JP4784195B2 - Head maintenance mechanism and inkjet printer - Google Patents

Description

The present invention relates to a head maintenance mechanism and an ink jet printer, and more particularly to a head maintenance mechanism and an ink jet printer that perform head maintenance of a recording head that performs image recording using high-viscosity ink.

  2. Description of the Related Art Conventionally, many image printers using an ink jet method have been used as image recording means capable of recording an image simply and inexpensively. An image printer using an inkjet system (hereinafter referred to as “inkjet printer”) uses, for example, a piezoelectric element such as a piezo element, a heater, or the like to record paper or the like as fine droplets of ink from a nozzle of a recording head. The image is recorded while being ejected toward the medium and penetrating or fixing the ink on the recording medium.

  Furthermore, in recent years, a photocurable ink jet printer has been known as a means for forming an image even on a recording medium such as a resin film having poor ink absorbability (see, for example, Patent Document 1). This is because a photocurable ink containing a photoinitiator having a predetermined sensitivity to specific light such as ultraviolet rays is used, and the ink that has landed on the recording medium is irradiated with light to cure the ink. It is fixed on a recording medium and can be easily printed even on transparent or opaque packaging materials.

  However, in such an ink jet printer, when the recording operation is continuously performed, the ink which is ejected from the nozzles of the recording head and becomes atomized may adhere to and accumulate in the vicinity of the nozzles to cause clogging. . In particular, in a photo-curable ink jet printer, the ink adhering to the vicinity of the nozzle may be cured by reflected light from an ultraviolet light source or the like. Even if the nozzles perform the ejection operation, ejection defects such as so-called nozzle shortage where ink droplets are not ejected or so-called ejection bending where ink droplets are not ejected in the correct direction may occur, which may cause problems in image recording.

  In addition, in order to normally eject ink from the nozzle, it is necessary to form a meniscus having a normal shape at the tip of the nozzle. For example, the ink adheres to the vicinity of the nozzle by performing a continuous recording operation. However, when this is cured by light irradiation, the shape of the meniscus breaks down and normal ink ejection cannot be performed, and high-definition image recording cannot be performed.

  Therefore, in order to perform normal image recording, it is necessary to appropriately perform a maintenance operation of the recording head. As a maintenance device that performs the maintenance operation of the recording head, there is a maintenance device that wipes ink using a blade made of silicon rubber or the like. However, photocurable inks such as the ultraviolet curable ink described above are difficult to wipe off with a blade because of their high viscosity and poor wettability.

  As a maintenance device in such an ink jet printer, conventionally, a sheet-like ink absorber such as paper that absorbs ink is brought into contact with the recording head to absorb and remove ink adhering to the vicinity of the nozzles of the recording head. An apparatus is known (see, for example, Patent Document 2). Such a maintenance device using an ink absorber does not require a large amount of ink to be discharged during maintenance, and thus can reduce ink consumption, and since it is in a sheet form, the recording head can be freely set. There is an advantage that it can be applied also to an ink jet printer using a line head which is difficult to move.

There is also a maintenance device that absorbs ink adhering to the nozzle surface and nozzles by pressing the absorbing paper that absorbs ink to form protruding portions, and then moving the absorbing paper sequentially against the nozzle surface. It has been proposed (see, for example, Patent Document 3). In addition, “US Pat. No. 4,935,753” disclosed in Patent Document 3 discloses a maintenance device that absorbs ink adhering to the nozzle surface and the nozzle by sequentially moving the endless belt-like body against the nozzle surface. Has also been proposed.
JP 2001-310454 A Japanese Patent No. 2705756 JP-A-11-115215

  However, simply adhering the ink absorber to the recording head and performing the wiping operation cannot always remove the ink adhering to the nozzles and nozzle surfaces. In particular, in ink with high viscosity and high wettability, it is not easy to remove ink adhering to the nozzle or the nozzle surface.

  Further, simply wiping the nozzle or nozzle surface with the ink absorber cannot reliably suck out ink from each nozzle because the ink absorber does not sufficiently adhere to the nozzle surface. For this reason, even if a maintenance operation such as a wiping operation is performed, it is difficult to re-form a normal meniscus at the tip of the nozzle, and there has been a problem that ink ejection from each nozzle does not sufficiently recover.

  Further, as described in Patent Document 3 and U.S. Pat. No. 4,935,753, in a configuration in which an absorbing member that absorbs ink is moved to abut against the nozzle surface to perform a maintenance operation, it abuts against one end of the nozzle surface. The absorbed body sequentially moves on the nozzle surface while absorbing ink. For this reason, there is a problem that the ink non-absorbing portions cannot be brought into close contact with the individual nozzles and sufficient ink absorption cannot be performed.

  Further, water repellent treatment is generally performed on the nozzle surface to make it difficult for ink to adhere to the nozzle surface. However, in the configuration described in Patent Document 3 and US Pat. No. 4,935,753, Further, since the absorber that absorbs ink is brought into contact with the nozzle surface while being moved, there is a problem that the water-repellent treatment applied to the nozzle surface may be deteriorated or the nozzle may be damaged.

Accordingly, the present invention has been made to solve the above-described problems, and provides a head maintenance mechanism and an ink jet printer that can appropriately prepare a meniscus using an ink absorber and perform nozzle maintenance. It is intended.

In order to solve such a problem, the invention described in claim 1 performs a maintenance operation of the nozzle of the recording head provided with a plurality of nozzles for ejecting ink and the nozzle surface on which the nozzle is formed. In the head maintenance mechanism,
An ink wiping device comprising: an ink absorber having ink absorptivity; and a pressing member that contacts the nozzle surface while moving along the ink absorber;
The area of the contact portion of the pressing member that contacts the ink absorber at the time of pressing is at least 50% or more of the area of the contact portion of the ink absorber that contacts the nozzle surface at the time of pressing.

According to the first aspect of the invention having such a configuration, the maintenance operation is performed by bringing the ink absorber into contact with the nozzle surface while moving the pressing member along the ink absorber. The area of the contact portion of the pressing member that contacts the ink absorber during pressing is at least 50% or more of the area of the contact portion of the ink absorber that contacts the nozzle surface during pressing.

According to a second aspect of the present invention, in the head maintenance mechanism according to the first aspect, the area of the contact portion of the pressing member that contacts the ink absorber when pressed is in contact with the nozzle surface when pressed. It is characterized by being 80% or more of the area of the contact portion of the ink absorber.

In the invention according to claim 2 having such a configuration, the area of the contact portion of the pressing member that contacts the ink absorber when pressed is 80% or more of the area of the contact portion of the ink absorber that contacts the nozzle surface when pressed. It comes to become.

The invention described in claim 3 is the head maintenance mechanism according to claim 1 or 2 , wherein the pressing member includes an inner layer formed of at least a deformable material, and an outer layer holding the inner layer. It is characterized by having a multi-layer structure.

The invention according to claim 3 having such a configuration presses the ink absorber against the nozzle surface by a pressing member having a multilayer structure including at least an inner layer formed of a deformable material and an outer layer holding the inner layer. It is like that.

According to a fourth aspect of the present invention, in the head maintenance mechanism according to the third aspect , the outer layer is formed of a material having corrosion resistance against ink.

In the invention according to claim 4 having such a configuration, the ink absorber is pressed against the nozzle surface by a pressing member having an outer layer formed of a material having corrosion resistance against ink.

The invention described in claim 5 is the head maintenance mechanism according to claim 3 or 4 , wherein the outer layer is made of polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene, polyamide / nylon, It is characterized by being formed of any material of polyoxymethylene, tetrafluoroethylene / perfluorovinyl ether fluorine-containing rubber, and polybutylene terephthalate.

The invention according to claim 5 having such a configuration is composed of polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene, polyamide / nylon, polyoxymethylene, tetrafluoroethylene / perfluorovinyl ether fluoropolymer, The ink absorber is pressed against the nozzle surface by a pressing member having an outer layer formed of any material of polybutylene terephthalate.

According to a sixth aspect of the present invention, in the head maintenance mechanism according to any one of the third to fifth aspects, the inner layer is any one of gas, liquid, gel, or any of the above It is characterized by being formed of a composite material obtained by combining a plurality of such materials.

The invention according to claim 6 having such a configuration is that ink is applied by a pressing member including an inner layer formed of any one material of gas, liquid, gel, or a composite material obtained by combining a plurality of any of the above materials. The absorber is pressed against the nozzle surface.

The invention described in claim 7 is the head maintenance mechanism according to any one of claims 3 to 6 , wherein the inner layer is made of polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene. , Polyamide / nylon, polyoxymethylene, tetrafluoroethylene / perfluorovinylether fluorine rubber, and polybutylene terephthalate.

The invention according to claim 7 having such a configuration includes polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene, polyamide / nylon, polyoxymethylene, tetrafluoroethylene / perfluorovinyl ether-based fluororubber, The ink absorber is pressed against the nozzle surface by a pressing member having an inner layer formed of any material of polybutylene terephthalate.

The invention described in claim 8 is the head maintenance mechanism according to any one of claims 3 to 7 , wherein a volume of the inner layer is smaller than a volume of a space formed by the outer layer. It is characterized by.

In the invention according to claim 8 having such a configuration, the ink absorber is pressed against the nozzle surface by a pressing member in which the volume of the inner layer is smaller than the volume of the space formed by the outer layer.

Invention described in claim 9, the head maintenance mechanism as claimed in any one of claims 8, wherein the maintenance operation comprises more than wipe least twice, the wiping operation Of these, at least the second and subsequent times are performed by the ink wiping device.

The invention according to claim 9 having such a configuration includes at least two wiping operations as a maintenance operation of the nozzles of the recording head and the nozzle surface on which the nozzles are formed, and at least the second and subsequent wiping operations. Is performed by an ink wiping device including an ink absorber.

Invention described in claim 10, in the head maintenance mechanism as claimed in any one of claims 9, a head maintenance control unit for controlling the various sections,
The head maintenance control unit controls the ink wiping device so that the second and subsequent wiping operations are performed at a speed of 1 mm / s to 30 mm / s.

In the invention according to claim 10 having such a configuration, the head maintenance control unit controls the ink wiping device so that the second and subsequent wiping operations are performed at a speed of 1 mm / s to 30 mm / s. It has become.

The invention described in claim 11 is the head maintenance mechanism according to any one of claims 1 to 10 , wherein the ink absorber is a high density woven with a fineness of 0.5 denier or less. While being a fiber, the said high density fiber is formed from the material of any one among polyester, an acryl, nylon, or these combination, It is characterized by the above-mentioned.

The invention according to claim 11 having such a configuration is a high-density fiber woven with a fineness of 0.5 denier or less, and is a material of any one of polyester, acrylic, nylon, or a combination thereof. The ink adhering to the nozzle or the nozzle surface is absorbed by the ink absorber formed from the above, and the maintenance operation of the nozzle and the nozzle surface of the recording head is performed.

