JP5822733B2 - Nozzle surface cleaning device and image recording device - Google Patents

Description

  The present invention relates to a nozzle surface cleaning device and an image recording device, and more particularly, to a nozzle surface cleaning device and an image recording device that wipe a nozzle surface by pressing a wiping member against the nozzle surface.

  Various foreign substances such as ink residues and paper dust adhere to the nozzle surface of an ink jet head used in an image recording apparatus, for example, an ink jet recording apparatus. If foreign matter adheres to the nozzle surface, ink droplets ejected from the nozzles are affected, causing variations in the direction of ink droplet ejection and causing ink droplets to land at predetermined positions on the recording medium. Becomes difficult and causes image quality to deteriorate. Therefore, in the ink jet recording apparatus, it is important to regularly remove foreign matters by a maintenance method such as wiping.

  Further, when the inkjet head is on standby, a maintenance unit is provided to prevent non-ejection due to drying of the ink, and the ink is prevented from drying by covering with a cap. However, if the nozzle surface is covered with a cap to which ink is attached and left for a long period of time, there is a problem in that a mark of the cap remains on the nozzle surface.

  For example, Patent Document 1 below includes a wiper that wipes the vicinity of the nozzle hole and the other part (cap mark part), and wipes the wiper that wipes the cap mark part with a higher pressure than the wiper that wipes the vicinity of the nozzle hole. After that, there is described a head cleaning device that sequentially wipes the vicinity of the nozzle holes. By changing the wiping pressure of the wiper that wipes the cap marks, damage to the liquid-repellent film near the nozzle hole can be reduced, reducing the problem of ink ejection and achieving good image formation. It is described that can be.

JP 2010-105341 A

  However, when the maintenance method described in Patent Document 1 is applied to a maintenance method using a wiping member, a pressing roll for wiping the vicinity of the nozzle hole and a pressing roll for wiping the cap trace are required, so the apparatus is large. There was a problem of becoming. Further, since it is necessary to wipe the vicinity of the nozzle hole and the cap mark at least twice, there are problems that the maintenance time increases, the amount of wiping web used, and the amount of cleaning liquid used also increase.

  The present invention has been made in view of such circumstances, and provides a nozzle surface cleaning device and an image recording device that can prevent deterioration of the water-repellent film near the nozzle even when wiped with one pressing roll. The purpose is to do.

In order to achieve the above object, the present invention provides a nozzle surface cleaning device that cleans the nozzle surface of a droplet discharge head, a wiping member that wipes the nozzle surface, and a wiping member that presses and contacts the nozzle surface. A pressure roll for wiping, and a liquid repellent film is formed at least in the vicinity of the nozzle on the nozzle surface, and the pressure roll sandwiches the nozzle facing portion between the nozzle facing portion provided at a position facing the vicinity of the nozzle in a pressing roll edge formed at both ends of the pressing roll made of a nozzle facing portion and the pressing roll end, Ri Oh in hybrid roll made come together in different materials, the nozzle face by the pressing rolls Provided is a nozzle surface cleaning device in which the pressing force to be pressed is lower in the nozzle facing portion than the end portion of the pressing roll .

  According to the present invention, when the nozzle surface of the droplet discharge head is cleaned, different pressure materials are used for the press roll that presses and abuts through the wiping member in the region where the nozzle is formed and the both ends thereof. It is used as one hybrid roll. Therefore, it is possible to clean the area of the nozzle surface where the nozzle is formed and other areas using materials suitable for the nozzle surface, thus preventing separation of the liquid repellent film provided in the vicinity of the nozzle. can do.

  Moreover, since the several area | region of a nozzle surface can be wiped off with one press roll, size reduction of an apparatus can be achieved rather than using a several press roll. Further, since the nozzle surface can be cleaned by wiping once, the amount of the wiping member and the cleaning liquid used can be reduced, and the maintenance time can be shortened.

  Note that “near the nozzle” refers to a region in which a defective ejection direction may occur when foreign matter adheres to the nozzle surface.

Further , since the pressing force to the nozzle surface by the pressing roll is lower at the nozzle facing portion than the end portion of the pressing roll, it is possible to reduce the peeling of the liquid repellent film formed in the vicinity of the nozzle on the nozzle surface.

  In the nozzle surface cleaning device according to another aspect of the present invention, the pressing roll is preferably made of rubber, and the rubber hardness of the nozzle facing portion is preferably lower than the rubber hardness of the end of the pressing roll.

  According to the nozzle surface cleaning apparatus according to another aspect of the present invention, the nozzle when the pressure roll is pressed against the nozzle surface by making the rubber hardness of the nozzle facing portion lower than the rubber hardness of the end portion of the pressure roll. The pressing force of the facing portion can be lowered.

