JP2021030157A - Process liquid application device and printing device - Google Patents

Abstract

To suppress occurrence of jamming of a sheet material.SOLUTION: A process liquid application device comprises: an applying roller 206 that applies process liquid 201 to a sheet material P; a conveying roller pair 222 at an upstream side, arranged at an upstream side of the applying roller 206, which conveys the sheet material P; a conveying roller pair 231 at a downstream side, arranged at a downstream side of the applying roller 206, which conveys the sheet material P; and means that performs control by which linear velocity of the applying roller 206 is set to linear velocity of the conveying roller pair 222 at an upstream side or more and linear velocity of the conveying roller pair 231 at a downstream side is set to the linear velocity of the applying roller 206 or more.SELECTED DRAWING: Figure 3

Description

The present invention relates to a processing liquid applying device and a printing device.

Some printing devices include a pretreatment means (coating device) for applying (coating) a treatment liquid to a sheet material before printing.

Conventionally, it has a coating roller for applying a processing liquid to a recording medium and a pressure roller for crimping the recording medium to the coating roller, and is added to the coating roller at the start of coating of the processing liquid and during accelerated transportation of the recording medium. A treatment liquid coating device is known in which the transport speed V3 of the recording medium is higher than the peripheral speed V2 of the coating roller (V3> V2) when the pressure roller is crimped to start coating (V3> V2). Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-022874

By the way, in the treatment liquid application device (treatment liquid application device), for example, the transfer speed changes depending on the type of sheet material, and a speed difference occurs between the coating rotating body and the upstream side transfer rotating body and the downstream side transfer rotating body. There is a problem that jam occurs.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress the occurrence of jam in the sheet material.

In order to solve the above problems, the treatment liquid applying device according to the present invention is used.
A coating rotating body that applies the treatment liquid to the sheet material, and
An upstream transfer rotating body arranged on the upstream side of the coating rotating body and conveying the sheet material, and an upstream transport rotating body,
A downstream transfer rotating body arranged on the downstream side of the coating rotating body and conveying the sheet material, and a downstream transport rotating body.
It is provided with means for controlling the linear speed of the coating rotating body to be equal to or higher than the linear speed of the upstream transport rotating body and the linear speed of the downstream transport rotating body to be equal to or higher than the linear speed of the coating rotating body. It was configured.

According to the present invention, it is possible to suppress the occurrence of jam in the sheet material.

It is a schematic explanatory drawing of the printing apparatus which concerns on 1st Embodiment of this invention. It is a plane explanatory view of the ejection unit of the printing apparatus. It is explanatory drawing of the pretreatment part (coating apparatus) in the same embodiment. It is a block explanatory drawing of the part which concerns on the rotation control of a roller in the same embodiment. It is explanatory drawing which provides the explanation of the relationship between the thickness of the sheet material P and the linear velocity. It is explanatory drawing which provides the explanation of the relationship between the magnitude of a pressing force and the linear velocity. It is explanatory drawing which provides for the explanation of the relationship between single-sided coating and double-sided coating and linear velocity. It is explanatory drawing which provides for the explanation of the relationship between the magnitude of a coating amount and a linear velocity. It is explanatory drawing provided for the explanation of the combination of the thickness of a sheet material, the pressing force, and the coating amount. It is explanatory drawing of the table in the case of correcting (changing) the linear velocity of a coating roller. It is explanatory drawing of the table in the case of correcting (changing) the linear velocity of the upstream side transport roller pair. It is explanatory drawing of the table in the case of correcting (changing) the linear velocity of the upstream side transport roller pair. It is explanatory drawing which provides the explanation of the degree of linear velocity correction A to H. It is explanatory drawing which provides the explanation of an example of the correction amount at the time of correcting the linear velocity of a coating roller. It is a block explanatory drawing of the part which concerns on the rotation control of a roller in 2nd Embodiment of this invention. It is a flow chart which is also used for the explanation of the rotation speed control (line speed correction control). It is explanatory drawing which provides the explanation of the change of the distance between the shafts of a coating roller and a pressure roller in the 3rd Embodiment of this invention. It is explanatory drawing which provides the explanation of an example of the relationship between the distance between axes and the linear velocity of a coating roller. It is a block explanatory drawing of the part which concerns on the rotation control of a roller in the same embodiment.