The invention described in claim 12 is the head maintenance mechanism according to any one of claims 1 to 11 , wherein the ink has a viscosity at 23 ° C. of 10 to 50 [mPa · s]. The surface tension is 20 to 40 [mN / m].

In the invention according to claim 12 having such a configuration, an ink having a viscosity at 23 ° C. of 10 to 50 [mPa · s] and a surface tension of 20 to 40 [mN / m] is ejected from the recording head. In this case, the maintenance operation of the nozzles and nozzle surfaces of the recording head is performed.

Next, an invention according to a thirteenth aspect is the head maintenance mechanism according to any one of the first to twelfth aspects, including an activation energy ray-curable compound, wherein the activation energy is ultraviolet light. It is characterized by being.

Therefore, in the invention described in claim 13, when the ink containing the activation energy ray curable compound and the activation energy is ultraviolet light is ejected from the recording head, the maintenance operation of the nozzle of the recording head and the nozzle surface is performed. To do.

According to a fourteenth aspect of the present invention, there is provided a head maintenance mechanism according to any one of the first to thirteenth aspects;
And a recording head having a nozzle surface provided with a plurality of nozzles for ejecting ink.

According to a fourteenth aspect of the present invention, the maintenance operation of the nozzles and the nozzle surface of the recording head is performed by the head maintenance mechanism according to any one of the first to thirteenth aspects.

Next, the invention according to claim 15 is the ink jet printer according to claim 14 , wherein a suction cap that can be in close contact with the nozzle surface before the wiping operation;
And a suction pump for sucking ink in the nozzles by reducing a space generated between the nozzle surface and the suction cap when the suction cap is in close contact with the nozzle surface.

Therefore, in the invention described in claim 15 , before the wiping operation, the suction cap is brought into close contact with the nozzle surface, and the space formed between the nozzle surface and the suction cap is reduced by the suction pump, thereby sucking the ink in the nozzle. It is supposed to be.

Next, an invention according to claim 16 is the ink jet printer according to claim 14 or 15 , further comprising a control unit for controlling the recording head.
The control unit controls the recording head to perform a flushing operation before the wiping operation.

Therefore, in the invention described in claim 16 , the flushing operation is performed by the control unit controlling the recording head before the wiping operation.

Next, an invention according to claim 17 is the ink jet printer according to any one of claims 14 to 16 , wherein an ink tank that supplies ink to the recording head;
A liquid feed pump for feeding ink from the ink tank;
The liquid feeding pump is configured to pressurize the recording head before the wiping operation.

Therefore, in the invention described in claim 17 , before the wiping operation, the recording head is pressurized by the liquid feeding pump for feeding ink from the ink tank.

According to the first aspect of the present invention, the area of the contact portion of the pressing member that contacts the ink absorber during pressing is at least 50% or more of the area of the contact portion of the ink absorber that contacts the nozzle surface during pressing. Thus, the ink absorber can be sufficiently adhered to the nozzle surface. For this reason, it is possible to remove ink adhering to the nozzle and the nozzle surface, suck out unnecessary ink from the nozzle by the ink absorber closely attached to all the nozzles, and re-form a normal meniscus at the tip of the nozzle. There is an effect.

  In addition, since the maintenance operation is performed by moving the pressing member along the ink absorber and bringing the ink absorber into contact with the nozzle surface, maintenance is performed while moving the ink absorber relative to the nozzle surface. As described above, the portion where the ink has been absorbed once is not brought into contact with other nozzles, and the unabsorbed portion of the ink absorber can be brought into close contact with all the nozzles. As a result, it is possible to prevent the ink from reattaching and to increase the ink removing effect sufficiently.

  Furthermore, since the pressing member is moved along the ink absorber and the maintenance operation is performed without moving the ink absorber itself, there is no possibility that the water-repellent treatment applied to the nozzle surface is deteriorated or the nozzle is damaged. The life of the device can be extended.

According to the second aspect of the present invention, the area of the contact portion of the pressing member that contacts the ink absorber during pressing is at least 80% or more of the area of the contact portion of the ink absorber that contacts the nozzle surface during pressing. Thus, the ink absorber can be more closely adhered to the nozzle surface more reliably. For this reason, the ink adhering to the nozzle and the nozzle surface can be removed, and a normal meniscus can be re-formed at the tip of the nozzle.

According to the invention described in claim 3 , for example, by covering the surface with a material resistant to ink, the life of the pressing member can be extended while ensuring the flexibility of the pressing member. There is an effect.

According to the fourth aspect of the present invention, the outer layer of the pressing member that may come into contact with the ink is formed of a material that is resistant to corrosion with respect to the ink. There is an effect that can be.

According to the invention described in claim 5 , the outer layer of the pressing member that may come into contact with the ink is formed of polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene, polyamide / nylon, polyoxymethylene, tetrafluoro. Since it is formed of a material having corrosion resistance against ink such as ethylene / perfluorovinyl ether-based fluororubber or polybutylene terephthalate, there is an effect that the life of the pressing member can be extended.

According to the invention described in claim 6 , by forming the inner layer of the pressing member with a deformable material such as a gas, a liquid, or a gel, the adhesion between the pressing member and the nozzle surface can be improved. The ink adhering to the nozzle surface is sufficiently removed, and a normal meniscus can be re-formed at the tip of the nozzle.

According to the invention described in claim 7 , the outer layer of the pressing member is made of polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene, polyamide / nylon, polyoxymethylene, tetrafluoroethylene / perfluorovinyl ether fluorine. Since it is made of a flexible material such as rubber or polybutylene terephthalate, the adhesion between the pressing member and the nozzle surface can be improved, and the ink adhering to the nozzle and nozzle surface can be sufficiently removed and the nozzle There is an effect that a normal meniscus can be re-formed at the tip.

According to the invention described in claim 8 , since the volume of the inner layer is smaller than the volume of the space formed by the outer layer, when the pressing member is pressed against the nozzle surface, the pressing member deforms and expands, Extra power can be released. As a result, the adhesion between the pressing member and the nozzle surface can be improved. In particular, even when the nozzle surface has some irregularities, the ink absorber can be sufficiently adhered to the nozzle surface. The ink adhering to the surface is sufficiently removed and a normal meniscus can be re-formed at the tip of the nozzle.

According to the ninth aspect of the invention, since the wiping operation is performed at least twice as the maintenance operation of the nozzle of the recording head and the nozzle surface on which the nozzle is formed, the ink attached to the nozzle or the like is surely removed. can do. Further, at least the second and subsequent wipe operations are performed by the ink wiping device including the ink absorber, so that the meniscus can be adjusted by the second and subsequent wipe operations, and the nozzle is restored to a state suitable for ink ejection. There is an effect that sufficient maintenance can be performed.

When the wiping operation is performed at a high speed, the ink adhering to the nozzle surface can be wiped off and removed, but it is difficult to sufficiently absorb the ink from the nozzle. In this regard, according to the invention described in claim 10 , since the second and subsequent wipe operations are performed at a slow speed of 1 mm / s or more and 30 mm / s or less, the ink is surely absorbed from the nozzle by the ink absorber. This produces an effect that the meniscus is adjusted and the nozzle can be restored to a state suitable for ink ejection.

According to the invention described in claim 11 , even with ink having high viscosity and poor wettability, the ink absorber can be securely adhered to the nozzle to absorb the ink. Even when ink with high viscosity and poor wettability is used, the meniscus is properly adjusted, and the nozzle can be restored to a state suitable for ink ejection.

Next, according to the twelfth aspect of the invention, a highly viscous ink having a viscosity at 23 ° C. of 10 to 50 [mPa · s] and a surface tension of 20 to 40 [mN / m]. Even when image recording is performed using the ink, the ink absorber can be securely adhered to the nozzles to absorb the ink. For this reason, for example, even when ink having high viscosity and poor wettability such as ultraviolet curable ink is used, the meniscus can be properly adjusted and the nozzle can be recovered to a state suitable for ink ejection. Play.

According to the invention described in claim 13 , since image recording is performed using ink that can be cured efficiently by irradiating with ultraviolet rays, ink absorbing properties such as a resin film can be used regardless of the recording medium. High-definition images can be obtained even on scarce recording media. Even when such ink is used, the meniscus can be properly adjusted, and the nozzle can be recovered to a state suitable for ink ejection.

According to the fourteenth aspect of the present invention, since the ink wiping device including the ink absorber is provided as the head maintenance mechanism, the ink adhering to the nozzle and the nozzle surface of the recording head can be reliably removed, and the meniscus can be removed. The nozzle can be restored to a state suitable for ink ejection by adjusting the above.

According to the invention described in claim 15 , since the ink in the nozzle can be sucked and removed before the wiping operation, the meniscus is adjusted by the subsequent wiping operation to restore the nozzle to a state suitable for ink ejection. There is an effect that can be made.

According to the sixteenth aspect of the present invention, since the flushing operation is performed before the wiping operation, the wiping operation is performed after the nozzle portion is once filled with ink even when there is a nozzle with unstable ink ejection. It can be performed. For this reason, the ink in the nozzle can be effectively absorbed by the subsequent wiping operation and the meniscus can be adjusted relatively easily, and the nozzle can be recovered to a state suitable for ink ejection.

According to the invention described in claim 17 , since the recording head is pressurized by the liquid feeding pump before the wiping operation, for example, even when bubbles or the like are generated in the nozzle, all the nozzle portions are once filled with ink. In addition, a wiping operation can be performed. Therefore, the meniscus can be adjusted relatively easily by the subsequent wiping operation, and the nozzle can be restored to a state suitable for ink ejection.

  Hereinafter, a first embodiment of a head maintenance mechanism and an inkjet printer including the head maintenance mechanism according to the present invention will be described with reference to FIGS. 1 to 5.

  First, as shown in FIG. 1, in this embodiment, the ink jet printer is a serial head type ink jet printer, and includes a printer main body 1 and a support base 2 that supports the printer main body 1 from below. A platen 11 that supports the recording medium P from the non-recording surface is disposed in the printer main body 1 so as to extend in the longitudinal direction of the printer main body 1. The area where the platen 11 is provided is a recording area where image recording is performed, and the recording medium P is moved in the sub-scanning direction B which is a predetermined conveying direction on the platen 11 by the recording medium conveying mechanism 30 (see FIG. 5). It is designed to be transported.

  A bar-shaped guide rail 3 extending in the longitudinal direction of the printer main body 1 is provided above the platen 11 and upstream of the recording medium P in the sub-scanning direction B. A carriage 4 is supported on the guide rail 3, and the carriage 4 reciprocates along the guide rail 3 in the main scanning direction A perpendicular to the sub-scanning direction B by a carriage drive mechanism 31 (see FIG. 5). It has become.

