JP2024084978A - Liquid ejection device - Google Patents

Abstract

[Problem] Providing a path for turning over the medium to record on both sides of the medium tends to lead to an increase in the size of the device. [Solution] A liquid ejection device is characterized by comprising a first conveyor belt mechanism that adsorbs and conveys a first side of the medium, a first liquid ejection unit that is disposed opposite the first conveyor belt mechanism and ejects liquid onto a second side of the medium opposite to the first side, a second conveyor belt mechanism that is a conveyor belt mechanism to which the medium is delivered from the first conveyor belt mechanism and that adsorbs and conveys the second side of the medium, and a second liquid ejection unit that is disposed opposite the second conveyor belt mechanism and ejects liquid onto the first side of the medium. [Selected Figure] Figure 1

Description

The present invention relates to a liquid ejection device that ejects liquid onto a medium.

In an inkjet recording device, which is one example of a liquid ejection device, a configuration is known in which a medium, such as recording paper, is transported while being adsorbed to a transport belt. In such a configuration, a path is provided for reversing the medium, as shown in Patent Document 1, and a configuration is also known in which recording is performed on both sides of the medium.

JP 2022-112571 A

Providing a path to flip the media in order to record on both sides of the media can easily lead to an increase in the size of the device.

To solve the above problem, the liquid ejection device of the present invention is characterized by comprising a first conveyor belt mechanism that adsorbs and transports a first side of a medium, a first liquid ejection unit that is arranged opposite the first conveyor belt mechanism and ejects liquid onto a second side of the medium opposite the first side, a conveyor belt mechanism to which the medium is delivered from the first conveyor belt mechanism, a second conveyor belt mechanism that adsorbs and transports the second side of the medium, and a second liquid ejection unit that is arranged opposite the second conveyor belt mechanism and ejects liquid onto the first side of the medium.

FIG. 2 is a diagram showing a media transport path of the printer. FIG. 2 is a diagram illustrating a configuration of a first conveyor belt mechanism. FIG. 4 is a diagram illustrating a configuration of a second conveyor belt mechanism. FIG. FIG. 4 is a plan view of the wall portion that constitutes the pressure case. 6A and 6B are diagrams illustrating another embodiment of the first conveyor belt mechanism. 11A to 11C are diagrams showing the operation transition of a partition wall. 6A and 6B are diagrams illustrating another embodiment of the first conveyor belt mechanism. 13A and 13B are diagrams illustrating another embodiment of the first conveyor belt mechanism and the second conveyor belt mechanism.

The present invention will now be briefly described.
The liquid ejection device of the first aspect is characterized in that it comprises a first conveying belt mechanism that adsorbs and transports a first side of a medium, a first liquid ejection unit that is arranged opposite the first conveying belt mechanism and ejects liquid onto a second side of the medium opposite the first side, a conveying belt mechanism to which the medium is handed over from the first conveying belt mechanism, a second conveying belt mechanism that adsorbs and transports the second side of the medium, and a second liquid ejection unit that is arranged opposite the second conveying belt mechanism and ejects liquid onto the first side of the medium.

According to this aspect, the medium is handed over from the first conveyor belt mechanism to the second conveyor belt mechanism, and the first conveyor belt mechanism ejects liquid onto the second surface of the medium by the first liquid ejection unit, and the second conveyor belt mechanism ejects liquid onto the first surface of the medium by the second liquid ejection unit. This makes it possible to record onto both surfaces of the medium without providing a path for reversing the medium between the first liquid ejection unit and the second liquid ejection unit, and significantly reduces the size of the device.

A second aspect is an aspect dependent on the first aspect, characterized in that a liquid ejection direction by the first liquid ejection section and a liquid ejection direction by the second liquid ejection section are aligned along a vertical direction.
According to the present aspect, since the liquid ejection direction by the first liquid ejection unit and the liquid ejection direction by the second liquid ejection unit are along the vertical direction, the medium transport path when recording on the medium can be made linear along the horizontal direction, and the height dimension of the device can be reduced.

A third aspect is an aspect dependent on the second aspect, and is characterized in that the liquid ejection direction by the first liquid ejection section is vertically upward, and the liquid ejection direction by the second liquid ejection section is vertically downward.
According to the present aspect, since the liquid ejection direction by the first liquid ejection section is vertically upward and the liquid ejection direction by the second liquid ejection section is vertically downward, the effect of gravity can be utilized when transferring the medium from the first conveyor belt mechanism to the second conveyor belt mechanism, making it easier to transfer the medium from the first conveyor belt mechanism to the second conveyor belt mechanism.

A fourth aspect is an aspect dependent on the third aspect, characterized in that a part of the first transport belt mechanism and a part of the second transport belt mechanism overlap in the medium transport direction.
According to the present aspect, a portion of the first conveying belt mechanism and a portion of the second conveying belt mechanism overlap in the media conveying direction, so that the medium can be more reliably transferred from the first conveying belt mechanism to the second conveying belt mechanism and the device dimensions in the media conveying direction can be reduced.
Incidentally, this aspect is not limited to the third aspect, but may be subordinate to the first or second aspect.

