JP2000168062A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer in which a film forming means requiring replacement upon elapsing a predetermined time is integrated with a sheet feeding means in order to reduce the size and to decrease the number of parts and the timing for supplying coating agent (or the timing for replacing the film forming means) can be determined easily. SOLUTION: A maintenance unit 14 for an ink jet head 2 is fixed removably to a printer body 15. The maintenance unit 14 has a hollow casing 21 which contains means 22 for forming a coating film by applying an ink repellent coating agent onto an intermediate transfer belt 3 after a color image is transferred onto a recording sheet P, and means 24 for drawing a new ink absorbing maintenance sheet 23 between the nozzle face of the ink jet head 2 and the transfer face 3a of the intermediate transfer belt 3 and collecting the maintenance sheet 23 upon finishing maintenance operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer which forms an image on a recording medium by ejecting ink droplets on the intermediate transfer medium to form an intermediate transfer image and transferring the image to a recording medium. About.

[0002]

2. Description of the Related Art In an ink-jet printer as described above, since air bubbles or solids are liable to be mixed into nozzles of an ink-jet head to cause jetting failure, ink droplets are ejected from nozzles of the ink-jet head at power-on or at predetermined intervals. It is necessary to perform a maintenance operation such as a purge operation for forcibly discharging the ink droplets together with the unnecessary matter and a wiping operation for wiping the ink droplets adhered to the nozzle surface. For example, when performing a maintenance process on an inkjet head that can be moved by a carriage, after moving to a maintenance position different from the recording operation, a purge operation and a wipe operation are performed using an appropriate maintenance mechanism. Is common.

On the other hand, as an ink jet printer, an ink image is formed on an intermediate transfer medium using a long head,
A line-type ink jet printer that transfers this to recording paper is known. In such a type, when performing the above-described maintenance processing, a maintenance sheet having a wide width and having an ink absorbing property faces a nozzle surface. It is necessary to perform a purge operation and a wipe operation.

However, in such an ink-jet printer, as a result of employing a long head having a long width,
If the maintenance process is performed by moving to the maintenance position, a very large space for moving the maintenance sheet is required. Therefore, it is against the demand for downsizing the ink jet printer. In addition, if a special mechanism is employed without using a maintenance sheet, the structure of the ink jet printer becomes complicated and causes an increase in cost.

[0005] Therefore, the applicant has previously proposed an ink jet printer having a relatively simple structure and capable of performing a simple maintenance process and maintaining good recording performance regardless of the size of the ink jet head. An application has been made in which a sheet is integrated with at least a supply member and a winding member thereof to form a maintenance unit, and the maintenance unit is detachable from a printer main body (Japanese Patent Application No. 10-279).
No. 014).

In such a case, a coating agent having ink repellency, such as silicone oil, is used to enhance the releasability of the ink attached to the intermediate transfer medium.
It is also known that a coating agent applying unit for forming a coating film by applying the intermediate transfer image after transferring the image onto a recording medium is provided integrally with an ink discharge unit from which purged ink droplets are discharged. .

[0007]

In the apparatus provided with such a coating agent applying means, when the coating agent runs out, it is necessary to replace the coating applying means in order to replenish the coating agent. As described above, since the ink discharge unit is integrated with the ink discharge unit, the ink discharge unit does not need to be replaced, but needs to be replaced together.

In view of this, it is conceivable that the coating application means is separated from the ink discharge section to be unitized to facilitate replacement. However, if only the coating agent application means is unitized to form a coating agent application unit. However, the number of units that need to be replaced increases, which causes an increase in the number of parts. In addition, the volume occupied by the units in the ink jet printer increases, which is disadvantageous in downsizing. In addition, if such a unit is used, it is difficult to grasp the amount of consumption of the coating agent, and it is difficult to determine the time to supply the coating agent.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the size reduction and the number of parts are reduced by integrating a film forming means and a sheet feeding means which need to be replaced after a certain period of time. In addition to being advantageous in planning,
It is an object of the present invention to provide an ink jet printer that can easily determine a supply time of a coating agent (or a replacement time of a film forming unit) that is difficult to determine.

[0010]

According to a first aspect of the present invention, there is provided an ink jet head having a plurality of nozzles for ejecting ink droplets, and an intermediate head for forming an intermediate transfer image by the ink droplets ejected by the ink jet head. A transfer medium, and an inkjet printer including a transfer unit for transferring an intermediate transfer image formed on the intermediate transfer medium to a recording medium, wherein the intermediate transfer image is transferred to a recording medium, A film forming means for forming a coating film by applying a coating agent having ink repellency onto a transfer medium, a sheet storage unit for storing a new maintenance sheet having ink absorption properties, and a sheet storage unit supplied from the sheet storage unit after maintenance. The sheet storage unit for storing the maintenance sheet and the maintenance sheet are interposed between the inkjet head and the intermediate storage. And a sheet feeding unit having a pull-out member to draw between the medium and the film forming unit and the sheet feed means is that the maintenance unit is housed in a casing is configured.

