JP2016175709A - Drying equipment and printing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide drying equipment and a printing system which can prevent yellowing of paper caused by heat and can cool a heating part.SOLUTION: Drying equipment 100 comprising a heating part 30 and multiple rollers 41, 44 conveying a recording medium 10 and cooling the heating part when heating action by the heating part is stopped or in a stand-by state comprises a roller move mechanism 49 holding at least one roller in the multiple rollers movably, and conveys the recording medium to at least one of a downstream direction of the conveying direction of the recording medium and an upstream direction of the conveying direction by the move of the roller move mechanism in the cooling time of the heating part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a drying apparatus and a printing system.

  2. Description of the Related Art Conventionally, there is known a drying apparatus that dries a recording medium by a heating unit that heats the recording medium on which a deposit such as ink or pretreatment liquid is applied.

As this type of drying apparatus, for example, Patent Document 1 describes the following drying apparatus. This drying apparatus includes a heating unit that heats a long recording medium, and a plurality of rollers that wrap and convey the recording medium in the drying apparatus. The recording medium conveyed by the plurality of rollers is dried by passing through the heating unit and conveyed to the outside of the drying apparatus.
In addition, the drying device includes a discharge fan for discharging the air in the heating unit to the outside. With this discharge fan, an air flow is formed in the heating unit when the heating operation by the heating unit is stopped, and the heating roller can be cooled by this air flow.

Normally, the drying device needs to stop the heating operation by the heating unit or lower the temperature of the heating unit in the standby state when working in the device after stopping the device or switching the set temperature of the heating unit. is there.
However, the drying apparatus of Patent Document 1 does not mention the operation of the recording medium when the heating operation of the heating unit is stopped. If the paper continues to contact the high temperature heating roller, the heat of the heating roller may cause the paper to turn yellow (yellowing).

In order to achieve the above-described problem, the present invention includes a heating unit that heats a recording medium and a plurality of rollers that convey the recording medium, and the heating operation by the heating unit is stopped or in a standby state. In the drying device for cooling the heating unit in the case,
A roller moving mechanism for movably holding at least one of the plurality of rollers, and when the heating unit is cooled, the roller moving mechanism moves to move the recording medium in the downstream direction and the transport The recording medium is transported to at least one of upstream in the direction.

  According to the present invention, it is possible to suppress yellowing of the paper due to heat and cool the heating unit.

1 is a schematic configuration diagram illustrating an example of a printing system including a drying device according to the present embodiment. The schematic block diagram which shows an example of the drying apparatus. The figure which shows an example of control of the drying apparatus. The figure explaining an example of the cooling operation of the heating part of the drying apparatus. The figure explaining an example of other operations of the cooling operation The graph which shows the relationship between cooling time and heating part temperature.

Hereinafter, an embodiment of a drying apparatus 100 as a recording medium heating apparatus to which the present invention is applied will be described with reference to the drawings.
First, a configuration of a printing system including the drying apparatus 100 according to the present embodiment will be described.
FIG. 1 is a schematic configuration diagram illustrating an example of a printing system including a drying apparatus 100 according to the present embodiment.
As shown in FIG. 1, the printing system 500 includes a printing apparatus 200 that is a pre-processing apparatus on the upstream side of the conveyance path of the recording medium 10 with respect to the drying apparatus 100 of the present embodiment, and a post-processing apparatus on the downstream side of the conveyance path. A winding device 300 is provided.

The printing apparatus 200 prints an image on a long recording medium 10 wound up on a roll.
The drying device 100 is an additional drying device that is installed between the printing device 200 and a winding device 300 described later, and improves the ink fixing property applied on the recording medium. The drying apparatus 100 will be described in detail later.
The winding device 300 is a recording medium processing device that continuously winds up the recording medium 10 appropriately dried inside the drying device 100.

Next, the configuration of the drying apparatus 100 according to the present embodiment will be described in detail.
FIG. 2 is a schematic configuration diagram illustrating an example of the drying apparatus 100 according to the present embodiment.
As shown in FIG. 2, the drying apparatus 100 according to this embodiment includes a tension unit 20, a drying unit 30 that is a heating unit, and a cooling unit 40. Further, the drying apparatus 100 according to the present embodiment includes a conveyance path for conveying the roll-shaped recording medium 10 inside the tension unit 20, the drying unit 30, and the cooling unit 40.

