JP2022122212A - Printing conveyance device - Google Patents

Abstract

To provide a printing conveyance device which can realize recording of high-quality images by reducing temperature irregularity on a conveyance belt conveying a medium to be recorded, and which is superior in cost performance.SOLUTION: A printing conveyance device includes: an endless metal belt which adsorbs and fixes a medium to be recorded; a suction member which adsorbs a medium to be recorded via the endless metal belt; a belt heating member for heating a surface of the endless metal belt; a negative pressure chamber which applies negative pressure to the suction member; an air exhaustion port for exhausting air inside the negative pressure chamber; and a printing unit which prints an image at a prescribed printing width in a direction that is substantially orthogonal to a conveyance direction for applying ink onto a surface of the medium to be recorded. In the printing conveyance device, the suction member has a suction region of a suction width according to the printing width in the orthogonal direction, and in the suction region, multiple openings of through-holes communicating with the negative pressure chamber are disposed. The multiple openings are arranged at an interval in the conveyance direction, and in the orthogonal direction, they are arranged in the suction region in a positional relationship with which the openings are arranged according to one or multiple openings across the entire region of the suction width.SELECTED DRAWING: Figure 4

Description

The present invention relates to a printing and conveying apparatus that prints while conveying a recording medium, and more particularly, to a printing and conveying apparatus that prints while conveying a heated recording medium.

In the case of printing on a recording medium such as a sheet-shaped thin long web, a method is generally used in which the recording medium is fixed by suction to a conveying belt and conveyed while maintaining a constant distance between the inkjet head and the recording medium. .

Also, in inkjet printing, it is effective to appropriately control the wetting and spreading of the ink after the ink is ejected and applied to the recording medium in order to ensure the print image quality. In order to control such wetting and spreading, a technique is used in which the drying and curing state of the ink is appropriately controlled after the ink is applied and before it is completely dried.

By the way, in recent years, in the field of printing, there is an increasing demand for using so-called water-based ink, which uses water as a solvent and has less impact on the environment and the human body, and inkjet printing also uses water-based ink. Demand is increasing. Water-based ink is mainly composed of water, unlike actinic ray-curable ink, which is instantly cured and dried by irradiation with actinic rays such as UV. Therefore, in order to control the wetting spread and drying and curing of the water-based ink applied to the recording medium and to ensure the print quality, it is necessary to control the drying and curing of the water-based ink by controlling the heating condition of the recording medium. There is a need to.

However, providing a recording medium conveying unit and a heating unit separately leads to an increase in the size of the inkjet printer. Also, it is necessary to heat the transport unit uniformly. Therefore, it is effective to configure the transport unit and the heating unit as one unit.
As an inkjet printer that prints while heating the recording medium while adsorbing and fixing the recording medium while heating the ink, a vacuum chamber and a heater unit are incorporated in the inner peripheral surface of the conveying belt. Japanese Patent Application Laid-Open No. 2002-100003 discloses an inkjet printer that prints and conveys a recording medium while heating, adsorbing and fixing the recording medium.

JP 2009-274399 A Japanese Patent No. 5876858

Here, in order to improve the printing image quality by making the wetting and spreading and drying and curing of the water-based ink applied to the conveyed recording medium as uniform as possible, it is necessary to uniformly heat the entire recording medium. important. For example, in a suction member that contacts the inner peripheral surface of a conveying belt by suction from a vacuum chamber, uneven heating of the recording medium occurs due to a difference in heat conduction between a portion with a suction port and a portion without a suction port. Differences occur in the state of wetting and spreading and drying and curing, leading to deterioration in print image quality. In particular, in a one-pass inkjet drawing apparatus in which an image is formed by applying ink to the recording medium while the recording medium passes the side facing the nozzle surface of the inkjet head once, the above problem is more pronounced. occurs in
As a method for coping with this problem, for example, as disclosed in Patent Document 1 and Patent Document 2, a porous member having countless fine pores is used as an adsorption member that contacts the inner peripheral surface of the conveying belt. is also conceivable. However, in the case of such a porous member, since suction is performed by minute pores, even if the generated adsorption force is weak, the adsorption force can be expanded by enlarging the minute pores of the porous member. It is difficult to make adjustments such as improving the resistance, and it is necessary to increase the negative pressure applied to the porous member. For this reason, in order to generate the required suction force for the conveying belt, compared to the suction member whose suction force can be easily improved by adjusting the size of the suction port to be formed, etc. There was a problem of inefficiency.
In addition, since the adsorption member gradually wears out due to friction with the inner peripheral surface of the conveyor belt, it may be necessary to replace it according to the state of use. there were.

