Image recording apparatus with wipe unit and nozzle maintenance unit

An image recording apparatus is disclosed having a recording head including a plurality of nozzles for jetting an ink and a maintenance unit for performing a maintenance operation to the nozzles. The maintenance unit includes an absorbing member to wipe an ink adhered to the nozzles and receive an ink residue purged from the nozzles during the maintenance operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image recording apparatus and, more particularly, to an image recording apparatus to perform image recording by an ink jet system.

2. Description of the Related Art

As an image recording method for record images easily and at low cost, many types of image recording apparatuses using an ink jet system have been used. The image recording apparatus using ink jet system is such that ink is jetted from nozzles of a recording head as fine ink droplets toward a recording medium such as a paper or the like with, for example, a piezoelectric element such as a piezo element or a heater, and the recording head is moved over the recording medium while making the ink penetrate into or fix onto the recording medium to thereby record images on the recording medium.

Recently, as a method for forming images even onto a recording medium with poor ink absorptivity such as resin film, an image recording apparatus which uses ultraviolet curable ink has been known (refer to for example, JP-Tokukai-2001-310454A), in which ultraviolet curable ink comprising photo initiator with a predetermined sensitivity to ultraviolet rays is used, and the ink placed on the recording medium is cured by irradiation with ultraviolet rays to be fixed thereto. This method allows images to be easily recorded even onto transparent or nontransparent packing material.

However, in the image recording apparatus of the ink jet system, the ink jetted from the nozzles of the recording head is turned into spray to disperse, causing the ink to adhere to a portion outside the recording medium. For example, in the case that the ink dispersed is adhered to a portion near the nozzles, the ink would stack in the nozzle to cause clogging, thereby raising a problem for image recording.

The ink dispersed from the nozzles may adhere to a platen as well as the portion near the nozzles. Specially, in the case of using cationic polymerizable ultraviolet curable ink or the like whose main component is a monomer, the monomer has a property to make resin such as plastic melt. Therefore, a platen made of plastic is melted at a portion to which the ink is attached, causing irregularity on the surface thereof, thereby raising a problem that the recording medium may not be carried smoothly for image recording. A platen made of metal such as aluminum would not be damaged by the melt on the surface, however, because the ultraviolet ray curable ink is cured by irradiation with light, the ink adhered to the platen may be cured, thereby causing irregularity on the surface of the platen. Therefore, the same problem is raised so that the recording medium is inhibited from being carried.

The ink which turned into spray may adhere to a portion of a maintenance unit. For example, when the ink adheres to a suction cap provided on the maintenance unit, the ink is cured on the suction cap by irradiation with light. It would inhibit a contact between the nozzle face of the recording head and the suction cap for maintenance of the recording head, resulting in failing to perform an appropriate maintenance of the nozzles.

Accordingly, for performing stable and high definition image recording, the ink which turned into spray to be dispersed on each part of the nozzles of the recording head, the platen, and the maintenance unit should be appropriately removed to keep an appropriate condition for image recording.

For removing the ink adhered to a portion around the nozzles of the recording head, there is known to provide a space for purging ink residue within a recording head movable region. The maintenance is performed by purging ink residue to the provided space every time a certain amount of image recording is completed (for example, see, JP-2675887B).

However, providing a specific space for purging ink residue would cause the need to make the apparatus be large by the size of the space. Since the ink residue purged into the space needs to be fed to a waste ink tank, a mechanism for suctioning and feeding the ink jetted to the space is required. However, providing such a mechanism would make the apparatus be large and complicated, thereby raising a problem to increase the cost for manufacturing the apparatus.

Specially, use of ink with high viscosity such as cationic polymerizable ultraviolet curable ink for performing image recording would cause a problem that the ink is difficult to be fed to the waste ink tank. For example, the ink with high viscosity easily adheres to the waste ink path when feeding the ink, and further the ink suctioned would clog in the waste ink path, thereby failing to perform the suction operation. Therefore, for smoothly feeding ink to the waste ink tank, a special member needs to be provided for raising a suction pressure to suction ink residue purged, resulting in a problem that the apparatus becomes large and the cost for manufacturing the apparatus is increased.

Appropriate maintenance operations for portions of the platen or the suction cap are also required, however, in the related art, the maintenance operations have not been performed for these portions. Thus, the apparatus could not be kept in a proper condition by appropriately removing ink which turned into spray for performing image recording, thereby raising a problem that it is difficult to stably perform high definition image recording.

SUMMARY OF THE INVENTION

The present invention is developed in view of the above described points, and an object of the present invention is to provide an image recording apparatus which can properly perform a maintenance operation to each portion of a recording head, a platen, a maintenance unit and the like and perform high definition image recording without making the apparatus be large and complicated.

In order to attain the above described object, in accordance with a first aspect of the present invention, an image recording apparatus comprises:

a recording head comprising a plurality of nozzles for jetting an ink; and

a maintenance unit for performing an maintenance operation to the nozzles, the maintenance unit comprising an absorbing member to wipe an ink adhered to the nozzles and receive an ink residue purged from the nozzles during the maintenance operation.