The fifth aspect is an aspect dependent on the fourth aspect, characterized in that at least a portion of the first conveyor belt mechanism and at least a portion of the second liquid ejection unit overlap in the vertical direction, and at least a portion of the second conveyor belt mechanism and at least a portion of the first liquid ejection unit overlap in the vertical direction.

According to the present aspect, at least a portion of the first conveying belt mechanism and at least a portion of the second liquid ejection section overlap in the vertical direction, and at least a portion of the second conveying belt mechanism and at least a portion of the first liquid ejection section overlap in the vertical direction, thereby reducing the vertical dimension of the device.
Incidentally, this aspect is not limited to the above-mentioned fourth aspect, and may be subordinate to the above-mentioned second or third aspect.

The sixth aspect is a dependent aspect of the first aspect, and is characterized in that the first conveyor belt mechanism includes an endless conveyor belt having a plurality of holes formed therein, and a suction mechanism that adsorbs the medium to the conveyor belt by sucking through the holes, and the area of the conveyor belt facing the first surface of the medium includes an adsorption area that adsorbs the medium to the conveyor belt by the suction mechanism, and a release area that is located downstream of the adsorption area in the media conveying direction and releases the medium from the conveyor belt by exhausting exhaust air generated by the suction mechanism through the holes.

According to this aspect, the area of the conveying belt that comes into contact with the first surface of the medium has an adsorption area that adsorbs the medium using the suction mechanism, and a peeling area that is located downstream of the adsorption area in the medium conveying direction and peels the medium from the conveying belt by discharging exhaust air generated by the suction mechanism through the hole, so that the peeling area can properly peel the medium from the conveying belt, and ultimately the medium can be properly handed over to the second conveying belt mechanism.
In addition, since the peeling area is configured to peel the medium from the conveying belt by discharging the exhaust air generated by the suction mechanism through the hole, the peeling area can be formed at low cost by effectively utilizing the exhaust air generated by the suction mechanism.
Incidentally, this aspect is not limited to the first aspect, but may be subordinate to any of the second to fifth aspects.

The seventh aspect is an aspect dependent on the sixth aspect, and is characterized in that the suction mechanism includes a suction fan, a negative pressure chamber in which negative pressure is formed by the suction fan and which draws in air through the holes in the conveyor belt, a positive pressure chamber in which positive pressure is formed by the suction fan and which exhausts the exhaust gas through the holes in the conveyor belt, and a partition wall separating the negative pressure chamber and the positive pressure chamber, which moves in a direction that changes the volume ratio between the negative pressure chamber and the positive pressure chamber, thereby changing the area ratio between the adsorption region and the peeling region.

According to this aspect, the area ratio between the adsorption area and the peeling area can be changed by moving the partition wall, so that the degree of adsorption of the medium by the adsorption area and the degree of peeling of the medium by the peeling area can be adjusted, and the medium can be more appropriately adsorbed and peeled off.

An eighth aspect is an aspect dependent on the seventh aspect, and is characterized in that the recording apparatus further comprises a control unit that controls movement of the partition wall, and the control unit controls the partition wall in accordance with recording conditions.
According to this aspect, the control unit that controls the movement of the partition wall controls the partition wall in accordance with the recording conditions, so that the medium can be appropriately attracted and peeled off in accordance with the recording conditions.

A ninth aspect is an aspect dependent on the first aspect, further comprising a peeling claw that peels the medium off the first transport belt mechanism.
According to this aspect, since a peeling claw that peels the medium from the first transport belt mechanism is provided, the medium can be appropriately transferred from the first transport belt mechanism to the second transport belt mechanism.
Incidentally, this aspect is not limited to the first aspect, but may be subordinate to any of the second to eighth aspects.

The tenth aspect is a dependent aspect of the first aspect, and is characterized in that the first conveyor belt mechanism includes an endless conveyor belt having a plurality of holes formed therein, and a suction mechanism that attracts a medium to the conveyor belt by suctioning through the holes, the suction mechanism includes a suction fan, and a negative pressure chamber in which a negative pressure is created by the suction fan and that suctions through the holes in the conveyor belt, and a control unit that controls the suction fan controls the suction fan in accordance with recording conditions.

According to this aspect, the control unit that controls the suction fan controls the suction fan in accordance with the recording conditions, and therefore it is possible to appropriately suck the medium in accordance with the recording conditions.
Incidentally, this aspect is not limited to the first aspect, but may be subordinate to any of the second to ninth aspects.

An eleventh aspect is a dependent aspect of the first aspect, and is characterized in that the first conveyor belt mechanism is arranged at an angle relative to the second conveyor belt mechanism so that a downstream portion of the first conveyor belt mechanism in the conveying direction approaches the second conveyor belt mechanism.
According to the present aspect, the first conveying belt mechanism is positioned at an angle relative to the second conveying belt mechanism so that the downstream portion of the first conveying belt mechanism in the conveying direction approaches the second conveying belt mechanism. This reduces the curvature of the medium when it is handed over from the first conveying belt mechanism to the second conveying belt mechanism, and in particular prevents the medium from floating in the suction area of the second conveying belt mechanism.
Incidentally, this aspect is not limited to the first aspect, but may be subordinate to any of the second to tenth aspects.

