Sheet loading device, printing device

Abstract

To achieve stable guide of sheets.SOLUTION: A sheet loading device includes guide means 523 for receiving a downward end part of a sheet P conveyed and guiding the sheet to sheet conveyance direction downward side and blowing means 550 for blowing air to the guided sheet P. The blowing means 550 includes a plurality of fans 551 (F1-F12) arranged between a plurality of belts 530 arranged at intervals in a direction orthogonal to the sheet conveyance direction, is configured to change an air blowing region by selecting a driven fan 551 and blows air toward the inside of the region of the sheet P guided from the blowing means 550 according to the size of the guided sheet P.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a sheet stacking device and a printing device.

Background Art

[0002] As a sheet stacking device used in a printing device or the like, there is one provided with guiding means for holding the downstream end of the sheet with a guide member and guiding it downstream in the sheet conveyance direction (Patent Document 1). Further, when discharging the sheet, there is known one provided with a blowing unit that blows air toward the sheet near the discharge port (Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a blowing means as disclosed in Patent Document 2 is provided in a configuration for guiding a sheet by the guiding means as disclosed in Patent Document 1, there is a possibility that the guiding of the sheet is hindered by the blowing.

[0005] The present invention has been made in view of the above problems, and an object thereof is to enable stable guiding of a sheet.

Means for Solving the Problems

[0006] To solve the above problems, a sheet stacking device according to the present invention includes: guiding means for receiving the downstream end of the conveyed sheet and guiding it downstream in the sheet conveyance direction; blowing means for blowing out air, and The blowing means can change the area where the air is blown out, and blows the air from the blowing means into the area of the guided sheet according to the size of the guided sheet. The guiding means has an endless belt that moves in a circular motion. The endless belt has a guide member. The guide member Downstream side of the sheet has a role of guiding the end portion. The guide member has a gap larger than the thickness of the sheet without the gripping force for gripping the sheet and is configured in this way.

[0007] According to the present invention, the sheet can be stably guided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. A printing apparatus as a liquid discharging apparatus according to a first embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a schematic explanatory view of the printing apparatus.

[0010] The printing apparatus 1 includes a loading unit 10 for loading a sheet P, a preprocessing unit 20, a printing unit 30, a drying unit 40, an unloading unit 50, and a reversing mechanism unit 60. The printing apparatus 1 applies a pretreatment liquid (coats) to the sheet P supplied from the loading unit 10 as needed by the pretreatment unit 20 which is a pretreatment means, applies a liquid in the printing unit 30 to perform required printing, dries the liquid adhering to the sheet P in the drying unit 40, and then discharges the sheet P to the unloading unit 50.

[0011] The loading unit 10 includes a loading tray 11 (lower loading tray 11A, upper loading tray 11B) for accommodating a plurality of sheets P, and a feeding device 12 (12A, 12B) for separating and feeding out the sheets P from the loading tray 11 one by one, and supplies the sheet P to the preprocessing unit 20.

[0012] The preprocessing unit 20 includes, for example, an application unit 21 which is a treatment liquid application means for applying a treatment liquid having an effect of aggregating the coloring material of the ink and preventing back printing to the printing surface of the sheet P.

[0013] The printing unit 30 includes a drum 31 which is a supporting member (rotating body) for supporting the sheet P on its circumferential surface and rotating, and a liquid discharging unit 32 for discharging a liquid toward the sheet P supported by the drum 31.

[0014] Further, the printing unit 30 includes a transfer cylinder 34 for receiving the sheet P sent from the preprocessing unit 20 and transferring the sheet P between the drum 31, and a delivery cylinder 35 for receiving the sheet P conveyed by the drum 31 and delivering it to the drying unit 40.

[0015] The sheet P conveyed from the preprocessing unit 20 to the printing unit 30 has its tip gripped by the gripping means (sheet gripper) provided on the transfer cylinder 34 and is conveyed as the transfer cylinder 34 rotates. The sheet P conveyed by the transfer cylinder 34 is delivered to the drum 31 at the opposing position to the drum 31.