The tension unit 20 includes three guide rollers 21, 22, 23 (hereinafter referred to as 21-23), two dancer rollers 24, 25, and an upstream lifting mechanism 26 that is an upstream roller moving mechanism.
Each guide roller 21 to 23 is supported by bearings at both ends in the axial direction so as to freely rotate, and is installed to rotate following the conveyance of the recording medium 10.
Both end portions in the axial direction of the dancer rollers 24 and 25 are held by an upstream elevating mechanism 26 which will be described later so as to freely rotate, and are installed so as to rotate following the conveyance of the recording medium 10.

The upstream elevating mechanism 26 is provided to hold both end portions in the axial direction of the two dancer rollers 24 and 25 so that the inside of the tension portion 20 can be raised and lowered. The vertical position of the two dancer rollers 24 and 25 can be adjusted by moving the upstream lifting mechanism 26 up and down.
The upstream elevating mechanism 26 is a tension mechanism that applies tension to the recording medium 10 when the drying unit 30 is operated by moving the two dancer rollers 24 and 25 held by the upstream elevating mechanism 26. A tension is applied to the recording medium 10 by widening the interval between the pair of rollers around which the recording medium 10 is wound by the lifting operation of the upstream lifting mechanism 26.

  In addition, the tension unit 20 forms a transport path by winding the recording medium 10 around the three guide rollers 21 to 23 and the two dancer rollers 24 and 25 in the tension unit 20. The recording medium 10 passes through this conveyance path, and is sent to the drying unit 30 that is located downstream of the tension unit 20 in the conveyance direction of the recording medium 10 (hereinafter simply referred to as downstream in the conveyance direction).

The drying unit 30 includes a plurality of heating rollers 31, 32, 33, 34, 35, and 36 (hereinafter referred to as 31 to 36), and has a closed structure in which the entire drying unit 30 is covered with a heat insulating wall.
The plurality of heating rollers 31 to 36 include a heater having a predetermined heat capacity in the center of each of the heating rollers 31 to 36, and the conveyance area of the recording medium 10 is covered by the heat generation area of each heater. Each heating roller 31 to 36 has both ends in the axial direction held by bearings so that it can freely rotate, and is installed to rotate following the conveyance of the recording medium 10.
In addition, the drying unit 30 forms a transport path by winding the recording medium 10 around the plurality of heating rollers 31 to 36 in the drying unit 30. When the recording medium 10 passes through this conveyance path, the heating rollers 31 to 36 supply the amount of heat necessary for fixing and drying the ink applied to the recording medium 10 or the pre-coating liquid. Dried. And it is sent to the cooling part 40 located in the conveyance direction downstream with respect to the drying part 30.

The cooling unit 40 includes four dancer rollers 41, 42, 43, and 44 (hereinafter referred to as 41 to 44), four guide rollers 45, 46, 47, and 48 (hereinafter referred to as 45 to 48), and a downstream roller. It has a downstream lifting mechanism 49 as a moving mechanism and a cooling fan 50.
Both end portions in the axial direction of the dancer rollers 41 to 44 are held by a downstream raising / lowering mechanism 49 (described later) so as to be freely rotatable, and are installed to rotate following the conveyance of the recording medium 10.

The downstream raising / lowering mechanism 49 is provided so that the axial direction both ends of the four dancer rollers 41-44 may be hold | maintained, and the inside of the cooling part 40 can be raised / lowered. The vertical position of the four dancer rollers 41 to 44 can be adjusted by moving the downstream lifting mechanism 49 up and down.
The downstream lifting mechanism 49 is a tension mechanism that applies tension to the recording medium 10 during operation of the drying unit 30 by moving the four dancer rollers 41 to 44 held by the downstream lifting mechanism 49. A tension is applied to the recording medium 10 by widening the interval between the pair of rollers around which the recording medium 10 is wound by the lifting operation of the downstream lifting mechanism 49.
Furthermore, the downstream lifting mechanism 49 is a recording medium cooling mechanism that cools the recording medium 10 conveyed from the drying unit 30 when the drying unit 30 is in operation. The downstream lifting mechanism 49 adjusts the conveyance distance of the recording medium 10 in the cooling unit 40 by moving the four dancer rollers 41 to 44 held by the downstream lifting mechanism 49 and adjusts the cooling time of the recording medium 10. doing.

