JP4144556B2 - Liquid discharge head cleaning device and liquid discharge device - Google Patents

Description

  The present invention relates to a liquid discharge head cleaning device that discharges a predetermined liquid from a liquid discharge nozzle and a liquid discharge device including the same, and more particularly, a surface of the liquid discharge head that contacts the nozzle surface is a fibrous absorbent body The liquid discharge head cleaning device and the liquid discharge device improve the cleaning effect of the nozzle surface by absorbing the liquid adhering to the nozzle surface and removing the dust by the cleaning roller formed in (1).

  2. Description of the Related Art Conventionally, for example, an ink jet printer has been widely used as a liquid ejecting apparatus that ejects a predetermined liquid supplied into a liquid ejecting head from a liquid ejecting nozzle. This ink jet printer performs printing by ejecting a minute amount of ink droplets onto a recording sheet from minute ink ejection nozzles provided on the nozzle surface of a print head. In such an ink jet printer, when the print head does not perform a printing operation continuously for a long time and ink droplets are not ejected from the ink ejection nozzle of the print head, the ink remains in the vicinity of the ink ejection nozzle by the previous printing operation. In some cases, the ink as it was was evaporated and dried to thicken and solidify. In this case, in the subsequent printing operation, normal ink ejection becomes difficult, and the image quality may deteriorate.

  For this reason, conventionally, a slightly hard rubber blade or the like is pressed against the nozzle surface of the print head and slid to remove the ink thickened and solidified on the nozzle surface by wiping. The nozzle surface was being cleaned. In relation to this, a technique is disclosed in which a plurality of blades are attached to a rotating shaft and rotated to further increase the wiping effect (see, for example, Patent Document 1).

Further, a wiping member formed of a porous foam has been proposed as an improved wiping member such as a cleaning blade or a cleaning roller for wiping the nozzle surface of the print head. This uses the capillary force generated in the pores (cells) formed inside the porous foam to wipe off dirt and foreign matter while absorbing ink adhering to the nozzle surface of the print head. By setting the average value of the pore diameters formed in the foam to be equal to or smaller than the pore diameter of the ink discharge nozzle, a further excellent cleaning effect can be expected (see, for example, Patent Document 2).
JP 57-34969 A Japanese Patent No. 2738855

  However, in the technique described in Patent Document 1, the ink adhered to the nozzle surface is wiped by pressing a slightly hard rubber blade or the like against the nozzle surface of the print head and sliding the nozzle surface. As a result, a large force is applied to the nozzle surface by the blade, which may damage the nozzle surface. In addition, the blade has to rely only on the wiping effect, but ink may remain in the ink discharge nozzles only by wiping. Even when a plurality of blades are used, the nozzle surface may be damaged in the same manner as described above, and ink remains in the vicinity of the ink discharge nozzle, which causes a problem of ink discharge failure.

  Further, in the technique described in Patent Document 2, it is possible to control the average value of pore diameters formed in the inside depending on the manufacturing conditions of the porous foam constituting the cleaning roller. The pore diameter in the foam varies greatly depending on the temperature, humidity, lot, etc. at which it is produced. Therefore, since it is difficult to stabilize the average value of the pore diameter in the foam, it is not easy to mass-produce products of the same standard, and there is a problem that it is not suitable for mass production. Further, the pores in the foam may be deformed by bringing the cleaning roller into pressure contact with the nozzle surface of the print head. Therefore, it is not easy to set the pore diameter in the foam in the micron order in consideration of the usage state of the cleaning roller. As a result, when wiping the nozzle surface of the print head with such a cleaning roller, uneven ink wiping may occur on the nozzle surface.

  Accordingly, the present invention addresses such problems and absorbs the liquid adhering to the nozzle surface by a cleaning roller whose surface contacting the nozzle surface of the liquid discharge head is formed of a fibrous absorbent body. An object of the present invention is to provide a liquid discharge head cleaning device and a liquid discharge device that remove dust and improve the cleaning effect of the nozzle surface.