  On the carriage 4, ink of each color (for example, yellow (Y), magenta (M), cyan (C), and black (K)) used in the ink jet printer according to this embodiment is ejected to the recording medium P. A recording head 5 is mounted. Head units 6 and 7 are composed of four recording heads 5 of yellow (Y), magenta (M), cyan (C), and black (K), and in this embodiment, two head units 6 are used. , 7 are arranged with their positions shifted in the sub-scanning direction B. The ink used in the ink jet printer is not limited to those illustrated, and for example, light yellow (LY), light magenta (LM), light cyan (LC), and other colors such as white ink and transparent ink are used. You can also In this case, a recording head corresponding to each color is mounted on the carriage. The number of recording heads 5 and the number of head units are not limited to those exemplified here, and a larger number of recording heads and head units may be mounted on the carriage.

  In the recording head 5, a plurality of nozzles 8 (see FIG. 4) that eject ink are formed in a row along the sub-scanning direction B, and face the recording medium P on which the nozzles 8 of the recording head 5 are formed. The surface to be used is the nozzle surface 9 (see FIG. 4). The nozzle surface 9 is preferably subjected to a water repellent treatment such as a fluorine processing treatment such as FEP (fluorinated ethylene propylene resin) so that the ink hardly adheres.

  For example, a piezo element (not shown) as a piezoelectric element that is deformed by applying a voltage as an actuator is attached to the nozzle 8 of each recording head 5. By applying a driving voltage to the piezo element, the piezo element is deformed, an ink flow path (not shown) is compressed, and ink is ejected from the nozzle 8. Ink is drawn into the inside of the nozzle 8 at the tip portion of the nozzle 8 to form a curved surface shape (meniscus). When the meniscus shape is properly adjusted, normal ink discharge is performed. Be able to.

  Here, the ink used in this embodiment will be described. When the ink is cured, the polymerizable compound contained in the ink undergoes a polymerization reaction, but the ink used for image recording in the present embodiment includes an activated energy ray-curable compound as the polymerizable compound, and the polymerization reaction is performed. It is an ultraviolet curable ink using ultraviolet rays as activation energy to be started.

  The ultraviolet curable ink is roughly classified into a radical curable ink containing a radical polymerizable compound and a cation curable ink containing a cationic polymerizable compound as a polymerizable compound. It can be applied as an ink to be used, and a hybrid ink in which a radical curable ink and a cationic curable ink are combined may be applied as an ink used in this embodiment.

  However, since a cationic curable ink that has little or no inhibition of polymerization reaction by oxygen is superior in functionality and versatility, a cationic curable ink is particularly used in the present embodiment. The cation curable ink used in the present embodiment is specifically a mixture containing at least a cation polymerizable compound such as an oxetane compound, an epoxy compound, and a vinyl ether compound, a photo cation initiator, and a coloring material. It has the property of being cured by irradiation with ultraviolet rays.

  The ink in the present embodiment is a liquid having a viscosity at 25 ° C. of 10 to 50 [mPa · s] and a surface tension of 20 to 40 [mN / m], so-called high viscosity and wettability. It is considered bad ink.

  In order to enable high-definition image recording, it is desirable to reduce the viscosity of the ink so that one dot is ejected as a fine droplet of 2 to 20 pl. It is preferable to arrange a heater (not shown) so as to heat the ink and lower the viscosity before the ink is ejected.

  On both sides of the recording head 5 of the carriage 4 in the main scanning direction A, there are provided ultraviolet irradiation devices 10 for irradiating the ink discharged from the nozzles 8 to the recording medium P and curing the ink.

  A head maintenance mechanism 32 that performs a maintenance operation of the nozzles 8 and the nozzle surfaces 9 of the recording head 5 is provided at one end outside the recording area within the movable range of the carriage 4. Here, in the ink jet printer according to the present embodiment, when a predetermined number of image recordings are performed, the carriage 4 is moved to a predetermined position of the head maintenance mechanism 32 to perform a maintenance operation. The timing for shifting to the maintenance operation is not limited to the predetermined number of image recordings. For example, the maintenance operation is performed when a predetermined time has elapsed from the start of image recording or every time a predetermined number of image recordings are performed. May be. Further, the timing at which the user performs the maintenance operation of the recording head 5 may be arbitrarily set.

  As shown in FIG. 2, in this embodiment, the head maintenance mechanism 32 includes an ink suction device 33 that sucks ink from the nozzles 8 of the recording head 5, and the first time that the ink remaining on the nozzle surface 9 is wiped off after sucking the ink. And the ink wiping device 12 that performs the second and subsequent wiping operations on the nozzle 8 and the nozzle surface 9.

  The ink suction device 33 is provided with a number of suction caps 35 that cover the nozzle surface 5 of the recording head 5 corresponding to the recording head 5 at positions facing the recording head 5 when the carriage 4 moves to the head maintenance mechanism 32. It has been. An ink communication pipe 36 that communicates with the inside of the suction cap 35 is provided on the bottom surface of the suction cap 35. A suction pump 37 is provided in the middle of the ink communication pipe 36, and a waste ink tank 38 for receiving the sucked ink is provided at the lower end of the ink communication pipe 36. As the suction pump 37, for example, a tube pump or the like can be used. However, it is sufficient if a suction force sufficient to suck ink in the nozzle 8 can be secured, and other mechanisms are applied. Is also possible.

  The blade 34 is disposed in the vicinity of the suction cap 35. The blade 34 is formed of, for example, a resin such as silicon rubber, or other flexible material, and the ink adhering to the nozzle surface 9 is wiped off by sliding the tip of the blade 34 against the nozzle surface 9. It can be done.

  As shown in FIG. 3, the ink wiping device 12 has a polygonal box-shaped member 13, and an opening 14 is formed at the center of the upper surface of the box-shaped member 13.

  Inside the box-shaped member 13 and at both ends in the sub-scanning direction B, the ink absorber 15 is wound up by being rotationally driven by the feed shaft 16 and the roll shaft driving mechanism 40 (see FIG. 5) for feeding the ink absorber 15. Winding shafts 17 are respectively provided. A long sheet-like ink absorber 15 is wound around the feed shaft 16 in a roll shape. The ink absorber 15 is guided by a plurality of guide rollers 18 so as to be partially exposed from the opening 14, and is wound around the winding shaft 17, and the ink absorption exposed from the opening 14 is absorbed. The body 15 faces the nozzle surface 9 of the recording head 5 during the maintenance operation. An ink absorber moving device 19 is configured by the feed shaft 16, the winding shaft 17, the guide roller 18, and the roll shaft driving mechanism.

  In addition, the ink absorber 15 is large enough to cover at least the entire nozzle surfaces 9 of the plurality of recording heads 5 constituting each head unit 6, 7, that is, in the present embodiment, each head unit 6, 6. 7, the width dimension is larger than the width dimension of the nozzle surface 9 in the main scanning direction A.

  The ink absorber 15 is formed of a high density fiber that is an ultrafine fiber having a fineness of about 0.1 denier, and the high density fiber is any one of polyester, acrylic, nylon, or the like. It is comprised with the material which combined. Thus, since the ink absorber 15 is made of high-density fibers, it easily adsorbs the material that comes into contact with the surface of the ink absorber 15, and promptly draws ink from the tip of the nozzle 8 of the recording head 5 regardless of the viscosity or wettability of the ink. Can be absorbed. In other words, the ink absorber 15 in the present embodiment is, for example, an ultraviolet curable ink, or other inks having higher viscosity and poorer wettability than commonly used inks such as oil-based or solvent-based inks. The ink can be reliably absorbed from the tip of the ink.

  A support base 20 is provided between the feed shaft 16 and the take-up shaft 17 and below the ink absorber 15, and a box-shaped member 13 of FIG. Support shafts 21 that are rotatably supported on both side surfaces in the main scanning direction A are attached. Above the both side surfaces of the box-shaped member 13, as shown in FIG. 3, the central portion corresponding to the recording head 5 extends in the horizontal direction so as to be substantially parallel to the nozzle surface 9 of the recording head 5, and A guide hole 22 having a shape in which both ends are bent downward is formed. As shown in FIG. 4, both end portions of the guide hole 22 are set as a retreat area C, and the carriage 4 is moved when the ink wiping device 12 is not operated or when the ink wiping device is operated. When the carriage 4 is moved, the tip of the recording head 5 does not directly contact the pressing member 23 when the carriage 4 is moved.

  As shown in FIG. 2, a pressing member 23 is attached to the upper end portion of the support base 20 so as to be movable up and down, and a guide shaft engaged with the guide hole 22 is located above both sides of the pressing member 23. 24 is attached. Then, the support base drive mechanism 41 (see FIG. 5) causes the support base 20 to swing, so that the pressing member 23 swings along with the swing operation of the support base 20. As a result, the guide shaft 24 of the pressing member 23 is guided to the guide hole 22, and the back surface of the ink absorber 15 moves along the sub-scanning direction B while the pressing member 23 moves up and down with respect to the support base 20. It has come to be. In the present embodiment, the support base moving device 25 is configured by the support base 20, the support shaft 21, the guide hole 22, the guide shaft 24, and the support base drive mechanism 41.

  In the present embodiment, as shown in FIG. 3, the pressing member 23 is formed in an arc shape in cross section by curving the thin plate member, and the pressing member 23 has a plurality of slits 26 in the width direction. It is formed with a predetermined interval. Further, the width dimension of the pressing member 23 is at least equal to or larger than the width dimension of the ink absorber 15, and the ink absorber 15 is pressed against the nozzle surface 9 of the recording head 5 with an appropriate pressure. As shown in FIG. 4, the support member 20 is swung and the pressing member 23 is reciprocated once in the sub-scanning direction B, as shown in FIG. The ink absorber 15 can be brought into contact over the entire area of the nozzle surface 9. The pressing member 23 only needs to be able to uniformly press the ink absorber 15 against the nozzle surface 9, and the shape and the like are not limited to those exemplified here.

  The pressing member 23 is made of any one material selected from polypropylene, polyethylene, 4-fluorinated ethylene, and 4,6-fluorinated propylene. The pressing member 23 using such a material swells and dissolves even when ink containing an organic solvent such as a cationic ultraviolet curable ink adheres to the pressing member 23 when it is brought into contact with the nozzle surface 9. Can be used for many years without.

  In addition, an ink tank 29 that supplies ink of each color to the recording head 5 via an ink supply path (not shown) is provided at the other outer end of the recording area, which is a movable range of the carriage 4. A liquid feed pump (not shown) for feeding ink from the ink tank 29 to the recording head 5 is provided in the middle of the ink supply path. Thereby, even a highly viscous ink with poor wettability as used in this embodiment can be reliably fed from the ink tank 29 to the recording head 5.