A twelfth aspect is an aspect dependent on the first aspect, characterized in that a liquid ejection direction by the first liquid ejection section and a liquid ejection direction by the second liquid ejection section are aligned along a horizontal direction.
According to the present aspect, since the liquid ejection direction by the first liquid ejection unit and the liquid ejection direction by the second liquid ejection unit are along the horizontal direction, the medium transport path can be made straight along the vertical direction, and the horizontal dimension of the device can be reduced.
Incidentally, this aspect is not limited to the first aspect, but may be applied to any of the second to tenth aspects.

The present invention will be specifically described below.
In the following, an inkjet printer 1 that performs recording by ejecting liquid, typically ink, onto a medium, typically recording paper, will be described as an example of a liquid ejection device. In the following, the inkjet printer 1 will be abbreviated to printer 1.

The X-Y-Z coordinate system shown in each figure is an orthogonal coordinate system, with the X-axis direction being the medium width direction intersecting the medium transport direction and also being the device depth direction. The X-axis direction is also the width direction of transport belts 11 and 31, which will be described later. Of the X-axis directions, the -X direction is the direction from the front of the device to the rear of the device, and the +X direction is the direction from the rear of the device to the front of the device.
The Y axis direction is the width direction of the device, and as seen by the operator of the printer 1, the +Y direction in which the arrow points is the left side, and the opposite, -Y direction is the right side. The Z axis direction is the vertical direction, or the height direction of the device, and the +Z direction in which the arrow points is the upward direction, and the opposite, -Z direction is the downward direction.
In the following description, the direction in which the medium is transported may be referred to as "downstream" and the opposite direction may be referred to as "upstream."

The medium transport path is indicated by a dashed line in Fig. 1. In the printer 1, the medium is transported through the medium transport path indicated by the dashed line.
The printer 1 is equipped with a medium cassette 3 at the bottom of the device main body 2. The medium cassette 3 is provided so as to be detachable from the front side of the device. The symbol P indicates the medium stored in the medium cassette 3. Hereinafter, the medium will be referred to as medium P with the symbol P attached.
A feed roller 4 for feeding the medium P accommodated in the medium cassette 3 is provided for the medium cassette 3 .

The medium P sent out from the medium cassette 3 is fed to the first conveyor belt mechanism 10 via a curved feeding path Ts. A medium detection unit 51 is provided upstream of the first conveyor belt mechanism 10, and a control unit 50 (described later) can execute various controls of the first conveyor belt mechanism 10 and the second conveyor belt mechanism 30 (described later) by detecting the leading edge of the medium P using the medium detection unit 51.
The first transport belt mechanism 10 is a mechanism that transports the medium P while adsorbing a first surface S1 (see FIG. 2) of the medium P to the transport belt 11. The first surface S1 of the medium P is the lower surface of the medium P when the medium is stored in the medium cassette 3. The first transport belt mechanism 10 will be described in detail later.

A first line head 5 that ejects ink onto a second surface S2 (see FIG. 2) opposite to the first surface S1 of the medium P is provided at a position facing the first transport belt mechanism 10. The second surface S2 of the medium P is the upper surface of the medium P when it is stored in the medium cassette 3. The first line head 5 is an example of a first liquid ejection unit that ejects liquid onto the second surface S2 of the medium P.
The first line head 5 has ink ejection nozzles (not shown) arranged on an ink ejection surface 5a from which ink is ejected. The first line head 5 is an ink ejection head in which the ink ejection nozzles (not shown) are arranged to cover the entire area in the medium width direction, and is configured as an ink ejection head capable of recording over the entire medium width without movement in the medium width direction.
However, instead of the first line head 5, an ink ejection head of a type that performs recording by moving in the medium width direction may be used.

The medium P, on which recording has been performed on the first surface S1 while being transported by the first transport belt mechanism 10, is transferred from the first transport belt mechanism 10 to the second transport belt mechanism 30.
The second transport belt mechanism 30 is a mechanism that transports the medium P while adsorbing the second surface S2 (see FIG. 3) of the medium P to the transport belt 31. The second transport belt mechanism 30 will be described in detail later.

A second line head 6 that ejects ink onto the first surface S1 of the medium P is provided at a position facing the second conveyor belt mechanism 30. The second line head 6 is an example of a second liquid ejection unit that ejects liquid onto the first surface S1 of the medium P.
The second line head 6 has ink ejection nozzles (not shown) arranged on an ink ejection surface 6a from which ink is ejected. The second line head 6 is an ink ejection head in which the ink ejection nozzles (not shown) are arranged to cover the entire area in the medium width direction, and is configured as an ink ejection head capable of recording over the entire medium width without movement in the medium width direction.
However, instead of the second line head 6, an ink ejection head of a type that performs recording by moving in the medium width direction may be used.

The medium P transported by the second transport belt mechanism 30 is sent to the discharge roller pair 7 via a curved discharge path Te, and is discharged onto the discharge tray 8 by the discharge roller pair 7 .
The device main body 2 is equipped with a control unit 50 that performs various controls on the printer 1. The operation of all movable parts in the printer 1 is controlled by the control unit 50. The control unit 50 performs various controls based on various setting information set via an operation unit (not shown) provided on the printer 1 and execution commands given via the operation unit. However, the control unit 50 can of course accept various settings and various execution commands based on information sent from an external computer (not shown) that can access the printer 1.
The control unit 50 is equipped with a CPU, RAM, non-volatile memory, etc. (not shown), and programs that realize the various controls described below and various parameters required to execute the programs are stored in the non-volatile memory.