According to the first aspect of the present invention, the film forming means and the sheet feeding means, which need to be replaced after a certain period of time, are housed in the same casing to be integrated into a maintenance unit. ing. Therefore, the film forming means and the sheet feeding means are attached at the same time,
It is removed.

According to a second aspect of the present invention, in the ink jet printer of the first aspect, the maintenance unit includes:
It is detachably attached to the printer body.

According to the second aspect of the present invention, the maintenance unit is detachably mounted on the printer body, and the unit can be easily replaced after a certain period of time.

According to a third aspect of the present invention, in the ink jet printer according to the first or second aspect, the ink jet head is further movably movable in a direction perpendicular to the surface of the intermediate transfer medium, so that the nozzle face of the ink jet head can be moved. An interval switching unit for switching an interval with the surface of the intermediate transfer medium in a plurality of stages; and an engaging member which is detachably engaged with the pull-out member. With the gap between the transfer medium and the surface of the transfer medium widened, the engagement member is engaged with the draw-out member, and the maintenance sheet is drawn out, so that the space between the nozzle surface of the inkjet head and the surface of the intermediate transfer medium is formed. The nozzle of the ink jet head is moved by the sheet pulling means to be positioned and the gap switching means. In a state where the interval between the surface and the surface of the intermediate transfer medium is widened and the maintenance sheet is pulled out by the pull-out member, the ink jet head performs a purge operation of ejecting ink droplets, and the ink jet head is ejected by the space switching means. And a control unit for narrowing an interval between the nozzle surface of the head and the surface of the intermediate transfer medium and pressing the nozzle surface of the inkjet head against the maintenance sheet to perform a wiping operation.

According to the third aspect of the present invention, the interval between the nozzle surface of the ink jet head and the surface of the intermediate transfer medium can be widened by the interval switching means. Is engaged with the pull-out member, and the maintenance sheet is pulled out and positioned between the nozzle surface of the inkjet head and the surface of the intermediate transfer medium. Then, in a state where the maintenance sheet is pulled out by the pull-out member, the ink jet head performs a purging operation of ejecting ink droplets, and the interval switching means performs the nozzle surface of the ink jet head and the surface of the intermediate transfer medium. , The nozzle surface of the inkjet head is pressed against the maintenance sheet to perform a wiping operation. This series of maintenance operations is efficiently controlled by the control means.

According to a fourth aspect of the present invention, in the ink jet printer of the first aspect, the control unit alternately moves the maintenance sheet by the sheet feeding unit and the movement of the maintenance sheet by the sheet feeding unit during a wiping operation. Is to be repeated.

According to the fourth aspect of the invention, when the maintenance processing is started and the maintenance sheet is set,
The vertical movement of the ink jet head is performed in the vertical direction of the recording surface by the interval switching means, and the maintenance sheet is pulled out alternately by the sheet pulling means, and the ink droplets attached to the nozzle surface of the ink jet head are The synergistic effect of the vertical movement of the inkjet head and the horizontal movement of the maintenance sheet facilitates wiping by the maintenance sheet, and more efficiently removes ink droplets.

According to a fifth aspect of the present invention, in the ink jet printer according to any one of the first to fourth aspects, the sheet feeding means pulls out the sheet from the sheet storage section in a state where the maintenance sheet is pulled out by the pulling member. The part up to the member is located on the intermediate transfer medium side, and the part from the drawer member to the sheet storage unit is located on the inkjet head side.

According to the fifth aspect of the present invention, when the maintenance sheet is pulled out by the draw-out member and the maintenance sheet is started to be pulled out, the maintenance sheet pulled out from the sheet storage section is replaced with the intermediate transfer medium. After moving on the transfer surface side, the moving direction is reversed by the drawer member and the arrangement is changed upward, so that the nozzle surface side of the inkjet head is moved from the drawer member to the sheet storage section. Therefore, even when unnecessary ink droplets are ejected from the nozzles of the ink jet head and adhere to the maintenance sheet, the maintenance unit is thereafter transferred to the sheet storage unit side, so that there is no risk of soiling the surface of the intermediate transfer medium. .

According to a sixth aspect of the present invention, in the ink jet printer according to any one of the first to fifth aspects, the film forming means has a coating agent in an amount corresponding to a length of a maintenance sheet of the sheet feeding means. is there.

According to the sixth aspect of the present invention, since the film forming means has an amount of the coating agent corresponding to the length of the maintenance sheet of the sheet feeding means, the maintenance sheet of the sheet feeding means is used and exchanged. Is required, and the time when the coating agent of the film forming means is consumed and the replenishment is required substantially coincides with each other, so that it is relatively easy to determine the replacement time. It is possible to replace the coating agent of the film forming means, for which it is difficult to determine the replenishing time only by making a determination, without having to determine the replenishing time, while the coating agent is almost consumed.

According to a seventh aspect of the present invention, in the ink jet printer according to any one of the first to sixth aspects, the ink droplets are ink droplets of heat-melted ink.

