed into the nozzle and the tube. There has been such a problem, for instance, that it becomes difficult in the early time of replacement to adjust the amount of the cleaning liquid, which has remarkably lowered the operability. In addition, when the wiping member is replaced, the spray nozzle needs to be detached. After the wiping member has been replaced, the position of the spray nozzle needs to be adjusted, and also from this point, the lowering of the operability has been shown.

The present invention is designed with respect to such circumstances, and an object is to provide a nozzle face cleaning device and an image recording device which can reduce mixing of air bubbles into a cleaning liquid supply flow channel, facilitate replacement of a web, and consequently can enhance operability.

In order to achieve the above described objects, the present invention provides a nozzle face cleaning device configured to clean a nozzle face of an ejection head which includes: a wiping member which has a long shape and water absorbing properties; cleaning liquid adding means configured to add a cleaning liquid to the wiping member, to bring the wiping member to a wet state by the cleaning liquid in an amount suitable for wiping the ejection head; pressing means configured to make the wiping member to which the cleaning liquid has been added abut on and pressed against the nozzle face; and wiping means that has wiping member travel driving means configured to make the wiping member travel in a longitudinal direction along a predetermined conveyance path, the wiping means configured to wipe the nozzle face with the wiping member to which the cleaning liquid has been added, by relatively moving the wiping member and the ejection head so that the wiping member which has been made abut on and pressed against the nozzle face slides along the nozzle face while being travelled by the wiping member travel driving means, wherein the cleaning liquid adding means includes a cleaning liquid supply flow channel, and a cleaning liquid adding nozzle which is detachably connected to the cleaning liquid supply flow channel and adds the cleaning liquid to the wiping member therethrough, wherein the cleaning liquid adding nozzle is provided in a case in which the wiping member, the wiping member travel driving means and the pressing means are integrated, and the cleaning liquid supply flow channel is opened to the air in a connected portion of the cleaning liquid supply flow channel with the cleaning liquid adding nozzle.

According to the present invention, the cleaning liquid supply flow channel and the cleaning liquid adding nozzle are included as the cleaning liquid adding means, wherein the cleaning liquid supply flow channel is opened to the air and is connected to a cleaning liquid supply nozzle. The nozzle face cleaning device supplies the cleaning liquid from the cleaning liquid supply flow channel to the cleaning liquid supply nozzle, by opening the flow channels to the air, dividing the flow channels and passing the cleaning liquid in the flow channels. Because of this, when the cleaning liquid supply nozzle is replaced, the air bubbles are not mixed in the cleaning liquid. Accordingly, the cleaning liquid supply nozzle can be easily replaced, and the amount of the cleaning liquid in the early time of the replacement can also be easily adjusted.

In addition, the cleaning liquid adding nozzle is provided in the case in which the wiping member, the wiping member travel driving means and the pressing means are integrated, and even when the cleaning liquid supply flow channel has been detached from the cleaning liquid adding nozzle, the cleaning liquid adding nozzle can be kept at a predetermined position. Accordingly, even when the cleaning liquid adding nozzle and the cleaning liquid supply flow channel are connected to each other again, the cleaning liquid adding nozzle does not need to be positioned. Furthermore, also when the wiping member is replaced, the cleaning liquid adding nozzle is fixed, even when the wiping member has been detached. Accordingly, the cleaning liquid adding nozzle does not need to be positioned, and the operability can be enhanced.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that a position at which the cleaning liquid is added to the wiping member from the cleaning liquid adding nozzle is provided in the upper side in a vertical direction of the wiping member, and that the cleaning liquid is added to the wiping member by the dripping of the cleaning liquid from the cleaning liquid adding nozzle.

The nozzle face cleaning device according to the other aspect of the present invention can supply the cleaning liquid by dripping the cleaning liquid onto the wiping member from the cleaning liquid supply nozzle. Accordingly, the nozzle face cleaning device can reliably add the cleaning liquid to a predetermined position, and accordingly can reduce the amount of the cleaning liquid. When the spray nozzle is used, the cleaning liquid is not occasionally added to the predetermined position, and there has been a large amount of a waste cleaning liquid, but in the present embodiment, the amount of the cleaning liquid can be reduced.

It is preferable that the nozzle face cleaning device according to other aspect of the present invention has a cutout portion in a portion at which the cleaning liquid supply flow channel is opened to the air.

The nozzle face cleaning device according to the other aspect of the present invention has the cutout portion in the portion at which the cleaning liquid supply flow channel is opened to the air, and accordingly can facilitate the cleaning liquid to flow through this cutout portion, and can pass the cleaning liquid in a direction of having the cutout portion.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that the cleaning liquid supply flow channel and the cleaning liquid adding nozzle are connected to each other through a rubber seal member.

In the nozzle face cleaning device according to the other aspect of the present invention, the cleaning liquid supply flow channel and the cleaning liquid adding nozzle are connected to each other through the rubber seal member. Accordingly, a connected portion of the cleaning liquid supply flow channel with the cleaning liquid adding nozzle can be firmly sealed, and liquid leakage does not occur. Thereby, the nozzle face cleaning device can efficiently add the cleaning liquid to the wiping member.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that a tip portion of the cleaning liquid adding nozzle has a bent shape.

The nozzle face cleaning device according to the other aspect of the present invention has the cleaning liquid adding nozzle of which the tip is the bent shape, thereby can drip the cleaning liquid from the tip having the bent shape, and accordingly can supply the cleaning liquid to a fixed position.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that a shape of the tip portion of the cleaning liquid adding nozzle is an acute angle.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that a shape of the tip portion of the cleaning liquid adding nozzle is a semicircular shape of which the curvature radius R is 1 cm or smaller.