Accordingly, since the maintenance unit comprises the absorbing member, the ink adhered to the nozzle face can be wiped out and appropriately removed. Since ink residue is purged onto the absorbing member to wipe ink, an additional space for purging ink residue is not required, and there is no need to feed ink residue purged to a waste ink tank or the like. Thus, a save-spacing and a cost-saving can be realized.

Preferably, in the apparatus of the first aspect of the present invention, the maintenance unit comprises a drive mechanism for moving an ink absorbed portion of the absorbing member to a new position after the absorbing member absorbed the ink.

Accordingly, since the image recording apparatus comprises the mechanism for moving the ink absorbed portion after the absorbing member absorbed ink, ink absorption is not performed by the ink absorbed portion of the absorbing member again, thereby preventing the ink absorbed in absorbing member from readhering to some other portions. Therefore, the ink adhered to a portion other than the recording medium can appropriately be removed, enabling the image recording apparatus to always keep condition for performing high definition image recording.

Preferably, in the apparatus of the first aspect of the present invention, each of the inks is a type of being cured by an irradiation with light, and the maintenance unit comprises a light irradiation device for irradiating the ink absorbed in the absorbing member with light.

Accordingly, since the ink is cured by irradiating the ink adhered portion of the absorbing member with light after the absorbing member absorbed the ink, it can be prevented that the ink absorbed in absorbing member readhere to some other portions. Thus, exchange of the absorbing member or the like can be easily performed.

Preferably, in the apparatus of the first aspect of the present invention, the light irradiation device irradiates a small amount of light of 1 mJ/cm2to 30 mJ/cm2.

Accordingly, since the light irradiation device irradiates a small amount of light, only the ink adhered to the absorbing member can be properly cured.

Preferably, in the apparatus of the first aspect of the present invention, the absorbing member is formed with a high density fiber having a fineness of 0.1 denier or less.

Accordingly, since the absorbing member is formed with high density fibers, when wiping the ink adhered to the nozzles or purging ink residue from the nozzles, the ink can be easily and immediately absorbed by the capillary action or the like, thereby the ink is removed from the nozzle faces.

Preferably, in the apparatus of the first aspect of the present invention, the ink has a viscosity of 10 to 500 mPa·s at 25° C. and a surface tension of 20 to 40 mN/m.

Accordingly, for example even in the case of using the ink with high viscosity such as ultraviolet curable ink having high viscosity and low wetting property, the maintenance operation of purging ink residue can be performed smoothly and easily.

Preferably, in the apparatus of the first aspect of the present invention, the ink comprises an active energy ray curable compound, and an active energy ray comprises an ultraviolet ray.

Accordingly, the maintenance operation can properly be performed even in the case of using the ink which is cured by irradiation with ultraviolet rays for image recording. When ultraviolet curable ink is used for image recording, the ink is cured by irradiation with ultraviolet rays after jetting the ink, so that the quality of recorded images can be maintained over a prolonged period.

Moreover, use of ultraviolet curable ink for image recording is successful in performing high definition image recording onto a recording medium with low ink absorptivity such as resin film or a recording medium with no ink absorptivity as well as the recording medium with high ink absorptivity such as paper.

In accordance with a second aspect of the present invention, an image recording apparatus comprises:

a recording head comprising a plurality of nozzles for jetting an ink onto a recording medium; and

a wipe unit provided on at least one of an upstream side and a downstream side of the recording head in a moving direction, the wipe unit comprising an absorbing member for absorbing an ink which was jetted and adhered to a portion other than the recording medium.

According to this configuration, the ink adhered to a portion other than the recording medium can be appropriately suctioned and removed, so that it can be prevented that the ink adhered to the portion other than the recording medium readhere to the recording medium or the like, and there is less possibility that the maintenance operation is inhibited by the ink adhered. Thus, it can be realized to always perform high definition image recording.

Preferably, in the apparatus of the second aspect of the present invention, the apparatus further comprises a platen for supporting the recording medium, wherein the absorbing member absorbs an ink adhered to the platen.

According to this configuration, the ink adhered to the platen can be properly suctioned and removed, so that irregularity is not generated on the surface of the platen by the ink adhered thereto, enabling to perform the carrying operation of the recording medium without being inhibited by the ink. Thus, it can be realized to always perform image recording stably.

Preferably, in the apparatus having the platen of the second aspect of the present invention, the wipe unit comprises a drive mechanism for moving an ink absorbed portion of the absorbing member to a new position after the absorbing member absorbed the ink.

Accordingly, since the image recording apparatus comprises the mechanism for moving the ink absorbed portion after the absorbing member absorbed ink, ink absorption is not performed by the ink absorbed portion of the absorbing member again, thereby preventing the ink absorbed n absorbing member from readhering to some other portions. Therefore, the ink adhered to a portion other than the recording medium can appropriately be removed, enabling the image recording apparatus to always keep a condition for performing high definition image recording.