The present invention has been made in view of the above-mentioned problems, and solves the above-mentioned problems. Printing with excellent cost performance that can reduce temperature unevenness of a conveying belt that conveys a recording medium and realize high-quality image recording. A transport device is provided.

In order to achieve the above object, the inventor of the present invention discovered the following configuration as a result of diligent ingenuity.

That is, a printing and conveying device that prints while conveying a recording medium in a predetermined conveying direction,
an endless metal belt that is wound around two or more transport rollers and has a plurality of suction holes for adsorbing and fixing the recording medium on the outer peripheral surface to transport the recording medium;
a suction member disposed so as to be in contact with the inner peripheral surface of the endless metal belt and for sucking the recording medium via the endless metal belt;
a belt heating member disposed facing the inner peripheral surface of the endless metal belt for heating the surface of the endless metal belt via the suction member;
a negative pressure chamber connected to the suction member and configured to apply a negative pressure to the suction member;
By applying ink to the surface of the recording medium that is arranged to face the outer peripheral surface of the endless metal belt and that is transported in a state of being adsorbed by the endless metal belt, an orthogonal direction substantially orthogonal to the transport direction and a printing unit having an inkjet head for printing an image with a predetermined print width,
The suction member has a suction area having a suction width corresponding to the printing width in the orthogonal direction, and a plurality of openings of through holes communicating with the negative pressure chamber are arranged in the suction area. The sections are spaced apart with respect to the conveying direction and arranged in the suction area in a positional relationship with respect to the orthogonal direction such that the openings are arranged over the suction width by one or more of the openings. It is characterized by

Further, in the present invention, there is provided a print conveying device for printing while conveying a recording medium in a predetermined conveying direction,
an endless metal belt that is wound around two or more transport rollers and has a plurality of suction holes for adsorbing and fixing the recording medium on the outer peripheral surface to transport the recording medium;
a suction member disposed so as to be in contact with the inner peripheral surface of the endless metal belt and for sucking the recording medium via the endless metal belt;
a belt heating member disposed facing the inner peripheral surface of the endless metal belt for heating the surface of the endless metal belt via the suction member;
a negative pressure chamber connected to the suction member and configured to apply a negative pressure to the suction member;
By applying ink to the surface of the recording medium that is arranged to face the outer peripheral surface of the endless metal belt and that is transported in a state of being adsorbed by the endless metal belt, an orthogonal direction substantially orthogonal to the transport direction and a printing unit having an inkjet head for printing an image with a predetermined print width,
The suction member has a suction area with a suction width corresponding to the printing width in the orthogonal direction, and a plurality of openings of through holes communicating with the negative pressure chamber in the transport direction are arranged in the suction area, The plurality of openings are spaced apart in the conveying direction, and have a plurality of overall areas corresponding to the printing width of the recording medium in the orthogonal direction while the conveyed recording medium passes through the suction area. is positioned in the suction area so as to pass through at least one of the openings of the.

Further, in the present invention, a plurality of openings having a width equal to or larger than the printing width in the orthogonal direction are arranged at intervals in the transport direction.

In the present invention, each of the opening rows, which are rows of the openings arranged at intervals in the orthogonal direction, is arranged in the conveying direction so as to be displaced in the orthogonal direction, and the opening rows are and the openings in the rows of openings on the front and rear sides with respect to the orthogonal direction are arranged so as to partially overlap each other.