The nozzle face cleaning device according to the other aspects of the present invention has the cleaning liquid adding nozzle of which the shape of the tip is the acute angle or the semicircular shape, and thereby can enhance dripping properties of the tip shape, and can supply a predetermined amount of the cleaning liquid.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that a surface of the cleaning liquid adding nozzle is formed from a water-repellent material.

The nozzle face cleaning device according to the other aspect of the present invention has the cleaning liquid adding nozzle of which the surface is formed from the water-repellent material, and accordingly can enhance the dripping properties of the cleaning liquid; and accordingly can facilitate the wiping member to add a predetermined amount of the cleaning liquid.

In a method of forming the surface of the cleaning liquid adding nozzle into the water-repellent material, a material having water repellency and adequate dripping properties can be used for a material of the cleaning liquid adding nozzle. In addition, a surface of the cleaning liquid adding nozzle can be coated with a water-repellent material.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that the nozzle face is arranged so as to be tilted against a horizontal plane, and the pressing means is arranged so as to be tilted so as to correspond to the nozzle face.

The nozzle face cleaning device according to the other aspect of the present invention has a tilted head of which the nozzle face is arranged so as to be tilted against the horizontal plane, but even so, can wipe the nozzle face by tilting the pressing means so as to correspond to the nozzle face.

In the nozzle face cleaning device according to other aspect of the present invention, it is preferable that a position at which the cleaning liquid is added to the wiping member from the cleaning liquid adding nozzle is provided in the upper side of tilt.

The nozzle face cleaning device according to the other aspect of the present invention adds the cleaning liquid in the upper side of the tilt, and thereby can spread the cleaning liquid on the wiping member by gravity. Accordingly, the nozzle face cleaning device can add the cleaning liquid in the width direction of the wiping member by providing a cleaning liquid nozzle in one portion in the width direction of the wiping member, and accordingly the device can be miniaturized.

It is preferable that the nozzle face cleaning device according to other aspect of the present invention supplies the cleaning liquid to the cleaning liquid adding nozzle by water head difference.

The nozzle face cleaning device according to the other aspect of the present invention supplies the cleaning liquid by the water head difference, and thereby can supply the cleaning liquid without using a pump, a nozzle, an ejection member (spray) or the like for supplying the cleaning liquid; and accordingly, can miniaturize the device, and can keep an inner part of the mechanism clean.

In order to achieve the above described objects, the present invention provides an image recording device which includes: conveyance means configured to convey a recording medium; a droplet ejection head configured to eject an ink droplet onto a recording medium which is conveyed by the conveyance means to form an image; and the nozzle face cleaning device that cleans the nozzle face of the droplet ejection head and is described above.

The image recording device according to the present invention includes the nozzle face cleaning device, and can enhance its ejection stability. In addition, the nozzle face cleaning device can be miniaturized, and accordingly the image recording device can enhance the selectivity of arrangement for each component of itself. In addition, the wiping member can reliably wipe the nozzle face in the state of having the cleaning liquid added thereon, and accordingly can prevent the nozzle face from being damaged.

The nozzle face cleaning device and the image recording device of the present invention have the cleaning liquid supply flow channel and the cleaning liquid adding nozzle divided at a place at which the cleaning liquid supply flow channel is opened to the air in the connected portion of the cleaning liquid supply flow channel with the cleaning liquid adding nozzle; also enable the cleaning liquid supply flow channel and the cleaning liquid adding nozzle to be attached to and detached from each other; and accordingly can prevent the air bubbles from entering into the cleaning liquid supply flow channel, when the cleaning liquid adding nozzle is replaced. In addition, the nozzle face cleaning device and the image recording device are structured so that the cleaning liquid adding nozzle is integrated with a case in which the pressing member, the wiping member and the like for wiping the nozzle face are integrated, accordingly the cleaning liquid can be set at a predetermined position, and the cleaning liquid adding nozzle does not need to be positioned. Accordingly, the nozzle face cleaning device and the image recording device can enhance the operability when the cleaning liquid adding nozzle, the wiping member and the like are replaced.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Preferable embodiments of the nozzle face cleaning device and the image recording device according to the present invention are described below with reference to the attached drawings. An ink jet recording device is described as one example of the image recording device.

<<Structure of Image Recording Section of Ink Jet Recording Device>>

FIG. 1is a side view illustrating a schematic structure of an image recording section of the ink jet recording device.

As is illustrated inFIG. 1, the image recording section10of the ink jet recording device of the present embodiment conveys a recording medium (sheet)12with a drum of an image recording drum14(conveyance means). Then, the image recording section10makes ink jet heads (droplet ejection head)16C,16M,16Y and16K which are arranged in the periphery of the image recording drum14eject ink droplets (ink droplet) of each color of C (cyan), M (magenta), Y (yellow) and K (black), in the conveyance step due to the image recording drum14, and records an image of a color image on the surface of the recording medium12.

The image recording drum14is rotatably provided while both ends of the rotary shaft18thereof are supported by a pair of bearings22(seeFIG. 2). The pair of bearings22are provided on a body frame20of the ink jet recording device, both of the ends of the rotary shaft18are supported by the pair of bearings22, and thereby the image recording drum14is horizontally attached (The rotary shaft18is attached in parallel to a horizontal installation plane).

A motor is connected to the rotary shaft18of the image recording drum14through an unillustrated rotation transmission mechanism. The image recording drum14is driven by this motor, and is rotated.

In addition, a gripper24which grips the tip part of the recording medium12is provided on the peripheral surface of the image recording drum14(In the present example, the grippers are installed in two places on the outer peripheral surface). The recording medium12is held on the outer peripheral surface of the image recording drum14while the tip part is gripped by this gripper24.