  As the recording medium P used in the present embodiment, various papers such as plain paper, recycled paper and glossy paper, various fabrics, various non-woven fabrics, resin, metal, glass and the like which are applied to ordinary inkjet printers. Can be applied. Moreover, as a form of the recording medium P, a roll shape, a cut sheet shape, a plate shape, or the like is applicable.

  Furthermore, as the recording medium P used in the present embodiment, known recording media such as various papers whose surfaces are coated with a resin, a film containing a pigment, and a foam film can be applied.

  Next, a control configuration of the ink jet printer according to the present embodiment will be described with reference to FIG.

  The ink jet printer includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores various processing programs, and a RAM (Random Access Memory) that temporarily stores various data (none of which are shown). And a control unit 42 for controlling each unit of the ink jet printer. The control unit 42 develops the processing program recorded in the ROM in the work area of the RAM and executes the processing program by the CPU. In the present embodiment, the control unit 42 also serves as a head maintenance control unit that controls the head maintenance mechanism 32, as will be described later.

  The controller 42 is connected to a power source (not shown) that supplies power to the ink jet printer.

  Further, the ink jet printer has an input unit 43 as setting means for setting and inputting a timing for performing a maintenance operation of the recording head 5, image recording conditions, and the like. Information input from the input unit 43 is controlled by a control unit. 42 is sent. The input unit 43 is, for example, a keyboard or an operation panel, and the user can perform various settings by operating the input unit 43.

  Further, the control unit 42 controls the carriage drive mechanism 31 to reciprocate the carriage 4 in the main scanning direction A, and repeats the conveyance and stop of the recording medium P in accordance with the operation of the carriage 4. The recording medium conveyance mechanism 30 is controlled so as to be intermittently conveyed in the sub-scanning direction B.

  Further, the control unit 42 operates the recording head 5 to discharge a predetermined amount of ink from the recording head 5 onto the recording medium P, and controls the ultraviolet irradiation device 8 to apply the ink landed on the recording medium P. A predetermined image is formed by irradiating ultraviolet rays from an ultraviolet light source to cure and fix the ink.

  Further, the control unit 42 controls the carriage drive mechanism 31 to move the carriage 4 to the head maintenance mechanism 32 so that the maintenance operation of the recording head 5 is performed. That is, in the present embodiment, when the carriage 4 moves above the ink suction device 33, the control unit 42 raises the ink suction device 33 to a position where the suction cap 35 comes into close contact with the nozzle surface 9 of the recording head 5. When the suction cap 35 comes into close contact with the nozzle surface 9, the control unit 42 operates the suction pump 37 to suck the air in the space between the suction cap 35 and the nozzle surface 9 of the recording head 5, By reducing the pressure, foreign matter such as ink in the nozzle 8 is sucked and removed.

  Further, the control unit 42 moves the carriage 4 above the blade 34 and, as the first wiping operation, causes the blade 34 to slidably contact the nozzle surface 9 to perform the wiping operation on the nozzle surface 9. 31 is controlled. Thereby, the ink adhering to the nozzle surface 9 is wiped off and removed. The first wiping operation is performed at a relatively fast speed of, for example, 30 mm / s or more.

  Further, the control unit 42 drives the support base driving mechanism 41 of the ink wiping device 12 to move in the sub-scanning direction B while pressing the pressing member 23 against the nozzle surface 9 of the recording head 5 via the ink absorber 15. Let As a result, the wipe operation for the nozzle 8 of the recording head 5 is performed by the ink absorber 15 as the second and subsequent wipe operations. At this time, the control unit 42 moves the pressing member 23 at a speed slower than the wiping operation by the blade 34 as the first wiping operation, specifically, at a speed of 1 mm / s to 30 mm / s. It has become. As a result, the ink is reliably absorbed by the ink absorber 15 from the tip of the nozzle 8, and a meniscus is re-formed at the tip of the nozzle 8, and the shape thereof can be adjusted.

  In particular, in the case of ink having high viscosity and poor wettability as used in the present embodiment, the meniscus may not be normally re-formed at the tip of the nozzle 8 only by performing a wiping operation at a high speed. An experimental result was obtained that the ink could not be ejected normally even if the ink was ejected in a state where the meniscus was not normally re-formed. For example, when ink is ejected after performing a maintenance operation with a fast wiping operation, normal ink ejection can be performed only about half. On the other hand, if the first wipe operation is performed at a relatively high speed and then the second and subsequent wipe operations are performed at a speed slower than the first wipe operation, the maintenance operation is performed even with high viscosity ink. An experimental result has been obtained that it is possible to perform normal ink ejection almost certainly later, and the ink absorber 15 reliably absorbs ink from the tip of the nozzle 8 by a slow wiping operation. It was confirmed that remodeling was possible.

  In addition, the control unit 42 drives the roll shaft driving mechanism 40 to appropriately wind the ink absorber 15 around the winding shaft 17. In the present embodiment, the ink non-absorbing portion is exposed from the opening portion 14 each time the wipe operation is performed once.

  Next, a head maintenance method according to this embodiment will be described.

  When the power of the ink jet printer is turned on, power is supplied from the power source to each part of the ink jet printer. When predetermined image information is sent to the ink jet printer and the recording medium P is conveyed to a predetermined position in the recording area, the carriage 4 reciprocates along the guide rail 3 directly above the recording medium P.

  Then, during the movement of the carriage 4, the control unit 42 operates the recording head 5 based on image information sent from an external device (not shown), the input unit 43, and the like toward each recording medium P from each nozzle 8. Ink is ejected. The control unit 42 controls the ultraviolet irradiation device 10 to irradiate the ink landed on the recording medium P from the ultraviolet irradiation device 10 with ultraviolet rays. At this time, each head unit 6, 7 is configured by ultraviolet rays irradiated from the ultraviolet irradiation device 10 on the downstream side of the recording head 5 constituting each head unit 6, 7 in the moving direction of the carriage 4. The ink ejected from the recording head 5 is quickly cured and fixed on the recording medium P.

  Thereafter, the image is recorded on the recording medium P by the ink jet printer repeating the above operations.

  When the image recording is performed a predetermined number of times, the control unit 42 moves the carriage 4 to a predetermined position of the head maintenance mechanism 32. Then, when the control unit 42 operates each part of the head maintenance mechanism 32, the maintenance operation of the nozzle 8 and the nozzle surface 9 of the recording head 5 is performed.

  Specifically, first, when the carriage 4 moves above the ink suction device 33, the control unit 42 operates the ink suction device 33 to bring the suction cap 35 into close contact with the nozzle surface 9. Then, the control unit 42 operates the suction pump 37 to depressurize the space between the nozzle surface 9 and the suction cap 35 so that foreign matters such as ink remaining in the nozzle 8 are removed by suction. Thereafter, the control unit 42 moves the carriage 4 above the blade 34 and slides the tip of the blade 34 against the nozzle surface 9 so that the wipe operation for the nozzle surface 9 is performed as the first wipe operation. Note that the wiping operation by the blade 34 is performed at a relatively high speed of, for example, 30 mm / s or more. Thereby, the ink remaining on the nozzle surface 9 is wiped away.

  Further, the control unit 42 moves the carriage 4 above the ink wiping device 12, operates the ink wiping device 12, and performs the second and subsequent wiping operations. As a result, the ink is absorbed by the ink absorber 15 from the nozzle 8.

  That is, the control unit 42 moves the carriage 4 so that the nozzle surface 9 of the recording head 5 constituting the head unit 6 is positioned at a position facing the ink absorber 15. And the control part 42 operates the support stand drive mechanism 41, and moves the pressing member 23 along the guide hole 22 from a retracted position, as shown in FIG. At a position where the nozzle surface 9 of the recording head 5 and the pressing member 23 face each other, the pressing member 23 comes into contact with the ink absorber 15 from the back surface, so that the ink absorber 15 is in close contact with one end portion of the nozzle surface 9. . Then, by reciprocating the pressing member 23 along the guide hole 22, the ink is sequentially absorbed by the ink absorber 15 from the tip of each nozzle 8 over the entire nozzle surface 9 of the recording head 5. At this time, the speed at which the wiping operation is performed by reciprocating the pressing member 23 is slower than the speed of the wiping operation by the blade 34 and is 1 mm / s or more and 30 mm / s or less, and the pressing member 23 is moved slowly. By doing so, the ink is surely absorbed by the ink absorber 15 and the meniscus formed at the tip of the nozzle 8 can be adjusted.

  Thereafter, the control unit 42 separates the ink absorber 15 and the nozzle surface 9 of the recording head 5 with the pressing member 23 positioned at the retracted position C. Further, when the control unit 42 operates the roll shaft driving mechanism 40, the ink absorber 15 is wound around the winding shaft 17. As a result, the unabsorbed portion of the ink absorber 15 is exposed from the opening 14.

  Subsequently, the control unit 42 moves the carriage 4 by the width of the head unit 6 according to the position of the ink absorber 15, and similarly performs the maintenance operation by the ink wiping device 12 on the head unit 7. In this way, the wiping operation by the ink wiping device 12 is completed by repeating the operation of sequentially moving the pressing member 23, the ink absorber 15 and the carriage 4 for each of the head units 6 and 7.

  Then, with the pressing member 23 positioned at the retreat position C, the ink absorber 15 and the nozzle surface 9 of the recording head 5 are separated from each other. In this state, the roll shaft driving mechanism 40 is operated, and the ink absorber 15 Is taken up by the take-up shaft 17 and the unabsorbed portion of the ink absorber 15 is exposed from the opening 14.

  When the series of maintenance in the head maintenance mechanism 32 is completed in this way, the carriage 4 returns to the recording area again, and image recording is resumed.

  As described above, in the ink jet printer according to the present embodiment, the first wiping operation by the blade 34 is performed, and after the ink adhering to the nozzle surface 9 is removed, the pressing member 23 of the ink wiping device 12 is moved to 1 mm / mm. The second and subsequent wipe operations are performed by moving at a relatively slow speed of s to 30 mm / s. As a result, even with high viscosity and poor wettability, the ink can be reliably absorbed by the ink absorber 15 from the tip of the nozzle 8 and the meniscus formed at the tip of the nozzle 8 can be properly adjusted. As a result, ink can be normally ejected from each nozzle 8 of the recording head 5, and high-definition image recording can be performed.

  In addition, the ink absorber 15 of the ink wiping device 12 can absorb the ink at the tip of the nozzle 8 so that the meniscus in the nozzle 8 can be adjusted. Can do. In addition, since it is not necessary to provide a tray for empty ejection of ink, the number of members can be reduced, and the ink jet printer can be reduced in size and cost.