In the present invention, at least a portion of the suction member that contacts the inner peripheral surface of the endless metal belt is made of a resin selected from high-density polyethylene resin, polyvinyl chloride, and fluororesin. It is characterized by

In the present invention, an angle adjusting unit for adjusting the angle of the conveying direction of the recording medium that intersects the axial direction of the conveying roller is mounted on at least one of the axial ends of the conveying roller. It is characterized by

Further, in the present invention, the conveying roller is characterized in that it has a crown shape in which the diameter of the central portion in the axial direction is larger than the diameter of the end portions in the axial direction.

The present invention solves the above problems by adopting the configuration described above, and provides a printing and conveying apparatus excellent in cost performance that can realize high-quality image recording by reducing temperature unevenness of a conveying belt that conveys a recording medium. We were able to.

1 is a perspective view of a print transport device; FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 4 is a BB cross-sectional view of the conveying roller; It is a perspective view of the suction member in the embodiment of the present invention. FIG. 4 is a perspective view of a suction member in another embodiment of the invention; FIG. 10 is a diagram showing an example of possible arrangements of openings in the suction member;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the overall configuration of the print transport apparatus according to this embodiment will be described.

FIG. 1 is a perspective view of an overall view of a printing and conveying apparatus according to this embodiment, and FIG. 2 is a cross-sectional view taken along line AA of FIG. In this embodiment, two transport rollers 11 are arranged at both ends of the print transport device, and an endless metal belt 13 having a plurality of suction holes for transporting the recording medium while being adsorbed and fixed on the outer peripheral surface is wound around the rollers. It is hung and placed. At least one of the transport rollers 11 is connected to a drive unit (motor) (not shown) for transmitting driving force to the endless metal belt 13 . A suction member 15 having a plurality of suction ports for sucking the recording medium through the endless metal belt 13 is arranged so as to be in contact with the inner peripheral surface of the endless metal belt 13 . Furthermore, a belt heating member 17 for heating the endless metal belt 13 is arranged to face the inner peripheral surface of the endless metal belt 13 via the suction member 15 . a negative pressure chamber 19 connected to the suction member 15 and configured to apply a negative pressure to the suction member 15; It has an exhaust port 14 for exhausting the air in the space. The exhaust port 14 has a function of discharging air by appropriately arranging a blower or the like. With such a configuration, a negative pressure can be applied to the inside of the negative pressure chamber 19 .

Further, a printing unit 16 is arranged to face the outer peripheral surface of the endless metal belt 13 and applies ink to the surface of the recording medium.
In this embodiment, water-based ink is used, and the printing unit 16 has four colors of cyan (C), magenta (M), yellow (Y), and black (K) corresponding to the number of inks. A plurality of inkjet heads for ejecting ink are arranged in the conveying direction of the recording medium, and in addition to these, inkjet heads for ejecting special color ink such as white are appropriately arranged, thereby forming the printing unit 16. Configure. In each color inkjet head constituting the printing unit 16, a plurality of nozzles are arranged at a predetermined pitch in a direction (substantially perpendicular direction in this embodiment) to the transport direction. An image is printed on a recording medium with a print width corresponding to the nozzles.

When not printing, the printing unit 16 is retracted from above the endless metal belt 13 and moved to the capping and maintenance position. It is ready for printing. At the time of printing, the recording medium adsorbed and fixed to the endless metal belt 13 is heated by the endless metal belt 13 heated by the belt heating member 17 and conveyed, and the recording medium is mounted on the printing unit 16. When passing through the print area under the head, the ink ejected from the plurality of nozzles of each color inkjet head lands and is applied to the surface of the recording medium, and the image of the print width is printed.

The belt heating member 17 is arranged to face the inner peripheral surface of the endless metal belt 13, and can heat the entire contact portion between the endless metal belt 13 and the recording medium under the suction member 15 via the suction member 15. are arranged at appropriate intervals.