In addition, this image recording drum14is provided with an unillustrated absorption holding mechanism (for instance, electrostatic absorption and vacuum absorption). The recording medium12which is wound on an outer peripheral surface of the image recording drum14while a tip part is gripped by the gripper24is held on the outer peripheral surface of the image recording drum14while a rear face part thereof is absorbed by the absorption holding mechanism.

Incidentally, in the ink jet recording device of the present embodiment, the recording medium12is delivered to the image recording drum14through a conveyance drum26from the step in the preceding stage. The conveyance drum26is arranged in parallel to the image recording drum14, and delivers the recording medium12to the image recording drum14at synchronized timing.

In addition, the recording medium12on which the image has been recorded is delivered to the step in the latter stage through a conveyance drum28. The conveyance drum28is arranged in parallel to the image recording drum14, and receives the recording medium12from the image recording drum14at synchronized timing.

Four ink jet heads16C,16M,16Y and16K are structured by line heads corresponding to the width of the recording medium, and are radially arranged so as to have a fixed interval on a concentric circle which regards the rotary shaft18of the image recording drum14as a center.

Incidentally, in the present example, the four ink jet heads16C,16M,16Y and16K are arranged so as to become symmetric while sandwiching the image recording drum14. Specifically, the ink jet head16C of the cyan and the ink jet head16K of the black are symmetrically arranged with respect to a vertical line passing through the center of the image recording drum14, and the ink jet head16M of the magenta and the ink jet head16Y of the yellow are also symmetrically arranged.

As for each of thus arranged ink jet heads16C,16M,16Y and16K, the nozzle faces30C,30M,30Y and30K which are formed on the respective lower ends of the heads are arranged so as to face the outer peripheral surface of the image recording drum14, and the nozzle faces30C,30M,30Y and30K thereof are also positioned each at a position having a predetermined height from the outer peripheral surface of the image recording drum14(Gaps having the same distance are formed between an outer peripheral surface of image recording drum14and nozzle faces30C,30M,30Y and30K, respectively.). In addition, the columns of the nozzles which are formed on the respective nozzle faces30C,30M,30Y and30K are arranged so as to be perpendicular to the conveyance direction of the recording medium12.

The droplets of the inks are ejected perpendicularly toward the outer peripheral surface of the image recording drum14from thus arranged ink jet heads16C,16M,16Y and16K, through the respective nozzles which are formed in the nozzle faces30C,30M,30Y and30K.

FIG. 3is a perspective plan view of the nozzle face of the ink jet head.

Incidentally, the structures of each of the ink jet heads16C,16M,16Y and16K are common, and accordingly, here, the structure of the nozzle face30(30C,30M,30Y and30K) is described below as the ink jet head16.

As is illustrated inFIG. 3, the nozzle face30is formed to have a rectangular shape, a nozzle-formed region30A having a fixed width is formed in the middle part in the width direction (conveyance direction of recording medium), and nozzle protection regions30B are formed symmetrically so as to sandwich the nozzle-formed region30A.

The nozzle-formed region30A is a region in which the nozzles are formed, and predetermined liquid-repellent treatment is applied to the surface thereof (in other words, the surface is coated with liquid-repellent film).

Here, as is illustrated inFIG. 3, the ink jet head16of the present embodiment is structured by a so-called matrix head, and nozzles N are arranged in a two-dimensional matrix form in the nozzle-formed region30A. More specifically, the columns of the nozzles are formed, in which a plurality of nozzles N are arranged in a direction of being tilted against the conveyance direction of the recording medium12by a predetermined angle, at a fixed pitch, and a large number of the columns of the nozzles are arrayed in a direction (longitudinal direction of head) perpendicular to the conveyance direction of the recording medium12, at a fixed pitch. By having such an arrangement structure of the nozzles, a substantial gap among the nozzles N which are projected to a longitudinal direction (a direction perpendicular to the conveyance direction of the recording medium12) of the head can be narrowed, and the density of the nozzles N can be increased.

Incidentally, in the matrix head, the column of the nozzles which are projected to the longitudinal direction of the head is regarded as a substantial column of nozzles.

The nozzle protection regions30B arranged in both sides of the nozzle-formed region30A are regions for protecting the nozzle-formed region30A. The nozzle-formed region30A is retracted from this nozzle protection region30B by a predetermined amount, and is formed into a recessed shape (approximately by 0.2 mm).

Incidentally, in the ink jet head16of the present embodiment, only the nozzle-formed region30A is subjected to the liquid-repellent treatment (while nozzle protection region30B is not subjected to liquid-repellent treatment). In this case, when a liquid has been deposited onto the nozzle protection region30B, the liquid gets wet and spreads on the nozzle protection region30B.

In addition, the ink jet head16of the present embodiment ejects the droplet of the ink from the nozzle N by a so-called piezo method. Specifically, the nozzles N which are formed in the nozzle face30each communicate with respective pressure chambers P; and the pressure chamber P vibrates the wall face of itself by a piezo element, thereby expands and shrinks the volume of the pressure chamber P, and ejects the droplet of the ink from the nozzle N.

Incidentally, the ejection method of the ink is not limited to this method, and can include also methods of ejecting the ink by a thermal method and an electrostatic actuator.

The image recording section10is structured as in the above description. In this image recording section10, the recording medium12is delivered from the step in the preceding stage to the image recording drum14through the conveyance drum26, is absorbed and held on the peripheral surface of the image recording drum14, and is rotated and conveyed to the conveyance drum26. Then, the recording medium passes under each of the ink jet heads16C,16M,16Y and16K in the conveyance step, when the recording medium passes under the heads, the droplet of the ink, which has been ejected from each of the ink jet heads16C,16M,16Y and16K, is struck onto a recording face, and a color image is formed on the recording face. The recording medium12on which the image has been recorded is delivered to the conveyance drum28from the image recording drum14, and is conveyed to the step in the latter stage.