A printing device as a device for discharging a liquid according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic explanatory view of the printing apparatus.

The printing device 1 includes a carry-in section 10 for carrying in the sheet material P, a pretreatment section 20, a printing section 30, a drying section 40, a carry-out section 50, and a reversing mechanism section 60. In the printing apparatus 1, the pretreatment unit 20, which is a pretreatment means, applies (coats) a pretreatment liquid to the sheet material P, which is carried (supplied) from the carry-in unit 10, as needed, and the printing unit 30 applies (coats) a liquid. Is applied to perform the required printing, the liquid adhering to the sheet material P is dried by the drying unit 40, and then the sheet material P is discharged to the carry-out unit 50.

The carry-in unit 10 separates the carry-in tray 11 (lower carry-in tray 11A, upper carry-in tray 11B) for accommodating a plurality of sheet materials P and the sheet material P from the carry-in tray 11 and sends them out one by one (12A). , 12B), and the sheet material P is supplied to the pretreatment section 20.

The pretreatment section 20 includes, for example, a coating section 21 which is a treatment liquid applying means for aggregating the color material of the ink and applying a treatment liquid having an action effect of preventing show-through to the printed surface of the sheet material P. ..

The printing unit 30 includes a drum 31 which is a supporting member (rotating body) that supports the sheet material P on the peripheral surface and rotates, and a liquid discharge unit 32 that discharges liquid toward the sheet material P supported on the drum 31. I have.

Further, the printing unit 30 receives the sheet material P sent from the pretreatment unit 20 and passes the sheet material P to and from the drum 31, and receives the sheet material P conveyed by the drum 31 and reverses it. A delivery drum 35 to be passed to the mechanism unit 60 is provided.

The tip of the sheet material P transported from the pretreatment unit 20 to the printing unit 30 is gripped by a gripping means (sheet gripper) provided on the transfer cylinder 34, and is conveyed as the transfer cylinder 34 rotates. The sheet material P conveyed by the transfer cylinder 34 is delivered to the drum 31 at a position facing the drum 31.

A gripping means (seat gripper) is also provided on the surface of the drum 31, and the tip of the sheet material P is gripped by the gripping means (seat gripper). A plurality of suction holes are dispersedly formed on the surface of the drum 31, and a suction airflow is generated inward from the required suction holes of the drum 31 by the suction means.

The tip of the sheet material P delivered from the transfer cylinder 34 to the drum 31 is gripped by the sheet gripper, and is adsorbed and supported on the drum 31 by the suction airflow by the suction means, and is conveyed as the drum 31 rotates. Will be done.

The liquid discharge unit 32 includes a discharge unit 33 (33A to 33D) which is a liquid discharge means. For example, the discharge unit 33A is a cyan (C) liquid, the discharge unit 33B is a magenta (M) liquid, the discharge unit 33C is a yellow (Y) liquid, and the discharge unit 33D is a black (K) liquid. Discharge each. In addition, a discharge unit that discharges a special liquid such as white or gold (silver) can also be used.

The discharge operation of each discharge unit 33 of the liquid discharge unit 32 is controlled by a drive signal corresponding to the print information. When the sheet material P supported on the drum 31 passes through the region facing the liquid discharge unit 32, the liquids of each color are discharged from the discharge unit 33, and an image corresponding to the print information is printed.

The reversing mechanism unit 60 is a mechanism for reversing the sheet material P by a switchback method when double-sided printing is performed on the sheet material P delivered from the delivery cylinder 35, and the inverted sheet material P is a printing unit. It is sent back to the upstream side of the delivery cylinder 34 through the transport path 61 of 30.