  In the present embodiment, the ink absorber 15 is wound around the winding shaft 17 every time a reciprocating wipe operation is performed. However, the timing at which the ink absorber 15 is wound is limited to the example illustrated here. Instead, the winding may be performed every time the wiping operation is performed by reciprocating several times. Thus, the consumption of the ink absorber 15 can be suppressed by reducing the number of windings of the ink absorber 15.

  In the present embodiment, the first wiping operation is performed by the blade 34 formed of resin or the like. However, the configuration for performing the first wiping operation is not limited to the example illustrated here. As long as the ink adhering to the nozzle 8 and the nozzle surface 9 can be wiped off and removed, other configurations may be used. For example, the first time by a sponge roller using a sponge with high ink absorbability. It is good also as composition which performs a wipe operation.

  Further, the ink wiping device 12 may perform both the first wiping operation and the second and subsequent wiping operations.

  In this case, the first wipe operation is performed at a relatively high speed of 30 mm / s or more, and the second and subsequent wipe operations are performed at a relatively slow speed of 1 mm / s or more and 30 mm / s or less. . As a result, the ink adhering to the nozzle 8 and the nozzle surface 9 is wiped and removed by the first wiping operation, and ink is absorbed from the tip of the nozzle 8 and formed in the nozzle 8 by the second and subsequent wiping operations. Meniscus can be arranged.

  In this case, it is preferable that the winding operation of the ink absorber 15 is performed after the first wiping operation. In the first wiping operation, the ink adhering to the nozzle 8 and the nozzle surface 9 is wiped off, so that the amount of ink adhering to the ink absorber 15 is relatively large. In the second and subsequent wipe operations, only a small amount of ink is absorbed by the ink absorber 15. For this reason, after the first wiping operation is performed and before the second and subsequent wiping operations, the winding operation of the ink absorber 15 is performed to expose the unabsorbed portion of the ink, so that the second and subsequent wiping operations are exposed. It is possible to prevent the ink absorbed by the ink absorber 15 during the wiping operation from re-adhering to the nozzles and the like and increase the absorption capacity of the ink absorber. In addition, the winding operation of the ink absorber is performed only after the first wiping operation in which the amount of ink adhering to the ink absorber is relatively large, and when performing the second and subsequent wiping operations a plurality of times, the ink absorber By using the same part, the consumption of the ink absorber can be minimized.

  In the present embodiment, the control unit 42 that controls each part of the ink jet printer, such as the recording head 5, the carriage drive mechanism 31, and the recording medium transport mechanism 30, also serves as a head maintenance control unit that controls the head maintenance mechanism 32. However, the control unit 42 for controlling the head maintenance mechanism 32 is not limited to this. For example, a head maintenance control unit that controls only the head maintenance mechanism 32 may be separately provided. In addition, a configuration may be adopted in which each control unit is controlled by a separate control unit.

  In the present embodiment, the ink absorber 15 is pressed by one pressing member 23 having a length corresponding to the entire nozzle surface 9 of the head units 6 and 7 in the main scanning direction A. Although the maintenance operation is performed for each head unit 6, 7, a plurality of pressing members 23 having a length corresponding to the nozzle surface 9 for each recording head 5 are provided, and the nozzle surface 9 for each recording head 5 is provided. The ink absorber 15 may be in close contact with the ink.

  In the present embodiment, the second and subsequent wiping operations performed by the ink wiping device 12 are performed by reciprocating the pressing member 23. The number of wiping operations by the ink wiping device 12 is as follows. It is not limited to what was illustrated to. For example, the wiping operation may be performed only once, or the pressing member 23 may be reciprocated a plurality of times to perform the wiping operation. In order to reliably prepare the meniscus, it is preferable to repeatedly perform a wiping operation a plurality of times. In the case where the wiping operation by the ink wiping device 12 is performed a plurality of times, the ink absorber 15 may not be wound during that time. In the second and subsequent wiping operations, only a small amount of ink adheres to the ink absorber 15, so that each time the wiping operation is performed, there is a problem in that the ink is reattached to the nozzle 8 or the like without performing winding. There is no. And the consumption of the ink absorber 15 can be suppressed by reducing the number of windings in this way.

  In this embodiment, the serial type recording head 5 is used, but the present invention can also be applied to a line type recording head 5. In that case, the arrangement direction when the ink wiping device 12 is arranged in the printer main body 1 may be changed, and if the direction in which the nozzle rows are formed is parallel to the longitudinal direction of the ink absorber 15. Good.

  In the present embodiment, the support drive mechanism 41 is provided and the pressing member 23 is reciprocated to cause the ink absorber 15 to absorb ink. However, the ink absorber 15 is sequentially attached to the recording head 5. The configuration brought into contact with the nozzle surface 9 is not limited to that exemplified here. For example, the support member driving mechanism 41 is not provided, and the roll shaft driving mechanism 40 that moves the ink absorber 15 is always operated, so that the pressing member 23 is in contact with the back surface of the ink absorber 15 and the ink absorber. The ink absorber 15 may be sequentially brought into contact with the nozzle surface 9 of the recording head 5 by winding and moving 15.

  In addition, as the ink jet printer 1 to which the ink jet printer according to the present invention can be applied, either an on-demand type or a continuous type recording head 7 may be used. In addition, as a discharge method, for example, an electro-mechanical conversion method (for example, a single cavity type, a double cavity type, a bender type, a piston type, a shear mode type, a shared wall type, etc.), an electro-thermal conversion method (for example, , Thermal ink jet type, bubble jet (registered trademark) type), electrostatic suction type (for example, electric field control type, slit jet type, etc.) and discharge type (for example, spark jet type, etc.) The recording head 7 may be used.

  In this embodiment, image recording is performed using ink that is cured by irradiation with ultraviolet rays. However, the ink is not necessarily limited to this, and for example, ultraviolet rays, electron beams, X-rays, and visible rays. The ink may be cured by irradiating light other than ultraviolet rays such as electromagnetic waves such as infrared rays. In this case, a polymerizable compound that is polymerized and cured with light other than ultraviolet light and a photoinitiator that initiates a polymerization reaction between the polymerizable compounds with light other than ultraviolet light are applied to the ink. In the case of using a photocurable ink that is cured by light other than ultraviolet light, a light source that emits the light is applied instead of the ultraviolet light source. Further, image recording may be performed using ink that is cured without being irradiated with light. In this case, it is not necessary to provide an apparatus for irradiating light, and the apparatus configuration can be simplified.

  In addition, it is needless to say that the present invention is not limited to the above embodiment and can be modified as appropriate.

  Next, a second embodiment of the head maintenance mechanism according to the present invention and an inkjet printer including the head maintenance mechanism will be described with reference to FIG. Since the second embodiment is different from the first embodiment only in the configuration of the head maintenance mechanism, the differences from the first embodiment will be particularly described below.

  In the present embodiment, the ink jet printer includes the recording head 5 including a piezoelectric element such as a piezoelectric element (not shown) as an actuator, as in the first embodiment. The recording head 5 is provided with a nozzle surface (not shown) on which nozzles (not shown) for discharging ink are formed. The ink jet printer includes a head maintenance mechanism 32 that performs a maintenance operation on the nozzles and nozzle surfaces of the recording head 5.

  In the present embodiment, the head maintenance mechanism 32 performs a first wipe operation (not shown) for wiping off ink adhering to the nozzle surface of the recording head 5 and a second and subsequent wipe operations for the nozzle. And an ink wiping device 12.

  The ink wiping device 12 is the same as that of the first embodiment, and includes an ink absorber (not shown) that absorbs ink and a pressing member (not shown) that presses the ink absorber from the back surface. Further, the ink wiping device 12 includes a support base drive mechanism 41, and moves the pressing member while pressing the pressing member against the nozzle surface of the recording head 5 by the support base drive mechanism 41. A wipe operation to absorb is performed. The ink wiping device 12 includes a roll shaft drive mechanism 40 that winds up the ink absorber, and appropriately winds up the ink absorber that has absorbed the ink.

  In addition, as shown in FIG. 6, the inkjet printer includes a control unit 42 similar to that of the first embodiment. Also in this embodiment, as in the first embodiment, the control unit 42 also serves as a head maintenance control unit that controls the head maintenance mechanism 32. Various information input from the input unit 43 is sent to the control unit 42.

  The control unit 42 controls the recording head 5 to apply a drive voltage to the piezo element, thereby deforming the piezo element, compresses an ink flow path (not shown), and discharges a predetermined amount of ink from the nozzle. Yes.

  In particular, in the present embodiment, the control unit 42 controls the recording head 5 to apply a driving voltage to the piezo element and perform ink from the nozzle before performing the wiping operation by the blade and the ink wiping device 12 as a maintenance operation. A flushing operation for empty discharge is performed. That is, during the maintenance operation, the control unit 42 first controls the carriage drive mechanism 31 to move to a position corresponding to the head maintenance mechanism, and controls the recording head 5 to control the ink absorber of the ink wiping device 12. Ink is ejected empty.

  Further, the control unit 42 operates the support base driving mechanism 41 of the ink wiping device 12 to operate the roll shaft driving mechanism 40 and wind up the ink absorber. In the present embodiment, the ink absorber is wound up after the flushing operation is performed, and the unabsorbed portion of the ink absorber is exposed from the opening.

  In the present embodiment, the inkjet printer includes a recording medium conveyance mechanism 30 that intermittently conveys a recording medium (not shown) in a predetermined direction, as in the first embodiment, and the control unit 42 conveys the recording medium. The recording medium is sequentially conveyed by controlling the mechanism 30. The recording head 5 is mounted on a carriage (not shown), and the ink jet printer includes a carriage driving mechanism 31 that drives the carriage. The control unit 42 controls the carriage drive mechanism 31 to reciprocate in a direction orthogonal to the recording medium conveyance direction.

  Further, similarly to the first embodiment, the control unit 42 controls the ultraviolet irradiation device 10 to irradiate the ink ejected onto the recording medium with ultraviolet rays from the ultraviolet irradiation device 10, thereby curing and fixing the ink. A predetermined image is formed.

  Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  Next, a head maintenance method according to this embodiment will be described.

  When the image recording is performed a predetermined number of times, the control unit 42 moves the carriage above the ink wiping device 12 of the head maintenance mechanism 32. The control unit 42 operates the recording head 5 to apply a predetermined voltage to the piezo element, and causes the ink to be ejected onto the ink absorber of the ink wiping device 12. When the ink is ejected, the control unit 42 controls the roll shaft driving mechanism 40 to wind up the ink absorber and expose the unabsorbed portion.

  Thereafter, the control unit 42 moves the carriage above the blade and causes the tip of the blade to slide in contact with the nozzle surface, whereby the wipe operation for the nozzle surface is performed as the first wipe operation. Note that the wiping operation by the blade is performed at a relatively high speed of, for example, 30 mm / s or more. Thereby, the ink remaining on the nozzle surface is wiped off.