Now, in the image recording section10structured as has been described above, each of the ink jet heads16C,16M,16Y and16K is attached to a head supporting frame40, and is arranged in the periphery of the image recording drum14, as is illustrated inFIG. 2.

The head supporting frame40is structured by a pair of side plates42L and42R which are provided so as to be perpendicular to the rotary shaft18of the image recording drum14, and by a connection frame44which connects the pair of side plates42L and42R on the upper end.

The pair of side plates42L and42R is formed into a plate shape, and are arranged so as to face each other while sandwiching the image recording drum14. In the inside of the pair of side plates42L and42R, attaching portions46C,46M,46Y and46K for attaching the respective ink jet heads16C,16M,16Y and16K thereto are provided (though only attaching portion46Y is illustrated, for convenience, inFIG. 2).

The attaching portions46C,46M,46Y and46K are radially arranged so as to have a fixed interval on the concentric circle which regards the rotary shaft18of the image recording drum14as the center. Portions to be attached48C,48M,48Y and48K (though only portion to be attached48Y is illustrated, for convenience, inFIG. 2) which are formed on both ends of the respective ink jet heads16C,16M,16Y and16K are fixed to the respective attaching portions46C,46M,46Y and46K, and thereby the ink jet heads are attached to the head supporting frame40. The respective ink jet heads16C,16M,16Y and16K are thus attached to the head supporting frame40, and thereby are radially arranged so as to have a fixed interval on the concentric circle which regards the rotary shaft18of the image recording drum14as the center.

The head supporting frame40is provided so as to slidably move in parallel to the rotary shaft18of the image recording drum14while being guided by an unillustrated guide rail. The head supporting frame40is driven by an unillustrated linear driving mechanism (for instance, feeding screw mechanism or the like), and moves between “image recording position” illustrated by a solid line inFIG. 2and “maintenance position” illustrated by a dashed line inFIG. 2.

When the head supporting frame40is positioned on the image recording position, the respective ink jet heads16C,16M,16Y and16K are arranged in the periphery of the image recording drum14, and become a state of being capable of recording an image.

The maintenance position is set at a position into which the respective ink jet heads16C,16M,16Y and16K are retracted from the image recording medium14. In this maintenance position, a moisture-retaining unit50is provided for retaining the moisture of the respective ink jet heads16C,16M,16Y and16K.

The moisture-retaining unit50is provided with caps52C,52M,52Y and52K (though only cap52Y is illustrated, for convenience, inFIG. 2) which cover the nozzle faces of the respective ink jet heads16C,16M,16Y and16K. When the device is halted for a long period of time, the nozzle faces are covered with these caps52C,52M,52Y and52K. Thereby, the non-ejection due to dryness is prevented.

Incidentally, these caps52C,52M,52Y and52K are provided with an unillustrated pressurization and suction mechanism, which is structured so as to be capable of pressurizing and sucking the inner part of the nozzle.

In addition, these caps52C,52M,52Y and52K are provided with an unillustrated cleaning liquid supply mechanism, which is structured so as to be capable of supplying the cleaning liquid to the inner part of the nozzle.

A waste liquid tray54is arranged in the lower position of the caps52C,52M,52Y and52K. The cleaning liquid which has been supplied to the caps52C,52M,52Y and52K is disposed into this waste liquid tray54, and is collected into a waste liquid tank58through a waste liquid collection pipe56.

A nozzle face cleaning device64for cleaning the nozzle faces30C,30M,30Y and30K of the respective ink jet heads16C,16M,16Y and16K is provided between the image recording position and the maintenance position. The nozzle faces30C,30M,30Y and30K of the respective ink jet heads16C,16M,16Y and16K are cleaned by this nozzle face cleaning device64, in a process in which the respective ink jet heads move from the maintenance position to the image recording position or in a process in which the respective ink jet heads move from the image recording position to the maintenance position.

The structure of this nozzle face cleaning device64is described below.

<<Structure of Nozzle Face Cleaning Device>>

The nozzle face cleaning device64brings a wiping web into pressure-contact with the nozzle faces30C,30M,30Y and30K of the respective ink jet heads16C,16M,16Y and16K, and makes the wiping web wipe the nozzle faces30C,30M,30Y and30K. The nozzle face cleaning device64is arranged in the moving path of the head supporting frame40. When the ink jet heads16C,16M,16Y and16K are moved from the maintenance position to the image recording position, the respective nozzle faces30C,30M,30Y and30K can be wiped by the wiping web.

FIG. 4is a side view of the nozzle face cleaning device which is viewed from the side of the maintenance position.

As is illustrated inFIG. 4, the nozzle face cleaning device64is provided with wiping units100C,100M,100Y and100K which are provided so as to correspond to the respective ink jet heads16C,16M,16Y and16K, and with a body frame102of the cleaning device, on which the wiping units100C,100M,100Y and100K are set.

(Structure of Body Frame of Cleaning Device)

The body frame102of the cleaning device is horizontally installed, and is provided so as to be capable of moving up and down by an unillustrated elevating device. This body frame102of the cleaning device is formed into such a box shape that the upper end is opened, and has wiping unit mounting portions104C,104M,104Y and104K formed therein for mounting the respective wiping units100C,100M,100Y and100K.

The wiping unit mounting portions104C,104M,104Y and104K are formed as spaces in which the wiping units100C,100M,100Y and100K can be accommodated, respectively, and each upper part is formed so as to be opened. The wiping units100C,100M,100Y and100K are set in the respective wiping unit mounting portions104C,104M,104Y and104K by being inserted vertically downward from the respective openings in the upper parts of the respective wiping unit mounting portions104C,104M,104Y and104K.