In order to achieve the above object, a liquid discharge head cleaning device according to the present invention provides a liquid discharge head having a nozzle surface in which a row of liquid discharge nozzles for discharging a predetermined liquid is provided corresponding to the full width of the recording medium. A cleaning device for a liquid discharge head that moves relative to the nozzle surface to clean the nozzle surface, wherein a surface that contacts the nozzle surface of the liquid discharge head is formed of a fibrous absorbent body and is in pressure contact with the nozzle surface A cleaning roller that moves while being driven to rotate in a state and wipes the nozzle surface and then returns to the wiping start position away from the nozzle surface, and has a length that is an integral multiple of the circumferential length of the cross section of the cleaning roller. Wiping is performed by setting different distances for the distance that the roller rotates following movement while the roller is in pressure contact with the nozzle surface.

With such a configuration, the length that is an integral multiple of the circumferential length of the cross section of the cleaning roller that wipes the nozzle surface of the liquid discharge head is different from the distance that the cleaning roller moves by being driven to rotate while being pressed against the nozzle surface. The fiber formed on the surface that contacts the nozzle surface of the cleaning roller by setting the length and moving the cleaning roller relative to the liquid discharge head while being driven to rotate while being pressed against the nozzle surface absorber in to remove the dust as well as absorbing the liquid adhering to the nozzle face after performing the wiping of the nozzle surface, returning the cleaning roller to wipe start position away from the nozzle surface.

The liquid discharge apparatus according to the present invention includes a liquid discharge head having a nozzle surface in which a row of liquid discharge nozzles for discharging a predetermined liquid is provided corresponding to the entire width of the recording medium, and a relative to the liquid discharge head. And a cleaning device that cleans the nozzle surface by moving the nozzle surface, wherein the cleaning device is configured such that the surface that contacts the nozzle surface of the liquid ejection head is fibrous. A cleaning roller that is formed of an absorbent member, moves while being driven and rotated in a state of being pressed against the nozzle surface, wipes the nozzle surface, and then returns to the wipe start position away from the nozzle surface. The nozzle is driven and rotated in the state where the cleaning roller is in pressure contact with the nozzle surface and a length that is an integral multiple of the circumferential length of the cross section of the roller. It is to wipe set of the distance to relatively move in a direction perpendicular to the longitudinal direction have different lengths.

With such a configuration, the length that is an integral multiple of the circumferential length of the cross section of the cleaning roller that wipes the nozzle surface of the liquid discharge head is different from the distance that the cleaning roller moves by being driven to rotate while being pressed against the nozzle surface. The fiber formed on the surface of the cleaning roller that contacts the nozzle surface by moving relative to the liquid discharge head while being driven and rotated while the cleaning roller is in pressure contact with the nozzle surface after performing the wipe the nozzle surface to remove dust while absorbing the liquid adhering to the nozzle surface in the absorber quality return a cleaning roller to wipe start position away from the nozzle surface.

According to the first and second aspects of the invention, the liquid adhering to the nozzle surface of the cleaning roller that contacts the nozzle surface of the liquid discharge head absorbs the liquid adhering to the nozzle surface and removes dust. be able to. Further, the cleaning roller is placed on the nozzle surface such that the integral multiple of the circumferential length of the cross section of the cleaning roller is different from the distance that the cleaning roller is driven and rotated while being pressed against the nozzle surface. Since the nozzle surface is wiped while being driven and rotated in the pressure contact state, the cleaning roller is moved away from the nozzle surface and returned to the wiping start position. The nozzle surface can be wiped by changing the position in contact with the surface. Therefore, the cleaning effect of the nozzle surface can be improved. Thereby, it is possible to improve the discharge stability of the liquid discharged from the liquid discharge head.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of an ink jet printer as an example of a liquid ejection apparatus according to the present invention. The ink jet printer 1 forms an image by ejecting ink droplets on a recording paper (recording medium) , and includes a printer main body 2, a head cartridge 3 (see FIG. 2), and a recording paper tray 4. ing.

  A printer main body 2 shown in FIG. 1 includes a transport mechanism for transporting recording paper stored in a recording paper tray 4, and a control device for appropriately performing printing on recording paper as an ejection target. The recording paper tray 4 is detachably attached to a tray insertion slot 5 provided at the lower part of the front surface. The tray insertion port 5 also serves as a recording paper discharge port so that the recording paper printed by the printer main body 2 is discharged from the discharge receiving portion 4 a on the upper surface of the recording paper tray 4. It has become. In addition, a display panel (display unit) 6 is provided at the upper front of the printer main body 2 so as to display the state of the entire operation of the ink jet printer 1.