The drying unit 40 dries the liquid adhering to the sheet material P at the printing unit 30. As a result, the liquid content such as water in the liquid evaporates, the colorant contained in the liquid is fixed on the sheet material P, and the curl of the sheet material P is suppressed.

The carry-out unit 50 includes a carry-out tray 51 on which a plurality of sheet materials P are loaded. The sheet material P conveyed from the drying unit 40 is sequentially stacked and held on the carry-out tray 51.

Next, an example of the head unit constituting the discharge unit will be described with reference to FIG. FIG. 2 is a plan explanatory view of the head unit as viewed from the nozzle surface side.

The head unit 300 is formed by arranging a plurality of heads 100 for discharging liquid in a staggered manner on a head mounting member 302.

Each head 100 has a plurality of rows of nozzles (here, four rows are taken as an example, but the present invention is not limited) in which a plurality of nozzles 104 for discharging liquid are arranged.

In the present embodiment, the example in which the printing means includes the liquid discharging means is described, but printing can be performed by means other than the liquid discharging means.

Next, the pretreatment section (coating device) including the treatment liquid applying device according to the present invention will be described with reference to FIG. FIG. 3 is an explanatory diagram of the preprocessing unit.

The pretreatment section 20 includes a coating section 21 which is a treatment liquid applying means (coating means) for applying the treatment liquid 201 which is a coating liquid to the sheet material P, an upstream transport path 22, and a downstream transport path 23. The reverse transport path 24, the straight transport path 25, and the like are provided.

The upstream transfer path 22 is a path for transporting the sheet material P sent to the pretreatment section 20 toward the coating section 21, and is a direction in which a plurality of transport roller pairs for transporting the sheet material P are orthogonal to the transport direction. The transport roller pairs 221 and 222 arranged in the above are arranged.

The downstream transfer path 23 is a path for transporting the sheet material P coated with the treatment liquid 201 by the coating section 21 toward the printing section 30 on the downstream side, and a plurality of transport roller pairs 231 are arranged.

When the treatment liquid 201 is applied to both surfaces of the sheet material P, the reverse transfer path 24 receives the sheet material P coated with the treatment liquid 201 on one surface from the middle of the downstream transfer path 23, reverses the sheet material P, and then reverses the sheet material P again. , It is a path to send toward the transfer roller pair 222 of the upstream side transfer path 22, and a plurality of transfer roller pairs 241 are arranged.

A branch claw 26 for switching from the inlet of the reverse transport path 24 is provided in the middle of the downstream transport path 23.

The straight transfer path 25 is a path in which the sheet material P sent from the carry-in section 10 is merged in the middle of the downstream transfer path 23 as it is without applying the treatment liquid 201 at the coating section 21. When the coating unit 21 can be in a non-coated state, the sheet material P to which the processing liquid 201 is not applied is transported from the upstream transport path 22 through the downstream transport path 23 without separately providing the straight transport path 25. You can also do it.

The coating unit 21 processes the treatment liquid storage tank (supply pan) 202 containing the treatment liquid 201, the pumping rollers 203 for pumping the treatment liquid 201, the intermediate rollers 204 and 205 for controlling the film thickness, and the sheet material P. The coating roller 206, which is a coating rotating body for coating the liquid 201, is provided. Further, the coating unit 21 includes a pressure roller 207 which is a pressure rotating body facing the coating roller 206 and a pressing roller 208 which presses against the pressure roller 207.

The coating unit 21 pumps the treatment liquid 201 by the pumping roller 203, controls the film thickness by the intermediate rollers 204 and 205, transfers the treatment liquid 201 to the coating roller 206, and has a required thickness on the peripheral surface of the coating roller 206. A liquid film of the treatment liquid 201 of the above is formed.