Incidentally, the respective wiping unit mounting portions104C,104M,104Y and104K are provided with unillustrated locking mechanisms, which are structured so as to be capable of locking the respective mounted wiping units100C,100M,100Y and100K. The locking mechanisms are structured so as to automatically work, for instance, when wiping units100C,100M,100Y and100K are inserted into the respective wiping unit mounting portions104C,104M,104Y and104K.

Next, the structure of the wiping units100C,100M,100Y and100K is described below.

Incidentally, the basic structures of the respective wiping units100C,100M,100Y and100K are common, and accordingly, here, the structure of the wiping unit is described below as the wiping unit100. The wiping unit mounting portions104C,104M,104Y and104K are also similar to the above case of the wiping units, and the structure is described as the wiping unit mounting portion104.

FIG. 5is a plan view of the wiping unit,FIG. 6is a side view of the wiping unit which is viewed from the side of the image recording position, andFIG. 7is a sectional view of a front portion of the wiping unit.

As is illustrated inFIG. 5toFIG. 7, in the wiping unit100, a wiping web (wiping member)110which is formed into a strip shape is wound around a pressing roller118(pressing means) that has been provided so as to be tilted. The wiping unit100brings the wiping web110which is wound around this pressing roller118, into pressure-contact with the nozzle face of the ink jet head. The wiping unit100moves the ink jet head16from the maintenance position illustrated inFIG. 2to the image recording position, makes the wiping web110travel along the conveyance path, while bringing the wiping web110into pressure-contact with the nozzle face, and thereby makes the wiping web110wipe and clean the nozzle face30of the ink jet head16.

This wiping unit100includes: a case112; the pressing roller118; an unwinding shaft114for unwinding the wiping web110which is formed into the strip shape; a winding shaft116for winding the wiping web110; a pre-stage guide120for guiding the wiping web110so that the wiping web110which has been unwound from the unwinding shaft114is wound around the pressing roller118; a post-stage guide122for guiding the wiping web110so that the wiping web110which has been wound around the pressing roller118is wound around the winding shaft116; and a grid roller (driving roller)124for conveying the wiping web110. In the present embodiment, “wiping means” is wiping member travel driving means which is formed of ink jet head moving means, the unwinding shaft114, the winding shaft116, and the grid roller124.

A material to be used for the wiping web110includes, for instance, a knit or woven sheet using ultrafine fibers of PET (polyethylene terephthalate), PE (polyethylene), NY (nylon (registered trademark), polyamide-based synthetic fiber), acrylic and the like. The wiping web110is formed into the strip shape having a width (width equal to or larger than width of nozzle face) corresponding to the width of the nozzle face in a head to be wiped.

The pressing roller118is arranged above the unwinding shaft114(In present example, the pressing roller118, the unwinding shaft114and the winding shaft116are arranged on the same straight line.), and is arranged so as to be tilted against the horizontal plane by a predetermined angle. Specifically, this pressing roller118is a unit for bringing the wiping web110into pressure-contact with the nozzle face30of the ink jet head16, and accordingly is arranged so as to be tilted so as to match the tilt of the nozzle face30of the ink jet head16to be wiped (being arranged so as to be parallel to nozzle face).

The pre-stage guide120includes a first pre-stage guide160and a second pre-stage guide162. The pre-stage guide120guides the wiping web110which has been unwound from the unwinding shaft114so that the wiping web110is wound around the pressing roller118that is installed so as to be tilted.

On the other hand, the post-stage guide122includes a first post-stage guide164and a second post-stage guide166. The post-stage guide122guides the wiping web110which has been wound around the pressing roller118that is installed so as to be tilted so that the wiping web110is wound around the winding shaft116which is horizontally installed.

These pre-stage guide120and post-stage guide122are symmetrically arranged so as to sandwich the pressing roller118. Specifically, the first pre-stage guide160and the first post-stage guide164are symmetrically arranged so as to sandwich the pressing roller118, and the second pre-stage guide162and the second post-stage guide166are also symmetrically arranged so as to sandwich the pressing roller118.

The first pre-stage guide160is formed into a plate shape having a predetermined width, and is vertically installed so as to stand on an elevating stage170. In this first pre-stage guide160, an upper rim part160A is formed as a winding section for the wiping web110, and the surface is formed into an arc shape. In addition, this upper rim part160A is formed so as to be tilted against the horizontal plane by a predetermined angle. Thereby, the traveling direction of the wiping web110is changed.

The first post-stage guide164has the same structure as that of the first pre-stage guide160. Specifically, the first post-stage guide164is formed into a plate shape having a predetermined width, and is vertically installed so as to stand on the elevating stage170. In addition, an upper rim part164A thereof is formed as a winding section for the wiping web110, the surface is formed into an arc shape, and is formed so as to be tilted against the horizontal plane by a predetermined angle.

These first pre-stage guide160and first post-stage guide164are symmetrically arranged so as to sandwich the pressing roller118. The wiping web110which has been unwound from the unwinding shaft114is wound around the first pre-stage guide160, and thereby the direction thereof is converted to a direction approximately perpendicular to the pressing roller118from a direction perpendicular to the unwinding shaft114. In addition, the wiping web110which has been wound around the second post-stage guide166that is described later is wound around the first post-stage guide164, and thereby the direction thereof is converted to a direction perpendicular to the winding shaft116.

The second pre-stage guide162is structured as a guide roller which has flanges162L and162R on both ends thereof. This second pre-stage guide162is arranged between the first pre-stage guide160and the pressing roller118, and guides the wiping web110which has been wound around the first pre-stage guide160so that the wiping web110is wound around the pressing roller118. Specifically, the second pre-stage guide162finely adjusts the traveling direction of the wiping web110so that the wiping web110of which the direction has been converted to a direction approximately perpendicular to the pressing roller118by the first pre-stage guide160travels in a direction perpendicular to the pressing roller118. In addition, the flanges162L and162R on both ends prevent the wiping web110from obliquely traveling.