According to the seventh aspect of the present invention, the heat-melted ink is used as the ink, and the recording medium has a strong adhesion to the intermediate transfer medium and a large separation load, but the coating agent is applied to the surface of the intermediate transfer medium. Thus, the separability of the recording medium from the intermediate transfer medium is improved.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an ink jet head printer according to the present invention, in which
FIG. 10 is an explanatory view showing a state in which the purging operation is performed by lifting the apparatus up to the position shown in FIG. As shown in FIG. 1, an inkjet head printer 1 has a plurality of inkjet heads 2 each having a plurality of nozzles for ejecting ink droplets of hot melt ink (hot melt ink). A color image (intermediate transfer image) is formed by ejecting ink droplets for each color to the intermediate transfer belt 3 as a color image, and finally the color image formed on the intermediate transfer belt 3 is transferred to the recording paper P. Is configured.

The ink-jet head 2 includes, as heads for each color, a yellow head 2a for ejecting yellow ink, a magenta head 2b for ejecting magenta ink, a cyan head 2c for ejecting cyan ink,
And black head 2d for ejecting black ink
Is provided. Each of the heads 2a to 2d is filled with ink of a corresponding color into a plurality of ink chambers (not shown), and transfers ink from a plurality of nozzles formed on the lower nozzle surface to a transfer surface which is an outer surface of the intermediate transfer belt 3. Injected toward 3a. The ink jet head 2 is a line type head whose longitudinal direction is a direction perpendicular to the paper surface of FIG. 1, and a number of nozzles are arranged along the longitudinal direction.

Further, the ink jet head 2 is moved by an interval switching means (not shown) so as to be able to advance and retreat in the vertical direction with respect to the transfer surface 3a of the intermediate transfer belt 3, so that the nozzle surface thereof and the intermediate transfer belt 3 can be moved. The interval with the transfer surface 3a (front surface) is configured to be switchable and set in a plurality of steps, so that the inkjet head 2 can be moved to a predetermined position according to the operation. Here, by switching the interval by the interval switching means, the ink jet head 2 can be moved to the first position (at which the nozzle surface of the ink jet head 2 is separated from the intermediate transfer belt 3 at least at the time of recording standby and at the time of a purge operation described later). 1 and 6), and at the time of the recording operation and the later-described wiping operation, the intermediate transfer belt 3
It is necessary to be able to move to a second position (see FIGS. 4 and 5) in which the nozzle surface of the inkjet head 2 is close to the transfer surface 3a of FIG. In order to determine the position of the nozzle surface of the inkjet head 2 in the direction perpendicular to the transfer surface 3a of the intermediate transfer belt 3 (that is, the interval between them) with high accuracy, a position sensor may be provided in the inkjet head 2. Specifically, for example, a light beam is applied to the transfer surface 3a of the intermediate transfer belt 3 to measure the level of the reflected light, or a position sensor that can determine the position by providing a mechanical stopper at a predetermined position is provided. be able to.

The intermediate transfer belt 3 is an endless belt made of a flexible material that does not expand and contract, and is provided between a fixing roller 4 and a belt guide roller 5 that are provided at regular intervals. Are wound rotatably in a state where a predetermined tension is applied, and when traveling below the inkjet head 2 at a predetermined rotation speed, ink droplets are ejected from each nozzle, whereby the inkjet head 2 is rotated. A color image (intermediate transfer image) is formed by causing ink droplets ejected from the printer to adhere to the transfer surface 3a of the intermediate transfer belt 3. The intermediate transfer belt 3 travels near two ends of a portion where a color image is formed by the inkjet head 2 while being guided by two belt guide rollers 6 and 7.

The color image formed on the transfer surface 3a of the intermediate transfer belt 3 is sent out from a paper feed cassette 16 located below the intermediate transfer belt 3 by a paper feed rubber roller 17, and is fed to a paper path S. Is finally transferred to the recording paper P transported along. The paper cassette 16
Is a sheet receiving plate 16a that supports the stacked recording sheets P from below, a compression spring 16b that urges the sheet receiving plate 16a upward, and a recording sheet P of the uppermost layer is prevented from being accidentally removed. And a paper presser 16c for pressing from above.

The recording paper P sent out by the paper feed rubber roller 17 is first sandwiched between the pinch roller 9 provided in the paper path S and the paper feed rubber roller 10.
The intermediate image is guided from the intermediate transfer belt 3 to a transfer portion where a color image is transferred. Then, finally, the recording sheet P is pressed and sandwiched together with the intermediate transfer belt 3 by the fixing roller 4 and the pressure rubber roller 12, and the color image on the transfer surface 3a of the intermediate transfer belt 3 is recorded on the recording sheet P. Before being pressure-transferred to the recording paper P, the recording paper P is heated by the halogen lamp 11 housed in the paper heating roller 8 while being sandwiched between the paper heating roller 8 and the paper feeding rubber roller 10, and the color is formed by heating and melting ink. The transfer of the image is facilitated.