Then, the sheet material P transported via the upstream side transport roller pair 222, which is the upstream side transport rotating body, passes through the nip portions of the coating roller 206 and the pressure roller 207, so that the treatment liquid 201 is transferred to the sheet material P. It is applied. The upstream transfer roller pair 222 is a pair of the upstream transfer drive roller 222a and the driven roller 222b.

The sheet material P coated with the treatment liquid 201 is conveyed further downstream via the downstream transfer roller pair 231 which is the downstream transfer rotating body of the downstream transfer path 23 and the plurality of transfer rollers 232 and 233. Alternatively, it is transported to the reverse transport path 24. The downstream transfer roller pair 231 is a pair of the downstream transfer drive roller 231a and the driven roller 231b.

In the present embodiment, of the two rollers of the transfer roller pair 231 and 232, the transfer roller, which is a rotating body on the side in contact with the coating surface of the sheet material P coated with the treatment liquid 201, is used as a drive roller and is used as a peripheral surface. A bead roller provided with fine particles is used. As a result, it is possible to reduce that the treatment liquid 201 applied to the sheet material P is scraped off by the transport roller pairs 231 and 232.

Next, the portion related to the rotation control of the rollers in the present embodiment will be described with reference to the block explanatory diagram of FIG.

The rotation control means 801 controls the rotation of the coating roller 206 via the roller drive unit 811. The rotation control means 801 drives and controls the upstream transfer drive roller 222a via the roller drive unit 812 to control the rotation of the upstream transfer roller pair 222. The rotation control means 801 drives and controls the downstream transfer drive roller 231a via the roller drive unit 813 to control the rotation of the downstream transfer roller pair 231.

The storage means 802 includes the pressing force by the pressurizing roller 207, the type of the sheet material P, the coating amount, and the rotation speed (linear speed) of the coating roller 206, the upstream transport roller pair 222, and the downstream transport roller pair 231. A table in which relationships are defined in advance is stored.

The rotation control means 801 inputs information on the pressing force, the thickness of the sheet material P, and the coating amount, and from the table stored in the storage means 802, the coating roller 206, the upstream transfer roller pair 222, and the downstream transfer roller pair Each rotation speed (line speed) of 231 is read out.

Then, the rotation control means 801 controls the rotation of the coating roller 206, the upstream transfer roller pair 222, and the downstream transfer roller pair 231 (linear speed) according to the read rotation speed (linear speed), and applies the coating. Control is performed so that the linear velocity of the roller 206 is equal to or higher than the linear velocity of the upstream transfer roller vs. 222 and the linear velocity of the downstream transfer roller vs. 231 is equal to or greater than the linear velocity of the coating roller 206.

By giving each information of the pressing force, the thickness of the sheet material P, and the coating amount to the table of the storage means 802, the corresponding coating rollers 206, the upstream transfer roller pair 222, and the downstream transfer roller pair from the storage means 802 are provided. Information on each rotation speed (linear speed) of 231 may be given to the rotation control means 801.

Next, fluctuations in the transport speed in the pretreatment section will be described with reference to FIGS. 5 to 10. FIG. 5 is an explanatory view for explaining the relationship between the thickness of the sheet material P and the linear velocity, FIG. 6 is an explanatory diagram for explaining the relationship between the magnitude of the pressing force and the linear velocity, and FIG. 7 is a single-sided coating (giving) and double-sided coating. An explanatory diagram for explaining the relationship between (granting) and the linear velocity, and FIG. 8 is an explanatory diagram for explaining the relationship between the magnitude of the coating amount and the linear velocity.

Since the linear velocity can be expressed by linear velocity (m / s) = rotation speed (rps) × peripheral length (usually πd), the linear velocity increases as the peripheral length of the rotating body increases.

Further, the pressure roller 207 made of a metal roller is pressed (pressurized) against the coating roller 206 made of a rubber roller.

As shown in FIG. 5A, when the sheet material P is thin paper Pa, the sheet material P does not absorb the pressing force, the pressing force is directly applied to the coating roller 206, and the amount of deformation of the coating roller 206. Becomes larger. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is large, and the linear velocity is increased.