[0016] Gripping means (sheet gripper) is also provided on the surface of the drum 31, and the tip of the sheet P is gripped by the gripping means (sheet gripper). A plurality of suction holes are dispersedly formed on the surface of the drum 31, and a suction airflow directed inward from the required suction holes of the drum 31 is generated by the suction means.

[0017] Then, the sheet P delivered from the transfer cylinder 34 to the drum 31 has its tip gripped by the sheet gripper and is adsorbed and supported on the drum 31 by the suction airflow from the suction means, and is conveyed as the drum 31 rotates.

[0018] The liquid discharge unit 32 includes discharge units 33 (33A to 33D) which are liquid discharge means. For example, the discharge unit 33A discharges cyan (C) liquid, the discharge unit 33B discharges magenta (M) liquid, the discharge unit 33C discharges yellow (Y) liquid, and the discharge unit 33D discharges black (K) liquid, respectively. Also, in addition, discharge units for discharging special liquids such as white and gold (silver) can also be used.

[0019] Each discharge unit 33 of the liquid discharge unit 32 has its discharge operation controlled by a drive signal according to the printing information. When the sheet P carried on the drum 31 passes through the opposing area to the liquid discharge unit 32, liquids of various colors are discharged from the discharge unit 33, and an image according to the printing information is printed.

[0020] The drying unit 40 dries the liquid adhering to the sheet P in the printing unit 30. Thereby, the liquid components such as moisture in the liquid evaporate, the colorant contained in the liquid is fixed on the sheet P, and the curling of the sheet P is suppressed.

[0021] The reversing mechanism unit 60 is a mechanism that reverses the sheet P in a switchback manner when performing double-sided printing on the sheet P that has passed through the drying unit 40. The reversed sheet P is sent backward upstream of the transfer cylinder 34 through the transfer path 61 of the printing unit 30.

[0022] The unloading unit 50 is composed of a sheet stacking device according to the present invention, and includes an unloading tray 51 on which a plurality of sheets P are stacked and a sheet conveying device 502. The sheet P conveyed through the reversing mechanism unit 60 is sequentially stacked and held on the stack unit 501.

[0023] Next, the sheet stacking device according to the first embodiment of the present invention will be described with reference to FIG. 2. FIG. 2 is a side explanatory view of the sheet stacking device.

[0024] The sheet stacking device 500 includes a stack unit 501 which is a stacking unit on which a sheet bundle PB is stacked. The stack unit 501 has a table 511 on which the sheet bundle PB is stacked, a front end fence (jogger) 512, a rear end fence 513, and fences on both sides.

[0025] The sheet stacking device 500 includes conveying rollers 521 and 522 that convey the sheet P sent from the reversing mechanism unit 60, and guiding means 523. The guiding means 523 receives the leading end portion (downstream end portion) of the sheet P sent out from the conveying roller 522 and conveyed toward the stack unit 501, and guides it downstream in the sheet conveying direction.

[0026] The guiding means 523 includes an endless belt 530 wound between a driving roller 531 and a driven roller 532, and a guide member 541 attached to the belt 530.

[0027] When the sheet P is detected upstream of the conveying roller 522, the guiding means 523 causes the belt 530 to rotate after a certain period of time, and the leading end portion of the sheet P is inserted into the guide member 541 due to the difference between the linear speed of the guide member 541 and the linear speed of the conveying roller 522.

[0028] Then, as the belt 530 moves in a circular motion, the guide member 541 moves and guides the leading end portion of the sheet P downstream in the sheet conveyance direction while holding the leading end portion of the sheet P.