  Further, an upper lid 7 is attached to the upper surface side of the printer main body 2 so as to be openable and closable. When the upper lid 7 is opened, a storage portion 8 for accommodating the head cartridge 3 is formed on the upper surface side of the printer main body portion 2. ing. In the storage portion 8 of the printer main body 2, the head cartridge 3 is stored as indicated by an arrow Z and is held in a detachable state. The head cartridge 3 has an elongated casing extending over the entire width in the width direction of the printer main body 2, that is, the width direction of the recording paper. For example, four color inks of yellow Y, magenta M, cyan C, and black K are used. An image is formed by discharging onto a recording sheet, and includes an ink tank 9, a print head 10, and a head cap 11.

  FIG. 2 is a partial cross-sectional side view showing the configuration of the head cartridge 3 shown in FIG. Inside the head cartridge 3, four ink tanks 9 (9y, 9m, 9c, 9k) are loaded. The ink tank 9 serves as a liquid container for storing ink (predetermined liquid), and ink of four colors Y, M, C, and K is accommodated in each ink tank 9. The ink tank 9 supplies ink stored in the ink tank 9 into the print head 10. The print head 10 is called a full-line liquid discharge head that discharges ink supplied from the ink tank 9 corresponding to the entire width of the recording paper, and nozzles constituting a nozzle surface 12a on the lower surface thereof. A member 12 is provided, and an array of ink discharge nozzles (liquid discharge nozzles) 13 corresponding to the entire width of the recording paper is provided on the nozzle member 12.

  FIG. 3 is an enlarged sectional view showing the vicinity of the nozzle surface 12a of the print head 10 shown in FIG. A head chip 14 is provided above the nozzle member 12 disposed on the lower surface of the print head so as to correspond to the position of the ink discharge nozzle 13. The head chip 14 includes a logic circuit that controls ink ejection based on a printing signal and a transistor that drives a heating resistor 15 described later. The heating chip 15 is disposed at a position facing the ink ejection nozzle 13. I have. When the heating resistor 15 generates heat, ejection energy is applied to the ink in the ink pressurizing chamber 16, and ink droplets are ejected from the ink ejection nozzle 13.

  Further, a flow path plate 17 is provided on the upper surface of the head chip 14. The flow path plate 17 is a member that forms an ink flow path 18 for supplying ink in the ink tank 9 shown in FIG. 2 to the ink pressurizing chamber 16. The flow path plate 17 is shown separately in the left and right in FIG. 3, but is connected to each other to form an integral structure. The flow path plate 17 is disposed between the head frames 19 and 19 that support the nozzle member 12.

  As shown in FIG. 2, a head cap 11 is detachably mounted on the lower surface side of the print head 10. The head cap 11 moves relative to the print head 10 in the direction indicated by the arrow A or B, and protects the nozzle surface 12a of the print head 10 in the mounted state shown in FIG. It has become. Specifically, it is formed in a long and narrow box shape having rising pieces on the four circumferences, and the whole is made of a hard resin or the like, and a cleaning roller 20 is provided inside thereof.

  The cleaning roller 20 constitutes a cleaning device that cleans the nozzle surface 12a while moving relative to the nozzle surface 12a of the print head 10, and is formed in a columnar shape. It is attached to the longitudinal direction of the head cap 11 at one side of the inside, and is parallel to the longitudinal direction of the nozzle surface 12 a of the print head 10. The cleaning roller 20 is provided with a rotating shaft 21 made of hard plastic or metal at the center thereof. As shown in FIG. 2, the rotating shaft 21 is erected from the bottom surface of the head cap 11. Is held rotatably.