2. Description of the Related Art In inkjet printing, after ink is ejected and applied to a recording medium in order to ensure print image quality, the print image quality deteriorates due to unintended wetting and spreading of the ink. Therefore, in order to ensure print image quality, it is necessary to appropriately control the wetting and spreading by curing the ink applied to the recording medium to such an extent that the wetting and spreading does not occur before wetting and spreading. Therefore, the endless metal belt 13 is heated by the belt heating member 17, the recording medium is heated by heat conduction from the heated endless metal belt 13, and the temperature of the recording medium is controlled. After the water-based ink applied from the inkjet head lands and is applied to the surface of the recording medium, the applied ink is dried and cured by the heat of the heated recording medium to the extent that it does not spread. In this way, the wetting and spreading of the ink applied to the recording medium can be appropriately controlled, and high-quality printing can be realized.

Next, details of the print transport apparatus according to this embodiment will be described.

At least two or more conveying rollers 11 are arranged to rotate and convey the endless metal belt 13 around it. The material and shape of the transport roller 11 can be appropriately selected.

However, since ink jet printing requires a high degree of ink landing accuracy, meandering of the endless metal belt 13 must be suppressed as much as possible. Therefore, as shown in FIG. 3, it is effective to form the conveying roller 11 in a crown shape in which the diameter at the central portion in the axial direction is larger than the diameter at both ends in the axial direction. By forming the crown shape, a difference in rotational speed is generated on the surface of the rotating transport roller 11 between the axial end portions and the axial center portion of the transport roller 11, and the endless metal belt 13 has a high-speed center portion. This creates a crown effect that stabilizes running. As a result, meandering of the endless metal belt 13 can be suppressed, and stable conveyance of the recording medium can be achieved.

In order to prevent meandering of the endless metal belt 13, the conveying roller 11 is provided with an angle adjusting unit 12 for adjusting the angle of the conveying direction of the recording medium intersecting the axial direction of the conveying roller 11. Installation on at least one of the axial ends of the roller 11 is conceivable.

An appropriate control method is assumed for the angle adjustment unit 12. For example, the running condition of the endless metal belt 13 is monitored by a sensor. One idea is to give an instruction to correct the meandering of the endless metal belt 13 and change the angle of the conveying roller 11 in the conveying direction. In this embodiment, the angle of the transport roller 11 in the substantially horizontal direction is changed.

In addition, as a method for changing the angle of the transport roller 11 in the transport direction by the angle adjustment unit 12, an appropriate device such as a motor, an air drive actuator, etc. is installed so that the angle of the transport roller 11 in the transport direction can be changed. It is assumed that a sensor or the like is connected to this so that it can be controlled as an angle adjustment unit.

In this embodiment, as shown in FIG. 1, the angle adjusting unit 12 can drive an air-driven actuator at one end of the conveying roller 11 in a substantially horizontal direction (substantially forward and backward in the conveying direction of the endless metal belt 13). placed like this. The running state of the endless metal belt 13 is monitored by a sensor unit to determine whether the endless metal belt 13 is running in the left or right position with respect to the running direction. An appropriate sensor unit such as a laser length measuring machine is used.

When the endless metal belt 13 meanders leftward or rightward with respect to the running direction by more than a predetermined threshold value, the actuator is driven so as to correct the running direction, and the substantially horizontal angle of the conveying roller 11 is adjusted. By correcting, the running position of the endless metal belt 13 is corrected and meandering of the endless metal belt 13 is prevented. For example, when the running position of the endless metal belt 13 meanders to the right from the center of the transport roller 11 with respect to the transport direction, the angle adjustment unit 12 is driven to change the angle of the transport roller 11 in the direction opposite to the transport direction. As a result, the running position of the endless metal belt 13 moves from the center of the conveying roller 11 to the left side, and meandering can be corrected.

The endless metal belt 13 is preferably made of stainless steel from the viewpoint of durability, flatness, thermal conductivity, and the like. A plurality of suction holes for sucking the recording medium are pierced through the entire circumference of the surface of the endless metal belt 13 . In this embodiment, the endless metal belt 13 has a thickness t of about 0.2 mm, suction holes arranged in a zigzag pattern, a diameter of about φ0.3 mm, and an aperture ratio of about 4%.