A separation pawl 13 is provided on the downstream side of the transfer portion formed by the fixing roller 4 and the pressure rubber roller 12 in the sheet conveying direction so as to be able to come into contact with and separate from the transfer surface 3a of the intermediate transfer belt 3. After the transfer to the sheet P is completed, the peeling pawl 13 moves to a position (see FIG. 6) in close contact with the transfer surface 3a of the intermediate transfer belt 3 to transfer the transferred recording sheet P after the transfer. The belt 3 is peeled off from the transfer surface 3a, and is discharged to an upper position along the paper path S. Thus, the recording paper P on which the desired color image has been transferred is obtained.

A maintenance unit 14 used for maintenance processing of the ink jet head 2 is provided near the belt guide roller 5 on the downstream side of the peeling nail 13 in the belt traveling direction and on the opposite side of the transfer portion. It is detachably attached to. Therefore, the user can replace the maintenance unit 14 as needed.

The maintenance unit 14 includes a casing 21 having a hollow shape, and a coating agent having ink repellency on the intermediate transfer belt 3 after transferring the color image onto the recording paper P inside the casing 21. Forming means 22 for applying a coating to form a coating film
And a new maintenance sheet 23 having ink absorbing properties
And a sheet feeder 24 that draws the sheet between the nozzle surface of the inkjet head 2 and the transfer surface 3a of the intermediate transfer belt 3 and collects the sheet after maintenance. Therefore,
The film forming unit 22 and the sheet feeding unit 24 for performing the maintenance process for obtaining excellent recording quality are housed in the casing 21 in a positional relationship such that the sheet feeding unit 24 is located on the upper side, and the maintenance unit 14 is It is configured. FIG. 1 shows a state in which the purging operation is being performed. Therefore, the maintenance sheet 23 is supplied from the inside of the casing 21 of the maintenance unit 14 through the space between the nozzle surface of the inkjet head 2 and the transfer surface 3 a of the intermediate transfer belt 3. It has been pulled out to around 4.

The film forming means 22 has an application roller 25 which is an application member for applying a coating agent (for example, silicone oil), and the application roller 25 is moved under the casing 21 by a moving means (not shown) only when necessary. It is configured so that it can be moved toward the side opening 21a and pressed against the transfer surface 3a of the intermediate transfer belt 3;
In a state where the application roller 25 is pressed against the transfer surface 3a of the intermediate transfer belt 3, the transfer surface 3a of the intermediate transfer belt 3 is transferred onto the transfer surface 3a of the intermediate transfer belt 3 through the circumferential surface of the application roller 25. A coating agent for improving the separability of the recording paper P is applied. The coating agent may be impregnated into the surface layer of the application roller 25, or may be stored in a tank, and may be supplied to the application roller 25 from the tank as appropriate. Further, the coating member is not limited to the roller shape, but may be a sheet-shaped coating member, and the shape can be appropriately changed according to the arrangement space in the casing 21 and the like.

The sheet feeding means 24 is a new ink-absorbing maintenance sheet 23 for wiping ink droplets adhered to the nozzle surface of the ink jet head 2.
And a sheet storage roller 27 that is disposed above the sheet storage roller 26 and stores the dirty maintenance sheet 23 supplied from the sheet storage roller 26 and subjected to maintenance processing. 1 and a pull-out roller 28 as a pull-out member drawn out between the nozzle surface of the inkjet head 2 and the transfer surface 3a of the intermediate transfer belt 3, and when pulling out the maintenance sheet 23 by the pull-out roller 28. And a sheet guide shaft 29 for guiding the maintenance sheet 23. Although not specifically shown, a drive motor (not shown) provided in the casing 21 or on the printer body 15 side is linked to the sheet storage roller 27, and
In the state where the maintenance sheet 23 is pulled out at 8,
By rotating the sheet storage roller 27 to take up and store the maintenance sheet 23, a new maintenance sheet 23 can be sequentially pulled out from the sheet storage roller 26.

Here, as the material of the maintenance sheet 23, not only paper excellent in ink absorbency but also synthetic resin material can be used. In this case, if an appropriate synthetic resin material is selected, it is possible to increase the ink absorbency, maintain the strength, reduce the cost, and obtain an optimum maintenance sheet according to the purpose. For example, a PET film can be used as a material of the maintenance sheet, and if the PET film is used, the maintenance sheet can be thinned, so that a longer maintenance sheet can be stored and wound up in the maintenance unit 14. . Further, in order to enhance the ink absorbency, it is possible to provide a large number of fine holes in the PET film or to knit the PET film.

As shown in detail in FIG. 2, the pull-out roller 28 is normally
Are housed in a state where they are positioned in the accommodating concave portion 21b of the casing 21 with the intermediate portion wound around. In this state, engaging recesses 30a, which are one ends of the lifting links 30 rotatably supported on the rotating shaft 30b in the casing 21, are detachably engaged with both ends of the shaft portion 28a of the drawer roller 28. Have been. Therefore, when the lifting link 30 is rotated in the counterclockwise direction about the rotation shaft 30b, the drawer roller 28 is lifted almost right above the storage recess 21b, and is set to a drawable position (see FIG. 3). In this drawable position, the engaging recess 30a of the lifting link 30 is opened toward the guide passage side of the guide rail 37, which will be described later, so that the draw roller 28 can be sent out to the guide rail 37 side. Is done.