Each guide roller 45 to 48 is supported by bearings at both ends in the axial direction so as to freely rotate, and is installed to rotate following the conveyance of the recording medium 10.
The cooling fan 50 is a cooling unit that is provided below the dancer rollers 41 to 44 and cools the recording medium 10 that has become a high temperature due to heating in the drying unit 30 when the drying unit 30 is in operation.
In the cooling unit 40, the recording medium 10 is wound around four dancer rollers 41 to 44 and four guide rollers 45 to 48 to form a conveyance path. The recording medium 10 that has passed through the drying unit 30 is cooled by the cooling fan 50 when passing through this transport path, and is sent to the winding device 300 that is located downstream in the transport direction of the drying device 100.

Next, an example of control of the drying apparatus of this embodiment will be described.
FIG. 3 is a diagram illustrating an example of control of the drying apparatus of the present embodiment.
As shown in FIG. 3, the control device 70 that is a control unit in the present embodiment is connected to the upstream lifting mechanism 26, the downstream lifting mechanism 49, the cooling fan 50, the operation unit 71, and the heating unit temperature sensor 72. ing.
The operation unit 71 is an information input unit through which an operator inputs a cooling instruction, and the heating unit temperature sensor 72 is a temperature detection unit that is installed in the drying unit 30 of the drying apparatus 100 and detects the temperature of the heating unit.

  When a cooling instruction is input to the operation unit 71, the control device 70 controls the upstream lifting mechanism 26, the downstream lifting mechanism 49, and the cooling fan 50 to perform a cooling operation described later. Then, control is performed so that the cooling operation of the drying unit 30 is performed until the detection value of the heating unit temperature sensor 72 becomes 70 degrees or less (maintenance temperature).

Next, the cooling operation of the drying unit 30 in the drying apparatus 100 of the present embodiment will be described.
FIG. 4 is a diagram for explaining an example of the cooling operation of the drying unit 30 provided in the drying apparatus 100.
When the controller 70 receives a cooling instruction for the drying unit 30 from the operator when the drying device 100 is stopped, the drying device 100 in the present embodiment performs the cooling operation of the drying unit 30 as follows.

First, as shown in FIG. 4, the downstream lifting mechanism 49 provided in the cooling unit 40 is lowered in the direction of arrow A in the drawing.
As the downstream elevating mechanism 49 is lowered, the distance between the guide rollers 45 to 48 and the dancer rollers 41 to 44 in the cooling unit 40 is widened, and the conveyance distance of the recording medium 10 in the cooling unit 40 is increased. Further, since tension is generated in the recording medium 10 by the lowering of the downstream lifting mechanism 49, the recording medium 10 in the drying unit 30 is pulled toward the cooling unit 40 and conveyed into the cooling unit 40.
At this time, the upstream lifting mechanism 26 is lifted in the direction of arrow B in the drawing so that the transport distance in the tension portion 20 is shortened by the transport amount of the recording medium 10 transported by the lowering of the downstream lifting mechanism 49. Let

  The recording medium 10 heated by passing through the drying unit 30 is cooled on the downstream side in the transport direction with respect to the drying unit 30 by the downstream lifting mechanism 49 and the lowering operation and the lifting operation of the upstream lifting mechanism 26. It is conveyed into the section 40 and cooled by the cooling fan 50. On the other hand, on the upstream side in the transport direction with respect to the drying unit 30, the relatively low temperature recording medium 10 staying in the tension unit 20 is transported to the drying unit 30 by the lifting and lowering operation, and the heat of the drying unit 30 is transferred by heat conduction. Absorb.

FIG. 5 is a diagram illustrating another operation of the cooling operation.
Next, as shown in FIG. 5, the downstream lifting mechanism 49 provided in the cooling unit 40 is raised in the direction of arrow C in the figure.
As the downstream elevating mechanism 49 is raised, the distance between the guide rollers 45 to 48 and the dancer rollers 41 to 44 in the cooling unit 40 of the cooling unit 40 is narrowed, so the transport distance of the recording medium 10 in the cooling unit 40 is reduced. Shorter. Thereby, the recording medium 10 in the drying unit 30 is conveyed to the tension unit 20 side.
At this time, the downstream lifting mechanism 49 is moved in the direction of arrow D in the drawing so that the transport distance in the tension unit 20 is increased by the amount of change of the recording medium 10 transported by the lifting of the downstream lifting mechanism 49. Lower.