FIG. 4 is a perspective view of the suction member 15 in the embodiment of the invention.

A negative pressure is applied to the suction member 15 to suck the endless metal belt 13 together with the recording medium. 13 need to be transported. Therefore, it is preferable that at least the portion of the suction member 15 that contacts the inner peripheral surface of the endless metal belt 13 is made of a resin material that has low surface frictional resistance and excellent abrasion resistance. Moreover, the resin material is cheaper than the porous member, and is advantageous in terms of cost. If the material is easily abraded, the suction holes of the endless metal belt 13 will be clogged with the dust of the worn resin, making it impossible to attract the recording medium. of particular importance. Therefore, as the resin material used for the suction member 15, high-density polyethylene resin (HDPE), fluororesin, polyvinyl chloride (PVC), etc. are assumed. Considering durability and ease of handling, fluororesin or high-density polyethylene resin is more desirable, but the material is not limited to these.

The suction member 15 is provided with a plurality of through-holes that communicate with a negative pressure chamber 19, which will be described later, by cutting or the like. A plurality of openings 20 are formed by these through holes on the surface of the suction member 15 on the belt side. As a result, the endless metal belt 13 and the recording medium can be attracted.

In this embodiment shown in FIG. 4, a plurality of rectangular openings 20 having a width equal to or greater than the print width in a direction substantially perpendicular to the transport direction are arranged side by side at predetermined intervals in the transport direction. The plurality of openings 20 form a suction area having a width (suction width) equal to or larger than the printing width. Further, in the printing and conveying apparatus according to the present embodiment, the heating member 17 heats the endless metal belt 13 via the suction member 15 . By providing a plurality of through holes in the suction member 15, the endless metal belt 13 is heated by both heat conduction and heat radiation. Thereby, the endless metal belt 13 can be heated not only by the heat conduction by the adsorption member but also by the heat radiation of the belt heating member 17 more efficiently. The space heated by the belt heating member 17 formed by the endless metal belt 13, the suction member 15 and the negative pressure chamber 19 is exhausted through the exhaust port 14, and the recording medium on the endless metal belt 13 is adsorbed and fixed. By doing so, the inside of the same space becomes a state close to a vacuum. As a result, the flow of air is extremely small, so that the endless metal belt 13 can be heated also by thermal radiation.

Regarding the shape and size of the opening 20 of the through-hole formed in the suction member 15, if the load generated when the recording medium and the endless metal belt 13 are sucked causes deflection or the like, printing accuracy is adversely affected. Therefore, it is desirable to have a shape that can ensure a predetermined rigidity. For example, as shown in FIG. 6, as the suction member 15, a row of openings 22 in which a plurality of substantially square openings are arranged at predetermined intervals in the conveying direction are arranged at intervals in a direction substantially perpendicular to the conveying direction. A form of arranging a plurality of units is also conceivable. However, there is a difference in heat conduction to the endless metal belt 13 between the position where the openings 22 are provided and the position where the openings 22 are not provided. Density unevenness may occur in the conveying direction at the position where the sheet is pressed.

On the other hand, in the present embodiment shown in FIG. 4, a plurality of rectangular openings 20 having a width equal to or larger than the print width extending in a direction substantially perpendicular to the transport direction are arranged at predetermined intervals in the transport direction. They are arranged side by side. As a result, while the recording medium conveyed in the conveying direction passes through the suction area, the area corresponding to the print width of the recording medium passes through the area where the opening 20 of the suction member 15 is arranged once. There is no part that does not occur.