On the other hand, the maintenance sheet 23 is attached to the nozzle body of the ink jet head 2 and the intermediate transfer belt 3 via the pull-out roller 28 on the printer body 15.
Withdrawal means 31 for drawing out between the transfer surface 3a and the transfer surface 3a
Is provided. The sheet pulling means 31 has an engaging member 32 which is engaged with the pulling roller 28 so as to be detachable. The engaging member 32 is provided on the shaft 2 of the pull-out roller 28.
8a and a base attached to a timing belt 34 extending rearward from the front end engaging portion 32a and rotatably wound around the timing pulley 33 with a fixing screw 35. And an end 32b.
The tip engaging portion 32a has a shape having a concave groove opened downward, and can be advanced to the pull-out position as shown by a solid line in FIG. Shaft 2 of the drawn-out roller 28
8a so that it can be pulled out.

A cam member 36 is provided between the maintenance unit 14 and the timing pulley 33 so as to be rotatable about a cam shaft 36a. The cam member 36 has a cam operating portion 36b which comes into contact with a contacted portion 30c which is the other end of the lifting link 30 exposed to the printer main body 15 through the upper opening 21c of the casing 21. This cam member 36 is not specifically shown,
It is configured to be driven to rotate by a motor via a gear mechanism or to be driven to rotate by a solenoid, and the cam operating portion 36b of the cam member 36 is in contact with the contacted portion 30c of the lifting link 30. The cam member 36
Is rotated clockwise, thereby rotating the lifting link 30 in a counterclockwise direction to move the pull-out roller 28 from the inside of the storage recess 21b to a pull-out position almost directly above it.

The lifting link 30 is rotated as shown in FIG. 3 by previously advancing the distal end engaging portion 32a of the engaging member 32 to a position where it can be pulled out just above the storage recess 21b. Then, the shaft portion 28a of the pull-out roller 28 is detachably engaged with the distal end engaging portion 32a while being engaged and supported by the engaging concave portion 30a of the lifting link 30, and the engaging member 32 is retracted as it is. As a result, the drawer roller 28 does not fall,
The maintenance sheet 23 can be pulled out to a predetermined position by being guided and moved by the guide rail 37 on the side. The casing 21 is also provided between the guide rail 37 on the printer body 15 side and the storage recess 21b.
A guide portion 21d is formed to guide the drawer roller 28 when the drawer roller 28 moves in and out.

In this way, at the start of the maintenance process, the ink jet head 2 is moved to the first upper position, and then the maintenance sheet 23 is pulled out by the pull-out roller 28, whereby the ink jet head 2
Since the maintenance sheet 23 can be spread and arranged below the nozzle surface, even if a long line-type head is employed, the maintenance processing is performed at the same position as the recording area without defining the maintenance area in the horizontal direction. (Purge operation and wipe operation) can be performed, which is advantageous in saving space and simplifying the configuration. Further, since the maintenance unit 14 for storing the maintenance sheet 23 (sheet feeding means 24) together with the film forming means 22 is detachable from the printer main body 15, the convenience is further improved.

In a state where the interval between the two nozzle surfaces of the ink jet head and the transfer surface 3a of the intermediate transfer belt 3 is widened by the interval switching means, the leading end engaging portion 32a of the engaging member 32 is pulled out. The maintenance sheet 23 is engaged with the shaft 28 a of the roller 28, and the maintenance sheet 23 is pulled out and positioned between the nozzle surface of the inkjet head 2 and the transfer surface 3 a of the intermediate transfer belt 3. The ink jet head 2 ejects ink in a state in which the ink jet head 2 is ejected, and the distance between the nozzle surface of the ink jet head 2 and the transfer surface 3a of the intermediate transfer belt 3 is reduced by the space switching means. Wiping operation for pressing the nozzle surface of the nozzle against the maintenance sheet 23 It is carried out by being controlled by control means not shown.

By the way, the film forming means 22 has an amount of coating agent corresponding to the length of the maintenance sheet 23 of the sheet feeding means 24.
The maintenance process is repeatedly performed, and the time when the maintenance sheet 23 of the sheet feeding means 24 is used and needs to be replaced substantially coincides with the time when the coating agent of the film forming means 22 is consumed and needs to be replenished. Is configured. That is, when the maintenance sheet 23 wound on the sheet storage roller 26 is wound up by the sheet storage roller 27 and almost disappears, the coating agent of the film forming means 22 is almost consumed. Therefore, the replacement time is determined only for the maintenance sheet 23 of the sheet feeding means 24, whose replacement time is relatively easy to determine, and the supply time is determined for the coating agent of the film forming means 22 for which the determination of the supply time is difficult. Even if it is not necessary, the replacement can be performed while the coating agent is almost consumed, so that the coating agent is not wasted.