  In the nozzle surface cleaning device according to another aspect of the present invention, the rubber hardness of the nozzle facing portion is preferably 10 to 30 degrees, and the rubber hardness of the end portion of the pressing roll is preferably 70 to 90 degrees.

  According to the nozzle surface cleaning device according to another aspect of the present invention, by setting the rubber hardness of the nozzle facing portion and the rubber hardness of the end portion of the pressing roll within the above ranges, the pressing force in the vicinity of the nozzle can be reduced. The surface can be wiped off.

  In the nozzle surface cleaning device according to another aspect of the present invention, the nozzle surface is formed by a nozzle formation region where the nozzle is formed and a nozzle protection region that protects the nozzle, and the entire surface of the nozzle formation region is liquid repellent. A film is provided, and the width of the nozzle facing portion is preferably equal to the width of the nozzle formation region.

  According to the nozzle surface cleaning apparatus according to another aspect of the present invention, since the nozzle facing portion is provided corresponding to the nozzle forming region where the nozzle is formed, it is possible to prevent peeling of the liquid repellent film in the nozzle forming region. Can do. Moreover, since the nozzle protection area can be wiped off at the end of the pressing roll, the deposits and cap marks can be wiped off with a high pressing force.

  Note that the width of the nozzle facing portion and the width of the nozzle formation region being equal are not limited to coincide completely, and an error of 5% of the width of the nozzle facing portion is within an allowable range.

  In the nozzle surface cleaning apparatus according to another aspect of the present invention, it is preferable that a liquid repellent film is formed on the entire nozzle surface.

  According to the nozzle surface cleaning apparatus according to another aspect of the present invention, when the nozzle facing portion is pressed against the nozzle surface, the end portion of the pressing roll can be used as a guide member for the nozzle facing portion, and the nozzle is high. It is possible to prevent the pressing force from being applied. Therefore, when the liquid repellent film is formed on the entire nozzle surface, it is possible to reduce peeling of the liquid repellent film formed on the nozzle surface.

  In the nozzle surface cleaning apparatus according to another aspect of the present invention, it is preferable that the pressing roll has the same diameter of the nozzle facing portion and the diameter of the end portion of the pressing roll.

  In the nozzle surface cleaning device according to another aspect of the present invention, it is preferable that the pressure roll has a diameter of the nozzle facing portion larger than the diameter of the end portion of the pressure roll.

  According to the nozzle surface cleaning device according to another aspect of the present invention, since the nozzle facing portion uses a material that reduces the pressing force when pressed against the nozzle surface, the diameter of the nozzle facing portion is set to a pressure roll. Even if it is equal to or larger than the diameter of the end portion, it can be wiped with a low pressing force.

  It is preferable that the nozzle surface cleaning apparatus which concerns on the other aspect of this invention is equipped with the washing | cleaning liquid provision means which provides a cleaning liquid to a wiping member.

  According to the nozzle surface cleaning apparatus according to another aspect of the present invention, since the cleaning liquid applying unit that applies the cleaning liquid to the wiping member is provided, the liquid can be prevented from being drawn from the nozzle, It is possible to prevent ejection failure due to fixation.

  In order to achieve the above object, the present invention provides a transport unit that transports a recording medium, a droplet discharge head that discharges droplets onto a recording medium transported by the transport unit, and records an image. It aims at providing an image recording device provided with the above-mentioned nozzle surface cleaning device which cleans a nozzle surface.

  According to the present invention, by providing the nozzle surface cleaning device, it is possible to reduce the peeling of the liquid repellent film formed on the nozzle surface, and thus it is possible to provide an image recording device with improved ejection stability. .

  According to the nozzle surface cleaning device and the image recording apparatus of the present invention, since pressure distribution can be given to the pressure on the nozzle surface with one pressing roll, the peeling of the water-repellent film is reduced with one pressing roll. The nozzle surface can be cleaned. Further, since the nozzle surface can be cleaned with a single pressing roll, the apparatus can be miniaturized and the need for wiping twice is eliminated, so that the maintenance time can be shortened.

It is a front view which shows the structure of the principal part of an inkjet recording device. It is a top view which shows the structure of the principal part of an inkjet recording device. It is a side view which shows the structure of the principal part of an inkjet recording device. It is a plane perspective view of the nozzle surface of the head. It is a schematic diagram which shows schematic structure of a wiping unit. It is a front fragmentary sectional view which shows the structure of the shaft support part which supports the shaft part of a press roll. It is a front fragmentary sectional view which shows the example of the shape of a press roll.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following, an ink jet recording apparatus will be described as an example of an image recording apparatus, but the present invention is not limited to this.

<Apparatus configuration of inkjet recording apparatus>
1 to 3 are a front view, a plan view, and a side view showing a configuration of a main part of the ink jet recording apparatus according to the present embodiment.