On the other hand, as shown in FIG. 5B, when the sheet material P is thick paper Pb, the sheet material P absorbs the pressing force and reduces the pressing force applied to the coating roller 206. The amount of deformation of the roller 206 is relatively small. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is small, and the linear velocity is relatively slow.

As shown in FIG. 6A, when the pressing force is large, the amount of deformation of the coating roller 206 becomes large. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is large, and the linear velocity is increased.

On the other hand, as shown in FIG. 6B, when the pressing force is small, the amount of deformation of the coating roller 206 is relatively small. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is small, and the linear velocity is relatively slow.

As shown in FIG. 7A, when coating is applied to one surface of thick paper, the sheet material P absorbs the pressing force, and the coating roller 206 deforms relatively little. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is small, and the linear velocity is relatively slow.

On the other hand, as shown in FIG. 7B, when the treatment liquid is applied to the other surface of the thick paper coated on one surface, the rigidity is lowered by the treatment liquid to which the sheet material P has already been applied, and the sheet material P is easily deformed. However, since the pressing force is not absorbed, the amount of deformation of the coating roller 206 is relatively large. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is small, and the linear velocity is relatively high.

As shown in FIG. 8A, when the coating amount (applied amount) is small (small), the effect on the rigidity of the sheet material P is small, the sheet material P absorbs the pressing force, and the coating roller 206 is deformed. Is relatively small. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is small, and the linear velocity is relatively slow.

On the other hand, as shown in FIG. 8B, when the coating amount (applied amount) is large (large), the rigidity of the sheet material P is lowered and easily deformed, and the pressing force is not absorbed. 206 has a relatively large amount of deformation. Therefore, the amount of elongation of the peripheral length of the coating roller 206 is small, and the linear velocity is relatively high.

Next, the relationship between the paper type (thickness), the pressing force, and the coating amount of the sheet material P will be described with reference to FIG. FIG. 9 is an explanatory diagram provided for explaining a combination of the thickness of the sheet material, the pressing force, and the coating amount.

First, the conditions for changing the pressing force are as follows. That is, when the thickness of the sheet material P is thick, the pressing force is increased, and when the thickness is thin, the pressing force is decreased. When the coating amount is reduced, the pressing force is increased, and when the coating amount is increased, the pressing force is decreased.

The conditions for changing the coating amount are as follows. That is, the coating amount varies depending on the composition of the coating layer of the sheet material P, but if the paper type (type) is the same, the coating amount becomes constant by making the paper passing conditions of the coating device the same. For paper type A, for which the tendency for the coating amount to increase is known in advance, the pressing force is increased and the coating amount is decreased. On the other hand, in the paper type B in which the tendency for the coating amount to decrease is known in advance, the pressing force is reduced and the coating amount is increased.

Thereby, it can be controlled so as to be within the target coating amount.

Therefore, when the paper type (thick paper, thin paper: thickness), pressing force, and coating amount of the sheet material P are set to large and small, respectively, a combination of NO1 to NO8 is established as shown in FIG.

Here, as for the degree of influence of the coating roller 206 on the linear velocity, the difference between thick paper and thin paper appears most prominently, then the magnitude of the pressing force, and then the magnitude of the coating amount.

When the sheet material P is thick paper, the sheet material P absorbs the pressing force, so that the linear velocity of the coating roller 206 is generally slowed down. When the pressing force is small, the linear velocity of the coating roller 206 becomes slower. When the coating amount is small, the linear velocity of the coating roller 206 becomes slower.

Therefore, when the combination of NO3 “thick paper, small pressure, small coating amount” in FIG. 9 is used, the linear velocity of the coating roller 206 is the slowest. Hereinafter, the order is NO3 → NO4 → NO1 → NO2.