Preferably, in the apparatus having the platen of the second aspect of the present invention, the ink is a type of being cured by an irradiation with light, and the wipe unit comprises a light irradiation device for irradiating the ink absorbed in the absorbing member with light.

Accordingly, since the ink is cured by irradiating the ink adhered portion of the absorbing member with light after the absorbing member absorbed the ink, it can be prevented that the ink absorbed in absorbing member readhere to some other portions. Thus, exchange of the absorbing member or the like can be easily performed.

Preferably, in the apparatus having the platen of the second aspect of the present invention, the absorbing member is formed with a high density fiber having a fineness of 0.1 denier or less.

Accordingly, since the absorbing member is formed with high density fibers, when wiping the ink adhered to the platen, the ink can be easily and immediately absorbed by the capillary action or the like, thereby the ink is properly removed.

Preferably, in the apparatus having the platen of the second aspect of the present invention, the ink has a viscosity of 10 to 500 mPa·s at 25° C. and a surface tension of 20 to 40 mN/m.

Accordingly, for example even in the case of using the ink with high viscosity such as ultraviolet curable ink having high viscosity and low wetting property, the maintenance operation to wipe the ink adhered to the platen can be performed smoothly and easily.

Preferably, in the apparatus having the platen of the second aspect of the present invention, the ink comprises an active energy ray curable compound, and an active energy ray comprises an ultraviolet ray.

Accordingly, the maintenance operation can properly be performed even in the case of using the ink which is cured by irradiation with ultraviolet rays for image recording. When ultraviolet curable ink is used for image recording, the ink is cured by irradiation with ultraviolet rays after jetting the ink, so that the quality of recorded images can be maintained over a prolonged period.

Moreover, use of ultraviolet curable ink for image recording is successful in performing high definition image recording onto a recording medium with low ink absorptivity such as resin film or a recording medium with no ink absorptivity as well as the recording medium with high ink absorptivity such as paper.

Preferably, in the apparatus of the second aspect of the present invention, the apparatus further comprises a suction cap in a movable range of the recording head for performing a maintenance of the nozzles by suctioning an ink in the nozzles of the recording head, wherein the absorbing member absorbs an ink adhered to the suction cap.

According to this configuration, since inhibition of contact between the nozzle face of the recording head and the suction cap, which is caused by fixation of the ink adhered to the suction cap, is not caused in the maintenance operation, enabling to always perform a proper maintenance operation. Thus, it can be realized to always form high quality images even when performing image recording continuously.

Preferably, in the apparatus having the suction cap of the second aspect of the present invention, the wipe unit comprises a drive mechanism for moving an ink absorbed portion of the absorbing member to a new position after the absorbing member absorbed the ink.

Accordingly, since the image recording apparatus comprises the mechanism for moving the ink absorbed portion after the absorbing member absorbed ink, ink absorption is not performed by the ink absorbed portion of the absorbing member again, thereby preventing the ink absorbed in absorbing member from readhering to some other portions. Therefore, the ink adhered to a portion other than the recording medium can appropriately be removed, enabling the image recording apparatus to always keep a condition for performing high definition image recording.

Preferably, in the apparatus having the suction cap of the second aspect of the present invention, each of the inks is a type of being cured by an irradiation with light, and the wipe unit comprises a light irradiation device for irradiating the ink absorbed in the absorbing member with light.

Accordingly, since the ink is cured by irradiating the ink adhered portion of the absorbing member with light after the absorbing member absorbed the ink, it can be prevented that the ink absorbed in absorbing member readhere to some other portions. Thus, exchange of the absorbing member or the like can be easily performed.

Preferably, in the apparatus having the suction cap of the second aspect of the present invention, the absorbing member is formed with a high density fiber having a fineness of 0.1 denier or less.

Accordingly, since the absorbing member is formed with high density fibers, when wiping the ink adhered to the suction cap, the ink can be easily and immediately absorbed by the capillary action or the like, thereby the ink is properly removed.

Preferably, in the apparatus having the suction cap of the second aspect of the present invention, the ink has a viscosity of 10 to 500 mPa·s at 25° C. and a surface tension of 20 to 40 mN/m.

Accordingly, for example even in the case of using the ink with high viscosity such as ultraviolet curable ink having high viscosity and low wetting property, the maintenance operation to wipe the ink adhered to the suction cap can be performed smoothly and easily.

Preferably, in the apparatus having the suction cap of the second aspect of the present invention, the ink comprises an active energy ray curable compound, and an active energy ray comprises an ultraviolet ray.

Accordingly, the maintenance operation can properly be performed even in the case of using the ink which is cured by irradiation with ultraviolet rays for image recording. When ultraviolet curable ink is used for image recording, the ink is cured by irradiation with ultraviolet rays after jetting the ink, so that the quality of recorded images can be maintained over a prolonged period.

Moreover, use of ultraviolet curable ink for image recording is successful in performing high definition image recording onto a recording medium with low ink absorptivity such as resin film or a recording medium with no ink absorptivity as well as the recording medium with high ink absorptivity such as paper.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the preferred embodiments of the present invention will be described in detail by reference toFIGS. 1 to 6.