Next, the first conveyor belt mechanism 10 will be described in detail with reference to FIGS.
The first conveyor belt mechanism 10 includes a conveyor belt 11 , a driving pulley 12 , a driven pulley 13 , and a suction mechanism 15 .
The conveyor belt 11 is an endless belt that is wound around a drive pulley 12 and a driven pulley 13. The conveyor belt 11 rotates when the drive pulley 12 is driven by a belt drive motor (not shown).

A suction mechanism 15 is provided inside the conveyor belt 11. The suction mechanism 15 is a mechanism that adsorbs the medium P to the conveyor belt 11 by sucking through holes 11a (see FIG. 4) formed in the conveyor belt 11, and includes a pressure case 16 and a suction fan 21.
A negative pressure chamber 17 is formed in the pressure case 16. The pressure case 16 has a wall portion 16a, and the conveyor belt 11 moves along the wall portion 16a.

The conveyor belt 11 has a plurality of holes 11a formed therein, as shown in FIG. 4. The wall portion 16a of the pressure case 16 has a plurality of openings 16b formed therein, as shown in FIG. 5. The holes 11a of the conveyor belt 11 are configured to overlap with the openings 16b of the wall portion 16a as the conveyor belt 11 rotates. As a result, when negative pressure is generated in the negative pressure chamber 17 in the pressure case 16, the medium P is sucked in through the openings 16b of the wall portion 16a and the holes 11a of the conveyor belt 11, and the medium P is adsorbed to the conveyor belt 11 and conveyed.

The suction fan 21 is connected to the negative pressure chamber 17 via a suction duct 22. When the suction fan 21 rotates, an airflow as shown by the arrow is generated in the suction duct 22, thereby creating a negative pressure in the negative pressure chamber 17.
The exhaust air generated by the suction fan 21 is discharged through an exhaust duct 23 and an exhaust port (not shown).
2, reference symbol As1 denotes an attraction region. In the attraction region As1, the medium P is subjected to an attraction action.

The suction fan 21 is driven by a motor (not shown) that is controlled by the control unit 50. The control unit 50 controls the rotation and stopping of the suction fan 21, and also controls the rotation speed during rotation.
Although the suction fan 21 is provided inside the conveyor belt 11 in FIG. 2, it may be provided outside the conveyor belt 11 .

A peeling claw 25 is provided downstream of the suction area As1. The peeling claw 25 is provided so that its upstream end comes into contact with the conveyor belt 11, and peels the medium P being conveyed by the conveyor belt 11 from the conveyor belt 11.

Next, the second transport belt mechanism 30 will be described in detail with reference to FIG.
The second conveyor belt mechanism 30 includes a conveyor belt 31 , a driving pulley 32 , a driven pulley 33 , and a suction mechanism 35 .
The conveyor belt 31 is an endless belt that is wound around a drive pulley 32 and a driven pulley 33. The conveyor belt 31 rotates when the drive pulley 32 is driven by a belt drive motor (not shown). The belt drive motor that drives the conveyor belt 31 may be the same as the belt drive motor (not shown) that drives the conveyor belt 11 of the first conveyor belt mechanism 10, or may be separate.

A suction mechanism 35 is provided on the inside of the conveyor belt 31. The suction mechanism 35 is a mechanism that adsorbs the medium P to the conveyor belt 31 by sucking through holes (not shown) formed in the conveyor belt 31, and includes a pressure case 36 and a suction fan 41. The holes (not shown) formed in the conveyor belt 31 are similar to the holes 11a of the conveyor belt 11 described with reference to FIG. 4.
The pressure case 36 has a wall portion 36a, and the conveyor belt 31 moves along the wall portion 36a.

The wall 36a of the pressure case 36 also has a number of openings (not shown). The openings (not shown) formed in the wall 36a are similar to the opening 16b described with reference to FIG. 5. The holes (not shown) in the conveyor belt 31 are configured to overlap with the openings (not shown) in the wall 36a as the conveyor belt 31 rotates. As a result, when negative pressure is generated in the negative pressure chamber 37 in the pressure case 36, the medium P is sucked through the openings (not shown) in the wall 36a and the holes (not shown) in the conveyor belt 31, and the medium P is adsorbed to the conveyor belt 31 and conveyed.

The suction fan 41 is connected to the negative pressure chamber 37 via a suction duct 42. When the suction fan 41 rotates, an airflow as shown by the arrows is generated in the suction duct 42, thereby creating a negative pressure in the negative pressure chamber 37.
The exhaust air generated by the suction fan 41 is discharged from an exhaust port (not shown) via an exhaust duct 43. In Fig. 3, reference symbol As2 denotes a suction region, and the medium P is subjected to a suction action in the suction region As2.