  Further, as shown in FIG. 3, a cushion portion 22 made of an elastic body such as porous foamed urethane or rubber is disposed on the outer peripheral surface of the rotating shaft 21 of the cleaning roller 20, and the outer peripheral surface thereof. Is provided with a fibrous absorbent body 23. When the cleaning roller 20 moves in the direction of arrow A while being driven to rotate in the direction of arrow C, the absorber 23 comes into contact with the nozzle surface 12a and is contaminated with ink droplets or foreign matter adhering to the nozzle surface 12a. It is a member for wiping off and cleaning, and is made by condensing a fibrous material that absorbs liquid, for example, chemical fibers such as polyethylene. As a result, a large number of pores having different sizes are formed between the individual fibers, as shown in FIG.

  In addition, the absorbent body 23 is a cloth formed by mechanically or chemically and thermally treating a fiber sheet without passing through the form of a yarn, and bonding the adhesive and the fibers themselves together with each other. You may form with a nonwoven fabric. Also in this case, a large number of pores having different sizes are formed inside the absorbent body 23 made of a nonwoven fabric.

  The cleaning roller 20 moves on the nozzle surface 12a while being driven to rotate while being in pressure contact with the nozzle surface 12a. In the absorbent body 23 constituting the outer peripheral surface of the cleaning roller 20, each fiber creates pores having a random size, and the nozzle surface 12 a of the nozzle member 12 is formed by the pores having different sizes. It is possible to wipe off the dirt adhering to the nozzle surface and apply the capillary force generated by these pores to the nozzle surface 12a.

  As described above, since the cleaning roller 20 is formed in a columnar shape, various fiber states on the surface of the absorber 23 can be brought into contact with the nozzle surface 12a. As a result, the fibrous absorbent body 23 adapted to the size and shape of dirt and ink droplets attached to the nozzle surface 12a comes into contact with the nozzle surface 12a. Therefore, it is possible to remove the dirt and ink droplets attached to the nozzle surface 12a that are difficult to remove while contacting with the absorber 23 in a state adapted to the dirt, while repeating the wipe a plurality of times.

At this time, as shown in FIG. 4, a length that is an integral multiple of the circumferential length of the cross section of the cleaning roller 20 is different from the distance that the cleaning roller 20 moves by being driven to rotate while being pressed against the nozzle surface 12a. It is set to length. For example, the distance that the cleaning roller 20 moves from the wipe start position S to the wipe end position E of the nozzle surface 12a is L, the length around the cross section of the cleaning roller 20 is a, and the rotation speed of the cleaning roller 20 is Let n be a predetermined length α,
L = n × a + α (where α ≠ a)
The relationship is established.

  As a result, as shown in FIG. 4, after the cleaning roller 20 located at the wipe start position S is in pressure contact with the nozzle surface 12a and moved in the direction of the arrow A while being driven to rotate, the wiper end position E is reached. When the cleaning roller 20 is moved downward in the direction of the arrow F and moved in the direction of the arrow B without being brought into contact with the nozzle surface 12a and returned to the wipe start position S, the above operation is repeated. The surface where the absorber 23 disposed on the outer peripheral surface 20 contacts the nozzle surface 12a at the wipe start position S can be made different from the previous time. Accordingly, by moving the cleaning roller 20 again in the direction of arrow A and wiping the nozzle surface 12a, the state of various fibers on the surface of the absorber 23 comes into contact with the nozzle surface 12a. Dirt and ink droplets adhering to the surface 12a can be removed. Accordingly, even if the wipes are repeated a plurality of times, dirt that cannot be easily removed can be removed by the fibrous absorbent body 23, and the cleaning effect of the nozzle surface 12a can be improved.

  Further, as shown in FIG. 5, the cleaning roller 20 wipes the nozzle surface 12a by making the wipe start position S for starting the wipe to the nozzle surface 12a different from the previous wipe start position S. You may do it. Accordingly, when the operation of cleaning the nozzle surface 12a by the cleaning roller 20 is repeatedly performed, the nozzle surface 12a can be wiped by changing the wiping start position S of the cleaning roller 20 each time. Therefore, as described above, even when the wipes are repeated a plurality of times, dirt that cannot be easily removed can be removed by the fibrous absorber 23, and the cleaning effect of the nozzle surface 12a can be improved. it can.