  Further, the control unit 42 moves the carriage above the ink wiping device 12, operates the ink wiping device 12, and performs the second and subsequent wiping operations. At this time, the speed at which the wiping operation is performed is slower than the speed of the wiping operation by the blade, and is 1 mm / s or more and 30 mm / s or less. The meniscus formed at the tip of the nozzle by being absorbed by the absorber can be adjusted.

  When the series of maintenance in the head maintenance mechanism 32 is completed as described above, the carriage returns to the recording area again and image recording is resumed.

  As described above, according to the present embodiment, before performing the wiping operation, the flushing operation for ejecting ink from the nozzles is performed, so that the ink in the nozzles can be reliably removed and all the nozzles can be removed by the flushing operation. Is filled with ink, and in this state, the wiping operation by the ink wiping device 12 is performed. For this reason, it becomes easy to absorb ink from the nozzle tip, and re-formation of the meniscus can be facilitated.

  Further, since the ink is ejected to the ink absorber of the ink wiping device 12 during the flushing operation, it is not necessary to separately provide a member for performing the ejection, and the configuration of the apparatus can be simplified.

  In this embodiment, during the flushing operation, ink is ejected idle to the ink absorber of the ink wiping device 12. However, for example, empty ink is received adjacent to the blade. An ejection tray may be provided, and ink may be ejected to the blank ejection tray.

  Further, similarly to the first embodiment, the ink wiping device 12 may perform both the first wiping operation and the second and subsequent wiping operations. In this case, the ink absorber winding operation is performed after the flushing operation and after the first wiping operation.

  Further, an ink suction device similar to that of the first embodiment may be provided as the head maintenance mechanism 32, and the maintenance operation may be performed by appropriately combining ink suction, flushing operation, and wiping operation.

  In addition, it is the same as that of 1st embodiment that this invention is not limited to this Embodiment.

  Next, a third embodiment of a head maintenance mechanism according to the present invention and an inkjet printer including the head maintenance mechanism will be described with reference to FIG. In the following, differences from the first embodiment and the second embodiment will be described.

  In the present embodiment, the ink jet printer includes a recording head 5 that includes a piezoelectric element such as a piezoelectric element (not shown) as an actuator, as in the first and second embodiments. The recording head 5 is provided with a nozzle surface (not shown) on which nozzles (not shown) for discharging ink are formed. The ink jet printer includes a head maintenance mechanism 32 that performs a maintenance operation on the nozzles and nozzle surfaces of the recording head 5.

  In the present embodiment, the head maintenance mechanism 32 performs a first wipe operation (not shown) for wiping off ink adhering to the nozzle surface of the recording head 5 and a second and subsequent wipe operations for the nozzle. And an ink wiping device 12.

  The ink wiping device 12 is the same as that of the first embodiment and the second embodiment, and an ink absorber (not shown) that absorbs ink and a pressing member (not shown) that presses this from the back surface. It has. Further, the ink wiping device 12 includes a support base drive mechanism 41, and the support base drive mechanism 41 moves the pressing member while pressing it against the nozzle surface of the recording head 5, thereby absorbing the ink at the nozzle tip by the ink absorber. A wipe operation is performed. The ink wiping device 12 includes a roll shaft drive mechanism 40 that winds up the ink absorber, and appropriately winds up the ink absorber that has absorbed the ink.

  Further, the ink jet printer is provided with an ink tank (not shown) that supplies ink of each color to the recording head 5 via an ink supply path (not shown). A liquid feed pump 45 (see FIG. 7) that feeds ink from the ink tank to the recording head 5 by applying pressure is provided in the middle of the ink supply path. Thus, even a highly viscous ink with poor wettability as used in the present embodiment can be reliably fed from the ink tank to the recording head 5.

  In addition, as shown in FIG. 7, the ink jet printer includes a control unit 42 similar to that in the first embodiment and the second embodiment. Also in this embodiment, as in the first embodiment and the second embodiment, the control unit 42 also serves as a head maintenance control unit that controls the head maintenance mechanism 32. Various information input from the input unit 43 is sent to the control unit 42.

  The control unit 42 controls the recording head 5 to apply a drive voltage to the piezo element, thereby deforming the piezo element, compresses an ink flow path (not shown), and discharges a predetermined amount of ink from the nozzle. Yes.

  In particular, in the present embodiment, the control unit 42 pressurizes the recording head 5 by operating the liquid feeding pump 45 before performing the wiping operation by the blade and the ink wiping device 12 as a maintenance operation. The action is to be performed. That is, during the maintenance operation, the controller 42 first operates the liquid feed pump 45 to apply pressure to the recording head 5 so that all nozzles of the recording head 5 are filled with ink. ing.

  Further, the control unit 42 operates the support base driving mechanism 41 of the ink wiping device 12 to operate the roll shaft driving mechanism 40 and wind up the ink absorber. In this embodiment, every time the wiping operation by the ink wiping device 12 is performed once, the ink absorber is wound up so that the unabsorbed portion of the ink absorber is exposed.

  Further, in the present embodiment, the ink jet printer includes a recording medium transport mechanism 30 that intermittently transports a recording medium (not shown) in a predetermined direction, as in the first and second embodiments, and the control unit 42. The recording medium is sequentially conveyed by controlling the recording medium conveying mechanism 30. The recording head 5 is mounted on a carriage (not shown), and the ink jet printer includes a carriage driving mechanism 31 that drives the carriage. The control unit 42 controls the carriage drive mechanism 31 to reciprocate in a direction orthogonal to the recording medium conveyance direction.

  In addition, as in the first and second embodiments, the control unit 42 controls the ultraviolet irradiation device 10 to irradiate the ink ejected on the recording medium with ultraviolet rays from the ultraviolet irradiation device 10. The ink is cured and fixed to form a predetermined image.

  In addition, since the other structure is the same as that of 1st embodiment and 2nd embodiment, the description is abbreviate | omitted.

  Next, a head maintenance method according to this embodiment will be described.

  When the image recording is performed a predetermined number of times, the control unit 42 moves the carriage above the head maintenance mechanism 32. The control unit 42 performs a pressurizing operation for operating the liquid feed pump 45 to apply pressure to the recording head 5. As a result, all nozzles are filled with ink.

  Thereafter, the control unit 42 moves the carriage above the blade and causes the tip of the blade to slide on the nozzle surface, whereby the first wiping operation is performed on the nozzle surface. Note that the wiping operation by the blade is performed at a relatively high speed of, for example, 30 mm / s or more. Thereby, the ink remaining on the nozzle surface is wiped off.

  Further, the control unit 42 moves the carriage above the ink wiping device 12, operates the ink wiping device 12, and performs the second and subsequent wiping operations. At this time, the speed at which the wiping operation is performed is slower than the speed of the wiping operation by the blade, and is 1 mm / s or more and 30 mm / s or less. By slowly wiping, the ink is surely absorbed by the ink absorber. Thus, the meniscus formed at the nozzle tip can be adjusted.

  When the series of maintenance in the head maintenance mechanism 32 is completed in this way, the carriage 4 returns to the recording area again, and image recording is resumed.

  As described above, according to the present embodiment, the pressure is applied to the recording head 5 by the liquid feeding pump 45 before the wiping operation is performed, so that all the nozzles are filled with ink. Thus, the wiping operation by the ink wiping device 12 is performed. For this reason, it becomes easy to absorb ink from the nozzle tip, and re-formation of the meniscus can be facilitated.

  Further, similarly to the first embodiment, the ink wiping device 12 may perform both the first wiping operation and the second and subsequent wiping operations. In this case, the winding operation of the ink absorber is performed after the first wiping operation.

  Further, an ink suction device similar to that of the first embodiment may be provided as the head maintenance mechanism 32, and the maintenance operation may be performed by appropriately combining ink suction, pressure operation, and wipe operation.

  In addition, it is the same as that of 1st Embodiment and 2nd Embodiment that this invention is not limited to this Embodiment.

  Next, a fourth embodiment of the head maintenance mechanism and the ink jet printer including the head maintenance mechanism according to the present invention will be described with reference to FIGS. In the fourth embodiment, only the configuration of the head maintenance mechanism is different from the first embodiment to the third embodiment. Therefore, in the following, in particular, the first embodiment to the third embodiment will be described. Different points will be described.

In the present embodiment, the ink jet printer includes a recording head 5 including a piezoelectric element such as a piezoelectric element (not shown) as an actuator, as in the first to third embodiments. The recording head 5 is mounted on a carriage (not shown), and the carriage is reciprocated along the width direction of the recording medium P by a driving mechanism (not shown).
The recording head 5 is provided with a nozzle surface 9 (see FIGS. 9 and 11) on which nozzles 8 (see FIGS. 9 and 11) for discharging ink are formed. The ink jet printer includes a head maintenance mechanism (not shown) that performs maintenance operations on the nozzles 8 and the nozzle surfaces 9 of the recording head 5.

  In the present embodiment, the head maintenance mechanism includes an ink wiping device 12 as shown in FIG. In addition to the ink wiping device 12, the head maintenance mechanism includes an ink suction device (not shown) that sucks ink from the nozzles 8 of the recording head 5, and wipes ink remaining on the nozzle surface 9 after sucking ink. A blade (not shown) or the like may be provided.

  As shown in FIG. 8, as in the first to third embodiments, the ink wiping device 12 has a polygonal box-shaped member 13. An opening 14 is formed.

  Inside the box-shaped member 13 and at both ends in the sub-scanning direction B, a feed shaft 16 for feeding the ink absorber 15 and a winding shaft 17 for winding the ink absorber 15 are disposed. A long sheet-like ink absorber 15 is wound around the feed shaft 16 in a roll shape. The ink absorber 15 is guided around the winding shaft 17 by a plurality of guide rollers 18 so that a part of the ink absorbing body 15 is exposed from the opening 14 when the winding shaft 17 is rotationally driven by a driving mechanism (not shown). The ink absorber 15 exposed from the opening 14 is opposed to the nozzle surface 9 of the recording head 5 during the maintenance operation. An ink absorber moving device 19 is configured by a driving mechanism that rotationally drives the feed shaft 16, the winding shaft 17, the guide roller 18, and the winding shaft 17 described above.

  In addition, the ink absorber 15 is large enough to cover at least the entire nozzle surfaces 9 of the plurality of recording heads 5 constituting each head unit 6, 7, that is, in the present embodiment, each head unit 6, 6. 7, the width dimension is larger than the width dimension of the nozzle surface 9 in the main scanning direction A.