On the other hand, when the sheet material P is thin paper, the sheet material P does not absorb the pressing force, so that the linear velocity of the coating roller 206 is generally increased. When the pressing force is large, the linear velocity of the coating roller 206 is further increased. .. Further, when the coating amount is large, the linear velocity of the coating roller 206 becomes high.

Therefore, when the combination of NO6 “thin paper, large pressure, large coating amount” in FIG. 9 is used, the linear velocity of the coating roller 206 becomes the fastest. Hereinafter, the order is NO6 → NO5 → NO8 → NO7.

Next, control of the rotation speed (linear speed) of the coating roller 206, the upstream transfer roller pair 222, and the downstream side transfer roller pair 231 will be described with reference to FIGS. 10 to 13. FIG. 10 shows the case where the linear velocity of the coating roller is corrected (changed), FIG. 11 shows the linear velocity of the upstream transport roller pair corrected (changed), and FIG. 12 shows the linear velocity of the upstream transport roller pair corrected (changed). ) Is an explanatory diagram provided for the explanation of each table in the case of. FIG. 13 is an explanatory diagram provided for explaining the degree of linear velocity correction A to H.

First, the relationship between the line speeds of the coating roller 206, the upstream transfer roller pair 222, and the downstream side transfer roller pair 231 is such that the line speed of the coating roller 206 is equal to or higher than the line speed of the upstream side transfer roller pair 222. The linear velocity of the pair 231 is controlled to be equal to or higher than the linear velocity of the coating roller 206. That is, the rotation speeds of the coating rollers 206, the upstream transport rollers 222, and the downstream transport rollers 231 are controlled so that the linear velocity has a relationship of upstream transport roller pair ≤ coating roller ≤ downstream transport roller pair. ..

As a result, stable transfer of the sheet material and application (coating) of the treatment liquid can be performed.

In this case, the difference between the linear speed of the upstream transport roller vs. 222 and the linear speed of the downstream transport roller vs. 231 is preferably within 10%.

Therefore, when correcting the linear velocity of the coating roller 206, the linear velocity is controlled by using a table as shown in FIG. At this time, the line speed of the upstream side transfer roller pair 222 and the line speed of the downstream side transfer roller pair 231 may be any line speed satisfying the relationship of upstream side transfer roller pair ≤ coating roller ≤ downstream side transfer roller pair.

Further, when correcting the linear velocity of the upstream transfer roller 222, the linear velocity is controlled by using a table as shown in FIG. At this time, the linear speed of the coating roller 206 and the linear speed of the downstream transport roller pair 231 may be any linear speed satisfying the relationship of upstream transport roller pair ≤ coating roller ≤ downstream transport roller pair.

Further, when correcting the linear velocity of the downstream transfer roller pair 231, the linear velocity is controlled by using a table as shown in FIG. At this time, the linear speed of the upstream transport roller pair 222 and the linear speed of the coating roller 206 may be any linear speed satisfying the relationship of upstream transport roller pair ≤ coating roller ≤ downstream transport roller pair.

As shown in FIG. 13, the linear velocity corrections A to H in each table are A> B> C> D> E> F> G> H, with A being the fastest and H being the slowest.

Next, an example of the correction amount when correcting the linear velocity of the coating roller 206 will be described with reference to FIG. FIG. 14 is an explanatory diagram for the same explanation.

Here, the paper types are classified into three categories: thick paper, thin paper, and medium-thick paper. It is shown by the correction amount (%).

As described above, these tables are stored in the storage means 802, and according to each information of the thickness of the sheet material, the pressing force, and the coating amount, the coating roller 206 and the upstream transfer roller pair 222 are stored according to the table. , At least one of the rotation speeds of the downstream transfer roller pair 231 is controlled to correct the linear velocity.

In this way, by controlling the linear velocity in the relationship of the upstream side transport roller pair ≤ coating roller ≤ downstream side transfer roller pair, the occurrence of jam in the sheet material is suppressed.