In this way, the arrangement relationship of the openings 20 is set so that the area facing the print width of the recording medium passes through the area where the openings 20 are arranged at least once while passing through the suction area. The purpose is as follows. That is, as described above, in the present embodiment, the endless metal belt 13 is heated by heat radiation and heat conduction from the belt heating member 17, so that the heat conduction from the endless metal belt 13 heats the recording medium. However, since the thermal conductivity of the portion with the openings 20 is different from that of the portion without the openings 20, the surface temperature of the endless metal belt 13 is different between the portions with the openings 20 and the portions without the openings 20. Become. Then, while the recording medium passes through the printing area, if there is a portion that passes through the opening 20 and a portion that does not pass through the opening 20 in the printing width direction of the recording medium, a difference occurs in the heating condition of the recording medium. Temperature unevenness occurs in the print width direction of the recording medium, causing differences in the state of wetting and spreading of the ink after it is applied to the recording medium, which may lead to deterioration in print quality. There is Therefore, by setting the shape and positional relationship of the openings 20 as described above, the heated state of the recording medium is made uniform in the printing width direction of the recording medium.

FIG. 5 is a perspective view of suction member 15 in another embodiment of the present invention. A plurality of rows of circular (can be replaced with polygonal, triangular, etc.) openings 21 arranged at intervals in a direction substantially perpendicular to the conveying direction are arranged so as to be offset from each other in a direction substantially perpendicular to the conveying direction. A plurality of openings 21 are arranged in a positional relationship in the conveying direction, and are arranged in a staggered positional relationship such that the circular openings 21 in the front and rear rows partially overlap with respect to the direction substantially orthogonal to the conveying direction. By arranging in this way, while the recording medium is conveyed through the printing area by the endless metal belt 13 via the suction member 15, the area of the part that passes through the opening 21 and the part that does not pass through the opening 21 can be adjusted to the area of the recording medium. can be made relatively uniform in the print width direction, thereby preventing uneven heating of the recording medium.

If the temperature of the endless metal belt 13 becomes too high, the ink adhering to the nozzle surface of the inkjet head, which is close to the recording medium placed on the surface of the endless metal belt 13 for printing, is dried. Various problems are expected to occur, such as the problem of clogged nozzles.

Therefore, it is preferable that the belt heating member 17 has a function of controlling the surface temperature of the portion of the surface of the endless metal belt 13 in contact with the recording medium to a target temperature. That is, in order to heat the temperature of the recording medium to an intended temperature, the output of the belt heating member 17 is controlled to raise the surface temperature of the endless metal belt 13 to be heated to the target temperature, which is a predetermined numerical value. The output of the belt heating member 17 is controlled so that the belt heating member 17 is heated to As a control method, an appropriate method is assumed, but a method of connecting a control device capable of inputting and setting a target temperature to the belt heating member 17 and combining this with a temperature sensor for control is conceivable. As a result, even if the surface temperature of the endless metal belt 13 actually heated by the belt heating member 17 fluctuates slightly, the surface temperature of the endless metal belt 13 can be controlled to a temperature approximately close to the target temperature. can.

In addition, in order to control the viscosity and the like of the ink supplied to the inkjet head to a state suitable for ejection, the printing unit 16 controls the ink supplied and ejected inside the inkjet head to a target temperature, which is a predetermined numerical value. Providing an ink heating member capable of heating is suitable for achieving stable ejection of ink and achieving high-quality printing. In this embodiment, the ink heating member is incorporated in the inkjet head, and is arranged so as to heat the ink near the nozzles inside the inkjet head so that the temperature of the ejected ink can be heated to the target temperature, which is a predetermined numerical value. there is

The ink heating member is preferably equipped with a function capable of controlling the temperature of the ejected ink by setting it to a predetermined target temperature suitable for the ejection stability of the ink. Any suitable control method may be used, but in general, an electric heater unit is installed near the ink path in the inkjet head so as to heat the ink, and the target temperature of the ink connected to the outside is controlled. Ink temperature control is performed by combining an inkjet head control unit that can be set and a temperature sensor that measures the ink temperature. As a result, even if the temperature of the ink actually heated and controlled by the heater unit fluctuates slightly, the temperature of the ink ejected by the ink-jet head can be controlled to a temperature approximately close to the target temperature. can be done.