[0029] Here, the guide member 541 has a gap larger than the thickness of the sheet P and does not have a gripping force such as gripping the sheet P just by inserting the leading end portion of the sheet P. The guide member 541 has a role of guiding the leading end portion of the sheet P and has a function of suppressing the flutter from the leading end portion to the middle portion of the sheet P. Note that the guide member 541 may be configured to use a clip having a gripping force for gripping the leading end portion of the sheet P.

[0030] When the guide member 541 reaches the guide end position, the linear velocity of the guide member 541 is made higher than the linear velocity of the conveying roller 522. As a result, the leading end portion of the sheet P is detached from the guide member 541 and falls onto the stack portion 501 and is loaded.

[0031] Further, blowing means 550 for blowing air toward the sheet P is provided. The blowing means 550 is arranged so as to be located inside the endless belt 530 in the height direction. By blowing air onto the sheet P by the blowing means 550, the stacked sheet P is pressed, and the air accumulated between the sheets P is pushed out to the outside of the sheet P.

[0032] Next, the guiding means and the blowing means in the first embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a plan explanatory view for this description, and FIG. 4 is a side explanatory view for the same.

[0033] The guiding means 523 has a plurality (four in this embodiment) of belts 530 arranged at intervals in a direction orthogonal to the sheet conveyance direction. Each belt 530 is wound around between a driving roller 531 and a driven roller 532. The plurality of driving rollers 531 and the plurality of driven rollers 532 are coaxial, and each belt 530 moves in a circular motion at the same linear velocity. Further, each belt 530 is provided with a guide member 541.

[0034] Between each belt 530 in the direction orthogonal to the sheet conveyance direction, a plurality of blowing portions arranged side by side in the sheet conveyance direction, namely, fans 551 (fans F1 to F12) as airflow generating means, are disposed respectively.

[0035] That is, the belt 530 for moving the guide member 541 is divided into a plurality of belts and arranged at intervals, and in the direction orthogonal to the sheet conveyance direction, the blowing portions (fans 551) of the blowing means 550 are disposed on the sides of the belts 530.

[0036] Thereby, the size of the apparatus can be reduced as compared with the case where the fans 551 (blowing means 550) are disposed above the belts 530.

[0037] Here, the stacking positions of the sheets Pa of the maximum size, the sheets Pb of the intermediate size, and the sheets Pc of the minimum size in the stacking unit 501 are set as the regions shown in FIG. 4.

[0038] At this time, in a plan view (a state seen from the direction perpendicular to the plane of the sheet P), the fans F1 to F3 are disposed at positions facing only the sheets Pa of the maximum size. Similarly, the fans F4 to F6 are disposed at positions facing the sheets Pa of the maximum size and the sheets Pb of the intermediate size.

[0039] Similarly, the fans F7, F9, F10, and F12 are disposed at positions facing the sheets Pb of the intermediate size and the sheets Pc of the minimum size. Similarly, the fans F8 and F11 are disposed at positions facing only the sheets Pc of the minimum size.

[0040] Therefore, the blowing means 550 can change the region where air is blown by changing the fans 551 (F1 to F12) to be driven.

[0041] Next, the portion related to the control of the fans in the present embodiment will be described with reference to the block explanatory diagram of FIG. 5.

[0042] The fan control means 701 controls the rotational drive of the plurality of fans 551 (F1 to F12) of the blowing means 550. The fan control means 701 inputs the size of the sheet P to be guided and selects the fan 551 that rotates and drives according to the size of the sheet P to be guided.

[0043] In this way, by selecting the fan 551 that rotates and drives among the plurality of fans 551 (F1 to F12), the area where air is blown out from the blowing means 550 is changed according to the size of the sheet P to be guided, and air is blown out within the area of the sheet P to be guided.

[0044] For example, when the largest-size sheet Pa is guided, air is blown out toward the area of the largest-size sheet Pa by rotating and driving the fans F1 to F12.

[0045] Also, when the medium-size sheet Pb is guided, air is blown out toward the area of the medium-size sheet Pb by rotating and driving the fans F4 to F12. At this time, since the fans F1 to F3 located outside the medium-size sheet Pb (in plan view) are not used, air is not blown out outside the sheet Pb.