  As shown in FIG. 1, the inkjet recording apparatus 10 is a single-pass line printer, and mainly includes a sheet conveying mechanism 20 that conveys a sheet (sheet) P that is a recording medium, and a sheet conveying mechanism 20. Maintenance of the head unit 30 that ejects cyan (C), magenta (M), yellow (Y), and black (K) ink droplets toward the transported paper P, and each head mounted on the head unit 30 The maintenance unit 40 for performing the above and the nozzle surface cleaning device 80 for cleaning the nozzle surface of each head mounted on the head unit 30.

  The paper transport mechanism 20 is constituted by a belt transport mechanism, and adsorbs the paper P to the traveling belt 22 and transports the paper P horizontally.

  The head unit 30 mainly includes a head 32C that ejects cyan ink droplets, a head 32M that ejects magenta ink droplets, a head 32Y that ejects yellow ink droplets, and a head 32K that ejects black ink droplets. The head support frame 34 to which the heads 32C, 32M, 32Y, and 32K are attached, and a head support frame moving mechanism (not shown) that moves the head support frame 34 are configured.

  The heads (inkjet heads) 32C, 32M, 32Y, and 32K are constituted by line heads corresponding to the maximum paper width of the paper P to be printed. Since the configurations of the heads 32C, 32M, 32Y, and 32K are the same, in the following, they are described as the heads 32 unless otherwise distinguished. The head 32 (32C, 32M, 32Y, 32K) is formed in a rectangular block shape, and a nozzle surface 33 (33C, 33M, 33Y, 33K) is formed on the bottom thereof.

  FIG. 4 is a perspective plan view of the nozzle surface of the head. The nozzle surface 33 is formed in a rectangular shape, and a nozzle row is formed along the longitudinal direction thereof. The head 32 of the present embodiment is constituted by a so-called matrix head, and the nozzles N are arranged in a two-dimensional matrix. In the matrix head, the substantial interval between the nozzles N projected in the longitudinal direction of the head 32 can be reduced, and the density of the nozzles N can be increased.

  Further, the nozzle surface 33 is formed with a nozzle forming region 33A having a certain width at the center in the width direction (recording medium conveying direction), and a nozzle protection region (wing cover) 33B is formed with the nozzle forming region 33A interposed therebetween. Is done. The nozzle formation region 33A is a region where a nozzle is formed, and a predetermined liquid repellent treatment is performed on the surface thereof (a liquid repellent film is coated). The nozzle formation region 33A and the nozzle protection region 33B are formed by retracting the nozzle formation region 33A in a concave shape, and protect the nozzle formation region 33A. The nozzle protection region 33B may or may not be subjected to a liquid repellent treatment.

  The head 32 of the present embodiment ejects ink droplets from the nozzles N by a so-called piezo method. Each nozzle N communicates with a pressure chamber, and ink droplets are ejected from the nozzle N by vibrating the wall surface of the pressure chamber with a piezo element. The ink ejection method is not limited to this, and a thermal ejection method may be employed.

  The head support frame 34 includes a head attachment portion (not shown) for attaching each head 32. Each head 32 is detachably attached to the head attachment portion. Each head 32 attached to the head support frame 34 is arranged orthogonal to the transport direction of the paper P. Further, the paper P is arranged in a predetermined order with a certain interval along the conveyance direction of the paper P (in this example, the paper P is arranged in the order of cyan, magenta, yellow, and black).

  The head mounting portion is provided on the head support frame 34 so as to be movable up and down, and is moved up and down by a lifting mechanism (not shown). Each head 32 attached to the head attaching portion is raised and lowered vertically with respect to the transport surface of the paper P by this lifting mechanism.

  The head support frame moving mechanism slides the head support frame 34 horizontally in a direction perpendicular to the transport direction of the paper P at a position above the paper transport mechanism 20. The head support frame moving mechanism includes, for example, a ceiling frame that is horizontally installed across the paper transport mechanism 20, a guide rail laid on the ceiling frame, a traveling body that slides on the guide rail, and its traveling It is comprised by the drive means (for example, feed screw mechanism etc.) which moves a body along a guide rail. The head support frame 34 is attached to the traveling body and slides horizontally.

  The head support frame 34 is driven by the head support frame moving mechanism, and is provided to be movable between a predetermined “image recording position” and “maintenance position”. The head support frame 34 is disposed above the paper transport mechanism 20 when positioned at the image recording position. As a result, printing can be performed on the paper P transported by the paper transport mechanism 20. On the other hand, when it is located at the maintenance position, it is arranged at the installation position of the maintenance unit 40.

  The maintenance unit 40 includes a cap 42 (42C, 42M, 42Y, 42K) that covers the nozzle surface 33 of each head 32. When the apparatus is stopped for a long time, the head 32 is moved to the installation position (maintenance position) of the maintenance unit 40 and the nozzle surface 33 is covered with the cap 42. Thereby, non-ejection due to drying is prevented.