  The ink absorber 15 is formed of high-density fibers that are ultrafine fibers having a fineness of 0.5 denier or less, as in the first to third embodiments. It is comprised by the material which combined any one among acrylic, nylon, etc. or these. Thus, since the ink absorber 15 is made of high-density fibers, it easily adsorbs the material that comes into contact with the surface of the ink absorber 15, and promptly draws ink from the tip of the nozzle 8 of the recording head 5 regardless of the viscosity or wettability of the ink. Can be absorbed. In other words, the ink absorber 15 in the present embodiment is, for example, an ultraviolet curable ink, or other inks having higher viscosity and poorer wettability than commonly used inks such as oil-based or solvent-based inks. The ink can be reliably absorbed from the tip of the ink.

  A support base 20 is provided between the feed shaft 16 and the take-up shaft 17 and below the ink absorber 15, and a box-shaped member 13 of FIG. Support shafts 21 that are rotatably supported on both side surfaces in the main scanning direction A are attached. Above the both side surfaces of the box-shaped member 13, as shown in FIG. 8, the central portion corresponding to the recording head 5 extends horizontally so as to be substantially parallel to the nozzle surface 9 of the recording head 5, and A guide hole 22 having a shape in which both ends are bent downward is formed.

  As shown in FIG. 9, both end portions of the guide hole 22 are set as a retreat area C, and the carriage is moved when the ink wiping device 12 is not operated or when the ink wiping device is operated. In this case, it is an area where a pressing member 23, which will be described later, is waiting, and the tip of the recording head 5 does not directly contact the pressing member 23 when the carriage is moved.

  As shown in FIGS. 8 to 11, a holding member 50 that holds the pressing member 23 is fixed to the upper end portion of the support base 20. A side wall is erected on the peripheral edge of the holding member 50, and the pressing member 23 is held on the support base 20 while maintaining a certain shape by the side wall. The holding member 50 may be any member as long as it can hold the pressing member 23 on the support base 20, and the shape of the holding member 50, such as the height of the side wall, is not limited to that shown in FIGS.

  As shown in FIG. 10, the pressing member 23 is deformed by applying pressure to the thin film-like outer layer 51 made of a material having corrosion resistance to ink, and can be restored to its original shape again. It is comprised from the inner layer 52 which has elasticity. The width dimension of the pressing member 23 is at least equal to or larger than the width dimension of the ink absorber 15, and the ink absorber 15 is uniform with respect to the nozzle surface 9 of the recording head 5 with an appropriate pressure. And the support member 20 is swung so that the pressing member 23 is reciprocated once in the sub-scanning direction B, whereby the ink absorbing member 15 is moved to the nozzle surface 9 by the pressing member 23. It is possible to make contact over almost the entire area. The pressing member 23 only needs to be able to uniformly press the ink absorber 15 against the nozzle surface 9, and the shape and the like are not limited to those exemplified here.

  Examples of the material for forming the outer layer 51 include polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), perfluoroalkoxyethylene (PFE), polystyrene (PS), polyamide / nylon (PA), poly Resins such as oxymethylene (POM), tetrafluoroethylene / perfluorovinyl ether fluororubber (FFKM), polybutylene terephthalate (PBT), and the like are applicable. By forming the outer layer 51 with a material having corrosion resistance to such an ink, it swells and dissolves even when an ink containing an organic solvent such as a cationic ultraviolet curable ink adheres. And can be used for a long time.

  The inner layer 52 is configured by, for example, filling a space formed by the outer layer 51 with a gel-like material, and the inner layer 52 includes, for example, PP, PE, PTFE, PFE, PS, PA, POM, FFKM. Various resins such as PBT and silicon are preferably used.

As shown in FIG. 11, the pressing member 23 is deformed so as to cover the nozzle surface 9 broadly when the ink absorber 15 is pressed against the nozzle surface 9 of the recording head during the maintenance operation, and excess force is released to the surroundings. The ink absorber 15 can be adhered to the nozzle surface 9 as widely and uniformly as possible.
Here, referring to Table 1, the area of the contact portion of the pressing member 23 that contacts the ink absorber 15 is the ratio of the area of the contact portion of the ink absorber 15 that contacts the nozzle surface 9 (hereinafter referred to as “adhesion rate”). And the elimination of the nozzle shortage of the recording head 5 after the maintenance operation will be described.

  Table 1 shows that the pressing member 23 and the ink absorber when the maintenance operation of the recording head 5 in which the nozzle row of the right row (R) and the left row (L) is formed on the nozzle surface 9 is performed 10 times. 15 shows the relationship between the adhesion rate with the number of nozzles 15 and the number of times the nozzle shortage has been eliminated.

  As shown in Table 1, when the adhesion rate is 50% or less, out of 10 maintenance operations of the recording head 5, the right column (R) and the left column (L) have nozzle missing five times. It was solved. When the adhesion rate was 70% or less, out of 10 maintenance operations, the nozzle shortage was eliminated 6 times in both the right row (R) and the left row (L). When the adhesion rate was 80% or more, out of 10 maintenance operations, the missing nozzle was eliminated 8 times in the right row (R) and 9 times in the left row (L).

  Therefore, in order to effectively eliminate the nozzle shortage, the area of the contact portion of the pressing member that contacts the ink absorber 15 is at least 50% or more of the area of the contact portion of the ink absorber 15 that contacts the nozzle surface 9. It is preferable to be 80% or more. Therefore, in this embodiment, the pressing member 23 is configured so that the adhesion rate is 80% or more.

  For example, as shown in FIG. 12A, the sheet 53 formed of a resin such as PP or PE is curved as the pressing member 23 to form a cross-sectional shape in an arc shape, and the ink absorber 15 and In the case where a plurality of slits 54 are formed at predetermined contact intervals in the width direction of the pressing member 23 at the contact portion, the adhesion rate is 50% or less. Further, for example, as shown in FIG. 12B, the cross-sectional shape is obtained by curving a sheet 55 formed by Gore-Tex Hyper Sheet (registered trademark) obtained by specially processing PTFE as the pressing member 23. In the case of using an arc-shaped one, the adhesion rate was 70% or less. In contrast to this, in the case of the pressing member 23 in which the thin inner layer 51 formed of PP or the like is filled with the elastic inner layer 52 as in this embodiment, the adhesion rate is 80% or more. Was confirmed by experiments.

  The amount of the inner layer 52 filled in the outer layer 51 is adjusted so that the volume of the inner layer 52 is smaller than the volume of the space formed by the outer layer 51. In the present embodiment, the outer layer 51 is filled with the inner layer 52 in an amount of 95% or less of the volume of the space formed by the outer layer 51, more preferably 70 of the volume of the space formed by the outer layer 51. % Or less. The amount of the inner layer filled in the outer layer 51 is not necessarily limited to 95% or less, but by making the amount of the inner layer filled in the outer layer 51 less than 100% of the volume of the space formed by the outer layer 51, When the pressing member 23 is pressed against the nozzle surface 9 of the recording head 5 via the ink absorber 15, excess force can be released to the surroundings, and the adhesion of the pressing member 23 to the nozzle surface 9 can be improved. it can.

  Note that the material forming the inner layer 52 may be any material as long as it has elasticity capable of being deformed and restored to its original shape by applying pressure, and is not limited to those exemplified here. In addition, the inner layer 52 may be configured by filling a gas such as air or a fluid such as water or oil in a space formed by the outer layer 51 in addition to the gel material. Further, the pressing member 23 is not limited to the thin layer outer layer 51 and the inner layer 52 configured by filling various materials in the space formed by the outer layer 51, and further includes a plurality of layers. You may be comprised from. In this case as well, the entire volume of what is filled in the outer layer 51 is set to be less than 100%, preferably less than 70%, of the space formed by the outer layer.

  A guide shaft 24 that is engaged with the guide hole 22 is attached above both sides of the support base 20. Then, the support member 20 is swung by a drive mechanism (not shown), so that the pressing member 23 is swung along with the swing operation of the support block 20. As a result, the guide shaft 24 of the pressing member 23 is guided to the guide hole 22, and the back surface of the ink absorber 15 moves along the sub-scanning direction B while the pressing member 23 moves up and down with respect to the support base 20. It has come to be. In the present embodiment, the support base moving device 25 is composed of a support base 20, a support shaft 21, a guide hole 22, a guide shaft 24, and a drive mechanism that swings the support base 20.

  In the present embodiment, the ink jet printer includes a control unit (not shown) that controls each unit of the apparatus, as in the first to third embodiments. In the present embodiment, the control unit also serves as a head maintenance control unit that controls the head maintenance mechanism, as in the first to third embodiments. As shown in the first to third embodiments, for example, a head maintenance control unit that controls only the head maintenance mechanism may be separately provided.

  In this embodiment, the control unit moves the carriage to the head maintenance mechanism to perform the maintenance operation of the recording head 5 as in the first to third embodiments. That is, in the present embodiment, the control unit drives the driving mechanism of the ink wiping device 12 to press the pressing member 23 against the nozzle surface 9 of the recording head 5 via the ink absorber 15, while in the sub-scanning direction B. Move to, and perform the wipe operation. The number of times of performing the wiping operation is not particularly limited, but it is preferable to perform the wiping operation twice or more in order to re-form a meniscus at the tip of the nozzle 8 and restore it to a state suitable for ejection. When performing the wiping operation twice or more, in the second and subsequent wiping operations, the control unit moves the support base drive mechanism 41 so as to move the pressing member 23 at a speed of 1 mm / s to 30 mm / s. It is designed to drive. By performing the second and subsequent wiping operations at a relatively slow speed in this way, the ink is reliably absorbed from the tip of the nozzle 8 to the ink absorber 15, and the meniscus is re-formed at the tip of the nozzle 8, The shape can be adjusted.

  In addition, since the configuration in which the control unit controls each unit of the apparatus and the configuration of each unit of the inkjet printer are the same as those in the first to third embodiments, the description thereof is omitted.

  Next, a head maintenance method according to this embodiment will be described.

  In the present embodiment, as in the first to third embodiments, the recording head 5 ejects ink while moving, and the ejected ink is irradiated with ultraviolet rays. Images are recorded sequentially.

  When the image recording is performed a predetermined number of times, the carriage moves to a predetermined position of the head maintenance mechanism, and the maintenance operation of the nozzle 8 and the nozzle surface 9 of the recording head 5 is performed by the head maintenance mechanism.

  Specifically, after the control unit moves the carriage above the ink wiping device 12, the control unit operates the ink wiping device 12 to perform a wiping operation a plurality of times. As a result, the ink is absorbed by the ink absorber 15 from the nozzle 8.

  When the wiping operation is performed a plurality of times as described above, the first wiping operation is performed at a relatively high speed of 30 mm / s or more, and the second and subsequent wiping operations are performed relatively slowly at 1 mm / s or more and 30 mm / s or less. Try to do it at the speed. Thereby, the ink adhering to the nozzle 8 and the nozzle surface 9 is wiped and removed by the first wiping operation, and the ink is absorbed from the tip of the nozzle 8 by the second and subsequent wiping operations, and formed at the tip of the nozzle 8. Can arrange the meniscus.