At this time, as described above, since the recording medium is heated, the ink that has landed on the surface of the recording medium is not completely cured, but is appropriately dried by the heat and cured to the extent that it does not spread. This makes it possible to control the wetting and spreading of the ink. By this control, unintended wetting and spreading of ink such as ink bleeding can be prevented, and high-quality printing can be realized.

A long roll-shaped sheet member is used as the recording medium used in the present embodiment. Paper such as coated paper is assumed as the material of the sheet member, but basically synthetic resin films made of resins such as polypropylene (OPP), polyethylene terephthalate (PET), and nylon are suitable. As for the ink applied to the recording medium, solvent ink that requires drying by heating can be assumed, but water-based ink that uses water as a solvent that has a low impact on the environment and the human body is more suitable. Become.

Here, the relationship between the setting of the target temperature of the ink ejected from the inkjet head mounted on the printing unit 16 and the setting of the target temperature of the endless metal belt 13 heated by the belt heating member 17 will be described.

First, the temperature of the ink ejected from the inkjet head is adjusted by the ink heating member inside the inkjet head according to the performance such as the viscosity and drying temperature of the ink.
In addition, from the viewpoint of increasing the printing speed, by increasing the temperature of the endless metal belt 13, the ink applied to the recording medium can be heated to a low temperature even in a short time when the recording medium passes over the surface of the endless metal belt 13. , the same amount of heat as in the case of conveying the recording medium at a lower speed can be applied to control the drying and curing of the ink.

However, the water-based ink used in the present embodiment is cured and dried when the contained water evaporates, unlike the actinic radiation curable ink whose curing can be easily controlled by actinic rays such as ultraviolet rays. Therefore, if the radiant heat of the heated endless metal belt 13 accelerates the drying and hardening of the ink on the nozzle surface of the inkjet head, the nozzles of the inkjet head will be clogged with the dried and hardened ink, resulting in ejection failure and other problems of the inkjet head. Increased risk of breakage.

Further, as described above, the temperature of the ink ejected from the inkjet head is controlled to the target temperature by the ink heating member in consideration of the viscosity and drying performance of the ink. Therefore, if the target temperature of the endless metal belt 13 is set too high, the temperature of the ink inside the inkjet head becomes higher than the target temperature of the ink due to the radiant heat of the endless metal belt 13, which lowers the ink viscosity. There is also a problem that the ejection stability of the ink is adversely affected.

Therefore, in order to solve these problems, the target temperature of the surface temperature of the endless metal belt 13 heated by the belt heating member 17 is set to be equal to or lower than the target temperature of the ink heated by the ink heating member. Control is effective.

For example, in the present embodiment, if the target temperature of the ink temperature is 55° C., the target temperature of the endless metal belt 13 is 55° C. If the target temperature of the ink temperature is 40° C., the target temperature of the endless metal belt 13 is 40° C. Thus, by setting the target temperature of the endless metal belt 13 to be the same according to the target temperature of the ink temperature, the target temperature of the surface temperature of the endless metal belt 13 heated by the belt heating member 17 is heated by the ink heating member. It is set so that the ink temperature to be applied is equal to or lower than the target temperature.

By performing such control, the target temperature of the ink supplied into the inkjet head heated by the ink heating member is set to a temperature that does not cause problems in terms of ink performance, such as ink viscosity and ink curing temperature. As long as the heat generated by the endless metal belt 13 (the target temperature of the endless metal belt 13) is equal to or lower than the target temperature of the ink, even if the heat radiation from the endless metal belt 13 is transmitted to the nozzle surface and inside of the inkjet head, Since there is almost no possibility that the temperature of the ink inside the inkjet head will be heated above the target temperature of the ink, the temperature of the ink inside the inkjet head is not affected, and the above problem can be solved.

In the recording medium printed by the printing and conveying apparatus according to the present embodiment, the applied ink is cured to such an extent that it does not wet and spread, but it is not heated and dried until it is completely dried and cured. Therefore, in this embodiment, the recording medium is conveyed to a drying device (not shown) after being printed by the printing and conveying apparatus according to this embodiment, and the ink is completely dried to complete the printing.