The recording medium 10 cooled in the cooling unit 40 is transported to the drying unit 30 by the ascending operation of the downstream lifting mechanism 49 and the descending operation of the upstream lifting mechanism 26, and the heat inside the drying unit 30 is transferred by heat conduction. To absorb. Further, the recording medium 10 that has absorbed the heat in the drying unit 30 is conveyed to the tension unit 20, so that the recording medium 10 carries the heat of the drying unit 30 to the tension unit 20.
The cooling operation of the drying unit 30 in the present embodiment is controlled so as to repeat the lifting and lowering operations of the downstream lifting mechanism 49 and the upstream lifting mechanism 26 shown in FIGS. Accordingly, the heat of the drying unit 30 can be repeatedly conveyed to the cooling unit 40 and the tension unit 20 through the recording medium 10, and the drying unit 30 can be cooled by the heat conduction of the recording medium 10.

  As described above, since the recording medium 10 can be moved in the drying apparatus 100 by the lifting operation of the upstream lifting mechanism 26 and the downstream lifting mechanism 49, the drying unit 30 is cooled by heat conduction of the recording medium 10. Can do. Further, since the cooling is performed while moving the recording medium 10 during the cooling operation of the drying unit 30, it is possible to suppress the yellowing of the paper due to the heat of the heating roller.

Patent Document 2 describes a fixing device including a heating part cooling member as described below in order to switch the set temperature of the heating part from a high temperature to a low temperature.
The fixing device disclosed in Patent Document 1 includes a fixing roller pair as a heating unit including a heating roller with a built-in heater and a pressure roller in pressure contact with the heating roller, and a cooling length held in a roll shape on the winding roller. A scale member is provided as a heating part cooling member.
In this fixing device, a cooling elongate member is passed between the fixing roller pair in a state where the recording medium is not conveyed between the fixing roller pair, so that the heat of the fixing roller pair is absorbed by the elongate cooling member. Has been taken away. Thereby, the fixing roller pair can be cooled, and the set temperature of the heating unit can be switched.
However, when the heating unit cooling mechanism of Patent Document 1 is applied to a drying device that includes a plurality of rollers that wrap and convey a recording medium and a heating unit that heats the recording medium, a long sheet (recording) is recorded in the heating unit. When the medium is stretched, the long cooling member cannot be used.

In the drying apparatus 100 according to the present embodiment, the drying unit 30 is cooled by members for drying the recording medium 10 such as the upstream lifting mechanism 26, the downstream lifting mechanism 49, and the cooling fan 50.
That is, the upstream lifting mechanism 26 is a tension mechanism that applies tension to the recording medium 10 when the drying unit 30 is in operation, and the downstream lifting mechanism 49 is transported from the drying unit 30 when the tension mechanism and the drying unit 30 are in operation. A recording medium cooling mechanism for cooling the recorded recording medium. The cooling fan 50 is a cooling means for cooling the recording medium that has become high temperature due to heating in the drying unit 30 during operation of the drying unit 30.
For this reason, the drying apparatus 100 according to the present embodiment can cool the drying unit 30 without providing a dedicated cooling fan for cooling the heating unit or a dedicated member for cooling such as a long cooling member. .

  In the above description, the configuration in which the drying unit 30 uses the cooling fan for the cooling operation has been described. However, the drying unit 30 may have a configuration in which the cooling fan is not used for the cooling operation.

In general, when the drying unit for drying the recording medium is configured by a plurality of heating rollers, the heating roller located on the most upstream side in the transport direction among the plurality of heating rollers has a surface temperature set at the time of drying the recording medium. Does not go up. This is because the heat of the heating roller is taken away by the paper by contact with the paper. Therefore, when the drying unit is stopped, the sheet is taken away from the heat of each heating roller or the atmosphere contained in the drying unit by conveying the sheet to the drying unit, and the drying unit can be cooled.
However, when the drying unit is cooled by transporting the paper in this way, the printing device positioned upstream of the drying device usually cannot perform the rewinding operation, so the transported paper is wasted for cooling the drying unit. turn into.