[0046] Furthermore, when the smallest-size sheet Pc is guided, air is blown out toward the area of the smallest-size sheet Pc by rotating and driving the fans F8 and F10. At this time, since all of the fans F1 to F6 that face entirely outside the smallest-size sheet Pc (in plan view) and the fans F7, F9, F11, and F12 that partially face are not used, air is not blown out outside the sheet Pc.

[0047] In this way, since air is blown out within the area of the sheet P to be guided and no air is blown out outside the sheet P to be guided, the guidance of the sheet P is stabilized.

[0048] Further, the fan control means 701 inputs the weight of the guided sheet P and changes the blowing amount (flow rate) from the driven fan 551 in the blowing means 550 according to the weight of the guided sheet P. The change in the blowing amount can be controlled, for example, by changing the duty ratio when driving the fan 551 by PWM control or by changing the rotational speed.

[0049] For example, as shown in FIG. 4, when the weights of the sheets Pd and Pe are such that Pd > Pe, the blowing amount from the fan 551 is controlled so that Pd > Pe.

[0050] Thereby, buckling of the sheet P with low stiffness can be prevented, and stable guiding can be performed.

[0051] Next, a second embodiment of the present invention will be described with reference to FIG. 6. FIG. 6 is a side explanatory view for explaining the guiding means and the blowing means in this embodiment.

[0052] In this embodiment, guide rail members 553, 553 are arranged in a direction perpendicular to the sheet conveyance direction through the inside of the plurality of belts 530. And a fan holding member 554 is movably supported on the guide rail members 553, 553, and a fan 551 constituting the blowing means 550 is mounted on the fan holding member 554.

[0053] Thereby, by pulling out the fan holding member 554 in a direction perpendicular to the sheet conveyance direction, the plurality of fans 551 can be pulled out integrally.

[0054] Next, a third embodiment of the present invention will be described with reference to FIG. 7. FIG. 7 is a plan explanatory view for explaining the guiding means and the blowing means in this embodiment.

[0055] In this embodiment, the blowing means 550 includes one or more airflow generating means (for example, the fans 551 of the above embodiment) and a shutter member 561 that changes the air blowing area by opening and closing the area through which the airflow generated by the airflow generating means passes. In the example of FIG. 7, by covering the areas of the fans F1 to F3 in FIG. 3 with the shutter member 561, the area 562 facing the sheet Pb is opened so that air can pass through.

[0056] As a result, the number of airflow generating means (blowing portions) can be reduced compared to the first embodiment.

[0057] Here, an example of the opening and closing mechanism of the shutter member 561 will be described with reference to FIG. 8. FIG. 8 is a plan explanatory view for explaining the opening and closing mechanism.

[0058] The shutter member 561 is movably held by guide members 570, 570. The shutter member 561 is moved along the guide member 570 by a cam 572 attached to a cam shaft 573. The shutter member 561 is biased by springs 571, 571 in a direction to abut against the cam 572.

[0059] An opening 561a is provided in the shutter member 561, and a facing member 581 having an opening 581a is disposed in front of the shutter member 561 (on the sheet P side). The opening 581a of the facing member 581 is an opening through which the air of the blowing means 550 is blown out.

[0060] In this opening and closing mechanism, when the cam 572 is in the state of FIG. 8(a), the shutter member 561 is in an open position where the opening 561a of the shutter member 561 coincides with the opening 581a of the facing member 581 due to the biasing force of the spring 571. At this time, the air blown out by the blowing means 550 is blown out toward the sheet P.

[0061] On the other hand, as shown in FIG. 8(b), by rotationally driving the cam 572 to move the shutter member 561 against the biasing force of the spring 571, the opening 561a of the shutter member 561 is set to a closed position where it does not coincide with the opening 581a of the opposing member 581. At this time, air is no longer blown from the blowing means 550 toward the sheet P.