11 transport roller 12 angle adjustment unit 13 endless metal belt 14 exhaust port 15 suction member 16 printing unit 17 belt heating member 19 negative pressure chamber 20 opening 21 opening

Claims (7)

A printing and conveying device for printing while conveying a recording medium in a predetermined conveying direction,
an endless metal belt that is wound around two or more transport rollers and has a plurality of suction holes for adsorbing and fixing the recording medium on the outer peripheral surface to transport the recording medium;
a suction member disposed so as to be in contact with the inner peripheral surface of the endless metal belt and for sucking the recording medium via the endless metal belt;
a belt heating member disposed facing the inner peripheral surface of the endless metal belt for heating the surface of the endless metal belt via the suction member;
a negative pressure chamber connected to the suction member and configured to apply a negative pressure to the suction member;
By applying ink to the surface of the recording medium that is arranged to face the outer peripheral surface of the endless metal belt and that is transported in a state of being adsorbed by the endless metal belt, an orthogonal direction substantially orthogonal to the transport direction and a printing unit having an inkjet head for printing an image with a predetermined print width,
The suction member has a suction area having a suction width corresponding to the printing width in the orthogonal direction, and a plurality of openings of through holes communicating with the negative pressure chamber are arranged in the suction area. The sections are spaced apart with respect to the conveying direction and arranged in the suction area in a positional relationship with respect to the orthogonal direction such that the openings are arranged over the suction width by one or more of the openings. A printing and conveying device characterized by: A printing and conveying device for printing while conveying a recording medium in a predetermined conveying direction,
an endless metal belt that is wound around two or more transport rollers and has a plurality of suction holes for adsorbing and fixing the recording medium on the outer peripheral surface to transport the recording medium;
a suction member disposed so as to be in contact with the inner peripheral surface of the endless metal belt and for sucking the recording medium via the endless metal belt;
a belt heating member disposed facing the inner peripheral surface of the endless metal belt for heating the surface of the endless metal belt via the suction member;
a negative pressure chamber connected to the suction member and configured to apply a negative pressure to the suction member;
By applying ink to the surface of the recording medium that is arranged to face the outer peripheral surface of the endless metal belt and that is transported in a state of being adsorbed by the endless metal belt, an orthogonal direction substantially orthogonal to the transport direction and a printing unit having an inkjet head for printing an image with a predetermined print width,
The suction member has a suction area with a suction width corresponding to the printing width in the orthogonal direction, and a plurality of openings of through holes communicating with the negative pressure chamber in the transport direction are arranged in the suction area, The plurality of openings are spaced apart in the conveying direction, and have a plurality of overall areas corresponding to the printing width of the recording medium in the orthogonal direction while the conveyed recording medium passes through the suction area. positioned in the suction area to pass through at least one of the openings of the. 3. The printing and transporting device according to claim 1, wherein a plurality of said openings having a width equal to or larger than said printing width in said orthogonal direction are arranged at intervals in said transporting direction. A plurality of rows of openings, which are rows of the openings arranged at intervals in the orthogonal direction, are arranged in the conveying direction so as to be shifted in the orthogonal direction, and the rows of openings are arranged forward and backward with respect to the orthogonal direction. 3. The print transport device according to claim 1, wherein the openings in the row of openings are arranged so as to partially overlap each other. At least a portion of the suction member that contacts the inner peripheral surface of the endless metal belt is made of a resin selected from high-density polyethylene resin, polyvinyl chloride, and fluororesin, 5. The print transport device according to any one of claims 1 to 4. An angle adjusting unit is mounted on at least one of axial ends of the transport roller for adjusting an angle of the transport direction of the recording medium that intersects the axial direction of the transport roller. 6. A print transport apparatus according to any one of claims 1 to 5, wherein 7. The printing and conveying apparatus according to claim 1, wherein the conveying roller has a crown shape in which the diameter of the central portion in the axial direction is larger than the diameter of the end portions in the axial direction. .

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