Next, the maintenance process performed in the ink jet printer 1 will be described. The maintenance process is performed when the power of the inkjet printer 1 is turned on or when a predetermined time has elapsed.

When the maintenance process is started, first,
When the inkjet head 2 is moved upward,
The first position (see FIG. 1) is set, and the maintenance sheet 2
A vertical spacing is ensured for drawing 3. Therefore, the nozzle surface of the inkjet head 2 is set so as to be located above the uppermost portion of the passage when the draw-out roller 28 is pulled out. At this time, the pressure rubber roller 12, the application roller 25, and the peeling pawl 13 are separated from the transfer surface 3a of the intermediate transfer belt 3.

The first position shown in FIG. 1 is a position where a purge operation is performed, and a position at the time of recording standby in order to avoid an influence on the intermediate transfer belt 3 due to heat generated from the ink jet head 2. It is also said.

Next, as shown in FIG. 3, the lifting link 30 is rotated to lift the pull-out roller 28 to a position where the pull-out roller 28 can be pulled out to engage with the distal end engaging portion 32a of the engaging member 32. Is rotated to move the engaging member 32 rightward in FIG. 3, thereby pulling out the pull-out roller 28 along the guide rail 37. As means for moving the pull-out roller 28 to the right in FIG. 3, other well-known means can be used in addition to the means using the timing belt 34 described above. For example, the drawer roller 28 can be engaged with the carriage in a detachable manner, and can be moved while being guided by a guide rail provided along the moving direction.

By moving the pull-out roller 28 in this manner, the state in which the maintenance sheet 23 is accommodated in the casing 21 of the maintenance unit 14 is changed to the transfer surface 3a of the intermediate transfer belt 3 as shown in FIG.
And between the nozzle surface of the inkjet head 2 and the entire nozzle surface of the inkjet head 2.
The state in which the maintenance sheet 23 is disposed below the lower part is obtained. As a result, when ink droplets are ejected from a plurality of nozzles on the nozzle surface of the inkjet head 2, the ink droplets are absorbed by the maintenance sheet 23 without adhering to the transfer surface 3 a of the intermediate transfer belt 3. Will be done.

After the maintenance sheet 23 is pulled out as shown in FIG. 1, a purge operation is performed by ejecting ink droplets from the ink jet head 2. At the time of this purging operation, the ink droplets ejected from the plurality of nozzles of the inkjet head 2 are quickly absorbed by the maintenance sheet 23. In this purging operation, if foreign matter such as air bubbles or dust enters the nozzles of the inkjet head 2, it causes ejection failure. Therefore, the foreign matter is forcibly ejected from the nozzles together with the ink droplets, and a good ejection state is obtained. This is one of the maintenance processes performed for holding.

Next, in order to perform a wiping operation on the nozzle surface of the ink jet head 2, the ink jet head 2 is moved downward in the vertical direction, and as shown in FIG.
This is the second position. At this position, the nozzle surface of the inkjet head 2 is pressed against the surface of the maintenance sheet 23 with a certain amount of pressure. Also at this time, the pressure rubber roller 12, the application roller 25
And the release pawl 13 is provided on the transfer surface 3 a of the intermediate transfer belt 3.
From the state.

Then, by rotating and driving the sheet storage roller 27 to take up the maintenance sheet 23, the nozzle surface of the ink jet head 2 is wiped off by the new maintenance sheet 23 which is successively transferred, and the wiping operation is performed. In the wiping operation, when the above-described purging operation is performed, the ejected ink droplets are attached to the nozzle surface of the inkjet head 2. Therefore, when the recording operation by the inkjet head 2 is performed, the intermediate transfer is performed. This is one of the maintenance processes performed to wipe off the transfer surface 3a of the belt 3 in advance so as not to stain it.

At the time of the wiping operation, the maintenance sheet 23 is transported from the sheet storage roller 26 to the sheet storage roller 27 via the pull-out roller 28 as the sheet storage roller 27 is driven to rotate. That is, inside the maintenance unit 14 (casing 21), the sheet storage roller 26 is disposed on the lower side and the sheet storage roller 27 is disposed on the upper side. After being transferred on the side of the transfer surface 3a, the transfer direction is changed at the position of the pull-out roller 28, and the transfer is performed on the side of the nozzle surface of the inkjet head 2. As a result, after wiping the ink droplets on the nozzle surface of the inkjet head 2, the maintenance sheet 23 does not pass through the transfer surface 3 a side of the intermediate transfer belt 3 and is immediately wound on the sheet storage roller 27. ,
There is no possibility that the transfer surface 3a of the intermediate transfer belt 3 will be stained after the wiping operation.

When the nozzle surface of the inkjet head 2 is cleaned by performing the wiping operation for a predetermined time in this manner, the wiping operation is terminated, and the inkjet head 2 is moved to the second position by the interval switching means (not shown). (See FIG. 5). Specifically, the inkjet head 2 is returned to the original upper position (see FIG. 1),
The transfer of the new maintenance sheet 23 is stopped, and the drawer roller 28 is moved to the left so as to return the drawer roller 28 together with the maintenance sheet 23 to the original position in the maintenance unit 14. Thereby, a series of maintenance processing is completed, and thereafter, it is possible to shift to the recording operation by the inkjet head 2.