This second pre-stage guide162is provided so as to be tilted by a predetermined angle while one end of the second pre-stage guide162is cantilevered and supported by a bracket168A. The bracket168A is formed into a shape of the plate of which the tip is bent, and of which the base end is fixed to the upper end of the rear face of the case body126, as is illustrated inFIG. 6. The bracket168A is provided so as to project vertically toward the upper part from the upper end of the case body126. The second pre-stage guide162is cantilevered and supported by the bent portion of the tip of this bracket168A, and is rotatably supported by the bent portion.

The second post-stage guide166has the same structure as that of the second pre-stage guide162. Specifically, the second post-stage guide166is structured as a guide roller which has flanges166L and166R on both ends thereof, and is provided so as to be tilted by a predetermined angle while one end thereof is cantilevered and supported by a bracket168B. The bracket168B is formed into a shape of the plate of which the tip is bent, and of which the base end is fixed to the upper end of the rear face of the case body126. The second post-stage guide166is cantilevered and supported by the bent portion of the tip of this bracket168B, and is rotatably supported by the bent portion.

This second post-stage guide166is arranged between the pressing roller118and the first post-stage guide164, and guides the wiping web110which has been wound around the pressing roller118so that the wiping web110is wound around the first post-stage guide164.

These second pre-stage guide162and second post-stage guide166are symmetrically arranged so as to sandwich the pressing roller118. The wiping web110of which the direction has been converted to a direction approximately perpendicular to the pressing roller118by the first pre-stage guide160is wound around the second pre-stage guide162, and thereby the traveling direction of the wiping web110is finely adjusted so that the wiping web110travels in a direction perpendicular to the pressing roller118. In addition, the traveling direction of the wiping web110which has been wound around the pressing roller118is finely adjusted by the second post-stage guide166so that the wiping web110is wound around the first post-stage guide164. Then, the wiping web110is wound around the first post-stage guide164, and thereby the direction of the wiping web110is converted to a direction perpendicular to the winding shaft116.

Thus, the pre-stage guide120and the post-stage guide122switch the traveling direction of the wiping web110step by step, and thereby guide the wiping web110so that the wiping web110is naturally wound around the pressing roller118.

The grid roller124is installed in parallel to the winding shaft116(which is parallel to horizontal plane), and the rotary shaft thereof is rotatably supported by a bearing which is provided on the case body126. As for the rotary shaft, the base end is provided so as to project to the outside of the case body126, and a grid roller gear186is fixed on the projecting base end. This grid roller gear186is rotationally driven, and thereby the grid roller124is rotated.

Here, a driving mechanism of the wiping unit100which includes this grid roller124is described.

In the wiping unit100of the present embodiment, the winding shaft116is rotationally driven, the grid roller124is also rotationally driven, and thereby the wiping web110travels toward the winding shaft116from the unwinding shaft114.

As in the above description, a winding shaft gear158is attached to the winding shaft116. On the other hand, the grid roller gear186is attached to the grid roller124. These winding shaft gear158and grid roller gear186are engaged with a rotation transmission gear188, as is illustrated inFIG. 7.

The rotation transmission gear188has the rotary shaft horizontally provided which is rotatably supported by a bearing190that is provided on the case body126. When this rotation transmission gear188is rotated, the winding shaft gear158and the grid roller gear186thereby rotate in the same direction. These winding shaft gear158and grid roller gear186rotate, and thereby the winding shaft116and the grid roller124rotate.

When the wiping unit100is mounted on the wiping unit mounting portion104of the cleaning device body frame102, the rotation transmission gear188for rotating the winding shaft gear158and the grid roller gear186is engaged with a driving gear192which is provided in the wiping unit mounting portion104(seeFIG. 4).

The driving gear192is attached to the output shaft of the motor194, and is arranged at a position at which the rotation transmission gear188is engaged with the driving gear192, when the wiping unit100is mounted on the wiping unit mounting portion104.

A motor194is formed, for instance, of a pulse motor, and is attached to the bottom part of the wiping unit mounting portion104. The drive of this motor194is controlled by an unillustrated control device.

The driving mechanism of the wiping unit100is structured as described above.

As in the above description, when the wiping unit100is mounted on the wiping unit mounting portion104of the body frame102of the cleaning device, the rotation transmission gear188which is provided on the case112of the wiping unit100is engaged with the driving gear192that is provided on the wiping unit mounting portion104. When the motor194is driven in this state, the driving gear192rotates which is attached to the output shaft of the motor194, the rotation is transmitted to the rotation transmission gear188, and the rotation transmission gear188rotates.

When the rotation transmission gear188rotates, the rotation of the rotation transmission gear188is transmitted to the winding shaft gear158and the grid roller gear186, and the winding shaft gear158and the grid roller gear186rotate. As a result, the winding shaft116and the grid roller124rotate. When these winding shaft116and grid roller124rotate, the wiping web110is thereby unwound from an unwinding core138which is mounted on the unwinding shaft114, passes through a predetermined traveling path, and is wound into a winding core142which is mounted on the winding shaft116.

Thus, when the wiping unit100is mounted on the wiping unit mounting portion104, the rotation transmission gear188is engaged with the driving gear192, and the winding shaft116and the grid roller124are enabled to be driven.

In addition, as illustrated inFIG. 5toFIG. 7, the nozzle face cleaning device64is provided with a cleaning liquid adding nozzle300(cleaning liquid adding means) which adds the cleaning liquid to the wiping web110. The wiping web110to which the cleaning liquid has been added wipes the nozzle face30, and thereby the nozzle face30can be cleaned. The cleaning liquid adding nozzle300is fixed to the side face of the case112which forms the wiping unit100, by a fixing plate302, and is integrally formed with the case112. The cleaning liquid adding nozzle300is provided in the upper part of the wiping unit100, and adds the cleaning liquid to the wiping web110by dripping the cleaning liquid onto the wiping unit100from the cleaning liquid adding nozzle300.