  The cap 42 includes a pressurization / suction mechanism (not shown) for pressurizing and sucking the inside of the nozzle, and a cleaning liquid supply mechanism (not shown) for supplying a cleaning liquid into the cap 42. A waste liquid tray 44 is disposed below the cap 42. The cleaning liquid supplied to the cap 42 is discarded in the waste liquid tray 44 and recovered from the waste liquid tray 44 to the waste liquid tank 48 through the waste liquid recovery pipe 46.

The nozzle surface cleaning device 80 is disposed between the paper transport mechanism 20 and the maintenance unit 40. The nozzle surface cleaning device 80 is configured such that when the head support frame 34 moves from the image recording position to the maintenance position, the nozzle surface 33 of the head 32 is a wiping web provided with a cleaning liquid.
The nozzle surface 33 is cleaned by wiping.

<Device configuration of nozzle surface cleaning device>
The nozzle surface cleaning device 80 mainly includes wiping units 100C, 100M, 100Y, and 100K attached to the wiping device main body frame 82, and a wiping device main body lifting mechanism (not shown) that lifts and lowers the wiping device main body frame 82. .

  The wiping units 100 </ b> C, 100 </ b> M, 100 </ b> Y, and 100 </ b> K wipe the nozzle surface 33 by bringing the wiping web (112 in FIG. 5) formed in a belt shape into contact with the nozzle surface 33 of the head 32. The wiping units 100 </ b> C, 100 </ b> M, 100 </ b> Y, and 100 </ b> K are provided for each head, and are installed on the wiping device main body frame 82 according to the installation interval of the heads 32. In addition, since the structure of each wiping unit 100C, 100M, 100Y, 100K is the same, the structure is demonstrated as the wiping unit 100 here.

  FIG. 5 is a schematic diagram illustrating a schematic configuration of the wiping unit 100. As shown in the figure, the wiping unit 100 includes a transport unit 110 that transports the wiping web 112, a cleaning liquid application unit 140 that supplies a cleaning liquid to the wiping web 112, and excess cleaning liquid from the wiping web 112 that is supplied with the cleaning liquid. And a cleaning liquid recovery unit 150 for recovery.

(Conveyor configuration)
The conveying unit 110 is driven to rotate by a sending-side web core 114 that sends out the wiping web 112 before wiping, and a winding motor (not shown), thereby winding up the wiping web 112 that has been wiped off. 116, the first guide roll 118 that rotates in contact with the wiping web 112 delivered from the delivery-side web core 114 and guides to the cleaning liquid application unit 140, and the wiping web 112 delivered from the cleaning liquid application unit 140 The second guide roll 120 that rotates and guides to the pressing roll 122, and the pressing roll 122 that causes the wiping web 112 to contact the nozzle surface 33 of the head 32 with a predetermined pressure.

  The wiping web 112 is formed of a sheet made of knitting or weaving using ultra fine fibers such as PET, PE, NY, and is formed in a belt shape having a width corresponding to the width of the nozzle surface 33 of the head 32. The wiping web 112 is provided in a state in which the wiping web 112 is wound around the delivery-side web core 114 in a roll shape and the tip is fixed to the take-up-side web core 116.

  The delivery-side web core 114 is fitted and attached to a delivery shaft (not shown) that is supported at a horizontal end and fixed horizontally. The delivery shaft has a double tube structure, and an outer cylinder is rotatably supported around the inner cylinder. A reverse rotation prevention mechanism and a friction mechanism are disposed between the inner cylinder and the outer cylinder, and the outer cylinder is configured to rotate only in one direction (the feeding direction of the wiping web 112) with a certain resistance. .

  The winding-side web core 116 is fitted and attached to a winding shaft (not shown) that is rotatably supported horizontally. A take-up motor is connected to the take-up shaft, and the take-up web core 116 is driven by the take-up motor to rotate in one direction (winding direction of the wiping web 112). The take-up shaft has a double structure, and an outer cylinder is rotatably supported around the inner cylinder. A torque limiter is disposed between the inner cylinder and the outer cylinder, and is configured such that the outer cylinder slides with respect to the inner cylinder when a load (torque) exceeding a certain level is applied. Thereby, it is possible to prevent excessive tension from being applied to the wiping web 112.

  The first guide roll 118 is rotatably supported by a horizontally installed shaft (not shown), and guides the wiping web 112 delivered from the delivery-side web core 114 toward the cleaning liquid application unit 140.

  The second guide roll 120 is rotatably supported by a horizontally installed shaft (not shown), and guides the wiping web 112 delivered from the cleaning liquid application unit 140 toward the pressing roll 122.