In the drying apparatus 100 of the present embodiment, when the drying unit 30 is cooled, the transport distance of the recording medium 10 in the cooling unit 40 is shortened by raising the downstream lifting mechanism 49 compared to before the drying unit 30 is cooled. ing. Further, when the drying unit 30 is cooled, the transport distance of the recording medium 10 in the tension unit 20 is increased by the lowering of the upstream elevating mechanism 26 compared to before the drying unit 30 is cooled.
Thereby, when the drying unit 30 is cooled, the recording medium 10 can be transported in the direction opposite to the transport direction of the recording medium 10 when the drying unit 30 is in operation. Therefore, when the drying unit 30 is cooled, the drying unit 30 can be cooled by heat conduction of the recording medium 10 without continuing to transport the recording medium 10.

Further, in the drying apparatus 100 of the present embodiment, the amount of change in the conveyance distance due to the lifting / lowering operation of the downstream lifting mechanism 49 that changes when the drying unit 30 is cooled compared to before the drying unit 30 is cooled is as follows. It has become. That is, the upstream elevating mechanism 26 is raised so that the amount of change in the transport distance displaced by the downstream elevating mechanism 49 is equal to the amount of change in the transport distance displaced by the elevating operation of the upstream elevating mechanism 26. .
Specifically, the transport distance on the upstream side in the transport direction with respect to the drying unit 30 is increased by the transport amount of the recording medium 10 transported upstream in the transport direction with respect to the drying unit 30 by the lowering of the downstream lifting mechanism 49. The upstream lifting mechanism 26 is raised so as to be shorter. As a result, the recording medium can be stored in the cooling unit 40 by the amount of the recording medium conveyed by the lowering of the downstream lifting mechanism 49.

  Therefore, when the drying unit 30 is cooled, the recording medium 10 can be moved only in the drying device 100, and the recording medium that stays in the devices positioned upstream and downstream in the conveyance direction of the recording medium with respect to the drying device 100. The drying unit 30 can be cooled without moving. For this reason, the drying unit 30 can be cooled by transporting the recording medium 10 without affecting the devices positioned upstream and downstream in the transport direction.

Note that when the cooling operation of the drying unit 30 is performed, the recording medium 10 on the downstream side of the cooling unit 40 may be slightly pulled into the cooling unit 40 by the lowering of the downstream lifting mechanism 49.
Therefore, in order to prevent the movement of the recording medium 10 during the cooling operation of the drying unit 30 from affecting the apparatus located downstream with respect to the drying apparatus 100, for example, the driving of each lifting mechanism 26, 49 is performed by an encoder. You may control. In addition, among the plurality of rollers 41 to 48 provided in the cooling unit 40, the guide roller 48 located at the most downstream in the recording medium conveyance direction is used as a conveyance roller, and the recording medium is arranged between the pair of guide rollers 48. It is good also as a structure to nip. As a result, the recording medium 10 is not conveyed downstream of the guide roller 48 unless the guide roller 48 is rotationally driven. Therefore, it is possible to prevent the recording medium 10 from moving toward the conveyance path outside the drying apparatus 100 during the cooling operation of the drying unit 30.

In the above description, the configuration is such that both the lifting and lowering operations of the two lifting mechanisms 26 and 49 are controlled, but the configuration in which the effects of the present invention can be obtained is not limited thereto.
For example, the configuration of one of the two lifting mechanisms 26 and 49, for example, the configuration of the upstream lifting mechanism 26 is configured to apply tension to the recording medium 10 by the weight of the guide roller held by the lifting mechanism or a spring. . Then, when the drying unit 30 is cooled, only the downstream lifting mechanism 49 is lifted and lowered by the control device 50, and the movement of the two lifting mechanisms 26 and 49 may be controlled in an interlocking manner.