As shown inFIG. 1, in this embodiment, an image recording apparatus1is a serial print type, comprising a bar shaped carriage rail2which extends in a main scanning direction A. On the carriage rail2, a carriage3is reciprocably supported along the carriage rail2, and is adapted to reciprocate in the main scanning direction A by a carriage drive mechanism33(refer toFIG. 6).

The carriage3is provided with recording heads4,4. . . each of which is formed with nozzles5,5. . . for jetting ink as shown inFIG. 1. The recording heads4,4. . . are for jetting each color of inks of, for example, yellow (Y), magenta (M), cyan (C) and black (B) which corresponds with the color used in this embodiment from the nozzles5,5. . . onto a recording medium P.

An ultraviolet ray (UV) irradiation device7is provided on each side on the carriage3to be adjacent to the recording heads4,4. . . , for irradiating the ink jetted from the nozzles5,5. . . with ultraviolet rays.

A recording region Y is for performing recording onto the recording medium P, which is approximately in a middle portion of a carriage3movable range. In the recording region Y, there is provided a platen8for supporting a non-recording surface of the recording medium P while the recording operation. The platen8extends in the main scanning direction A to have a length slightly longer than a width of the recording medium P. The recording medium P is carried in a sub scanning direction which is perpendicular to the main scanning direction A by a recording medium carrying mechanism34(refer toFIG. 6) on the platen8while the image recording.

A maintenance region Z is for performing maintenance of nozzle faces6,6. . . on which the nozzles5,5. . . of the recording heads4,4. . . are formed. The maintenance region Z is provided on one side of the recording region Y within the carriage3movable range.

A maintenance unit9is provided in the maintenance region Z. As shown inFIG. 1, the maintenance unit9comprises suction caps10,10. . . as a cap member as many as the recording heads4,4. . . , each of which is positioned to correspond to one of the recording heads4,4. . . to cover the nozzle face6when the carriage3was moved to the maintenance region Z.

An ink communicating tube11is provided at the bottom surface of each of the suction caps10,10. . . to communicate with the inside thereof. Each of the ink communicating tubes11,11. . . is provided with a suction pump12in a middle portion thereof, and a waste ink tank13is disposed at a low end of the ink communicating tubes11,11. . . for receiving the ink suctioned.

There is provided an ink absorbing mechanism14near one end of the suction caps10,10. . . , which is for wiping the ink adhered to the nozzles5,5. . . of the recording heads4,4. . . and for purging ink residue from the nozzles5,5. . . .

As shown inFIG. 2, the ink absorbing mechanism14comprises a box shaped case member15having an opening on a side facing the recording heads4,4. . . when the carriage was moved to the maintenance region Z. A feed roller17is rotatably provided on one side of the inside of the case member15, and a sheet shaped long absorbing member16is rolled thereon. A winding roller18is rotatably provided on the other side of the inside of the case member15for winding the absorbing member16. At the upper portion of the case member15, there are provided guide rollers19a,19bfor guiding the absorbing member16fed from the feed roller17while giving a constant tension thereto above the feed roller17and the winding roller18, respectively. The feed roller17and the winding roller18are rotatably driven by a roller drive mechanism37(refer toFIG. 6). The feed roller17and the winding roller18are rotated to carry the absorbing member16guided by the guide rollers19a,19bwhile keeping a constant height, and the absorbing member16is wound by the winding roller18.

The absorbing member16has fineness of 0.1 denier or less, and is formed with high density fibers having extra fine thickness of approximately 1 to 5 μm. Examples of the high density fibers applicable include synthetic fibers such as polyester, acryl and nylon. Use of the absorbing member16comprising extra fine fibers having fineness of 0.05 to 0.2 denier, and preferably 0.1 denier or less is successful in immediately absorbing the ink adhered to the nozzles5,5. . . of the recording heads4,4. . . regardless of viscosity of the ink by the capillary action or the like. According to the absorbing member16in this embodiment, specially, even when performing image recording by using the UV curable ink having high viscosity in comparison with water-based or oil-based ink, the ink adhered to the nozzles5,5. . . can be certainly and promptly suctioned and removed.

The case member15is provided with an opening20extending in a width direction of the absorbing member16in one surface thereof, that is on the side on which the winding roller18is disposed. An ultraviolet ray (UV) irradiation section22having an ultraviolet ray (UV) light source21for irradiating the absorbing member16with a small amount of ultraviolet rays is provided adjacent to the opening20of the ink absorbing mechanism14. The UV light source21is, for example, an LED, high pressure mercury lamp, hot cathode ray tube or the like, which is capable of irradiating a small amount of ultraviolet rays of at least 1 mJ/cm2to 30 mJ/cm2. Ultraviolet rays may be directly radiated from the UV light source21, or may be emitted from a UV emitting device (not shown) and guided by optical fibers to be indirectly radiated.