  The pressing roll 122 is installed horizontally with one end of its shaft portion supported rotatably. The pressing roll 122 is configured corresponding to the width of the wiping web 112, and causes the wiping web 112 to contact the nozzle surface 33 of the head 32 with a predetermined pressure.

  FIG. 6 is a front partial cross-sectional view showing the configuration of the pressing roll 122 and the shaft support portion that supports the shaft portion. As shown in FIG. 6, the shaft support portions 180 </ b> L and 180 </ b> R are provided on an elevating stage 182 provided horizontally. The shaft support portions 180L and 180R are provided so as to be orthogonal to the axis of the pressing roll 122, and recessed portions 184L and 184R are formed inside thereof. The concave portions 184L and 184R are formed in a rectangular shape having the same width as the shaft portions 122L and 122R of the pressing roll 122, and are formed orthogonal to the nozzle surface of the inkjet head to be cleaned. . As for the press roll 122, shaft parts 122L and 122R at both ends thereof are loosely fitted into the recesses 184L and 184R of the shaft support parts 180L and 180R. As a result, the pressing roll 122 is supported so as to be swingable within a plane orthogonal to the nozzle surface of the inkjet head to be cleaned.

  Springs 186L and 186R are accommodated inside the recesses 184L and 184R, and the shafts 122L and 122R of the pressing roll 122 loosely fitted in the recesses 184L and 184R are urged upward by the springs 186L and 186R. Has been. Thereby, the peripheral surface of the press roll 122 can be brought into close contact with the nozzle surface, following the nozzle surface of the inkjet head to be cleaned.

  Next, the configuration of the pressing roll 122 will be described. The pressure roll 122 that presses the nozzle surface 33 is provided at the end of the pressure roll 122 with the nozzle facing portion 122A provided at a position facing the vicinity of the nozzle on the nozzle surface 33 and the nozzle facing portion 122A interposed therebetween. The pressure roller end portion 122B is different from the pressure roller end portion 122B in that the pressure force applied to the nozzle surface 33 is different from that of the pressure roller end portion 122B. It is comprised so that it may become. Specifically, the nozzle facing portion 122A and the pressing roll end portion 122B of the pressing roll 122 can be formed of different materials. For example, a member constituting the nozzle facing portion 122A is formed of soft rubber, and the pressing roll A member constituting the end 122B can be formed of hard rubber. Further, in this embodiment, the cleaning liquid is applied before wiping with the wiping web 112, but when the cleaning liquid is not applied to the wiping web 112, a sponge or the like is used as a material constituting the nozzle facing portion 122A. be able to. This is because when the cleaning liquid is not applied to the wiping web 112, there is no concern that the pressing roll 122 absorbs the cleaning liquid from the wiping web.

  As the soft rubber constituting the nozzle facing portion 122A of the pressing roll 122, it is preferable to use a material having a hardness in the range of 10 degrees to 30 degrees. Moreover, as hard rubber which comprises the press roll edge part 122B, it is preferable to use the material of hardness within the range of 70 degrees-90 degrees. The rubber hardness is a value measured using a durometer type A (Shore A) measuring instrument based on ISO7619.

  FIG. 7 is a diagram illustrating a relationship between an example of the shape of the pressing roll 122 and the shape of the nozzle surface 33 according to the present embodiment. In this embodiment, as shown to Fig.7 (a), the shape of the press roll 122 can make the diameter of the nozzle opposing part 122A and the diameter of the press roll end part 122B into the same diameter, and it can be set as a flat roll. Moreover, as shown in FIG.7 (b), the diameter of the press roll edge part 122B can be made smaller than the diameter of the nozzle opposing part 122A, and the nozzle opposing part 122A can expand and form.

  As described above, the nozzle formation region 33A and the nozzle protection region 33B of the nozzle surface 33 are formed by retreating the nozzle formation region 33A in a concave shape, but are formed by the nozzle formation region 33A and the nozzle protection region 33B. The step is several tens of μm. Therefore, since this level | step difference can be absorbed with the thickness of the wiping web 112, even if the press roll 122 is made into a flat roll as shown to Fig.7 (a), pressing force is determined by the difference in the hardness of the press roll 122. can do.

  Further, as shown in FIG. 7B, even when the diameter of the nozzle facing portion 122A is increased, the nozzle face 33 is reduced by decreasing the hardness of the nozzle facing portion 122A and increasing the hardness of the pressing roll end portion 122B. When pressed, the deformation of the nozzle facing portion 122A can be suppressed by the pressing roll end portion 122B. Accordingly, the pressing force applied to the nozzle surface 33 by the nozzle facing portion 122A can be reduced.