  As shown in FIG. 2, an ink receiving member 30 is laid on the bottom surface of the head cap 11. The ink receiving member 30 receives ink droplets preliminarily discharged from the ink discharge nozzles 13 of the print head 10 and is made of a hygroscopic member such as a sponge, and is formed on the entire bottom surface of the head cap 11. Thus, ink droplets that have been pre-discharged are received. This prevents the ink preliminarily ejected from the ink ejection nozzle 13 of the print head 10 from rebounding and absorbs the ink so that it does not collect on the bottom surface of the head cap 11. Therefore, it is possible to prevent the preliminary discharge ink from splashing back at the ink receiving member 30 and reattaching to the nozzle surface 12a.

  Next, an operation for maintaining the liquid discharge performance of the liquid discharge apparatus configured as described above will be described with reference to FIGS. First, the head cartridge 3 is housed as indicated by an arrow Z in the housing portion 8 of the printer main body 2 shown in FIG. A recording paper tray 4 is accommodated in the tray insertion slot 5. At this time, as shown in FIG. 6, it is assumed that the conveyance belt 32 that conveys the recording paper 31 in the recording paper tray 4 to the lower surface side of the print head 10 is in a lowered state. Next, when ink is ejected from the print head 10 to form an image on the recording paper 31, the head cap 11 is first moved in the direction of arrow A and removed from the print head 10, and the head cap 11 is removed from the nozzle member 12. Evacuate. That is, in the standby state shown in FIG. 7A, the head cap 11 mounted on the lower surface of the print head 10 is moved in the direction of arrow A as shown in FIG. Move relative.

  Here, since the cleaning roller 20 is provided inside the head cap 11, as shown in FIG. 7B, the head cap 11 is moved in the direction of arrow A and opened. The cleaning roller 20 moves on the nozzle surface 12a while being driven to rotate while the nozzle surface 12a is pressed with an appropriate pressure over the entire length. As a result, dust and thickened and solidified ink adhering to the nozzle surface 12a are wiped off by the cleaning roller 20 for cleaning.

  At this time, the action of the capillary force due to the random pores created by the individual fibers of the absorber 23 disposed on the outer peripheral surface of the cleaning roller 20 can be dispersed evenly on the nozzle surface 12a. Therefore, ink wiping unevenness hardly occurs on the nozzle surface 12a, and the cleaning effect of the nozzle surface 12a of the print head 10 can be improved. At this time, as in the prior art described in Patent Document 2, it is not necessary to use a porous foam whose average pore diameter is controlled on the surface where the cleaning roller contacts the print head. Standard products can be easily mass-produced.

  Further, as shown in FIG. 4, a length that is an integral multiple of the circumferential length of the cross section of the cleaning roller 20 and a distance L that is driven and rotated while the cleaning roller 20 is in pressure contact with the nozzle surface 12a. By setting the different lengths, it is possible to wipe the nozzle surface 12a by changing the surface where the cleaning roller 20 contacts the nozzle surface 12a in the repetition of the wiping operation. Therefore, when wiping by the cleaning roller 20 is repeatedly performed, the absorber 23 disposed on the outer circumferential surface of the cleaning roller 20 wipes the nozzle surface 12a with different surfaces contacting the nozzle surface 12a. be able to. Therefore, dirt that cannot be easily removed while repeating a plurality of wipes can be removed by the absorber 23 of the cleaning roller 20, and the cleaning effect of the nozzle surface 12a can be improved.

  Further, as shown in FIG. 5, the cleaning roller 20 wipes the nozzle surface 12a by making the wipe start position S for starting the wipe to the nozzle surface 12a different from the previous wipe start position. You may do it. In this case, the nozzle surface 12a can be wiped by changing the wipe start position S of the cleaning roller 20 each time. Therefore, the same effect as described above can be obtained.

After such a cleaning operation, as shown in FIG. 7C, the head cap 11 is retracted to the retracted position. In this state, after the transport belt 32 is raised, the recording paper 31 in the recording tray 4 is transported to the lower surface side of the print head 10. Then, ink droplets are ejected from the ink ejection nozzles 13 of the print head 10 onto the conveyed recording paper 31 to form an image. At this time, the nozzle surface 12a of the print head 10 is properly cleaned, it is possible to improve the ejection stability of the ink droplets ejected printhead 1 0 to, to form a high quality image Can do.