The position to provide the UV irradiation section22for irradiating the absorbing member16of the ink absorbing mechanism14with ultraviolet rays is not limited to that in this embodiment. For example, as shown inFIG. 3, the UV irradiation section22may be integrated with one side of the case member15which is the side where the winding roller18is provided. As shown inFIG. 4, the UV irradiation section22may be provided under the absorbing member16in the ink absorbing mechanism14, to face the absorbing member16between the winding roller18and the guide roller19apositioned above the winding roller18, thereby irradiating the side of the absorbing member16opposite to the ink absorbing side.

A wipe unit25is provided on one side of the carriage3of the maintenance region Z side, which is for absorbing the ink adhered to the surface of the platen8and the suction caps10,10. . . to remove them. As shown inFIG. 5, the wipe unit25can move up and down along a guide rail (not shown) provided on a side of the carriage3. Thus, while image recording operation, the wipe unit25can move upward to the position where the wipe unit25does not contact with the recording medium P. This configuration is not limited to that of this embodiment, for example, the wipe unit25may be fixed at one end of the upper surface thereof to the side of the carriage3, and the wipe unit25may be rotatable around the fixed end as a fulcrum upwardly with respect to the carriage3by a drive source which is not shown.

As shown inFIG. 5, the wipe unit25has a configuration similar to that of the ink absorbing mechanism14, that is, the wipe unit25comprises a boxed shaped case member26having an opening in one surface facing the platen8. A feed roller28is provided on one side of the upper portion inside of the case member26, on which a sheet shaped long absorbing member27is wound. The absorbing member27has a width approximately equal to the length of the platen8in the carrying direction of the recording medium P. A winding roller29is rotatably provided on the other side of the upper portion inside of the case member26, which is for winding the absorbing member27. At the lower portion of the case member26, rotatable guide rollers30a,30bare provided for guiding the absorbing member27fed from the feed roller28while giving a constant tension thereto under the feed roller28and the winding roller29, respectively. The feed roller28and the winding roller29are rotatably driven by the roller drive mechanism38(refer toFIG. 6). With the rotation of the feed roller28and the winding roller29, the absorbing member27is carried to be guided by the guide rollers30a,30bwhile keeping a constant height slightly higher than the height of the case member26, and then wound by the winding roller18.

The absorbing member27, which is similar to the absorbing member16provided in the ink absorbing mechanism14, has fineness of 0.1 denier or less, and is formed with high density fibers having an extra fine thickness of approximately 1 to 5 μm. Use of the absorbing member27comprising extra fine fibers with fineness of 0.05 to 0.2 denier, preferably 0.1 denier or less is successful in immediately absorbing the ink adhered to the platen8or the suction caps10,10. . . regardless of viscosity of the ink by the capillary action or the like. According to the absorbing member27in this embodiment, specially, even when performing image recording by using the UV curable ink having high viscosity in comparison with water-based or oil-based ink, the ink adhered to the platen8or the suction caps10,10. . . can be certainly and promptly suctioned to be removed.

The case member26is provided with an ultraviolet ray (UV) irradiation section32having an ultraviolet ray (UV) light source31for irradiating the absorbing member27with ultraviolet rays on one surface inside thereof, or the side on which the winding roller29is provided. The UV irradiation section32is disposed to face the absorbing member27tensioned between the winding roller29and the guide roller30apositioned below the winding roller29. The UV light source31is, for example, an LED, high pressure mercury lamp, hot cathode ray tube or the like, which is capable of radiating a small amount of ultraviolet rays of at least 1 mJ/cm2to 30 mJ/cm2. Ultraviolet rays may be directly radiated from the UV light source31, or may be emitted from a UV emitting device (not shown) and guided by optical fibers to be indirectly radiated.

The position to provide the UV irradiation section32for irradiating the absorbing member27of the wipe unit25with ultraviolet rays is not limited to that in this embodiment. For example, there may be provided an opening extending in a width direction of the absorbing member27in a surface of the wipe unit25, that is on the side on which the winding roller29is disposed, and the UV irradiation section32may be arranged adjacent to the opening of the wipe unit25. Further, with the opening provided in one surface of the wipe unit25, a light reflection member (not shown) may be provided on the UV irradiation device7which is mounted on the carriage3. In this case, when the wipe unit25performs the ink absorbing and removing operations, the UV irradiation device7emits ultraviolet rays, that pass through the opening to be radiated to the absorbing member27in the wipe unit25. Furthermore, the UV irradiation section32may be provided upside of the absorbing member27in the wipe unit25to face the absorbing member27tensioned between the winding roller29and the guide roller30abelow the winding roller29. In this case, the absorbing member27is irradiated with ultraviolet rays from the opposite side of the ink absorption side.

A home position region X is provided on a side opposite to the recording region Y across the maintenance region Z, the home position region X is for keeping the recording heads4,4. . . on standby except the time of image recording and the maintenance operation. In the home position region X, there is provided a light shielding unit23comprising light shielding caps24,24. . . as many as the recording heads4,4. . . , for protecting the nozzle faces6,6. . . of the recording heads4,4. . . from light, especially, ultraviolet rays when image recording is not performed.