The cleaning liquid adding nozzle300is provided with a hole304for a cleaning liquid flow channel, into which a cleaning liquid supply flow channel350illustrated inFIG. 8enters. When the cleaning liquid supply flow channel350is passed in the hole304for the cleaning liquid flow channel, the cleaning liquid supply flow channel350can supply the cleaning liquid to the cleaning liquid adding nozzle300.

The cleaning liquid can be supplied from a tank (not illustrated) which stores the cleaning liquid therein with the use of a pump, a water head difference or the like, but is preferably supplied with the use of the water head difference, in particular. When the cleaning liquid is supplied with the use of the water head difference, the cleaning liquid can be supplied by the opening and closing of a solenoid valve (not illustrated). In addition, the pump does not need to be used for supplying the cleaning liquid, accordingly the device can be miniaturized, and the device can be kept clean.

In addition, when the cleaning liquid is supplied by the opening and closing of the solenoid valve with the use of the water head difference, the supply can be controlled by ON/OFF so as to match the supply timing of the cleaning liquid, and the supply amount can be controlled. Thereby, the nozzle face can be wiped with a necessary amount of the cleaning liquid, and accordingly the amount of a cleaning liquid to be consumed can be reduced.

The cleaning liquid which has been supplied to the cleaning liquid adding nozzle300passes on the cleaning liquid adding nozzle300, and is dripped onto the wiping web110from the tip of the cleaning liquid adding nozzle300. Thus, the cleaning liquid is supplied to the wiping web110.

The tip of the cleaning liquid adding nozzle300is provided at the position in the upstream side of the second pre-stage guide162of the wiping unit100in the conveyance direction for the wiping web110. The cleaning liquid which is dripped from the cleaning liquid adding nozzle300is added to the wiping web110before the wiping web110passes through the second pre-stage guide162. In addition, the tip of the cleaning liquid adding nozzle300is arranged in the upper side of the tilt of the first pre-stage guide160and the second pre-stage guide162, in the width direction of the conveyance direction of the wiping web110. When the tip of the cleaning liquid adding nozzle300is arranged in such a position, the cleaning liquid which has been added to the wiping web110thereby spreads in the width direction of the wiping web110which is conveyed while being tilted along the tilt of the second pre-stage guide162, and can be added to the whole surface in the width direction of the wiping web110.

Incidentally, the position in the width direction of the wiping web110of the tip of the cleaning liquid adding nozzle300is not limited to the above described position in particular, and the cleaning liquid nozzle can also be structured so as to add the cleaning liquid to the whole surface in the width direction of the wiping web110.

In addition, the present embodiment has been described so as to have such a form that the cleaning liquid adding nozzle300drips the cleaning liquid onto the wiping web110, and thereby directly adds the cleaning liquid to the wiping web110, but is not limited to this form, and may have such a form that the cleaning liquid is dropped from the cleaning liquid adding nozzle300onto the second pre-stage guide162, and this second pre-stage guide162spreads the cleaning liquid to and indirectly adds the cleaning liquid to the whole surface in the width direction of the wiping web110.

In addition, in the present embodiment, the cleaning liquid adding nozzle300is integrally formed with the case112, and accordingly the cleaning liquid can be reliably added to a predetermined position of the wiping web110. In addition, the cleaning liquid is dripped from the cleaning liquid adding nozzle300, thereby the cleaning liquid can be added to the wiping web110, and accordingly a distance between the wiping web110and the cleaning liquid adding nozzle300can be shortened. Accordingly, the cleaning liquid can be reliably added to a predetermined position, and the amount of the cleaning liquid to be used can be reduced. When the cleaning liquid is added with the use of a conventional spray or the like, there are cases where a distance between a spray nozzle and the wiping web is large, and the cleaning liquid is not added to a predetermined position by being sprayed, and there has been the case where the amount of the cleaning liquid increases as a whole. In the present embodiment, the cleaning liquid can be reliably added to the predetermined position of the wiping web110by the dripping method, and accordingly the amount of the cleaning liquid to be consumed can be reduced.

FIG. 8is a perspective view of the cleaning liquid supply flow channel350,FIG. 9is a view in which the cleaning liquid adding nozzle300is mounted on the cleaning liquid supply flow channel350, andFIG. 10,FIG. 11AandFIG. 11Bare sectional views of the cleaning liquid supply flow channel350. Incidentally, in FIG.8andFIG. 9, the right side in each of the figures shows a state in which the cleaning liquid supply flow channel350and the cleaning liquid adding nozzle300are fixed, and the left side shows a state in which the cleaning liquid supply flow channel350and the cleaning liquid adding nozzle300are not fixed. The cleaning liquid adding nozzle is provided in each of the wiping units100C,100M,100Y and100K, and the cleaning liquid supply flow channel is provided correspondingly in each of the cleaning liquid adding nozzles.

As is illustrated in the figures, in the cleaning liquid supply flow channel350, an outlet352of the cleaning liquid supply flow channel350is opened to the air. The cleaning liquid which has passed through the cleaning liquid supply flow channel350and has been discharged from the outlet352of the cleaning liquid supply flow channel350passes on the cleaning liquid adding nozzle300, and is dripped onto the wiping web110.