The suction fan 41 is driven by a motor (not shown) that is controlled by the control unit 50. The control unit 50 controls the rotation and stopping of the suction fan 41, and also controls the rotation speed when the fan rotates.
Although the suction fan 41 is provided inside the conveyor belt 31 in FIG. 3, it may be provided outside the conveyor belt 31 .
As described above, in this embodiment, the second transport belt mechanism 30 has the same basic configuration as the first transport belt mechanism 10 described above, except that it does not include the peeling claw 25 .

Next, the effects of the printer 1 will be described mainly with reference to Fig. 1. The printer 1 includes a first transport belt mechanism 10 that adsorbs and transports the first side S1 of the medium P, a first line head 5 that is disposed opposite the first transport belt mechanism 10 and ejects ink onto a second side S2 of the medium P that is opposite the first side S1, a second transport belt mechanism 30 that is a transport belt mechanism to which the medium P is delivered from the first transport belt mechanism 10 and adsorbs and transports the second side S2 of the medium P, and a second line head 6 that is disposed opposite the second transport belt mechanism 30 and ejects ink onto the first side S1 of the medium P.
In other words, the medium P is handed over from the first transport belt mechanism 10 to the second transport belt mechanism 30, and in the first transport belt mechanism 10, ink is ejected onto the second side S2 of the medium P by the first line head 5, and in the second transport belt mechanism 30, ink is ejected onto the first side S1 of the medium P by the second line head 6. Therefore, it is possible to record on both sides of the medium P without providing a path for flipping the medium P between the first line head 5 and the second line head 6, which significantly reduces the size of the device.

In this embodiment, the ink ejection direction from the first line head 5 and the ink ejection direction from the second line head 6 are aligned vertically.
This allows the medium transport path when recording on the medium P to be linear along the horizontal direction, making it possible to reduce the height dimension of the device.

In addition, in this embodiment, the ink ejection direction by the first line head 5 is the +Z direction, i.e., vertically upward, and the ink ejection direction by the second line head 6 is the -Z direction, i.e., vertically downward. This makes it possible to utilize the effect of gravity when transferring the medium P from the first transport belt mechanism 10 to the second transport belt mechanism 30, making it easier to transfer the medium P from the first transport belt mechanism 10 to the second transport belt mechanism 30.

In addition, in this embodiment, a portion of the first conveyor belt mechanism 10 and a portion of the second conveyor belt mechanism 30 overlap in the media conveying direction. In FIG. 1, area Y1 indicates the area where a portion of the first conveyor belt mechanism 10 and a portion of the second conveyor belt mechanism 30 overlap in the media conveying direction. With this configuration, the medium P can be more reliably transferred from the first conveyor belt mechanism 10 to the second conveyor belt mechanism 30, and the device dimensions in the media conveying direction can also be reduced.

In this embodiment, at least a portion of the first transport belt mechanism 10 and at least a portion of the second line head 6 overlap in the vertical direction, and at least a portion of the second transport belt mechanism 30 and at least a portion of the first line head 5 overlap in the vertical direction.
1, an area Z1 indicates an area where a part of the first conveyor belt mechanism 10 and a part of the second line head 6 overlap in the vertical direction. An area Z2 indicates an area where a part of the second conveyor belt mechanism 30 and a part of the first line head 5 overlap in the vertical direction.
With this configuration, the vertical dimension of the device can be reduced.

Furthermore, the first conveyor belt mechanism 10 and the second line head 6 may be configured such that the entire first conveyor belt mechanism 10 overlaps with a part of the second line head 6 in the vertical direction, or the entire second line head 6 overlaps with a part of the first conveyor belt mechanism 10 in the vertical direction, or the entire first conveyor belt mechanism 10 and the entire second line head 6 overlap in the vertical direction.
Similarly, the second conveyor belt mechanism 30 and the first line head 5 may be configured such that the entire second conveyor belt mechanism 30 overlaps vertically with a part of the first line head 5, or the entire first line head 5 overlaps vertically with a part of the second conveyor belt mechanism 30, or the entire second conveyor belt mechanism 30 and the entire first line head 5 overlap vertically.

In addition, in this embodiment, a peeling claw 25 is provided to peel the medium P from the first conveyor belt mechanism 10. This allows the medium P to be properly handed over from the first conveyor belt mechanism 10 to the second conveyor belt mechanism 30.

It is also preferable that the control unit 50 that controls the suction fan 21 of the first transport belt mechanism 10 controls the suction fan 21 in accordance with the recording conditions. This makes it possible to appropriately suck the medium P in accordance with the recording conditions.
For example, if there is a first medium P1 and a second medium P2 that has a larger basis weight than the first medium P1, the second medium P2 is more likely to fall than the first medium P1 due to its weight. Therefore, as a first control example of the suction fan 21, when transporting the second medium P2, the suction fan 21 is rotated at a higher speed than when transporting the first medium P1 to ensure suction force. This allows the second medium P2 to be appropriately sucked. In this way, the basis weight of the medium P is an example of a recording condition.

For example, if the suction duct 22 is connected to the negative pressure chamber 17 at the center position in the media width direction (X-axis direction), the suction force is likely to decrease toward the ends in the media width direction. Therefore, as a second control example of the suction fan 21, when there is a third medium P3 and a fourth medium P4 that is larger in size in the media width direction than the third medium P3, the suction fan 21 is rotated faster when transporting the fourth medium P4 than when transporting the third medium P3 to ensure suction force. This allows the fourth medium P4 to be appropriately adsorbed. In this way, the medium size in the media width direction is one example of a recording condition.