A configuration of control according to this embodiment will be explained referring toFIG. 6.

In this embodiment, as shown inFIG. 6, the image recording apparatus1comprises a control section35for controlling the carriage drive mechanism33, the recording medium carrying mechanism34, the recording heads4,4. . . , the UV irradiation devices7,7. . . , and the maintenance unit9.

The control section35controls the operations of the carriage drive mechanism33and the recording medium carrying mechanism34such that the carriage3is reciprocated in the main scanning direction A and a carrying and a stop of the recording medium P is repeated corresponding to the operation of the carriage3to intermittently carry the recording medium P in the sub scanning direction.

The control section35also controls the UV irradiation devices7,7. . . to radiate ultraviolet rays therefrom.

Further, an input section36for accepting input of image recording conditions or the like and the recording heads4,4. . . are connected to the control section35, enabling the control section35to make the recording heads4,4. . . operate based on predetermined signals inputted from the input section36, and thereby jetting the ink on the recording medium P to form predetermined images.

The control section35controls the maintenance unit9to move to a position where each recording head4corresponds to one of the absorption caps10,10. . . of the maintenance unit9at the time of the maintenance operation, and also controls the suction pumps12,12. . . and the like to perform ink absorption from the nozzles5,5. . . of the recording heads4,4. . . .

Further, the control section35moves the maintenance unit9upward to make the absorbing member16of the ink absorbing mechanism14contact with the nozzle faces6,6. . . of the recording heads4,4. . . , thereby wiping the nozzle faces6,6. . . to remove the ink adhered thereto, and also operates the recording heads4,4. . . to purge ink residue from the nozzles5,5. . . to the ink absorbing mechanism14.

The ink adhered to the absorbing member16by wiping the recording heads4,4. . . or by purging ink residue from the nozzles5,5. . . are treated such that the control section35controls the UV irradiation section22of the ink absorbing mechanism14to irradiate a portion of the absorbing member16to which the ink is adhered with a small amount of ultraviolet rays radiated from the UV light source21. Further, the control section35controls the roller drive mechanism37to wind the absorbing member16to which the ink is adhered by the winding roller18.

The control section35controls the wipe unit25to make the absorbing member27of the wipe unit25contact with the platen8and the suction caps10,10. . . , thereby absorbing and removing the ink adhered to the platen8and the suction caps10,10. . . .

The ink adhered to the absorbing member27by absorbing and removing the ink adhered to the platen8and the suction caps10,10. . . are treated such that the control section35controls the UV irradiation section32to irradiate a portion of the absorbing member27to which the ink is adhered with a small amount of ultraviolet rays radiated from the UV light source31. Further, the control section35controls the roller drive mechanism38to wind the absorbing member27to which the ink is adhered by the winding roller29.

The ink used in the embodiment will be explained.

The ink applicable in this embodiment includes water-based ink, oil-based ink, active energy ray curable ink and the like, however, in view of preventing clogging of heads and easily performing maintenance, oil-based ink or active energy ray curable ink is preferably used.

Active energy ray curable ink is the ink adapted in “Curing System Utilizing Photo-Acid and Base Generating Agent (Section 1)” or “Photo-induced Alternating Copolymerization (Section 2)” of “Photo-Curing System (Chapter 4)” in “Photo-Curing Technique—Selection and Compounding Condition of Resin and Initiator, and Measurement and Assessment of Curing Degree (Technical Association Information)”. This ink includes color material, polymerizable compound, initiator and the like, and has a property to cure by cross-linking and polymerization reaction of monomers by catalysis of initiator when irradiated with active energy rays. However, when the ink which is adapted to the above described “Photo-Induced Alternating Copolymerization (Section 2)” is used in the embodiment, initiator may be excluded.

Active energy ray includes, for example, ultraviolet ray, electron beam, visible ray, infrared ray, X-ray or the like, however, in view of degree of freedom for choosing initiator and polymerizable compound, ultraviolet ray is preferable.

Polymerizable compound includes radical polymerizable compound, cationic polymerizable compound and anionic polymerizable compound, each of which may be used independently or a hybrid of which may be applied as ink.

Cationic polymerizable compound in which inhibition of polymerization by oxygen less occurs is preferably used. As cationic polymerizable compound, oxetane compound, epoxide compound, vinyl ether compound or the like is preferably used independently or as a mixture. However, the ink applicable for this embodiment is not limited thereto.

The ink applicable for this embodiment is, for example, oil-based ink in which pigment is dispersed in saturated hydrocarbon medium. As examples of such saturated hydrocarbon solvent, isoparaffin solvent and cycloparaffin solvent in a single use can be adapted, that are represented by Isopar Series or Exxole Series made EXXON CHEMICAL JAPAN, LTD. In view of storing stability under low temperature or the like, the freezing point of the ink is preferably −10° C. or below.