Subsequently, a recording operation is performed. That is, while rotating the intermediate transfer belt 3, a color image is formed on the transfer surface 3 a of the intermediate transfer belt 3 by ink droplets ejected from the inkjet head 2 on the transfer surface 3 a of the intermediate transfer belt 3 based on print data. (Intermediate transfer image) is formed. Prior to the recording operation, the application roller 25
Is pressed against the transfer surface 3a of the intermediate transfer belt 3, and the coating agent is applied in advance. Further, during the recording operation in which the ink droplets are ejected from the nozzles of the ink jet head 2, similarly to the case described above, the pressure rubber roller 1 is used.
2. The application roller 25 and the peeling nail 13 are separated from the intermediate transfer belt 3.

When the recording operation is completed, the recording paper P is sent to the standby position. At the same time, the halogen lamp 11 is turned on, and the paper heating roller 10 is heated.

Then, the transfer surface 3a of the intermediate transfer belt 3
In synchronization with the timing at which the color image formed thereon passes between the fixing roller 4 and the pressure rubber roller 12, the recording paper P warmed up between them is fed, and the recording paper P is transferred to the intermediate transfer belt 3. The color image formed on the transfer surface 3a of the intermediate transfer belt 3 while being pressed against the transfer surface 3a is pressure-transferred to the recording paper P. At the same time, peeling nail 1
3 is brought into contact with the transfer surface 3a of the intermediate transfer belt 3,
The recording paper P on which the transfer is completed is peeled off from the transfer surface 3a of the intermediate transfer belt 3 by the peeling pawl 13. At this time, since the application roller 25 is pressed against the transfer surface 3a of the intermediate transfer belt 3, the coating agent is applied to the transfer surface 3a of the intermediate transfer bell 3, and the transfer surface of the next intermediate transfer belt 3 is transferred. This will prepare for the formation of a color image on 3a (see FIG. 6).

In the above embodiment, the wiping operation is performed while the ink jet head 2 is stopped at the second position. In addition, the ink jet head 2 is moved up and down by an interval switching means (not shown). At the first position shown in FIG. 1 and the second position shown in FIG.
It is also possible to perform the wiping operation while repeating the operation of alternately moving between the positions. Further, in conjunction with the vertical movement of the inkjet head 2, it is also possible to alternately repeat the forward transfer and the reverse transfer of the maintenance sheet 23 at a constant cycle. By doing so, the maintenance sheet 23 for the nozzle surface of the inkjet head 2
During the wiping operation, the wiping operation by the maintenance sheet 23 is performed while the vertical movement of the ink jet head 2 and the left and right movement of the maintenance sheet 23 are applied. Ink droplets are more easily wiped off.

[0058]

The present invention is embodied in the form described above, and has the following effects.

According to the first aspect of the present invention, the film forming means and the sheet feeding means are housed and integrated in the same casing,
Since one maintenance unit is used, it is advantageous in reducing the number of components and reducing the size by saving space. In addition, the film forming means and the sheet feeding means which need to be replaced after a certain period of time are used simultaneously. Can be attached and detached.

According to the second aspect of the present invention, since the maintenance unit is detachably mounted on the printer main body, the collection of the used maintenance sheet and the replenishment of the coating agent can be performed only by replacing the maintenance unit. , Can be easily performed at the same time, and is excellent in convenience.

According to a third aspect of the present invention, there is provided a purge method in which the gap between the nozzle surface of the ink jet head and the surface of the intermediate transfer medium is widened, and the ink jet head ejects ink droplets in a state where the maintenance sheet is drawn by the drawer member. An operation is performed, and control is performed by a control unit such that a distance between a nozzle surface of the inkjet head and a surface of the intermediate transfer medium is reduced, and a nozzle surface of the inkjet head is pressed against the maintenance sheet to perform a wiping operation. Therefore, a series of maintenance processes can be efficiently performed by the control unit.

According to the fourth aspect of the present invention, the vertical movement of the ink jet head in the vertical direction of the recording surface and the pulling-out operation of the maintenance sheet are alternately performed, so that the vertical movement of the ink jet head and the maintenance sheet are alternately performed. The horizontal movement of the can effectively wipe the nozzle surface of the inkjet head,
The maintenance sheet wiping performance is improved.

According to a fifth aspect of the present invention, when the maintenance sheet is pulled out and transferred, the surface of the intermediate transfer medium is first transferred, and then the arrangement is changed upward to transfer the nozzle surface of the ink jet head. Therefore, after the ink droplets on the nozzle surface of the inkjet head are wiped off by the maintenance sheet, the possibility that the ink droplets adhere to the surface of the intermediate transfer medium is eliminated, and the surface of the intermediate transfer medium is stained. And highly reliable maintenance processing becomes possible.