  When the liquid repellent film is not formed in the nozzle protection region 33B, it is preferable to wipe the nozzle protection region 33B with the press roll end 122B as shown in FIGS. 7 (a) and 7 (b). By wiping with the pressing roll end 122B, a high pressing force can be applied to the nozzle protection region 33B. When the nozzle surface 33 is covered with the cap 42 at the maintenance position and left for a long period of time, a cap mark may remain on the nozzle surface 33, particularly the nozzle protection region 33B. Further, when the vicinity of the nozzle is wiped with a pressing force for wiping off the cap mark, there is a concern that the liquid repellent film near the nozzle is peeled off. By applying a high pressing force only to the nozzle protection region 33B, it is possible to easily wipe the cap marks.

  Further, when a liquid repellent film is formed in the nozzle protection area 33B, as shown in FIG. 7C, only the position facing the end of the nozzle protection area 33B is used as the pressure roll end 122B and the rubber hardness is high. It is preferable to form with a high material. When a liquid repellent film is formed in the nozzle protection area 33B, if the nozzle protection area 33B is wiped with the end of a press roll having a high rubber hardness, there is a concern that the liquid repellent film may be peeled off. As illustrated in FIG. 7C, the width of the pressing roll end 122 </ b> B is shortened so that the pressing roll end 122 </ b> B functions as a guide unit that supports pressing between the nozzle surface 33 and the pressing roll 122. be able to. By adopting such a configuration, the width of the nozzle facing portion 122A formed of soft rubber can be increased, and the nozzle protection region 33B can also be wiped by being pressed against the nozzle facing portion 122A. Therefore, peeling of the water repellent film in the nozzle protection region 33B can also be prevented.

  In addition, in FIG.7 (c), although the press roll 122 is described by the flat roll, as shown in FIG.7 (b), it can be set as the press roll which 122A of nozzle facing parts expanded. Even in this case, since the nozzle facing portion 122A is formed of soft rubber having a low rubber hardness, the pressing force of the nozzle facing portion 122A can be suppressed even if the entire pressing roll 122 is pressed with a constant pressure.

(Structure of cleaning liquid application part)
The cleaning liquid application unit 140 mainly supplies the cleaning liquid to the cleaning liquid nozzle 142 from the cleaning liquid tank 142, the cleaning liquid tank 144 in which the cleaning liquid is stored, the cleaning liquid pipe 146 that connects the cleaning liquid tank 144 and the cleaning liquid nozzle 142. And a cleaning liquid pump 148.

  The cleaning liquid nozzle 142 has a jet outlet having a width corresponding to the width of the wiping web 112, and jets the cleaning liquid from the jet outlet. The cleaning liquid nozzle 142 is installed so as to eject the cleaning liquid upward.

  When the wiping web 112 passes over the cleaning liquid nozzle 142, the cleaning liquid ejected from the ejection port is applied. As a result, the cleaning liquid is absorbed into the wiping web 112.

  The cleaning liquid nozzle 142 is connected to the cleaning liquid tank 144 via the cleaning liquid pipe 146. The cleaning liquid pump 148 is provided in the middle of the cleaning liquid pipe 146 and sends the cleaning liquid stored in the cleaning liquid tank 144 to the cleaning liquid nozzle 142.

(Configuration of cleaning liquid recovery unit)
The cleaning liquid recovery unit 150 mainly includes a squeeze roll pair 170 that squeezes the wiping web 112 to which the cleaning liquid is applied, a press adjustment mechanism 172 that adjusts the pressing force of the squeeze roll pair 170, a recovery receiving member 174, and a cleaning liquid tank 144. After the cleaning liquid is recovered, the cleaning liquid recovery pipe 160 for connecting the cleaning liquid, the recovery pump 160 for sending the cleaning liquid recovered by the recovery receiving member 174 to the cleaning liquid tank 144, the recovery liquid filter 162 for removing foreign matter in the recovered cleaning liquid, and And a moisture meter 164 for measuring the amount of (absorbed) cleaning liquid contained in the wiping web 112.

  The squeeze roll pair 170 is a squeezing means composed of two opposing rolls. Each squeeze roll has a width corresponding to the width of the wiping web 112 and is made of rubber that is not violated by a cleaning liquid such as silicon or EPDM, or a metal such as SUS.

  The squeeze roll pair 170 is disposed on the downstream side of the cleaning liquid nozzle 142 in the conveyance path of the wiping web 112. The squeeze roll pair 170 sandwiches and presses the wiping web 112 to which the cleaning liquid is applied, and squeezes the cleaning liquid from the wiping web 112. As a result, excess cleaning liquid is recovered from the wiping web 112, and the wiping web 112 is in a state of being wetted by an appropriate amount of cleaning liquid.

  The pressing adjustment mechanism 172 adjusts the pressing of the squeeze roll by the displacement of the cam (not shown). Thereby, the cleaning liquid recovered from the wiping web 112 can be increased by increasing the pressure, and the cleaning liquid recovered can be decreased by decreasing the pressure.