  In the above description, the cleaning roller 20 has the fibrous absorbent body 23 disposed on the outer peripheral surface of the cushion portion 22 disposed on the outer periphery of the rotating shaft 21. Without being limited thereto, the fibrous absorbent body 23 can be molded simultaneously with the cushion portion 22 to be integrated. In this case, the same effect as described above can be obtained.

  In the above description, an example applied to an ink jet printer has been described. However, the present invention is not limited to this, and any device that discharges liquid from a liquid discharge nozzle of a liquid discharge head may be used. . For example, the present invention can be applied to a facsimile machine or a copying machine whose recording system is an inkjet system.

The liquid ejected from the nozzles of the liquid ejection head of the liquid ejection apparatus is not limited to ink, and any other liquid ejection apparatus can be used as long as it can form a dot row or a dot by ejecting the liquid in the liquid chamber. Can be applied. For example, a liquid ejection device for ejecting a DNA-containing solution onto a pallet (recording medium) in DNA identification or the like, or a liquid containing conductive particles for forming a wiring pattern of a printed wiring board (recording medium) The present invention can also be applied to a liquid ejection device.

1 is a perspective view showing an embodiment of an ink jet printer as an example of a liquid ejection apparatus according to the present invention. It is a partial cross section side view which shows the structure of the head cartridge accommodated in the accommodating part of the inkjet printer shown in FIG. FIG. 3 is an enlarged sectional view showing the vicinity of a nozzle surface of the print head shown in FIG. 2. FIG. 4 is an explanatory diagram showing an operation of wiping by setting a length that is an integral multiple of the circumferential length of the cross section of the cleaning roller shown in FIG. 3 and a moving distance of the nozzle surface of the cleaning roller to different lengths. It is explanatory drawing which shows the operation | movement which makes the wipe start position with respect to the nozzle surface of the cleaning roller shown in FIG. 3 differ from the previous wipe start position. FIG. 2 is a partial cross-sectional side view showing a state in which a head cartridge is housed in a housing portion of the ink jet printer shown in FIG. 1. FIG. 7 is an explanatory diagram for explaining an operation of maintaining the ink ejection performance of the print head by moving the head cap shown in FIG. 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer 2 ... Printer main-body part 3 ... Head cartridge 9 ... Ink tank 10 ... Print head 11 ... Head cap 12 ... Nozzle member 12a ... Nozzle surface 13 ... Ink discharge nozzle 20 ... Cleaning roller 22 ... Cushion part 23 ... Absorber S ... Wipe start position E ... Wipe end position

Claims (2)

Cleaning of a liquid discharge head in which a row of liquid discharge nozzles for discharging a predetermined liquid moves relative to a liquid discharge head having a nozzle surface provided corresponding to the entire width of the recording medium to clean the nozzle surface A device,
The surface of the liquid discharge head that is in contact with the nozzle surface is formed of a fibrous absorber and moved while being driven and rotated while being in pressure contact with the nozzle surface. It has a cleaning roller that returns to the wipe start position .
Wiping is performed by setting a length that is an integral multiple of the circumferential length of the cross section of the cleaning roller and a distance that the cleaning roller is driven and rotated while being in pressure contact with the nozzle surface to be different lengths. Discharge head cleaning device. A liquid discharge head having a nozzle surface in which a row of liquid discharge nozzles for discharging a predetermined liquid is provided corresponding to the full width of the recording medium, and the nozzle surface is cleaned by moving relative to the liquid discharge head A liquid ejection apparatus that ejects liquid from the liquid ejection nozzle,
The cleaning device has a surface that contacts the nozzle surface of the liquid discharge head formed of a fibrous absorbent body and moves while being rotated while being in pressure contact with the nozzle surface. It is equipped with a cleaning roller that returns from the nozzle surface to the wipe start position ,
A length that is an integral multiple of the circumferential length of the cross section of the cleaning roller is different from a distance that the cleaning roller is driven to rotate while being in pressure contact with the nozzle surface and moves relatively in a direction perpendicular to the longitudinal direction of the nozzle surface. A liquid discharge apparatus characterized by wiping with a length set.

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