The ink used in this embodiment has high viscosity with viscosity of 10 to 500 mPa·s at 25° C. and surface tension of 20 to 40 mN/m. It is preferable that the ink has viscosity of 10 to 500 mPa·s at 30° C., however, viscosity of 15 to 500 mPa·s is more preferable to obtain high quality images. The ink having low viscosity would blur on the recording medium to thereby deteriorate the quality of recorded images. The ink having viscosity over 500 mPa·s would fail to obtain smoothness of images. Accordingly, the optimum viscosity for obtaining stable image quality is 15 to 500 mPa·s.

Further, preferably, the ink has viscosity of 3 to 30 mPa·s at 60° C., more preferably 3 to 20 mPa·s. The ink having viscosity of 3 below mPa·s would cause problems such as a failure of precisely placing the ink when jetting the ink at high speed, and the ink having viscosity over 30 mPa·s would result in deterioration of jetting property.

Next, operations of the embodiment will be explained.

In the embodiment, the carriage3mounting the recording heads4,4. . . are on standby above the light shielding unit23provided at the home position region X excluding the time of image recording and head maintenance operation. Each light shielding cap24provided on the light shielding unit23covers each nozzle face6of the recording heads4,4. . . to protect the nozzle faces6,6. . . from irradiation with light such as ultraviolet rays.

After signals for performing the recording operation are input from the input section36, the control section35controls the carriage drive mechanism33to move the recording heads4,4. . . to the recording region Y. At this time, the control section35moves the light shielding unit23downward to remove the light shielding caps24,24. . . from the recording heads4,4. . . .

When the carriage3reached to a predetermined position in the recording region Y, the control section35drives the carriage3to reciprocatingly move the recording heads4,4. . . in the main scanning direction A while moving the recording medium P in the sub scanning direction by the recording medium carrying mechanism34. At this time, the control section35activates the recording heads4,4. . . according to the input information and the predetermined image information from the input section36, to thereby jet required colors of inks from the nozzles5,5. . . . Further, the control section35controls the UV irradiation device7,7. . . to irradiate the ink jetted on the recording medium P with ultraviolet rays, thereby curing and fixing the ink onto the recording medium P to form an image.

Next, the control section35controls the carriage drive mechanism33to move the recording heads4,4. . . along the carriage rail2to the maintenance region Z.

When the recording heads4,4. . . reached to a predetermined position, the control section35moves the maintenance unit9upward, thereby making each suction cap10on the maintenance unit9cover and seal each nozzle face6of the recording heads4,4. . . . Thereafter, the control section35activates the suction pumps12,12. . . to add negative pressure to the inside of the suction caps10,10. . . , and suctions the ink in the nozzles5,5. . . . When the ink suctioned from the nozzles5,5. . . contacts an absorbing material (not shown) provided inside of each suction cap10to face the nozzle5, the ink is absorbed into the absorbing material. The ink absorbed is fed through the ink communicating tube11to the waste ink tank13to be stored therein.

After the completion of the absorbing operation, the control section35moves the maintenance unit9downward once, thereby the suction caps10,10. . . are separated from the nozzle faces6,6. . . .

Thereafter, the control section35moves the carriage3to the position above the ink absorbing mechanism14. When the recording heads4,4. . . mounted on the carriage3reached to the position corresponding to the absorbing member16of the ink absorbing mechanism14, the control section35moves the maintenance unit9upward to make the absorbing member16which is crossed over between the feed roller17and the winding roller18of the ink absorbing mechanism14contact with the nozzle faces6,6. . . of the recording heads4,4. . . . Thus, the ink adhered to the nozzle faces6,6. . . is absorbed in the absorbing member16. Then, the control section35activates the recording heads4,4. . . to purge ink residue from the all nozzles5,5. . . onto the absorbing member16. After the completion of absorbing the ink on the nozzle faces6,6. . . by the absorbing member16and the purging operation, the control section35moves the maintenance unit9downward to separate the recording heads4,4. . . and the absorbing member16of the ink absorbing mechanism14. When the recording heads4,4. . . are sufficiently separated from the absorbing member16, the control section35controls the roller drive mechanism37of the ink absorbing mechanism14to rotate the feed roller17and the winding roller18, thereby feeding the absorbing member16from the feed roller17to sequentially carry the ink adhered portion in a direction where the winding roller18is arranged. At this time, the control section35controls the UV irradiation section22to make the UV light source21irradiate the absorbing member16with a small amount of ultraviolet rays, thereby the absorbing member16is wound by the winding roller18while the ink adhered to the absorbing member16being sequentially cured until the absorbing member16with no ink adhered thereto is positioned between the guide rollers19aand19b.

The maintenance operation of the recording heads4,4. . . is then completed, and the inside of the nozzles5,5. . . recovers a good condition for performing image recording again.