  Therefore, by controlling the pressure adjusting mechanism 172 according to the amount of cleaning liquid measured by the moisture meter 164, the amount of cleaning liquid of the wiping web 112 after cleaning liquid recovery can be controlled to an appropriate amount.

  A recovery receiving member 174 for recovering the squeezed cleaning liquid is provided below the squeeze roll pair 170. The cleaning liquid recovered by the recovery receiving member 174 is sucked by the recovery pump 160 and guided to the cleaning liquid recovery pipe 158. After the impurities are removed in the recovery liquid filter 162, the cleaning liquid is sent to the cleaning liquid tank 144 and reused.

  The wiping web 112 that has been wetted by an appropriate amount of the cleaning liquid in this way is pressed against the nozzle surface 33 by the pressing roll 122 and sequentially wipes the nozzle surface 33 in unused areas.

(Operation of nozzle surface cleaning device)
Next, the operation of the nozzle surface cleaning device 80 configured as described above will be described.

  The operation of the nozzle surface cleaning device 80 is controlled by a control device (not shown) that controls the entire inkjet recording device 10. The control device wipes and cleans the nozzle surface 33 by the nozzle surface cleaning device 80 in the process of moving the head 32 from the image recording position to the maintenance position.

  The entire nozzle surface cleaning device 80 is configured to be movable up and down by a wiping device main body lifting mechanism. The nozzle surface cleaning device 80 is located at a predetermined standby position except during cleaning, and is positioned at a predetermined operation position that is a position raised by a predetermined amount from the standby position during cleaning.

  In a state where the nozzle surface cleaning device 80 is located at the operating position, the nozzle surfaces 33 of the heads 32 can be wiped by the wiping units 100. That is, when the head 32 passes through each wiping unit 100, the wiping web 112 wound around the pressing roll 122 can be pressed against the nozzle surface 33.

  The control device controls the conveyance of the wiping web 112 by the conveyance unit 110 in accordance with the timing at which each head 32 reaches the wiping unit 100. That is, driving of the winding motor is started. As a result, the wiping web 112 is unwound from the sending-side web core 114 and travels, and is taken up by the winding-side web core 116.

  The control unit controls the cleaning liquid application unit 140 simultaneously with the traveling of the wiping web 112 to wet the wiping web 112 with the cleaning liquid.

  The cleaning liquid nozzle 142 ejects the cleaning liquid sent from the cleaning liquid tank 144 by the cleaning liquid pump 148 upward. When the wiping web 112 passes over the cleaning liquid nozzle 142, the sprayed cleaning liquid is applied. As a result, the cleaning liquid is absorbed into the wiping web 112. At this time, a predetermined amount of cleaning liquid larger than the amount of cleaning liquid suitable for wiping and cleaning the nozzle surface 33 is applied to the wiping web 112. For example, an amount of the cleaning liquid that saturates the absorption capacity of the wiping web 112 is applied.

  Further, the control unit controls the cleaning liquid recovery unit 150 simultaneously with the traveling of the wiping web 112 to recover the cleaning liquid from the wiping web 112 to which the cleaning liquid is applied. The wiping web 112 to which the cleaning liquid is applied is squeezed by the squeeze roll pair 170, and excess cleaning liquid is recovered by the recovery receiving member 174. As a result, the wiping web 112 is in a state of being wetted with a cleaning liquid having a droplet amount (an amount suitable for wiping the nozzle surface 33).

  As described above, the excess cleaning liquid is collected and the wiping web 112 is wetted with an appropriate amount of the cleaning liquid, so that the absorption capacity of the wiping web 112 is optimal. As a result, it is possible to prevent the cleaning liquid from entering the nozzle N or sag during the wiping of the nozzle surface 33.

  The state in which the absorption capacity of the wiping web 112 is optimal differs depending on the material and thickness of the wiping web 112, the nozzle diameter, the ink composition, and the like. Further, the appropriate amount of cleaning liquid varies depending on the inkjet heads 32C, 32M, 32Y, and 32K. Therefore, the recovery amount of the cleaning liquid from the squeeze roll pair 170 is set as appropriate.

  The recovered cleaning liquid is guided to the cleaning liquid recovery pipe 158, and impurities such as dust are removed by passing through the recovery liquid filter 162 in the path. Thereafter, the liquid is sent to the cleaning liquid tank 144 and reused.

  The wiping web 112 from which the cleaning liquid has been collected by the squeeze roll pair 170 is measured by the moisture meter 164 for the amount of the cleaning liquid. By controlling the pressure adjusting mechanism 172 according to the measured amount of cleaning liquid, the amount of cleaning liquid recovered by the squeeze roll pair 170 is adjusted, and the amount of cleaning liquid of the wiping web 112 after cleaning liquid recovery is controlled to an appropriate amount. be able to.