Next, the second embodiment of the present invention will be described with reference to FIGS. 15 and 16. FIG. 15 is a block explanatory view of a portion related to roller rotation control in the same embodiment, and FIG. 16 is a flow diagram for explaining rotation speed control (linear speed correction control).

In the present embodiment, the upstream side line speed detecting means 822 for detecting the line speed of the upstream side transport roller pair 222 and the downstream side line speed detecting means 823 for detecting the line speed of the downstream side transport roller pair 231 are provided.

The rotation control means 801 is applied based on the linear speed of the upstream transport roller pair 222 detected by the upstream lateral speed detecting means 822 and the linear speed of the downstream transport roller pair 231 detected by the downstream linear speed detecting means 823. The linear velocity of the roller 206 is corrected, and the linear velocity is controlled in the relationship of upstream transfer roller pair ≤ coating roller ≤ downstream transfer roller pair.

With reference to FIG. 16, first, when the transfer (paper passing) of the sheet material P to the coating portion 21 is started, it is determined whether or not the sheet material P is the first sheet material P (step S1, hereinafter, It is simply written as "S1".)

Here, in the case of the first sheet material P, the linear velocity of the coating roller 206 is set based on the linear velocity of the upstream transfer roller pair 222, and the linear velocity of the coating roller 206 is set to the upstream transfer roller pair ≤ coating roller ≤ downstream transport roller. Correct so that there is a pair-to-pair relationship.

On the other hand, if it is not the first sheet material P, the linear velocity of the coating roller 206 is set based on the linear velocity of the downstream transfer roller pair 231. Correct so that the relationship is roller pair.

That is, the linear velocity of the sheet material P after coating, that is, the linear velocity of the downstream transfer roller pair 231 is used as a reference (based on the conveying speed of the sheet material P coated with the treatment liquid). However, in the case of the first sheet, the linear velocity of the downstream transfer roller vs. 231 is not the solid linear velocity of the sheet material P, so that the first sheet is a coating roller based on the linear velocity of the upstream transfer roller vs. 222. The linear velocity of 206 is corrected. In this case, the control can be switched to after passing a predetermined number of sheets (for example, 2 to 3 sheets) of the sheet material P, that is, based on the linear velocity of the downstream transfer roller pair 231.

As a result, the linear velocity can be controlled in the relationship of upstream side transport roller pair ≤ coating roller ≤ downstream side transport roller pair without using a table as in the first embodiment, and control becomes simple. ..

Next, the third embodiment of the present invention will be described with reference to FIGS. 17 to 19. FIG. 17 is an explanatory diagram used to explain the change in the distance between the axes of the coating roller and the pressure roller used for the explanation of the embodiment, and FIG. 18 is an explanatory view provided for explaining an example of the relationship between the distance between the axes and the linear velocity of the coating roller. FIG. 19 is a block explanatory view of a portion related to roller rotation control in the same embodiment.

With reference to FIG. 17, the distance between the axes (distance between the axes) L between the coating roller 206 and the pressurizing roller 207 is, for example, the distance L1 as shown in FIG. 17A when no pressurization is applied. .. On the other hand, when the coating roller 206 is pressurized by the pressurizing roller 207 via the sheet material P, as shown in FIG. 17B, depending on the thickness, pressing force, and coating amount of the sheet material P. The distance becomes L2, or the distance becomes L3 as shown in FIG. 17 (c).

The change in the distance L between the axes of the coating roller 206 and the pressure roller 207 correlates with the change in the amount of deformation of the coating roller 206, and the linear velocity changes with the change in the amount of deformation of the coating roller 206.

Here, the relationship between the inter-axis distance L and the speed is shown in FIG. The X-axis shows the "distance between the shafts when pressurized-the distance between the shafts when there is no load + the thickness of the sheet material", and the Y-axis shows the linear velocity of the coating roller.

When the value of the X-axis is zero, the linear velocity of the coating roller 206 is represented by (rotation speed x diameter x π). Then, the more the X-axis is on the minus side, that is, the larger the amount of crushing of the coating roller 206, the faster the linear velocity of the coating roller 206.