Next, the control section35moves the wipe unit25downward to the position where the absorbing member27which is crossed over between the feed roller28and the winding roller29of the wipe unit25contacts with the suction caps10,10. . . . When the absorbing member27contacts with the suction caps10,10. . . , the ink adhered to the suction caps10,10. . . is absorbed into the absorbing member27. After the completion of the ink absorbing and removing operations, the control section35moves the wipe unit25upward to separate the absorbing member27from the suction caps10,10. . . , and controls the roller drive mechanism38of the wipe unit25to rotate the feed roller28and the winding roller29, thereby feeding the absorbing member27from the feed roller28to sequentially carry the ink adhered portion in a direction where the winding roller29is arranged. At this time, the control section35controls the UV irradiation section32to make the UV light source31irradiate the absorbing member27with ultraviolet rays, therefore, the absorbing member27is wound by the winding roller29while the ink adhered to the absorbing member27being sequentially cured until the absorbing member27with no ink adhered thereto is positioned between the guide rollers30aand30b.

Accordingly, the ink adhered to the suction caps10,10. . . is removed, enabling the suction caps10,10. . . to contact with the nozzle faces of the recording heads and to recover an appropriate condition for performing ink suction operation.

Next, the control section35drives the carriage3to move it to the position above the platen8. Then, the control section35moves the wipe unit25downward to the position where the absorbing member27of the wipe unit25contacts with the upper surface of the platen8. Thereafter, the control section35moves the carriage3in the main scanning direction A to slide the absorbing member27on the platen8, thereby absorbing and removing the ink adhered to the platen8.

Accordingly, the platen8recovers an appropriate condition for image recording.

After the completion of absorbing and removing the ink adhered to the platen8by the wipe unit25, the control section35moves the wipe unit25upward to separate the absorbing member27from the platen8, and also rotates the feed roller28and the winding roller29by controlling the roller drive mechanism38of the wipe unit25, thereby feeding the absorbing member27from the feed roller28to sequentially carry the ink adhered portion in a direction where the winding roller29is arranged. At this time, the control section35controls the UV irradiation section32to make the UV light source31irradiate the absorbing member27with ultraviolet rays, thereby the absorbing member27is wound by the winding roller29while the ink adhered to the absorbing member27being sequentially cured until the absorbing member27with no ink adhered thereto is positioned between the guide rollers30aand30b.

Accordingly, in this embodiment, since the absorbing member of the ink absorbing mechanism formed with high density fibers having extra fine thickness is used for wiping the nozzle faces6,6. . . of the recording heads4,4. . . , the ink adhered to the nozzle faces6,6. . . can appropriately be absorbed and removed even in the case of using the ink with high viscosity for image recording.

Purging ink residue onto the absorbing member16is successful in saving space in the apparatus because an additional space for purging ink residue is not required. Further, since ink residue purged is absorbed into the absorbing member16, and the portion of the absorbing member16on which the ink residue adhered is wound, a mechanism for suctioning ink is not required, enabling to simplify the configuration of the apparatus and reduce the cost for manufacturing the apparatuses.

In this embodiment, after purging ink residue onto the absorbing member16, the ink is cured by irradiation with ultraviolet rays, so that there is less possibility that the ink may readhere to some other portions even while exchanging the absorbing member16or the like. Therefore, the maintenance of the ink absorbing mechanism14can easily be performed.

Further, in this embodiment, the absorbing member27of the wipe unit25formed with high density fibers having extra fine thickness is used for absorbing the ink adhered to the platen8and the suction caps10,10. . . , so that the ink can appropriately be removed even in the case of using the ink with high viscosity for image recording. Therefore, the platen8is prevented from being damaged caused by the ink fixed thereon, enabling to carry the recording medium P smoothly. Also, deterioration of the contact between the suction caps10,10. . . and the nozzle faces6,6. . . of the recording heads4,4. . . caused by the ink fixed onto the suction caps10,10. . . can be prevented, enabling to normally perform the maintenance operation.

Further, in this embodiment, after absorbing the ink adhered to the platen8and the suction caps10,10. . . by the absorbing member27, the absorbing member27is irradiated with ultraviolet rays to cure the ink absorbed therein, so that there is less possibility that the ink may readhere to some other portion even while exchanging the absorbing member27or the like. Therefore, the maintenance of the wipe unit25per se can easily be performed.

In this embodiment, the wipe unit25is provided only on the side of the maintenance region Z of the carriage3, however, the wipe unit25may be provided on both sides of the carriage3. In this case, the wipe unit25on the side of the maintenance region Z removes the ink adhered to the platen8and the maintenance unit9, and another wipe unit25on the side of the home position region X removes the ink adhered to the light shielding caps24,24. . . of the light shielding unit23.

Further, in this embodiment, the configuration is such that both of the ink absorbing mechanism14and the wipe unit25are provided, however, only one of them may be provided.

As the timing of winding the absorbing members16and27and ultraviolet ray irradiation, after the ink absorbing and removing operations by the ink absorbing mechanism14and the wipe unit25, ultraviolet rays may be radiated while winding the absorbing members16and27, or the absorbing members16and27may be wound after curing the ink by irradiation with ultraviolet rays.

The entire disclosure of Japanese Patent Application Nos. Tokugan 2003-120056 and Tokugan 2003-120067 which were filed on Apr. 24, 2003, including specification, claims, drawings and summary are incorporated herein by reference in its entirety.