The wiping web 112 to which the cleaning liquid is applied in this way is pressed against the nozzle surface 33 by the pressing roll 122 by running by driving of the winding motor, and the nozzle surface 33 is wiped and cleaned.

  At this time, the wiping web 112 travels in the direction opposite to the moving direction of the nozzle surface 33 and wipes the nozzle surface 33. Thereby, the nozzle surface 33 can be wiped off efficiently. In addition, the nozzle surface 33 can be wiped using the new surface (unused area) of the wiping web 112 at all times.

  Since the liquid repellent film is easily peeled off from the nozzle edge by wiping near the nozzle on the nozzle surface 33, the vicinity of the nozzle needs to be wiped with a low pressing force. Further, when the liquid repellent film is not formed on the nozzle surface other than the vicinity of the nozzle, it is necessary to wipe with high pressure in order to remove dirt such as a cap mark.

  As described above, the pressing roll 122 is a single pressing roll 122 and is formed of the nozzle facing portion 122A and the pressing roll end portion 122B of different materials. The pressure distribution of the pressure can be given. Therefore, since the nozzle surface 33 can be wiped with different pressing forces in the vicinity of the nozzle and other regions, the nozzle surface can be efficiently wiped with one pressing roll 122.

  Further, since the nozzle surface 33 can be cleaned with different pressing forces by using one pressing roll 122, it is not necessary to increase the size of the apparatus, and it is possible to prevent an increase in the amount of the cleaning liquid and the wiping web 112 to be used. can do.

  The wiping web 112 that has wiped the nozzle surface 33 is wound around the winding-side web core 116. Further, the head 32 is moved to the maintenance position, and the nozzle surface 33 is covered with the cap 42.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording apparatus, 20 ... Paper conveyance mechanism, 30 ... Head unit, 32 (32C, 32M, 32Y, 32K) ... Head, 33 ... Nozzle surface, 33A ... Nozzle formation area, 33B ... Nozzle protection area, 40 ... Maintenance Unit: 80 ... Nozzle surface cleaning device, 100 (100C, 100M, 100Y, 100K) ... Wiping unit, 110 ... Conveying unit, 112 ... Wiping web, 122 ... Press roll, 122A ... Press roll, 122B ... End of press roll, 140 ... Cleaning liquid application unit, 142 ... Cleaning liquid nozzle, 150 ... Cleaning liquid recovery unit, 170 ... Squeeze roll pair

Claims (9)

In the nozzle surface cleaning device for cleaning the nozzle surface of the droplet discharge head,
A wiping member for wiping the nozzle surface, and a pressing roll for pressing the wiping member against the nozzle surface and wiping with the wiping member,
A liquid repellent film is formed at least near the nozzle surface of the nozzle surface,
The pressing roll is composed of a nozzle facing portion provided at a position facing the vicinity of the nozzle, and pressing roll end portions formed at both ends of the pressing roll with the nozzle facing portion interposed therebetween,
And the nozzle face portion and the pressing roll end, Ri Oh in hybrid roll made come together in different materials,
The nozzle surface cleaning apparatus in which the pressing force pressed against the nozzle surface by the pressing roll is lower in the nozzle facing portion than the end portion of the pressing roll . The pressing roll is made of rubber,
The rubber hardness of the nozzle facing portion, the nozzle surface cleaning apparatus of claim 1 lower than the rubber hardness of the pressing roll end. The nozzle surface cleaning device according to claim 2 , wherein the rubber hardness of the nozzle facing portion is 10 to 30 degrees, and the rubber hardness of the end portion of the pressing roll is 70 to 90 degrees. The nozzle surface is formed by a nozzle formation region in which the nozzle is formed and a nozzle protection region that protects the nozzle,
The liquid repellent film is provided on the entire nozzle formation region,
The width of the nozzle facing portion, the nozzle surface cleaning device according to any one of 3 from the width equal to Claim 1 of the nozzle area. The nozzle surface cleaning apparatus of any one of Claim 1 to 3 with which the liquid-repellent film is formed in the said nozzle surface whole surface. The nozzle surface cleaning device according to any one of claims 1 to 5 , wherein the pressing roll has a diameter of the nozzle facing portion and a diameter of the end portion of the pressing roll. The nozzle surface cleaning device according to any one of claims 1 to 5 , wherein the pressing roll has a diameter of the nozzle facing portion larger than a diameter of the end portion of the pressing roll. The nozzle surface cleaning apparatus of any one of Claim 1 to 7 provided with the washing | cleaning liquid provision means which provides a cleaning liquid to the said wiping member. Conveying means for conveying the recording medium;
A droplet discharge head for recording an image by discharging droplets to the recording medium conveyed by the conveying means;
The nozzle surface cleaning device according to any one of claims 1 to 8 , wherein the nozzle surface of the droplet discharge head is cleaned.
An image recording apparatus comprising:

Images