  Moreover, you may comprise as follows. That is, the two lifting mechanisms 26 and 49 are both configured to apply tension to the recording medium 10 by the weight of the guide roller held by each lifting mechanism. Further, a drive roller that can rotate in both directions is provided between the two lifting mechanisms 26 and 49 in the conveyance path of the recording medium, and the drive of the drive roller is controlled when the drying unit 30 is cooled. It is good also as a structure which controls the movement of the raising / lowering mechanisms 26 and 49. FIG.

Next, a verification experiment conducted by the inventor will be described.
FIG. 6 is a graph showing the relationship between the heating section temperature and time.
The solid line a in the figure indicates the relationship between the heating part temperature and time when the cooling operation of the drying part 30 described above is performed, and the solid line b in the figure is the heating when the drying part 30 is cooled by natural cooling. The relationship between part temperature and time is shown.

This verification experiment was performed under the following conditions, and the results are shown in FIG.
Condition: A φ80 [mm] aluminum heating roller is cooled from 140 degrees to 70 degrees.
Cooling operation: 20-inch width paper is conveyed 2900 [mm] to the drying unit downstream and upstream in the conveyance direction every minute. This conveyance distance is a conveyance distance from the heating roller 31 located most upstream in the conveyance direction of the recording medium to the heating roller 36 located most downstream among the plurality of heating rollers 31 to 36 in the heating unit 30. is there.

As shown in FIG. 6, when the cooling operation was not performed, it took about 40 minutes to decrease to 70 degrees. On the other hand, when the cooling operation was performed, the temperature decreased to 70 degrees in about 13 minutes.
Also, as a result of this verification experiment, it was found that the paper took 5000 [J] of heat from the roller in one cooling operation.

Usually, the heating part is not easily lowered in temperature because the heat insulation is increased in order to increase the heating efficiency. For this reason, when the drying part is cooled by natural cooling of the heating part, it takes time to lower the temperature to a desired temperature. Further, when the drying unit is cooled by natural cooling, if the sheet continues to contact the high-temperature heating roller, the sheet turns yellow (yellowing) due to the heat of the heating roller.
From the above experimental results, it was found that according to the drying apparatus 100 of the present embodiment, the heating roller can be cooled more quickly than when the drying unit 30 is cooled by natural cooling. Thereby, it is possible to suppress the paper from being yellowed by the heat of the heating roller.

  In this verification experiment, the conveyance distance of the recording medium in the cooling operation is the conveyance distance from the heating roller 31 located at the most upstream side in the conveyance direction of the recording medium to the heating roller 36 located at the most downstream side. The transport distance at which the effect of the invention can be obtained is not limited to this. For example, the recording medium in the drying unit 30 may be a distance that is transported upstream or downstream in the transport direction with respect to the drying unit 30.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A heating unit such as a drying unit 30 that heats a recording medium such as the recording medium 10 and a plurality of rollers such as dancer rollers 24, 25, and 41 to 44 that transport the recording medium, and a heating operation by the heating unit In the drying device that cools the heating unit when stopped or in a standby state, the drying device includes a roller moving mechanism such as a downstream lifting mechanism 49 that movably holds at least one of the plurality of rollers. When the heating unit is cooled, the recording medium is transported to at least one of a downstream direction in the transport direction of the recording medium and an upstream direction in the transport direction by the movement of the roller moving mechanism.

  In this aspect, as described in the above embodiment, the drying unit 30 can be cooled by the heat conduction of the recording medium 10 by moving the recording medium 10 by the lifting and lowering operation of the downstream lifting mechanism 49. Further, since the cooling is performed while moving the recording medium 10 during the cooling operation of the drying unit 30, it is possible to suppress the yellowing of the paper due to the heat of the heating roller.

(Aspect B)
In the aspect A, when the heating unit such as the drying unit 30 is cooled, the recording medium such as the recording medium 10 on the upstream side in the transport direction with respect to the heating unit is moved by the movement of the roller moving mechanism such as the downstream lifting mechanism 49. At least one of the transport distance and the transport distance of the recording medium on the downstream side in the transport direction is longer than before the cooling of the heating unit.

  In this aspect, as described in the above embodiment, the distance between the guide rollers 45 to 48 and the dancer rollers 41 to 44 in the cooling unit 40 is widened by the lowering of the downstream lifting mechanism 49, and the downstream lifting mechanism 49. Since the recording medium 10 is tensioned by the lowering, the recording medium 10 in the drying unit 30 can be conveyed to the cooling unit 40 side.