In the present embodiment, the cleaning liquid adding nozzle300and the cleaning liquid supply flow channel350are formed into an attachable/detachable type. The cleaning liquid adding nozzle300and the cleaning liquid supply flow channel350are coupled to each other, by making the cleaning liquid supply flow channel350enter into the hole304for the cleaning liquid flow channel, which is provided on the cleaning liquid adding nozzle300, from the lower part. In addition, the coupled portion (connected portion) of the cleaning liquid adding nozzle300with the cleaning liquid supply flow channel350is provided with a rubber seal member354. This rubber seal member354seals the hole304for the cleaning liquid flow channel, adheres to and is fixed at the hole304; and accordingly can prevent a leakage of the liquid. Thus, the cleaning liquid can be efficiently supplied to the wiping member.

As for a method of fixing the cleaning liquid adding nozzle300and the cleaning liquid supply flow channel350, a hook306which is provided on the side part of the cleaning liquid adding nozzle300is engaged with a hook358which is provided on the side part of a supply flow channel fixing base plate356for fixing the cleaning liquid supply flow channel350(where the hook358is drawn only on the side of the cleaning liquid supply flow channel350in which the cleaning liquid adding nozzle300is not fixed inFIG. 8andFIG. 9, but the hook358is provided also on the side in which the cleaning liquid adding nozzle300is fixed), and thereby the cleaning liquid adding nozzle300and the cleaning liquid supply flow channel350are fixed.

FIG. 10,FIG. 11AandFIG. 11Bare sectional views of the cleaning liquid adding nozzle300and the cleaning liquid supply flow channel350. As is illustrated inFIG. 10,FIG. 11AandFIG. 11B, the cleaning liquid supply flow channel350is opened to the air, on the cleaning liquid adding nozzle300. When the outlet352of the cleaning liquid supply flow channel350is opened to the air, and when the cleaning liquid supply flow channel350and the cleaning liquid adding nozzle300can be attached to and detached from each other, as in the above way, the mixing of the air into the cleaning liquid supply flow channel350can be prevented. When the cleaning liquid is added with the use of the spray, as in a conventional way, it occasionally occurs that the air is mixed into the cleaning liquid supply flow channel when the spray is detached from the cleaning liquid supply flow channel. There has been a problem that when the cleaning liquid is added by the spray method in the state in which the air is mixed into the cleaning liquid supply flow channel, the amount of the cleaning liquid is not stable in an early period of the time when the cleaning liquid has been added. The cleaning device in the present embodiment can prevent the air from mixing into the cleaning liquid supply flow channel350, even when having replaced the cleaning liquid adding nozzle300, and can stably supply the cleaning liquid to the wiping web110.

In addition, as has been described above, the cleaning liquid adding nozzle300is integrated with the case112, and can be attached to and detached from the cleaning liquid supply flow channel350. Thereby the cleaning liquid supply flow channel350can be easily detached. Accordingly, when the wiping web110which has been used for wiping is replaced, complicated assembly is not needed, and the wiping web110can be easily replaced.

Furthermore, as is illustrated inFIG. 11AandFIG. 11B, the portion of the outlet352of the cleaning liquid supply flow channel350is formed into a pedestal structure which projects upward from the hole304for the cleaning liquid flow channel of the cleaning liquid adding nozzle300, and it is preferable that a part of this pedestal structure has a cutout portion360in the side of the direction in which the cleaning liquid adding nozzle300drips the cleaning liquid onto the wiping web110. The cleaning liquid adding nozzle300has the cutout portion360in the outlet352of the cleaning liquid supply flow channel350, and thereby can facilitate the cleaning liquid to flow in a predetermined direction. In addition, it is preferable that a tip308of the cleaning liquid adding nozzle300is bent to the side of the wiping web110so that a predetermined amount of the cleaning liquid can be exactly dripped onto a fixed position from the tip. Due to the structure that the tip308of the cleaning liquid adding nozzle300is bent to the side of the wiping web110, the cleaning liquid can be dripped from the bent tip308, and the cleaning liquid can be supplied to a fixed position.

In addition, it is preferable that in order that the tip308of the cleaning liquid adding nozzle300has adequate dripping properties, the angle is set at an acute angle as is illustrated inFIG. 12A, or is set at a semicircle having the curvature radius R of 1 cm or smaller, as is illustrated inFIG. 12B. When the tip is formed so as to have such a shape, the dripping properties from the tip can be made adequate.

Furthermore, it is preferable that the material of the cleaning liquid adding nozzle300is formed from a material having adequate dripping properties (water-repellent material) or is coated with the material having adequate dripping properties. Thereby, the cleaning liquid does not stay on the cleaning liquid adding nozzle300, and the cleaning liquid is enabled to easily flow. The material to be coated thereon can include fluororesin coating and the like.

In the above described embodiment, the nozzle face cleaning device has been described in which the pressing roller is tilted so as to match the tilt of the nozzle face of the ink jet head, but the present invention is not limited to the nozzle face cleaning device. The present invention can be applied also to a nozzle face cleaning device in which the pressing roller is horizontally provided so as to match the nozzle face of the horizontal head. In this case, it is preferable that the cleaning liquid adding nozzle is arranged so as to be capable of adding the cleaning liquid to the whole region in the width direction of the wiping web.

In addition, as for the wiping method, the cleaning device in the above described embodiment cleans the nozzle face by making the ink jet head move and also the wiping web travel, but it is also possible to wipe and clean the nozzle face by pressing the wiping web to the whole surface of the nozzle face and making only the wiping web travel, without making the ink jet head move. When the ink jet head is not moved, the wiping member travel driving means becomes wiping means, which includes the unwinding shaft114, the winding shaft116and the grid roller124.

Furthermore, the ink jet head is not limited to a line head in which a plurality of nozzles are arranged over a length corresponding to a full width of the recording medium, but can be applied also to a serial head in which the head reciprocally moves in a direction perpendicular to the conveyance direction of a recording medium.