Therefore, by detecting the distance L between the axes of the coating roller 206 and the pressure roller 207 and correcting the linear velocity of the coating roller 206, the relationship of upstream side transport roller pair ≤ coating roller ≤ downstream side transport roller pair. Can be controlled to be.

That is, as shown in FIG. 19, the means for controlling includes the inter-axis distance detecting means 831 for detecting the inter-axis distance between the coating roller 206 and the pressurizing roller 207. The inter-axis distance detecting means 831 can form a distance measuring sensor, a linear encoder, or the like.

Then, in the rotation control means 801, the linear speeds of the coating roller 206, the upstream transport roller pair 222, and the downstream transport roller pair 231 are set according to the shaft distance detected by the shaft distance detecting means 831. Control is performed so that the relationship is ≤ coating roller ≤ downstream transport roller pair.

As a result, the linear velocity can be controlled in the relationship of upstream side transport roller pair ≤ coating roller ≤ downstream side transport roller pair without using a table as in the first embodiment, and control becomes simple. ..
It should be noted that the first embodiment and the second and third embodiments can be combined.

Note that printing in the present application has the same meaning as image formation, recording, printing, printing, and the like. Further, the treatment liquid applying device (treatment liquid coating device) of the present application can also be applied to a device that prints a sheet material coated with the treatment liquid (coating liquid) by an electrophotographic process.

1 Printing device 10 Carry-in unit 20 Pre-processing unit (pre-processing means)
30 Printing part 40 Drying part 50 Carrying out part 21 Coating part (treatment liquid applying means)
22 Upstream side transfer path 23 Downstream side transfer path 24 Reverse transfer path 25 Straight transfer path 31 Drum 32 Liquid application part 34 Transfer cylinder 201 Treatment liquid 206 Coating roller (coating rotating body)
206 Pressurized roller (pressurized rotating body)
222 Conveying roller pair (upstream transport rotating body)
231 Conveying roller pair (downstream transport rotating body)
801 Rotation control means (means for controlling)

Claims (7)

A coating rotating body that applies the treatment liquid to the sheet material, and
An upstream transfer rotating body arranged on the upstream side of the coating rotating body and conveying the sheet material, and an upstream transport rotating body,
A downstream transfer rotating body arranged on the downstream side of the coating rotating body and conveying the sheet material, and a downstream transport rotating body.
It is provided with means for controlling the linear speed of the coating rotating body to be equal to or higher than the linear speed of the upstream transport rotating body and the linear speed of the downstream transport rotating body to be equal to or higher than the linear speed of the coating rotating body. A treatment liquid applying device characterized by this. The means for performing the control is
When at least one of the pressing force for pressing the sheet material against the coating rotating body, the thickness of the sheet material, and the amount of the treatment liquid applied changes, the coating rotating body, the upstream transport rotating body, and the downstream side The processing liquid applying device according to claim 1, wherein at least one rotation speed of the transport rotating body is changed. The treatment liquid applying device according to claim 1 or 2, wherein the means for performing the control performs control for changing the rotation speed of the coating rotating body. The treatment liquid applying device according to any one of claims 1 to 3, wherein the means for performing the control changes the rotation speed of the coating rotating body with reference to the rotation speed of the downstream transporting rotating body. The treatment liquid applying device according to any one of claims 1 to 3, wherein the means for performing the control changes the rotation speed of the coating rotating body with reference to the rotation speed of the upstream transport rotating body. A pressure rotating body that pressurizes the sheet material against the coating rotating body is provided.
The treatment liquid applying device according to any one of claims 1 to 3, wherein the number of rotations of the coating rotating body is changed according to the distance between the axes of the pressurized rotating body and the coating rotating body. The treatment liquid applying device according to any one of claims 1 to 6.
A printing apparatus comprising a printing means for applying a liquid to the sheet material to which the treatment liquid has been applied and printing with the treatment liquid application device.

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