For example, if there is a fifth medium P5 and a sixth medium P6 that is longer in the transport direction (Y-axis direction) than the fifth medium P5, the sixth medium P6 is heavier than the fifth medium P5 and is more likely to fall. Therefore, as a third control example of the suction fan 21, when transporting the sixth medium P6, the suction fan 21 is rotated faster than when transporting the fifth medium P5 to ensure suction force. This allows the sixth medium P6 to be appropriately adsorbed. In this way, the length of the medium P in the transport direction is an example of a recording condition.

For example, when the media transport speed is a first speed and a second speed that is faster than the first speed, the media adsorption time is shorter at the second speed and the media is more likely to fall than at the first speed. Therefore, as a fourth control example of the suction fan 21, when the media P is transported at the second speed, the suction fan 21 is rotated faster than when the media P is transported at the first speed to ensure suction force. This allows the media P to be appropriately adsorbed when transporting the media P at the second speed. In this way, the transport speed of the media P is one example of a recording condition.

Also, for example, when the printing duty is a first duty and a second duty that is higher than the first duty, the medium P is more likely to curl and the adsorption area is reduced, making it more likely to fall, when the printing duty is the second duty, than when the printing duty is the first duty. Here, the printing duty is the proportion of ink covering a unit area of the printing surface, and for example, a 50% printing duty means that 50% of the unit area of the printing surface is covered with ink. However, the printing duty may also be the proportion of dots actually formed to dots that can be formed per unit area.
Therefore, as a fifth control example of the suction fan 21, when the printing duty is the second duty, the suction fan 21 is rotated faster than when the printing duty is the first duty to ensure suction force. This allows the medium P to be appropriately attracted when transporting the medium P at the second duty. In this way, the printing duty is an example of a printing condition.

Similarly, the ease with which the medium P curls also varies depending on the environmental conditions. For example, in a first environmental condition and a second environmental condition that is lower in temperature and humidity than the first environmental condition, the medium P is more likely to curl under the second environmental condition than under the first environmental condition, and the suction area is reduced, making it more likely to fall. Therefore, as a sixth control example of the suction fan 21, under the second environmental condition, the suction fan 21 is rotated faster than under the first environmental condition to ensure suction force. This allows the medium P to be appropriately adsorbed when transporting the medium P under the second environmental condition. In this way, the environmental conditions are an example of recording conditions. The control unit 50 can acquire temperature and humidity information using a temperature and humidity detection unit (not shown).

The first to sixth control examples described above are applied to the first conveyor belt mechanism 10, but they may also be applied to the second conveyor belt mechanism 30 in addition to the first conveyor belt mechanism 10, or they may be applied to the second conveyor belt mechanism 30 instead of the first conveyor belt mechanism 10.
Further, of the first to sixth control examples described above, only one of them may be adopted, or two or more of them may be adopted in combination.

Next, another embodiment of the first conveyor belt mechanism will be described with reference to Fig. 6. In Fig. 6, reference numeral 10A denotes a modified version of the first conveyor belt mechanism 10 described above, and reference numeral 15A denotes a modified version of the suction mechanism 15 described above. Note that in Fig. 6, the same components as those already described are denoted by the same reference numerals, and duplicated explanations will be avoided below.
The suction mechanism 15A includes a pressure case 16A. The suction fan 21 is connected to the negative pressure chamber 17 via a suction duct 22. When the suction fan 21 rotates, an airflow as shown by the arrows is generated in the suction duct 22, thereby creating a negative pressure in the negative pressure chamber 17.
Reference numeral 19 denotes a partition wall that divides the inside of the pressure case 16A, and a negative pressure chamber 17 is formed in the −Y direction of the partition wall 19, and a positive pressure chamber 18 is formed in the +Y direction of the partition wall 19.

The suction fan 21 is connected to the positive pressure chamber 18 via the exhaust duct 23. When the suction fan 21 rotates, an airflow as shown by the arrows is generated in the exhaust duct 23, thereby generating a positive pressure in the positive pressure chamber 18.
Here, the openings 16b (FIG. 5) formed in the wall portion 16a are formed not only in the area facing the negative pressure chamber 17 but also in the area facing the positive pressure chamber 18. As a result, the exhaust air discharged to the positive pressure chamber 18 via the exhaust duct 23 is discharged to the outside of the conveyor belt 11 via the openings 16b in the wall portion 16a and the holes 11a in the conveyor belt 11. As a result, the medium P is peeled off from the conveyor belt 11.

In FIG. 6, the symbol Bs indicates the peeling region. The peeling region Bs is formed in the +Y direction relative to the suction region As1. The suction region As1 corresponds to the Y-axis range of the negative pressure chamber 17 formed in the -Y direction relative to the partition wall 19, and the peeling region Bs corresponds to the Y-axis range of the positive pressure chamber 18 formed in the +Y direction relative to the partition wall 19. In the suction region As1, the medium P is subjected to an adsorption action, and in the peeling region Bs, the medium P is subjected to a peeling action.