(Aspect C)
In aspect A or B, as the roller moving mechanism, an upstream roller moving mechanism such as an upstream elevating mechanism 26 positioned upstream in the conveyance direction of the recording medium with respect to the heating unit, and the heating unit A downstream roller moving mechanism such as a downstream lifting mechanism 49 located downstream in the transport direction, and the recording medium is moved by the movement of the downstream roller moving mechanism and the upstream roller moving mechanism when the heating unit is cooled. The recording medium is conveyed in at least one of the downstream direction in the conveying direction and the upstream direction in the conveying direction.

  According to this, the recording medium 10 can be moved only in the vicinity of the drying device 100 when the drying unit 30 is cooled.

(Aspect D)
In aspect C, the recording on the downstream side in the transport direction with respect to the heating unit such as the drying unit 30 changes as compared to before the cooling of the heating unit due to the movement of the downstream roller moving mechanism such as the downstream lifting mechanism 49. The amount of change in the conveyance distance of the recording medium such as the medium 10 and the movement of the upstream roller moving mechanism such as the upstream elevating mechanism 26 change compared to before the cooling of the heating unit, with respect to the heating unit. The upstream roller movement mechanism and the downstream roller movement mechanism move so that the amount of change in the conveyance distance of the recording medium on the downstream side in the conveyance direction becomes equal.

In this aspect, as described in the above embodiment, the recording medium can be stored in the cooling unit 40 by the amount of the recording medium transported by the lowering of the downstream lifting mechanism 49. Therefore, the recording medium 10 can be moved only within the drying device 100 when the drying unit 30 is cooled.
For this reason, it is possible to cool the drying unit 30 without moving the recording medium staying in the apparatus positioned upstream and downstream in the recording medium conveyance direction with respect to the drying apparatus 100. In addition, the drying unit 30 can be cooled by transporting the recording medium 10 without affecting the devices located upstream and downstream in the transport direction.

(Aspect E)
In aspect D, the transport distance of the recording medium on the downstream side in the transport direction with respect to the heating unit is shorter than that before cooling of the heating unit by the movement of the downstream roller moving mechanism and the upstream roller moving mechanism. The transport distance of the recording medium on the upstream side in the transport direction with respect to the heating unit is increased by the movement of the upstream roller moving mechanism as compared with before the cooling of the heating unit.

  In this aspect, as described in the above embodiment, when the drying unit 30 is cooled, the recording medium 10 can be transported in the direction opposite to the transport direction of the recording medium 10 when the drying unit 30 is in operation. It becomes. Therefore, the drying unit 30 can be cooled by heat conduction of the recording medium 10 without continuing to transport the recording medium 10 when the drying unit 30 is cooled.

(Aspect F)
In any one of the aspects C to E, at least one of the upstream roller moving mechanism such as the upstream lifting mechanism 26 and the downstream roller moving mechanism is a dancer roller held by the roller moving mechanism such as the upstream lifting mechanism 26. A tension mechanism that applies tension to the recording medium when the heating unit is operated by moving the positions of rollers such as 24 and 25.
According to this, as described in the above embodiment, the drying unit 30 can be cooled by the member for performing the drying operation of the recording medium in the drying device 100.

(Aspect G)
In any one of the aspects A to F, the downstream roller moving mechanism such as the downstream lifting mechanism 49 adjusts the transport distance by moving the position of the roller held by the downstream roller moving mechanism, and the heating And a recording medium cooling mechanism for cooling the recording medium conveyed from the section.
According to this, as described in the above embodiment, the drying unit 30 can be cooled by the member for performing the drying operation of the recording medium in the drying device 100.

(Aspect H)
In any one of Aspects A to G, a control unit such as a control device 70 that controls conveyance of the recording medium is provided.
As a result, as described in the above embodiment, it is possible to perform control so that the lifting / lowering operation of the downstream lifting mechanism 49 and the upstream lifting mechanism 26 is repeated during the cooling operation of the drying chamber 30. Therefore, the heat of the drying unit 30 can be repeatedly conveyed to the cooling unit 40 and the tension unit 20 via the recording medium 10, and the drying unit 30 can be cooled by heat conduction of the recording medium 10.