[0062] Next, a fourth embodiment of the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a side explanatory view for explaining the embodiment, and FIG. 10 is a plan explanatory view of the same.

[0063] In this embodiment, the blowing means 550 includes a chamber 552 and a pump 553 that sends air into the chamber 552. The chamber 552 is provided with openings 581A or 581B for blowing air at positions G1 to G12 corresponding to the positions of the fans F1 to F12 in the above embodiment.

[0064] And, as shown in FIG. 9 (omitted in FIG. 10), a shutter member 561 for opening and closing each opening 581A, 581B is movably disposed in the chamber 552. A cam 572 is disposed in contact with each shutter member 561. Each shutter member 561 is biased by a biasing member such as a spring in the direction of contacting the cam 572 in the same manner as in the third embodiment.

[0065] Here, in the direction orthogonal to the conveyance direction of the sheet P, a cam 572A for driving the shutter member 561 that opens and closes the openings 581A on both sides and a cam 572B for opening and closing the shutter member 561 that opens and closes the central opening 581B are provided. The cam 572A is attached to the cam shaft 573A, and the cam 572B is attached to the cam shaft 573B.

[0066] Thereby, the opening amount by the shutter member 561 that opens and closes the openings 581A on both sides and the opening amount by the shutter member 561 that opens and closes the central opening 581B can be individually controlled.

[0067] In addition, in each of the above embodiments, instead of the configuration in which the printing unit 30 of the printing apparatus 1 applies a liquid such as ink to perform required printing on the sheet P, it may be configured to perform required printing on the sheet P using toner.

[0068] Also, the material of the sheet P to be conveyed is not limited to paper, and the present invention may be applied to an apparatus that conveys a plastic film, cloth, metal sheet, etc.

Explanation of Reference Numerals

[0069] 1 Printing apparatus 10 Loading unit 20 Pretreatment unit 30 Printing unit 40 Drying unit 50 Discharge unit 60 Inversion mechanism unit 500 Sheet stacking apparatus 501 Stacking unit (loading unit) 522 Conveying roller 523 Guide means 530 Belt 541 Guide member 550 Blowing means 551 Fan (airflow generating means, blowing unit) 561 Shutter member

Claims

1. Guiding means for receiving the downstream end of the conveyed sheet and guiding it downstream in the sheet conveyance direction, and blowing means for blowing out air, wherein the blowing means can change the region where the air is blown out, and in accordance with the size of the sheet to be guided, the air is blown out from the blowing means into the region of the sheet to be guided, wherein the guiding means has an endless belt that moves in a circular motion, the endless belt has a guide member, the guide member has a role of guiding the downstream end of the sheet, the guide member has a gap larger than the thickness of the sheet and does not have a gripping force for gripping the sheet A sheet stacking device characterized by the above.

2. The blowing means can change the blowing amount, and the blowing amount is changed in accordance with the weight of the sheet to be guided The sheet stacking device according to claim 1, characterized by the above.

3. The guiding means has a plurality of endless belts that move in a circular motion, the plurality of belts are arranged at intervals in a direction orthogonal to the sheet conveyance direction, the blowing means is arranged between the belts The sheet stacking device according to claim 1 or 2, characterized by the above.

4. The guiding means has an endless belt that moves in a circular motion, the blowing means is held by a holding member that is movable in a direction orthogonal to the sheet conveyance direction inside the belt The sheet stacking device according to any one of claims 1 to 3, characterized by the above.

5. The blowing means includes a plurality of air flow generating means The sheet stacking device according to any one of claims 1 to 4, characterized by the above.

6. It has a shutter member for opening and closing the opening through which the air of the blowing means is blown out The sheet stacking device according to any one of claims 1 to 4, characterized by the above.

7. A printing device characterized by comprising the sheet stacking device according to any one of claims 1 to 6 ​

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