The partition wall 19 is provided so as to be movable along the Y-axis direction under the control of the control unit 50. The partition wall 19 can be provided so as to be movable in the Y-axis direction by, for example, a belt mechanism (not shown) and a motor (not shown) that drives the belt mechanism.
In this embodiment, the peeling region BS is set so as not to face the first line head 5 during ink ejection. This makes it possible to prevent the exhaust gas discharged from the positive pressure chamber 18 from adversely affecting the flight of the ink ejected from the first line head 5.
In FIG. 6, the peeling claw 25 is provided downstream of the peeling region Bs, but the position where the peeling claw 25 comes into contact with the conveyor belt 11 may be within the peeling region Bs.

As described above, the area of the conveying belt 11 that faces the first surface S1 of the medium P includes an adsorption area AS1 that adsorbs the medium P to the conveying belt 11, and a peeling area Bs that is located downstream of the adsorption area AS1 in the medium conveying direction and peels the medium P from the conveying belt 11 by exhausting exhaust air generated by the suction mechanism 15A.
This allows the medium P to be properly peeled off from the transport belt 11 by the peeling region Bs, and ultimately allows the medium P to be properly handed over to the second transport belt mechanism 30.
In addition, since the peeling area Bs is configured to peel the medium P from the conveying belt 11 by discharging the exhaust air generated by the suction mechanism 15A, the peeling area Bs can be formed at low cost by effectively utilizing the exhaust air generated by the suction mechanism 15A.

The suction mechanism 15A also has a negative pressure chamber 17 in which negative pressure is created by the suction fan 21 and which draws in air through the holes 11a (see FIG. 4) in the conveyor belt 11, a positive pressure chamber 18 in which positive pressure is created by the suction fan 21 and which exhausts air through the holes 11a (see FIG. 4) in the conveyor belt 11, and a partition wall separating the negative pressure chamber 17 and the positive pressure chamber 18, which changes the area ratio between the suction region As1 and the peeling region Bs by moving in a direction that changes the volume ratio between the negative pressure chamber 17 and the positive pressure chamber 18. This makes it possible to adjust the suction of the medium P by the suction region As1 and the peeling of the medium P by the peeling region Bs, allowing for more appropriate suction and peeling of the medium P.

It is also preferable that the control unit 50 that controls the movement of the partition wall 19 controls the partition wall 19 in accordance with the recording conditions. This makes it possible to appropriately adsorb and peel off the medium P in accordance with the recording conditions.
For example, the smaller the suction area As1 is made by moving the partition wall 19 in the -Y direction, the stronger the suction force in the suction area As1 becomes, so that control similar to the first to sixth control examples described above can be adopted depending on the recording conditions.

In addition, since it is difficult to adsorb the leading edge of the medium P, it is also preferable to make the adsorption area As1 small when adsorbing the leading edge of the medium P to ensure the adsorption force, and to increase the adsorption area As1 as the transport of the medium P progresses. The upper diagram in FIG. 7 shows the position of the partition wall 19 when adsorbing the leading edge of the medium P, and the partition wall 19 is located at the furthest position in the -Y direction in the range where it does not face the first line head 5. As the transport of the medium P progresses from this state, the partition wall 19 is moved in the +Y direction, that is, downstream in the transport direction, as shown by the change from the upper diagram to the lower diagram in FIG. 7. By moving the partition wall 19 in this manner, an appropriate adsorption force can be obtained when adsorbing the leading edge of the medium P, and the peeling action by the peeling area Bs can be strengthened when peeling off the leading edge of the medium P, allowing the medium P to be appropriately peeled off from the transport belt 11.

Next, another embodiment of the first conveyor belt mechanism will be described with reference to Fig. 8. In Fig. 8, reference numeral 10B denotes a modified example of the first conveyor belt mechanism 10 described above. In Fig. 8, the same reference numerals are used to designate the same components as those already described, and duplicated descriptions will be avoided below.
In this embodiment, the first conveyor belt mechanism 10 is disposed at an angle with respect to the second conveyor belt mechanism 30 so that the downstream portion of the first conveyor belt mechanism 10 in the conveying direction approaches the second conveyor belt mechanism 30. Furthermore, the ink ejection direction of the first line head 5 is not parallel to the vertical direction, but is a direction that includes a +Z direction component and a +Y direction component.
By configuring in this manner, the curvature of the medium P when it is handed over from the first conveying belt mechanism 10B to the second conveying belt mechanism 30 can be reduced, and in particular, floating of the medium P in the suction area As2 of the second conveying belt mechanism 30 can be suppressed.

Next, another embodiment of the first conveyor belt mechanism will be described with reference to Fig. 9. In Fig. 9, reference numerals 10C and 30C respectively denote modified versions of the first conveyor belt mechanism 10 and the second conveyor belt mechanism 30 described above. In Fig. 9, the same reference numerals are used to designate the same components as those already described, and duplicated descriptions will be avoided below.
In this embodiment, the ink ejection direction by the first line head 5 and the ink ejection direction by the second line head 6 are aligned along the horizontal direction. Therefore, the medium transport direction by the first transport belt mechanism 10C and the medium transport direction by the second transport belt mechanism 30C are aligned along the vertical direction.
According to this configuration, the medium transport path can be made linear along the vertical direction, and the horizontal dimension of the device can be reduced.

Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included within the scope of the present invention.

1... inkjet printer, 2... device main body, 3... medium cassette, 4... feed roller, 5... first line head, 6... second line head, 7... discharge roller pair, 8... discharge tray,
10, 10A, 10B, 10C...first conveyor belt mechanism, 11...conveyor belt, 11a...hole, 12...driving pulley, 13...driven pulley, 15...suction mechanism, 16...pressure case, 16a...wall, 17...negative pressure chamber, 18...positive pressure chamber, 19...partition wall, 21...suction fan, 22...suction duct, 23...exhaust duct, 25...peeling claw,
30, 30C... second conveyor belt mechanism, 31... conveyor belt, 32... driving pulley, 33... driven pulley, 35... suction mechanism, 36... pressure case, 37... negative pressure chamber, 41... suction fan, 42... suction duct, 43... exhaust duct,
50: control unit, 51: medium detection unit,
As1, As2...suction area, Bs...peeling area, Ts...feed path, Te...ejection path, P...medium, S1...first surface, S2...second surface

Claims (12)

a first conveyor belt mechanism that adsorbs and conveys a first surface of the medium;
a first liquid ejection unit disposed opposite the first conveyor belt mechanism and configured to eject liquid onto a second surface of the medium opposite to the first surface;
a second conveyor belt mechanism to which the medium is delivered from the first conveyor belt mechanism and which conveys the medium by adsorbing the second surface of the medium;
a second liquid ejection unit that is disposed opposite the second conveyor belt mechanism and ejects liquid onto the first surface of the medium;
A liquid ejection device comprising: 2. The liquid ejection device according to claim 1, wherein a liquid ejection direction by the first liquid ejection section and a liquid ejection direction by the second liquid ejection section are aligned along a vertical direction.
A liquid ejection device comprising: 3. The liquid ejection device according to claim 2, wherein the liquid ejection direction by the first liquid ejection section is vertically upward, and the liquid ejection direction by the second liquid ejection section is vertically downward.
A liquid ejection device comprising: 4. The liquid ejection device according to claim 3, wherein a portion of the first transport belt mechanism and a portion of the second transport belt mechanism overlap with each other in a medium transport direction.
A liquid ejection device comprising: 5. The liquid ejection device according to claim 4, wherein at least a portion of the first transport belt mechanism and at least a portion of the second liquid ejection unit overlap in a vertical direction,
at least a portion of the second conveyor belt mechanism and at least a portion of the first liquid ejection unit overlap in a vertical direction;
A liquid ejection device comprising: 2. The liquid ejection apparatus according to claim 1, wherein the first conveyor belt mechanism comprises:
An endless conveyor belt having a plurality of holes formed therein;
a suction mechanism that attracts the medium to the conveyor belt by suction through the hole,
The area of the conveyor belt facing the first surface of the medium is
an adsorption area for adsorbing the medium to the conveyor belt by the suction mechanism;
a separation area located downstream of the suction area in a medium transport direction, the separation area separating the medium from the transport belt by discharging exhaust air generated by the suction mechanism through the holes;
having
A liquid ejection device comprising: 7. The liquid ejection apparatus according to claim 6, wherein the suction mechanism comprises:
A suction fan and
a negative pressure chamber in which negative pressure is created by the suction fan and which draws air through the holes in the conveyor belt;
a positive pressure chamber in which a positive pressure is generated by the suction fan, and the exhaust gas is discharged through the hole in the conveyor belt;
a partition wall separating the negative pressure chamber and the positive pressure chamber, the partition wall being adapted to change an area ratio between the adsorption region and the separation region by moving in a direction that changes a volume ratio between the negative pressure chamber and the positive pressure chamber;
having
A liquid ejection device comprising: 8. The liquid ejection device according to claim 7, further comprising a control unit that controls the movement of the partition wall,
the control unit controls the partition wall in accordance with a recording condition.
A liquid ejection device comprising: 2. The liquid ejection device according to claim 1, further comprising a peeling claw that peels the medium off the first transport belt mechanism.
A liquid ejection device comprising: 2. The liquid ejection device according to claim 1,
The first conveyor belt mechanism includes:
An endless conveyor belt having a plurality of holes formed therein;
a suction mechanism that attracts the medium to the conveyor belt by suction through the hole,
The suction mechanism includes:
A suction fan and
a negative pressure chamber in which negative pressure is created by the suction fan, and the negative pressure chamber suctions air through the holes in the conveyor belt;
a control unit for controlling the suction fan controls the suction fan in accordance with a recording condition.
A liquid ejection device comprising: 2. The liquid ejection device according to claim 1, wherein the first conveyor belt mechanism is disposed at an angle with respect to the second conveyor belt mechanism so that a downstream portion of the first conveyor belt mechanism in a conveying direction approaches the second conveyor belt mechanism.
A liquid ejection device comprising: 2. The liquid ejection device according to claim 1, wherein a liquid ejection direction by the first liquid ejection unit and a liquid ejection direction by the second liquid ejection unit are aligned along a horizontal direction.
A liquid ejection device comprising:

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