According to the sixth aspect of the present invention, since the film forming means has an amount of coating agent corresponding to the length of the maintenance sheet of the sheet feeding means, it is necessary to replace the maintenance sheet of the sheet feeding means. The timing and the time when the replenishment of the coating agent of the film forming means is required can be substantially matched, so that it is possible to simply replace the maintenance sheet and determine when it is necessary to replace them together without waste. it can.

According to the seventh aspect of the present invention, since the heat-melted ink is used as the ink, the adhesion of the recording medium to the intermediate transfer medium is strong and the separation load is large, but the coating agent is applied to the surface of the intermediate transfer medium. Thereby, the separability of the recording medium from the intermediate transfer medium can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state in which a purge operation is performed by lifting an inkjet head to an upper first position in an inkjet printer according to the present invention.

FIG. 2 is a detailed view of a main part near a maintenance unit during a recording operation in which a maintenance sheet is not pulled out.

FIG. 3 is a detailed view of a main part near a maintenance unit during a maintenance process of pulling out a maintenance sheet.

FIG. 4 is an explanatory diagram illustrating a state in which the inkjet head is lowered to a second lower position and a wiping operation of a nozzle surface of the inkjet head is performed in the printer.

FIG. 5 is an explanatory diagram showing a state in which, in the printer, a color image is formed by ejecting ink droplets onto a transfer surface of an intermediate transfer belt with an ink jet head at a lower second position.

FIG. 6 is an explanatory diagram showing a state in which, in the printer, a color image is formed on a transfer surface of an intermediate transfer belt by an inkjet head, and then the color image is transferred to recording paper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet printer 2 Ink jet head 3 Intermediate transfer belt 3a Transfer surface 4 Fixing roller 12 Pressure rubber roller 13 Peeling nail 14 Maintenance unit 15 Printer main body 16 Paper feed cassette 21 Casing 21a Storage recess 22 Film forming means 23 Maintenance sheet 24 Sheet feeding means 25 Coating roller 26 Sheet storage roller 27 Sheet storage roller 28 Sheet pull-out roller 30 Lifting link 31 Sheet pull-out means 32 Engaging member 36 Cam member 37 Guide rail P Recording paper

Claims (7)

[Claims] An inkjet head having a plurality of nozzles for ejecting ink droplets, an intermediate transfer medium on which an intermediate transfer image is formed by ink droplets ejected by the inkjet head, and an ink jet head formed on the intermediate transfer medium. Transfer means for transferring the intermediate transfer image to a recording medium, wherein the intermediate transfer image is transferred to a recording medium, and then a coating agent having ink repellency is applied to the intermediate transfer medium. A film forming unit for forming a film, a sheet storage unit for storing a new maintenance sheet having ink absorbing properties, a sheet storage unit for storing the maintenance sheet supplied from the sheet storage unit after maintenance, and the maintenance sheet, Sheet having drawer member drawn out between head and intermediate transfer medium Ri and means, an ink jet printer and the film forming unit and the sheet feed means, characterized in that the maintenance unit is housed in a casing is configured. 2. The ink jet printer according to claim 1, wherein said maintenance unit is detachably mounted on a printer main body. 3. The method according to claim 1, further comprising: moving the inkjet head in a direction perpendicular to the surface of the intermediate transfer medium so as to advance and retreat, and switching an interval between a nozzle surface of the inkjet head and the surface of the intermediate transfer medium in a plurality of steps. Means, and an engaging member which is detachably engaged with the drawer member, and wherein the distance between the nozzle surface of the ink jet head and the surface of the intermediate transfer medium is increased by the distance switching means. A sheet pull-out unit that engages the composite member with the pull-out member, pulls out the maintenance sheet, and positions the maintenance sheet between the nozzle surface of the ink-jet head and the surface of the intermediate transfer medium; The distance between the nozzle surface of the head and the surface of the intermediate transfer medium is increased and the maintenance sheet is removed. In a state in which the ink is ejected by the ejection member, the inkjet head performs a purge operation of ejecting ink droplets, and the interval switching unit reduces the interval between the nozzle surface of the inkjet head and the surface of the intermediate transfer medium. 3. A control means for performing a wiping operation by pressing a nozzle surface of the inkjet head against the maintenance sheet.
The ink-jet printer as described. 4. The ink jet printer according to claim 1, wherein said control means alternately repeats movement by said interval switching means and movement of said maintenance sheet by said sheet feeding means during a wiping operation. 5. The sheet feeding means, in a state where the maintenance sheet is pulled out by the drawer member, a portion from the sheet storage section to the sheet drawer member toward the intermediate transfer medium, and the sheet from the drawer member to the sheet. The inkjet printer according to any one of claims 1 to 4, wherein a portion up to a storage section is positioned on the inkjet head side. 6. The ink jet printer according to claim 1, wherein said film forming means has a coating agent in an amount corresponding to a length of a maintenance sheet of said sheet feeding means. 7. The ink jet printer according to claim 1, wherein the ink droplets are ink droplets of heat-melted ink.