(Aspect I)
A pretreatment device such as a printing device 200 that applies an ink liquid or a pretreatment liquid to a recording medium, a drying device 100 that is installed downstream of the recording medium conveyance path with respect to the pretreatment device, and dries the recording medium. A printing system 500 having a drying device and a post-processing device such as a winding device 300 that is provided downstream of the conveyance path of the recording medium heating device and winds the recording medium or cuts it to an arbitrary size. In the printing system, the drying apparatus according to any one of the aspects A to H is used as the drying apparatus.
Thereby, it is possible to realize an image forming apparatus capable of suppressing yellowing of the sheet due to heat of the heating roller.

DESCRIPTION OF SYMBOLS 10 Recording medium 20 Tension part 26 Upstream raising / lowering mechanism 30 Drying part 40 Cooling part 49 Downstream raising / lowering machine 70 Control apparatus 100 Drying apparatus 200 Printing apparatus 300 Winding device 500 Printing system

JP 2014-177102 A JP-A-8-6410

Claims (9)

  In a drying apparatus that includes a heating unit that heats a recording medium and a plurality of rollers that convey the recording medium, and that stops the heating operation by the heating unit or cools the heating unit when in a standby state, A roller moving mechanism for movably holding at least one of the plurality of rollers, and when the heating unit is cooled, the roller moving mechanism moves to move the recording medium in the downstream direction and the transport direction. A drying apparatus for transporting the recording medium to at least one of upstream directions.   2. The drying apparatus according to claim 1, wherein when the heating unit is cooled, the recording medium is transported on the upstream side in the transport direction with respect to the heating unit, and the recording is performed on the downstream side in the transport direction by moving the roller moving mechanism. At least one of the transport distances of the medium is longer than that before cooling of the heating unit.   3. The drying apparatus according to claim 1, wherein, as the roller moving mechanism, an upstream roller moving mechanism that is located upstream of the heating unit in a conveyance direction of the recording medium, and a downstream of the heating unit in the conveyance direction. A downstream roller moving mechanism located on the side of the recording medium, and when the heating unit is cooled, the downstream roller moving mechanism and the upstream roller moving mechanism move to move the recording medium in the transport direction downstream of the heating unit. A drying apparatus that transports the recording medium in at least one of a direction and an upstream direction of the transport direction.   4. The drying apparatus according to claim 3, wherein the amount of change in the conveyance distance of the recording medium on the downstream side in the conveyance direction with respect to the heating unit changes as compared to before the cooling of the heating unit due to the movement of the downstream roller moving mechanism. The upstream roller moving mechanism so that the amount of change in the conveyance distance of the recording medium on the downstream side in the conveyance direction, which changes as compared to before the cooling of the heating unit, is equalized by the movement of the upstream roller movement mechanism. And the downstream roller moving mechanism moves.   5. The drying apparatus according to claim 4, wherein the transport distance of the recording medium on the downstream side in the transport direction with respect to the heating unit is set to be before the heating unit is cooled by the movement of the downstream roller moving mechanism and the upstream roller moving mechanism. The transport distance of the recording medium on the upstream side in the transport direction with respect to the heating unit is increased compared to before the cooling of the heating unit by the movement of the upstream roller moving mechanism. Drying equipment.   6. The drying device according to claim 1, wherein at least one of the upstream roller movement mechanism and the downstream roller movement mechanism moves a position of a roller held by the roller movement mechanism, thereby the heating unit. A drying apparatus for applying a tension to the recording medium during operation.   7. The drying device according to claim 1, wherein the downstream roller moving mechanism adjusts the transport distance by moving a position of a roller held by the downstream roller moving mechanism, and transports the heat from the heating unit. A drying apparatus, wherein the drying apparatus is a recording medium cooling mechanism for cooling the recording medium.   8. The drying apparatus according to claim 1, further comprising a control unit that controls conveyance of the recording medium.   A pretreatment device for applying an ink liquid or a pretreatment liquid to a recording medium; a drying device installed downstream of the recording medium conveyance path with respect to the pretreatment device; and drying the recording medium; and the recording medium heating device And a post-processing device that winds up or cuts the recording medium to an arbitrary size, and uses the drying device as any one of claims 1 to 8 as the drying device. A printing system characterized by that.

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