  In this case, it is preferable to perform the winding operation of the ink absorber 15 after the first wiping operation is performed.

  When a series of maintenance by the head maintenance mechanism is completed, the carriage returns to the recording area again and image recording is resumed.

  As described above, in the ink jet printer according to the present embodiment, the ink absorber 15 is pressed against the nozzle surface 9 using the pressing member 23 that can be deformed by being pressed against the nozzle surface 9, and a plurality of wiping operations are performed. The ink absorber 15 can be sufficiently adhered to the nozzle surface 9, and even in the case of ink having high viscosity and poor wettability, the ink is surely absorbed by the ink absorber 15 from the tip of the nozzle 8, and the tip of the nozzle 8. The meniscus formed in the part can be properly arranged. As a result, ink can be normally ejected from each nozzle 8 of the recording head 5, and high-definition image recording can be performed.

  Further, since the ink absorber 15 is pressed against the entire nozzle surface 9 by moving the pressing member 23, it is not necessary to move the ink absorber 15 itself, and it is applied to the nozzle surface 9 by a maintenance operation. In addition, there is no possibility that the water-repellent treatment is deteriorated or the nozzle 8 is damaged, and the life of the apparatus can be extended.

  In addition, the ink absorber 15 of the ink wiping device 12 can absorb the ink at the tip of the nozzle 8 so that the meniscus in the nozzle 8 can be adjusted. Can do. In addition, since it is not necessary to provide a tray for empty ejection of ink, the number of members can be reduced, and the ink jet printer can be reduced in size and cost.

  In the present embodiment, the pressing member 23 is a thin film-like outer layer 51 formed of a material that is resistant to ink, and can be deformed and restored to its original shape by applying pressure. However, the pressing member may be any member as long as the ink absorber 15 can be brought into close contact with the nozzle surface 9 and is limited to the configuration exemplified here. Not.

  For example, as shown in FIG. 13, the pressing member 60 is provided with an outer layer 51 whose cross-sectional shape is formed in an arc shape by curving a thin plate-like member at the upper end of the support base 20, and a cylindrical shape is formed inside the outer layer 51. It is good also as a structure provided with the formed inner layer 52. FIG. In this case as well, the outer layer is formed of a material that is resistant to ink, and the inner layer 52 can be deformed by pressing the pressing member 60 against the nozzle surface 9 and can return to its original shape. Formed by. Further, the volume of the inner layer is made smaller than the volume of the space formed by the outer layer.

  Further, as in the first to third embodiments, the timing of winding the ink absorber 15 is not limited to each reciprocating wipe operation, and every reciprocating wipe operation is performed. You may make it wind up. Thus, the consumption of the ink absorber 15 can be suppressed by reducing the number of windings of the ink absorber 15.

In the present embodiment, the first wiping operation and the second and subsequent wiping operations are both performed by the ink wiping device 12. However, the configuration for performing the first wiping operation is not limited to the example illustrated here. .
For example, as shown in the second embodiment, when the head maintenance mechanism is provided with a blade made of resin or the like, the first wiping operation may be performed by the blade.
Further, as the means for performing the first wiping operation, other configurations may be used as long as they can wipe off and remove the ink adhering to the nozzle 8 and the nozzle surface 9. The first wiping operation may be performed by a sponge roller using a high sponge.
Furthermore, when the head maintenance mechanism is provided with an ink suction device as shown in the first embodiment, ink is sucked by the ink suction device before the wipe operation is performed as the maintenance operation. It may be.
Further, as shown in the third embodiment, the recording head 5 is subjected to a wiping operation as a maintenance operation by a liquid feeding pump (not shown) that feeds ink from an ink tank (not shown) to the recording head 5. Alternatively, a pressurizing operation for applying pressure may be performed.

  In the present embodiment, the ink absorber 15 is pressed by one pressing member 23 having a length corresponding to the entire nozzle surface 9 of the head units 6 and 7 in the main scanning direction A. Although the maintenance operation is performed for each head unit 6, 7, a plurality of pressing members 23 having a length corresponding to the nozzle surface 9 for each recording head 5 are provided, and the nozzle surface 9 for each recording head 5 is provided. The ink absorber 15 may be in close contact with the ink.

  In the present embodiment, the pressing member 23 is moved along the nozzle row direction and pressed against the nozzle surface 9. However, the direction in which the pressing member 23 is moved is not limited to the example illustrated here. For example, the pressing member 23 may be moved in a direction orthogonal to the nozzle row and pressed against the nozzle surface 9 to perform a maintenance operation.

  Further, the recording head 5 to which the head maintenance mechanism according to the present invention is applicable is not limited to that shown in FIG. 9 or FIG. For example, the head maintenance mechanism according to the present invention can be applied even if the number, shape, and the like of the nozzles 8 provided in the recording head 5 are different from those shown in FIG. 9 or FIG.

  Other than that, the present invention is not limited to the present embodiment, as in the first to third embodiments.

1 is a perspective view of an ink jet printer to which a first embodiment of a head maintenance mechanism according to the present invention is applied. It is a front view which shows the principal part structure of the head maintenance mechanism in the inkjet printer shown in FIG. It is a perspective view showing one embodiment of an ink wiping device constituting a head maintenance mechanism according to the present invention. It is a front view which shows a part of ink wiping apparatus showing operation | movement of a pressing member. It is a principal block diagram showing an outline of a control configuration of the first embodiment of the ink jet printer according to the present invention. It is a principal block diagram showing an outline of a control configuration of a second embodiment of the inkjet printer according to the present invention. It is a principal part block diagram which showed the outline of the control structure of 3rd embodiment of the inkjet printer which concerns on this invention. It is a perspective view which shows the ink wiping apparatus which comprises the head maintenance mechanism which concerns on 4th embodiment. It is a front view which shows a part of ink wiping apparatus showing operation | movement of the pressing member shown in FIG. It is principal part sectional drawing of the pressing member of the ink wiping apparatus shown in FIG. It is a front view which shows a part of ink wiping apparatus which shows the state which the pressing member pressed the ink absorber against the nozzle surface. FIG. 12A and FIG. 12B are perspective views schematically showing modified examples of the pressing member. It is principal part sectional drawing of the modification of the pressing member in 4th embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Recording head 8 Nozzle 9 Nozzle surface 12 Ink wiping device 15 Ink absorber 16 Sending shaft 17 Winding shaft 19 Ink absorber moving device 23 Pressing member 25 Support stand moving device 40 Roll shaft drive mechanism 41 Support stand drive mechanism 45 Liquid feeding Pump 51 Outer layer 52 Inner layer P Recording medium A Main scanning direction B Sub scanning direction

Claims (17)

In a head maintenance mechanism that performs a maintenance operation of the nozzle of the recording head provided with a plurality of nozzles that eject ink and the nozzle surface on which the nozzle is formed,
An ink wiping device comprising: an ink absorber having ink absorptivity; and a pressing member that contacts the nozzle surface while moving along the ink absorber;
The area of the contact portion of the pressing member that contacts the ink absorber during pressing is at least 50% or more of the area of the contact portion of the ink absorber that contacts the nozzle surface during pressing. mechanism. Area of the contact portion of the pressing member in contact with the ink absorbing member in pressing the claim 1, characterized in that in pressing more than 80% of the area of the contact portion of the ink absorbing member in contact with the nozzle face The head maintenance mechanism described in 1. 3. The head maintenance mechanism according to claim 1 , wherein the pressing member has a multilayer structure including at least an inner layer formed of a deformable material and an outer layer that holds the inner layer. The head maintenance mechanism according to claim 3 , wherein the outer layer is formed of a material having corrosion resistance against ink. The outer layer is made of any material of polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene, polyamide / nylon, polyoxymethylene, tetrafluoroethylene / perfluorovinyl ether fluorine rubber, and polybutylene terephthalate. head maintenance mechanism according to claim 3 or claim 4, characterized in Rukoto. The inner layer, gas, liquid, claim 3, characterized in that it is formed of a composite material combining a plurality of any one material or any of the foregoing materials of the gel to claims 5 The head maintenance mechanism described. The inner layer is formed of any material of polypropylene, polyethylene, polytetrafluoroethylene, perfluoroalkoxyethylene, polystyrene, polyamide / nylon, polyoxymethylene, tetrafluoroethylene / perfluorovinyl ether fluorine rubber, and polybutylene terephthalate. The head maintenance mechanism according to claim 3 , wherein the head maintenance mechanism is a head maintenance mechanism. The head maintenance mechanism according to claim 3 , wherein a volume of the inner layer is smaller than a volume of a space formed by the outer layer. The maintenance operation includes the above wiping operation at least twice, to any one of claims 8 least second or subsequent one of said wipe from claim 1, characterized in that it is performed by the ink wiping device The head maintenance mechanism described. A head maintenance control unit that controls each part is provided.
Said head maintenance control unit, either the wiping operation of the second and subsequent claim, wherein the controller controls the ink wiping device to perform at a rate 1 mm / s or more 30 mm / s according to claim 9 The head maintenance mechanism according to claim 1. The ink absorber is a high-density fiber woven with a fineness of 0.5 denier or less, and the high-density fiber is formed of a material of any one of polyester, acrylic, nylon, or a combination thereof. The head maintenance mechanism according to any one of claims 1 to 10 , wherein the head maintenance mechanism is provided. The ink has a viscosity of 23 ° C. is 10 to 50 at [mPa · s], any one of claims 1 to 11 in which the surface tension is equal to or is 20~40 [mN / m] The head maintenance mechanism described in 1. The head maintenance mechanism according to any one of claims 1 to 12 , wherein the ink contains an activation energy ray-curable compound, and the activation energy is ultraviolet light. A head maintenance mechanism according to any one of claims 1 to 13 ,
An ink jet printer comprising: a recording head having a nozzle surface provided with a plurality of nozzles for ejecting ink. Before the wiping operation, a suction cap that can adhere to the nozzle surface;
The apparatus according to claim 14 , further comprising: a suction pump that depressurizes a space generated between the nozzle surface and the suction cap when the suction cap is in close contact with the nozzle surface and sucks ink in the nozzle. The inkjet printer as described. A control unit for controlling the recording head;
16. The ink jet printer according to claim 14 , wherein the control unit controls the recording head to perform a flushing operation before the wiping operation. An ink tank for supplying ink to the recording head;
A liquid feed pump for feeding ink from the ink tank;
The inkjet printer according to any one of claims 14 to 16 , wherein the liquid feed pump pressurizes the recording head before the wiping operation.